Engine Controls - Self-Diagnostics - 3.0L: Other Mazda 6 GG

Pending DTCs

Pending codes appear when a problem is detected in a monitored system. The Malfunction Indicator Light (MIL) is illuminated when a problem is detected in 2 consecutive drive cycles. The pending code is stored in Powertrain Control Module (PCM) during the first drive cycle when a failed system is detected. If a system does not fail during the second drive cycle, PCM concludes that system has returned to normal or problem was mistakenly detected, and deletes pending code. If system failure is detected during a second drive mode, PCM concludes that suspect system has failed, deletes pending code, illuminates MIL and stores Diagnostic Trouble Codes (DTC).

Intermittent Failures

Intermittent failures may cause Malfunction Indicator Light (MIL) to flicker or illuminate and go out after the intermittent fault goes away. However, the corresponding trouble code will be retained in PCM memory. If related fault does not reoccur within a certain time frame, related trouble code will be erased from PCM memory. Intermittent failures may be caused by a sensor, connector or wiring related problems. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.

FREEZE FRAME DATA

Freeze frame data is technical data which indicates engine's condition at time of first malfunction. This data will remain in memory even if another emission-related DTC is stored, with the exception of misfire or fuel system DTCs. Once freeze frame data for misfire or fuel system DTC is stored, it will overwrite any previous data after which freeze frame data will not be overwritten again.

PCM CONFIGURATION

Note. If PCM is replaced with a new one, PCM stores DTC P0602 and illuminates MIL even though no malfunction is detected. After completing "PCM Configuration" procedure, clear DTC P0602 using WDS or equivalent. MIL goes off after three drive cycles with no failure. (DTCs remain in PCM.)

1. Connect WDS or equivalent to DLC-2.
2. Set up WDS or equivalent (including vehicle recognition.
3. Select MODULE PROGRAMMING.
4. Select PROGRAMMABLE MODULE INSTALLATION.
5. Select PCM and perform procedures according to directions on WDS or equivalent screen.
6. Retrieve DTCs with WDS or equivalent, then verify there are no DTCs present. If DTC is present, perform applicable DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000) .

OBD-II DRIVE MODES

Performing Drive Mode inspects OBD-II system for proper operation and must be performed to ensure that no additional DTCs are present. During Drive Mode the following systems are monitored

1. EGR system
2. Oxygen sensor and oxygen sensor heater
3. Three Way Catalytic (TWC) converter
4. Fuel, misfire and Evaporative Emission (EVAP) system

Note. Vehicle speed and engine speed detected by the PCM may differ from that indicated by the speedometer and tachometer. Use the WDS or equivalent to monitor vehicle speed. If the OBD II system inspection is not completed during the Drive Mode, the following causes are considered: The OBD II system detects the malfunction. The Drive Mode procedure is not completed correctly. Disconnecting the battery will reset the memory. Do not disconnect the battery during and after Drive Mode. The WDS or equivalent can be used at anytime through the course of Drive Mode to monitor the completion status. Monitoring can be done by viewing the ON BOARD SYSTEM READINESS menu.

Note. The PCM adaptive memory status can be confirmed with RFCFLAG PID. If RFCFLAG PID is ON, Mode 1 - PCM Adaptive Memory Produce Drive Mode is not necessary, because PCM already has adaptive memory. If RFCFLAG PID is OFF, Mode 1 - PCM Adaptive Memory Produce Drive Mode should be performed before Mode 2 - EGR System Repair Verification Drive Mode or Mode 3 - HO2S Heater, HO2S & TWC Repair Verification Drive Mode.

Mode 1 - PCM Adaptive Memory Produce Drive Mode

1. Start engine and warm up completely.
2. Verify following conditions and correct if necessary. All accessory loads (A/C, headlights, blower fan, rear window defroster) are off. Initial ignition timing and idle speed are within specification.
3. Perform no load test, racing engine at 2500-3500 RPM for more than 15 seconds.
4. Continuously perform no load test, racing engine at 4500-5000 RPM for more than 15 seconds.
5. Idle engine for more than 60 seconds after cooling fan has stopped.
6. Turn ignition off then on again.
7. Access RFCFLAG PID to confirm PCM adaptive memory status. If RFCFLAG PID is "Learned", «MODE 1 - PCM ADAPTIVE MEMORY PRODUCE DRIVE MODE»(ref-151886-S16512332172003101600000) is completed. If RFCFLAG PID is still "Not Learned", go back to step 1 .

Mode 2 - EGR System Repair Verification Drive Mode

1. Access to RFCFLAG PID to confirm PCM adaptive memory status. If RFCFLAG PID is "Not Learned", perform "PCM Adaptive Memory Produce Drive Mode" first. If RFCFLAG PID is ON, start engine and warm up completely.
2. Verify all accessory loads (A/C, headlights, blower fan, rear window defroster) are off.
3. Drive vehicle as shown in graph. (Scheme 56)
4. Stop vehicle and access ON BOARD SYSTEM READINESS to inspect DRIVE MODE COMPLETION STATUS. If completed, Readiness Function Check (RFC) flag changes from NO to YES. If not completed, turn ignition off and repeat testing from step 3.
5. Access DIAGNOSTIC MONITORING TEST RESULTS menu of GENERIC OBD-II FUNCTIONS to inspect monitor results. If MEAS are within specification, repair is completed. If MEAS are not within specification, repair is not completed.
6. Verify no DTCs are available.

Scheme 56

Mode 3 - HO2S Heater, HO2S & TWC Repair Verification Drive Mode

1. Access to RFCFLAG PID to confirm PCM adaptive memory status. If RFCFLAG PID is "Not Learned", perform «MODE 1 - PCM ADAPTIVE MEMORY PRODUCE DRIVE MODE»(ref-151886-S16512332172003101600000) first. If RFCFLAG PID is ON, start engine and warm up completely.
2. Verify all accessory loads (A/C, headlights, blower fan, rear window defroster) are off.
3. Start engine and let idle it for more than 5 minutes.
4. Drive vehicle under one of following conditions: Vehicle speed is more than 55 MPH for one minute (MTX: 5th gear/ATX: D range). Vehicle speed is more than 50 MPH for one minute (MTX: 4th gear/ATX: D range).
5. Continue to drive vehicle while maintaining speed between 45-55 MPH for 3 minutes (MTX: 5th gear ATX: D range).
6. Stop vehicle and access ON BOARD SYSTEM READINESS to inspect Drive Mode completion status. If completed, RFC flag changes from NO to YES. If not completed, turn ignition off. Go back to step 3 .
7. Access DIAGNOSTIC MONITORING TEST RESULTS to inspect monitor results. If MEAS are within specification, repair is completed. If MEAS are not within specification, repair is not completed.
8. Verify no DTCs are available.

Mode 4 - EVAP System Repair Verification Drive Mode

Note. If MODE 4 - EVAP SYSTEM REPAIR VERIFICATION DRIVE MODE cannot be performed (you cannot drive vehicle under MODE 4 - EVAP SYSTEM REPAIR VERIFICATION DRIVE MODE condition), perform Evaporative System Test procedure as an alternative. See FUEL EVAPORATIVE SYSTEM - EXCEPT PROTEGE & PROTEGE5 under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. MODE 4 - EVAP SYSTEM REPAIR VERIFICATION DRIVE MODE can be performed regardless RFCFLAG condition.

1. Verify all following PIDs are within the following specifications. All PIDs must be within specifications before engine is started to initiate the evaporative system test: BARO: 21.3 in. Hg (72.3 kPa) or higher IAT: 41-95°F (5-35°C) FTL: 15-85 percent VPWR: 10.9-14.6 volts
2. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM.
3. Start engine and idle it for more than 10 seconds, then turn ignition off. Leave vehicle for 5 hours or more.
4. Start engine and idle for more than 15 minutes.
5. Drive vehicle at 40-50 MPH for more than 5 minutes.
6. Stop vehicle and turn ignition off.
7. Leave vehicle as is for 10 minutes or more.
8. Start engine.
9. Access to ON BOARD SYSTEM READINESS to inspect DRIVE MODE COMPLETION STATUS: If completed, RFC flag changes from NO to YES. If not completed, turn ignition off. Go back to step 1 .
10. Access DIAGNOSTIC MONITORING TEST RESULTS to inspect monitor results. If MEAS are not within specification, repair has not been completed.
11. Verify no DTCs are available.

SUMMARY

If no diagnostic trouble code is present but driveability problem still exists, proceed to TROUBLE SHOOTING - NO CODES article for symptom diagnosis or intermittent diagnostic procedures.

Detection Condition

Actual valve timing is over-advanced by 20 degrees from target valve timing for 5 seconds. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible Causes

Possible causes are

1. Loose timing chain or improper valve timing
2. PCM malfunction
3. Right side Variable Valve Timing (VVT) actuator is stuck in advance position
4. Spool valve in right side Oil Control Valve (OCV) is stuck in advance position

Actual valve timing is over-retarded by 10 degrees from target valve timing for 4 seconds. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Following oil runners are clogged or have leakage: Between oil pressure switch and right side OCV Between right side OCV and right side variable valve timing actuator In right side variable valve timing actuator
2. Loose timing chain or improper valve timing
3. Low engine oil pressure
4. PCM malfunction
5. Right side variable valve timing actuator is stuck in retard position
6. Spool valve in right side Oil Control Valve (OCV) is stuck in retard position

Actual valve timing is over-advanced by 20 degrees from target valve timing for 5 seconds. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Left side variable valve timing actuator is stuck in advance position
2. Loose timing chain or improper valve timing
3. PCM malfunction
4. Spool valve in left side Oil Control Valve (OCV) is stuck in advance position

Actual valve timing is over-retarded by 10 degrees from target valve timing for 4 seconds. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Following oil runners are clogged or have leakage: Between oil pressure switch and left side OCV Between left side OCV and left side variable valve timing actuator In left side variable valve timing actuator
2. Left side variable valve timing actuator is stuck in retard position
3. Loose timing chain or improper valve timing
4. Low engine oil pressure
5. PCM malfunction
6. Spool valve in left side OCV is stuck in retard position

PCM monitors right front HO2S heater control signal at PCM 104-pin harness connector terminal No. 93. If PCM turns right front HO2S heater off but HO2S heater circuit has low voltage, PCM determines right front HO2S heater circuit has a malfunction. Right front HO2S heater is controlled by a duty signal. This is a Continuous Monitor (HO2S heater). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Open circuit in Blue/Black wire between ignition relay and right front HO2S 4-pin harness connector terminal "C"
3. Open circuit in White/Black wire between right front HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 93
4. PCM malfunction
5. Right front HO2S heater malfunction
6. Short to ground circuit in White/Black wire between right front HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 93

Scheme 57

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect Right Front HO2S Connector For Poor Connection - Turn ignition off. Disconnect right front HO2S 4-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 9.
4. Inspect Right Front HO2S Heater Power Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between right front HO2S 4-pin harness connector terminal "C" (Blue/Black wire) and body ground. (Scheme 57) If battery voltage is present, go to next step. If battery voltage is not present, repair open circuit in Blue/Black wire between right front HO2S 4-pin harness connector terminal "C" and ignition relay harness connector or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
5. Inspect Right Front HO2S Heater Control Circuit For Short To Ground - Turn ignition off. Check for continuity between right front HO2S 4-pin harness connector terminal "D" and body ground. If continuity is not present, go to next step. If continuity is present, repair short circuit to ground in White/Black wire between right front HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 93 or replace wire harness. After repair, go to step 9.
6. Inspect Right Front HO2S Heater - Inspect right front HO2S heater. Refer to «HEATED OXYGEN SENSOR»(ref-151892-S27992571522003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If right front HO2S heater is okay, go to next step. If right front HO2S heater is faulty, replace right front HO2S. After repair, go to step 9.
7. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 9.
8. Inspect Right Front HO2S Heater Control Circuit For Open Circuit - Turn ignition off. Check for continuity in White/Black wire between right front HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 93. (Scheme 57) If continuity is present, go to next step. If continuity is not present, repair open circuit in White/Black wire between right front HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 93 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
9. Verify Trouble Shooting Of DTC P0031 Is Completed - Make sure to reconnect all disconnected connectors. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Turn ignition off. Start engine and warm it up completely. If PENDING CODE for same DTC is not present, go to next step. If PENDING CODE for same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
10. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors right front HO2S heater control signal at PCM 104-pin harness connector terminal No. 93. If PCM turns right front HO2S heater on but right front HO2S heater circuit has high voltage, PCM determines right front HO2S heater circuit has a malfunction. Right front HO2S heater is controlled by a duty signal. This is a Continuous Monitor (HO2S heater). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. PCM malfunction
3. Right front HO2S heater malfunction
4. Short to power circuit in White/Black wire between right front HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 93

PCM monitors right rear HO2S heater control signal at PCM 104-pin harness connector terminal No. 95. If PCM turns right rear HO2S heater off but right rear HO2S heater circuit has low voltage, PCM determines right rear HO2S heater circuit has a malfunction. This is a Continuous Monitor (HO2S heater). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible cause are

1. Connector or terminal malfunction
2. Open circuit in Blue/Black wire between ignition relay harness connector and right rear HO2S 4-pin harness connector terminal "C"
3. Open circuit in Yellow/Green wire between right rear HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 95
4. PCM malfunction
5. Right rear HO2S heater malfunction
6. Short to ground circuit in Yellow/Green wire between right rear HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 95

Scheme 58

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect Right Rear HO2S Connector For Poor Connection - Turn ignition off. Disconnect right rear HO2S 4-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 9.
4. Inspect Right Rear HO2S Heater Power Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between right rear HO2S 4-pin harness connector terminal "C" (Black/Blue wire) and body ground. (Scheme 58) If battery voltage is present go to next step. If battery voltage is not present, repair open circuit in Blue/Black wire between right rear HO2S 4-pin harness connector terminal "C" and ignition relay harness connector or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
5. Inspect Right Rear HO2S Heater Control Circuit For Short To Ground - Turn ignition off. Check for continuity between right rear HO2S 4-pin harness connector terminal "D" (Yellow/Green wire) and body ground. If continuity is not present, go to next step. If continuity is present, repair short circuit to ground in Yellow/Green wire between right rear HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 95 or replace wire harness. After repair, go to step 9.
6. Inspect Right Rear HO2S Heater - Inspect right rear HO2S heater. Refer to «HEATED OXYGEN SENSOR»(ref-151892-S27992571522003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If right rear HO2S heater is okay, go to next step. If right rear HO2S heater is faulty, replace right rear HO2S. After repair, go to step 9.
7. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 9.
8. Inspect Right Rear HO2S Heater Control Circuit For Open Circuit - Turn ignition off. Check for continuity between right rear HO2S 4-pin harness connector terminal "D" (Yellow/Green wire) and PCM 104-pin harness connector terminal No. 95. (Scheme 58) If continuity is present, go to next step. If continuity is not present, repair open circuit in Yellow/Green wire between right rear HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 95 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
9. Verify Trouble Shooting Of DTC P0037 Is Completed - Make sure to reconnect all disconnected connectors. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Turn ignition off. Start engine and warm it up completely. If PENDING CODE for same DTC is not present, go to next step. If PENDING CODE for same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
10. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors right rear HO2S heater control signal at PCM 104-pin harness connector terminal No. 95. If PCM turns right rear HO2S heater on but right rear HO2S heater circuit has high voltage, PCM determines right rear HO2S heater circuit has a malfunction. This is a Continuous Monitor (HO2S heater). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. PCM malfunction
3. Right rear HO2S heater malfunction
4. Short to power circuit in Green/Yellow wire between right rear HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 95

PCM monitors left front HO2S heater control signal at PCM 104-pin harness connector terminal No. 94. If PCM turns HO2S heater off but left front HO2S heater circuit has low voltage, PCM determines left front HO2S heater circuit has a malfunction. Left front HO2S heater is controlled by a duty signal. This is a Continuous Monitor (HO2S heater). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Left front HO2S heater malfunction
3. Open circuit in Blue/Black wire between ignition relay harness connector and left front HO2S 4-pin harness connector terminal "C"
4. Open circuit in White/Green wire between left front HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 94
5. PCM malfunction
6. Short to ground circuit in White/Green wire between left front HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 94

Scheme 59

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect Left Front HO2S Connector For Poor Connection - Turn ignition off. Disconnect left front HO2S 4-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 9.
4. Inspect Left Front HO2S Heater Power Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between left front HO2S 4-pin harness connector terminal "C" (Blue/Black wire) and body ground. (Scheme 59) If battery voltage is present go to next step. If battery voltage is not present, repair open circuit in Blue/Black wire between left front HO2S 4-pin harness connector terminal "C" and ignition relay harness connector or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
5. Inspect Left Front HO2S Heater Control Circuit For Short To Ground - Turn ignition off. Check for continuity between left front HO2S 4-pin harness connector terminal "D" (White/Green wire) and body ground. If continuity is not present, go to next step. If continuity is present, repair short circuit to ground in White/Green wire between left front HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 94 or replace wire harness. After repair, go to step 9.
6. Inspect Left Front HO2S Heater - Inspect left front HO2S heater. Refer to «HEATED OXYGEN SENSOR»(ref-151892-S27992571522003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If left front HO2S heater is okay, go to next step. If left front HO2S heater is faulty, replace left front HO2S. After repair, go to step 9.
7. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 9.
8. Inspect Left Front HO2S Heater Control Circuit For Open Circuit - Turn ignition off. Check for continuity between left front HO2S 4-pin harness connector terminal "D" (White/Green wire) and PCM 104-pin harness connector terminal No. 94. (Scheme 59) If continuity is present, go to next step. If continuity is not present, repair open circuit in White/Green wire between left front HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 94 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
9. Verify Trouble Shooting Of DTC P0051 Is Completed - Make sure to reconnect all disconnected connectors. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Turn ignition off. Start engine and warm it up completely. If PENDING CODE for same DTC is not present, go to next step. If PENDING CODE for same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
10. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors left front HO2S heater control signal at PCM 104-pin harness connector terminal No. 94. If PCM turns left front HO2S heater on but left front HO2S heater circuit has high voltage, PCM determines left front HO2S heater circuit has a malfunction. Left front HO2S heater is controlled by a duty signal. This is a Continuous Monitor (HO2S heater). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Left front HO2S heater malfunction
3. PCM malfunction
4. Short to power circuit in White/Green wire between left front HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 94

PCM monitors left rear HO2S heater control signal at PCM 104-pin harness connector terminal No. 96. If PCM turns left rear HO2S heater off but left rear HO2S heater circuit has low voltage, PCM determines left rear HO2S heater circuit has a malfunction. This is a Continuous Monitor (HO2S heater). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Left rear HO2S heater malfunction
3. Open circuit in Blue/Black wire between ignition relay and left rear HO2S 4-pin harness connector terminal "C"
4. Open circuit in Violet wire between left rear HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 96
5. PCM malfunction
6. Short to ground circuit in Violet wire between left rear HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 96

Scheme 60

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect Left Rear HO2S Connector For Poor Connection - Turn ignition off. Disconnect left rear HO2S 4-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 9.
4. Inspect Left Rear HO2S Heater Power Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between left rear HO2S 4-pin harness connector terminal "C" (Blue/Black wire) and body ground. (Scheme 60) If battery voltage is present go to next step. If battery voltage is not present, repair open circuit in Blue/Black wire between left rear HO2S 4-pin harness connector terminal "C" and ignition relay harness connector or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
5. Inspect Left Rear HO2S Heater Control Circuit For Short To Ground - Turn ignition off. Check for continuity between left rear HO2S 4-pin harness connector terminal "D" (Violet wire) and body ground. If continuity is not present, go to next step. If continuity is present, repair short circuit to ground in Violet wire between left rear HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 96 or replace wire harness. After repair, go to step 9.
6. Inspect Left Rear HO2S Heater - Inspect left rear HO2S heater. Refer to «HEATED OXYGEN SENSOR»(ref-151892-S27992571522003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If left front HO2S heater is okay, go to next step. If left front HO2S heater is faulty, replace left front HO2S. After repair, go to step 9.
7. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 9.
8. Inspect Left Rear HO2S Heater Control Circuit For Open Circuit - Turn ignition off. Check for continuity between left rear HO2S 4-pin harness connector terminal "D" (Violet wire) and PCM 104-pin harness connector terminal No. 96. (Scheme 60) If continuity is present, go to next step. If continuity is not present, repair open circuit in Violet wire between left rear HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 96 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
9. Verify Trouble Shooting Of DTC P0057 Is Completed - Make sure to reconnect all disconnected connectors. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Turn ignition off. Start engine and warm it up completely. If PENDING CODE for same DTC is not present, go to next step. If PENDING CODE for same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
10. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors left rear HO2S heater control signal at PCM 104-pin harness connector terminal No. 96. If PCM turns left rear HO2S heater on but left rear heater circuit has high voltage, PCM determines left rear HO2S heater circuit has a malfunction. This is a Continuous Monitor (HO2S heater). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Left rear HO2S heater malfunction
3. PCM malfunction
4. Short to power circuit in Violet wire between left rear HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 96

PCM compares actual input signal from Mass Airflow/Intake Air Temperature (MAF/IAT) sensor with expected input signal from MAF/IAT sensor which PCM calculates by input voltage from Throttle Position (TP) sensor or engine speed. If mass intake airflow amount is 0.90 lb./min. (6.8 grams/sec.) or less for 5 seconds and throttle opening angle is 50 percent or more with engine running, PCM determines detected mass intake airflow amount is too low. If the mass intake airflow amount is 14.43 lbs./min. (109.3 grams/sec.) or more for 5 seconds and engine speed is 2000 RPM or less with engine running, PCM determines detected mass intake airflow amount is too high. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in the PCM memory.

Possible causes are

1. Electrical corrosion in MAF RETURN circuit
2. Electrical corrosion in MAF signal circuit
3. MAF/IAT sensor malfunction
4. PCM malfunction
5. TP sensor malfunction
6. Voltage drops in ground circuit
7. Voltage drops in MAF signal circuit

PCM monitors input voltage from Mass Airflow/Intake Air Temperature (MAF/IAT) sensor when engine is running. If input voltage at PCM 104-pin harness connector terminal No. 88 is 0.21 volt or less, PCM determines MAF circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. MAF/IAT sensor malfunction
3. Open circuit in Gray/Black wire between MAF/IAT sensor 5-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 88
4. Open circuit in White wire between main relay harness connector terminal "C" and MAF/IAT sensor 5-pin harness connector terminal "A"
5. PCM malfunction
6. Short to ground circuit in Gray/Black wire between MAF/IAT sensor 5-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 88

Scheme 61

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect MAF/IAT Sensor Connector For Poor Connection - Turn ignition off. Disconnect MAF/IAT sensor 5-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminals. After repair, go to step 9.
4. Inspect MAF/IAT Sensor Power Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between MAF/IAT sensor 5-pin harness connector terminal "A" (White wire) and body ground. (Scheme 61) If battery voltage is present, go to next step. If battery voltage is not present, repair open circuit in White wire between main relay harness connector and MAF/IAT sensor 5-pin harness connector terminal "A" or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
5. Inspect MAF/IAT Sensor Signal Circuit For Short To Ground - Turn ignition off. Disconnect MAF/IAT sensor 5-pin harness connector. Check for continuity between MAF/IAT sensor 5-pin harness connector terminal "C" (Gray/Black wire) and body ground. If continuity is not present, go to next step. If continuity is present, repair short circuit to ground in Gray/Black wire between MAF/IAT sensor 5-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 88 or replace wire harness. After repair, go to step 9.
6. Inspect MAF/IAT Sensor - Inspect MAF/IAT sensor. Refer to «MASS AIRFLOW SENSOR»(ref-151892-S09739612212003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If MAF/IAT sensor is okay, go to next step. If MAF/IAT sensor is faulty, replace MAF/IAT sensor. After repair, go to step 9.
7. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 9.
8. Inspect MAF/IAT Sensor Signal Circuit For Open Circuit - Turn ignition off. Check for continuity in Gray/Black wire between MAF/IAT sensor 5-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 88. (Scheme 61) If continuity is present, go to next step. If continuity is not present, repair open circuit in Gray/Black wire between MAF/IAT sensor 5-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 88 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
9. Verify Trouble Shooting Of DTC P0102 Is Completed - Make sure to reconnect all disconnected connectors. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Turn ignition off. Start engine and warm it up completely. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
10. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors input voltage from Mass Airflow/Intake Air Temperature (MAF/IAT) sensor when engine is running. If input voltage at PCM 104-pin harness connector terminal No. 88 is 4.9 volts or more, PCM determines MAF circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. MAF/IAT sensor malfunction
3. Open circuit in Gray wire between MAF/IAT sensor 5-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 77
4. PCM malfunction
5. Short to power circuit in Gray/Black wire between MAF/IAT sensor 5-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 88

Intake air temperature reading is more than engine coolant temperature reading by 104°F (40°C) and ignition is on. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Intake Air Temperature (IAT) sensor malfunction
3. PCM malfunction

PCM monitors Mass Airflow/Intake Air Temperature (MAF/IAT) sensor signal at PCM 104-pin harness connector terminal No. 39. If PCM detects MAF/IAT sensor voltage of 0.16 volt or less, PCM determines MAF/IAT sensor circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. MAF/IAT sensor malfunction
3. PCM malfunction
4. Short to ground circuit in Blue/Black wire between MAF/IAT sensor 5-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 39
5. Short circuit to each other in wire harness between MAF/IAT sensor 5-pin harness connector terminal "D" (Blue/Black wire) and terminal "E" (Brown wire)

Scheme 62

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect MAF/IAT Sensor Connector For Poor Connection - Turn ignition off. Disconnect MAF/IAT sensor 5-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminals. After repair, go to step 8.
4. Inspect MAF/IAT Sensor Signal Circuit For Short To Ground - Turn ignition off. Disconnect MAF/IAT sensor 5-pin harness connector. Check for continuity between MAF/IAT sensor 5-pin harness connector terminal "D" and body ground. (Scheme 62) If continuity is not present, go to next step. If continuity is present, repair short circuit to ground in Blue/Black wire between MAF/IAT sensor 5-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 39 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 8.
5. Inspect MAF/IAT Sensor Circuits For Short To Each Other - Turn ignition off. Check for continuity between MAF/IAT sensor 5-pin harness connector terminal "D" (Blue/Black wire) and terminal "E" (Brown wire). If continuity is not present, go to next step. If continuity is present, repair short between circuits in wire harness between MAF/IAT sensor 5-pin harness connector and PCM 104-pin harness connector. After repair, go to step 8.
6. Inspect MAF/IAT Sensor - Inspect MAF/IAT sensor. Refer to «INTAKE AIR TEMPERATURE SENSOR»(ref-151892-S01193409072003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If MAF/IAT sensor is okay, go to next step. If MAF/IAT sensor is faulty, replace MAF/IAT sensor. After repair, go to step 8.
7. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to next step.
8. Verify Trouble Shooting Of DTC P0112 Is Completed - Make sure to reconnect all disconnected connectors. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Turn ignition off. Start engine and warm it up completely. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
9. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors Mass Airflow/Intake Air Temperature (MAF/IAT) sensor signal at PCM 104-pin harness connector terminal No. 39. If PCM detects MAF/IAT sensor voltage of 4.84 volts or more, PCM determines MAF/IAT sensor circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. MAF/IAT sensor malfunction
3. Open circuit in Blue/Black wire between MAF/IAT sensor 5-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 39
4. Open circuit in Brown wire between MAF/IAT sensor 5-pin harness connector terminal "E" and PCM 104-pin harness connector terminal No. 91
5. PCM malfunction
6. Short to power circuit in Blue/Black wire between MAF/IAT sensor 5-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 39

PCM monitors Engine Coolant Temperature (ECT) sensor signal at PCM 104-pin harness connector terminal No. 38. If PCM detects ECT sensor voltage of 0.14 volt or less, PCM determines ECT sensor circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. ECT sensor malfunction
3. Short to ground circuit between ECT sensor 2-pin harness connector terminal "A" (White/Blue wire) and PCM 104-pin harness connector terminal No. 38 (Light Green/Black wire)
4. Short between ECT sensor harness connector terminals "A" (White/Blue wire) and "B" (Brown/Green wire)
5. PCM malfunction

Scheme 63

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect ECT Sensor Connector For Poor Connection - Turn ignition off. Disconnect ECT sensor harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminals. After repair, go to step 8.
4. Inspect ECT Sensor Signal Circuit For Short To Ground - Turn ignition off. Disconnect PCM 104-pin harness connector. Check for continuity between ECT sensor harness connector terminal "A" and body ground. (Scheme 63) If continuity is not present, go to next step. If continuity is present, repair short circuit to ground in appropriate wire between ECT harness connector terminal "A" (White/Blue wire) and PCM 104-pin harness connector terminal No. 38 (Light Green/Black wire) or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 8.
5. Inspect ECT Sensor Circuit For Short With Each Other - Turn ignition off. Check for continuity between ECT sensor harness connector terminal "A" (White/Blue wire) and terminal "B" (Brown/Green wire). If continuity is not present, go to next step. If continuity is present, repair short between circuits in wire harness between ECT sensor harness connector and PCM 104-pin harness connector or replace wire harness. After repair, go to step 8.
6. Inspect ECT Sensor - Inspect ECT sensor. Refer to «ENGINE COOLANT TEMPERATURE SENSOR»(ref-151892-S08510237282003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If ECT sensor is okay, go to next step. If ECT sensor is faulty, replace ECT sensor. After repair, go to step 8.
7. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to next step.
8. Verify Trouble Shooting Of DTC P0117 Is Completed - Make sure to reconnect all disconnected connectors. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Turn ignition on, engine off. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
9. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors Engine Coolant Temperature (ECT) sensor signal at PCM 104-pin harness connector terminal No. 38. If PCM detects ECT sensor voltage of 4.57 volts or more, PCM determines ECT sensor circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. ECT sensor malfunction
3. Open circuit between ECT sensor 2-pin harness connector terminal "A" (White/Blue wire) and PCM 104-pin harness connector terminal No. 38 (Light Green/Black wire)
4. Open circuit between ECT sensor harness connector terminal "B" (Brown/Green wire) and PCM 104-pin harness connector terminal No. 91 (Brown wire)
5. PCM malfunction
6. Short to power circuit between ECT sensor 2-pin harness connector terminal "A" (White/Blue wire) and PCM 104-pin harness connector terminal No. 38 (Light Green/Black wire)

If PCM detects Throttle Position (TP) sensor No. 1 voltage at PCM 104-pin harness connector terminal No. 89 is 0.255 volt or less after ignition is on, PCM determines TP circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Open circuit between throttle body 6-pin harness connector terminal "D" (Yellow wire) and PCM 104-pin harness connector terminal No. 20 (Violet/Red wire)
3. Open circuit between throttle body 6-pin harness connector terminal "F" (White wire) and PCM 104-pin harness connector terminal No. 89 (Pink/Blue wire)
4. PCM malfunction
5. Short to ground circuit between throttle body 6-pin harness connector terminal "F" (White wire) and PCM 104-pin harness connector terminal No. 89 (Pink/Blue wire)
6. TP sensor No. 1 malfunction

If PCM detects TP sensor No. 1 voltage at PCM 104-pin harness connector terminal No. 89 is 4.72 volts or more after ignition is on, PCM determines TP circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Open circuit between throttle body 6-pin harness connector terminal "E" (Brown wire) and PCM 104-pin harness connector terminal No. 36 (Brown/Black wire)
3. PCM malfunction
4. Short to power circuit between throttle body 6-pin harness connector terminal "F" (White wire) and PCM 104-pin harness connector terminal No. 89 (Pink/Blue wire)
5. TP sensor No. 1 malfunction

PCM monitors Engine Coolant Temperature (ECT) sensor signal at PCM 104-pin harness connector terminal No. 38 after engine is cold started. If ECT voltage reading does not reach expected temperature in a certain period, PCM determines it has taken an excessive amount of time for engine coolant temperature to reach temperature necessary to start closed-loop fuel control. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. ECT sensor malfunction
3. PCM malfunction

DTC P0126: If ECT signal never exceeds 160°F (71°C) after engine runs for a certain period, PCM determines coolant thermostat is stuck open.

Monitoring Conditions

1. IAT: 14°F (-10°C) or less
2. Difference between ECT at engine start and minimum IAT: 43°F (6°C) or less
3. Vehicle speed: 3.7 MPH or more (MTX)
4. Vehicle speed: 5.8 MPH or more (ATX)

DTC P0128: PCM monitors MAF, IAT, VSS and ECT signals and calculates radiator heat radiation ratio while the following monitoring conditions are met. If calculated value exceeds the threshold, PCM determines coolant thermostat is stuck open.

Monitoring Conditions

1. ECT at engine start: 97°F (36°C) or less
2. IAT: 14°F (-10°C) or more
3. Difference between ECT at engine start and minimum IAT: 43°F (6°C) or less
4. Vehicle speed: 18.6 MPH or more (MTX)
5. Vehicle speed: 12.4 MPH or more (ATX)

This is a Continuous Monitor (thermostat). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Engine Coolant Temperature (ECT) sensor malfunction
2. Coolant thermostat malfunction
3. PCM malfunction

PCM monitors input voltage from HO2S (RF, LF) when the following monitoring conditions are met. If input voltage from suspected sensor remains 0.45 volt or less for 46 seconds, PCM determines there is no HO2S (RF, LF) inversion.

Monitoring Conditions

1. Engine speed is 1500 RPM or more
2. Engine coolant temperature is 158°F (70°C) or more

This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Air suction or leakage
2. Engine malfunction
3. Fuel delivery hose clogging or leakage
4. Fuel filter clogging
5. Fuel injector malfunction
6. Fuel pump malfunction
7. Fuel return hose clogging or leakage
8. HO2S (RF, LF) heater malfunction
9. HO2S (RF, LF) malfunction
10. Ignition coil malfunction
11. Insufficient compression
12. PCM malfunction
13. PCV valve malfunction
14. Pressure regulator malfunction
15. Purge solenoid hoses are hooked up incorrectly
16. Purge solenoid valve malfunction

PCM monitors inversion cycle period, lean-to-rich response time and rich-to-lean response time of the sensor. PCM calculates average of inversion cycle period-specified inversion cycles, average response time from lean-to-rich, and from rich-to-lean when following monitoring conditions are met. If any exceeds the threshold, PCM determines circuit has a malfunction.

Monitoring Conditions

1. Drive mode 3
2. Following conditions are to be met: Calculation load: 18-58 percent, depending on engine speed. Engine speed: 1400-2500 RPM (MTX) Engine speed: 1200-2500 RPM (ATX) Engine coolant temperature: 14°F (-10°C) or more

This is an intermittent monitor (O2 sensor). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Engine malfunction
2. Fuel filter clogged or restricted
3. Fuel leakage on fuel line from fuel distribution pipe and fuel pump
4. Fuel pump malfunction
5. Fuel return hose clogged
6. HO2S (RF, LF) deterioration
7. HO2S (RF, LF) heater malfunction
8. Insufficient compression
9. Leakage exhaust system
10. PCM malfunction
11. Pressure regulator malfunction
12. Purge solenoid hoses improper connection
13. Purge solenoid valve malfunction

PCM monitors input voltage from right and left front HO2Ss when monitoring conditions are met. If input voltage from HO2S never exceeds 0.55 volt for 94 seconds, PCM determines HO2S circuit is not activated.

Monitoring Conditions

1. Drive mode 3
2. Following conditions are to be met: Engine speed is 1500 RPM or more Engine coolant temperature is 158°F (70°C) or more

This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Engine malfunction
2. Insufficient compression
3. Leakage in exhaust system
4. Open or short to ground circuit between right or left front HO2S terminal and PCM terminal For DTC P0134: Right front HO2S 4-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 60 (Yellow wire). For DTC P0154: Left front HO2S 4-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 87 (Green wire).
5. PCM malfunction
6. Right front or left front HO2S deterioration
7. Right front or left front HO2S heater malfunction

PCM monitors input voltage from right and left rear HO2Ss. If input voltage from the HO2S is 0.45 volt or more for 6 seconds during deceleration fuel cut, PCM determines circuit input is high. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Right or left rear HO2S malfunction
2. PCM malfunction
3. Short to power circuit between right or left rear HO2S terminal and PCM terminal: For P0138: Right rear HO2S 4-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 35 (White wire) For P0158: Left rear HO2S 4-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 61 (Red wire)

PCM monitors input voltage from right or left rear HO2S when following monitoring conditions are met. If input voltage from sensor never exceeds 0.55 volt for 42 seconds, PCM determines sensor circuit is not activated.

Monitoring Conditions

1. Drive Mode 3
2. Following conditions are to be met: Engine speed is 1500 RPM or more Engine coolant temperature is 158°F (70°C) or more.

This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Engine malfunction
2. Insufficient compression
3. Leakage in exhaust system
4. Open or short to ground circuit between right or left rear HO2S terminal and PCM terminal: For DTC P0140: Right rear HO2S 4-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 35 (White wire) For DTC P0160: Left rear HO2S 4-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 61 (Red wire)
5. PCM malfunction
6. Right or left rear HO2S deterioration
7. Right or left rear HO2S heater malfunction

PCM monitors Short Term Fuel Trim (SHRTFT) and Long Term Fuel Trim (LONGFT) values while under closed loop fuel control. If fuel trim exceeds preprogrammed criteria, PCM determines fuel system is too lean. This is a Continuous Monitor (fuel). MIL illuminates if PCM detects above malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction conditions during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Fuel filter clogged or restricted
2. Fuel injector malfunction
3. Fuel leakage on fuel line from fuel delivery pipe and fuel pump
4. Fuel pump malfunction
5. Fuel return hose clogged
6. Insufficient compression
7. Leakage in exhaust system
8. MAF/IAT sensor malfunction
9. Misfire
10. PCM malfunction
11. Pressure regulator malfunction
12. Right or left front HO2S deterioration
13. Right or left front HO2S heater malfunction
14. Variable valve timing control system improper operation

PCM monitors Short Fuel Trim (SHRTFT) and Long Fuel Trim (LONGFT) values while under closed loop fuel control. If fuel trim exceeds preprogrammed criteria, PCM determines fuel system is too rich. This is a Continuous Monitor (fuel). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Fuel pump malfunction
2. Fuel return hose clogged
3. Misfire
4. PCM malfunction
5. PCV valve malfunction
6. Pressure regulator malfunction
7. Purge solenoid valve hoses improper connection
8. Purge solenoid valve malfunction
9. Right or left front HO2S deterioration
10. Right or left front HO2S heater malfunction

If PCM detects Throttle Position (TP) sensor No. 2 voltage at PCM 104-pin harness connector terminal No. 63 is 0.255 volt or less after ignition is on, PCM determines TP circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Open circuit between throttle body 6-pin harness connector terminal "C" (Gray wire) and PCM 104-pin harness connector terminal No. 63 (Brown/Yellow wire)
3. Open circuit between throttle body 6-pin harness connector terminal "D" (Violet/Red wire) and PCM 104-pin harness connector terminal No. 20 (Yellow wire)
4. PCM malfunction
5. Short to ground circuit between throttle body 6-pin harness connector terminal "C" (Gray wire) and PCM 104-pin harness connector terminal No. 63 (Brown/Yellow wire)
6. TP sensor No. 2 malfunction

Scheme 64

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect Throttle Body Connector For Poor Connection - Turn ignition off. Disconnect throttle body 6-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 9.
4. Inspect TP Sensor No. 2 Power Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between throttle body 6-pin harness connector terminal "D" (Yellow wire) and body ground. (Scheme 65) If voltage reading is 4.5-5.5 volts, go to next step. If voltage reading is not 4.5-5.5 volts, repair open circuit between throttle body 6-pin harness connector terminal "D" (Yellow wire) and PCM 104-pin harness connector terminal No. 20 (Violet/Red wire) or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
5. Verify TP Sensor No. 2 Signal Circuit For Short To Ground - Turn ignition off. Check continuity between throttle body 6-pin harness connector terminal "C" (Gray wire) and body ground. If continuity is not present, repair short circuit to ground in wire between throttle body 6-pin harness connector terminal "C" (Gray wire) and PCM 104-pin harness connector terminal No. 63 (Brown/Yellow wire) or replace wire harness. After repair, go to step 9.
6. Inspect TP Sensor No. 2 - Inspect TP sensor No. 2. Refer to «THROTTLE POSITION SENSOR»(ref-151892-S09967751312003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If no malfunction is present, go to next step. If TP sensor No. 2 is faulty, replace throttle body. After repair, go to step 9.
7. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 9.
8. Verify TP Sensor No. 2 Signal Circuit For Open Circuit - Turn ignition off. Check for continuity between throttle body 6-pin harness connector terminal "C" (Gray wire) and PCM 104-pin harness connector terminal No. 63 (Brown/Yellow wire). (Scheme 65) If continuity is present, go to next step. If continuity is not present, repair open circuit in suspected wire between throttle body 6-pin harness connector terminal "C" (Gray wire) and PCM 104-pin harness connector terminal No. 63 (Brown/Yellow wire) or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
9. Verify Trouble Shooting Of DTC P0222 Is Completed - Make sure to reconnect all disconnected connectors. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Turn ignition on, engine off. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
10. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

If PCM detects TP sensor No. 2 voltage at PCM 104-pin harness connector terminal No. 63 is 4.72 volts or more after ignition is on, PCM determines TP circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Open circuit between throttle body 6-pin harness connector terminal "E" (Brown wire) and PCM 104-pin harness connector terminal No. 36 (Brown/Black wire)
3. PCM malfunction
4. Short to power circuit between throttle body 6-pin harness connector terminal "C" (Gray wire) and PCM 104-pin harness connector terminal No. 63 (Brown/Yellow wire)
5. TP sensor No. 2 malfunction

The PCM monitors Crankshaft Position (CKP) sensor input signal interval time. PCM calculates change of interval time for each cylinder. If change of interval time exceeds preprogrammed criteria, PCM detects a misfire in corresponding cylinder. While engine is running, PCM counts number of misfires that occurred at 200 crankshaft revolutions and 1000 crankshaft revolutions and calculates misfire ratio for each crankshaft revolution. If ratio exceeds preprogrammed criteria, PCM determines that a misfire, which can damage catalytic converter or affect emission performance, has occurred. This is a Continuous Monitor (misfire). MIL illuminates if PCM detects misfire which affects emission performance in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. MIL flashes if PCM detects misfire which can damage catalytic converter during first drive cycle. Therefore, PENDING CODE is not available while MIL flashes. PENDING CODE is available if PCM detects misfire which affects emission performance during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Camshaft Position (CMP) sensor malfunction
2. CKP sensor malfunction
3. Damaged vacuum hoses or improper connection
4. EGR valve malfunction
5. Engine malfunction
6. Excess air suction in intake air system (between MAF/IAT sensor and dynamic chamber)
7. Fuel filter clogged
8. Fuel leakage in fuel line
9. Fuel line clogged
10. Fuel pressure regulator malfunction
11. Fuel pump malfunction
12. High-tension lead malfunction
13. Ignition coil malfunction
14. Insufficient compression
15. Mass Airflow/Intake Air Temperature (MAF/IAT) sensor contamination
16. PCM malfunction
17. PCV valve malfunction
18. Purge control solenoid valve malfunction
19. Related connector and terminal malfunction
20. Related wiring harness malfunction
21. Variable valve timing control system improper operation

PCM monitors Crankshaft Position (CKP) sensor input signal interval time. PCM calculates change of interval time for each cylinder. If change of interval time exceeds preprogrammed criteria, PCM detects a misfire in corresponding cylinder. While engine is running, PCM counts number of misfires that occurred at 200 crankshaft revolutions and 1000 crankshaft revolutions and calculates misfire ratio for each crankshaft revolution. If ratio exceeds preprogrammed criteria, PCM determines that a misfire, which can damage catalytic converter or affect emission performance, has occurred. This is a Continuous Monitor (misfire). MIL illuminates if PCM detects misfire which affects emission performance in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. MIL flashes if PCM detects misfire which can damage catalytic converter during first drive cycle. Therefore, PENDING CODE is not available while MIL flashes. PENDING CODE is available if PCM detects misfire which affects emission performance during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Air suction in intake air system (between dynamic chamber and cylinder head)
2. Fuel injector malfunction
3. High-tension lead malfunction
4. Inadequate engine compression due to engine internal malfunction
5. PCM malfunction
6. Related connector or terminal malfunction
7. Related wiring harness malfunction
8. Spark plug malfunction

PCM monitors input signal from Knock Sensor (KS) when engine is running. If input voltage at PCM 104-pin harness connector terminals No. 31 and No. 4 are excessively low or high, PCM determines KS circuit is malfunctioning. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. KS malfunction
3. Open circuit in Green wire between KS 2-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 4
4. Open circuit in Red wire between KS harness connector terminal "B" and PCM 104-pin harness connector terminal No. 31
5. PCM malfunction
6. Short between KS harness connector terminal "A" (Green wire) and terminal "B" (Red wire)
7. Short to ground circuit in Green wire between KS harness connector terminal "A" and PCM 104-pin harness connector terminal No. 4
8. Short to ground circuit in Red wire between KS harness connector terminal "B" and PCM 104-pin harness connector terminal No. 31

Scheme 65

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect KS Connector For Poor Connection - Turn ignition off. Disconnect KS connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 9.
4. Inspect KS Circuit For Short To Ground - Turn ignition off. Check for continuity between following circuits. (Scheme 66): KS harness connector terminal "A" (Green wire) and body ground KS harness connector terminal "B" (Red wire) and body ground If no continuity is present, go to next step. If continuity is present, repair short circuit to ground in suspected wire or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
5. Inspect KS Circuit For Short To Each Other - Turn ignition off. Disconnect KS harness connector. Check for continuity between KS harness connector terminal "A" (Green wire) and terminal "B" (Red wire). If no continuity is present, go to next step. If continuity is present, repair short between circuits between KS harness connector and PCM 104-pin harness connector terminals or replace wire harness. After repair, go to step 9.
6. Inspect Knock Sensor - Perform KS inspection. Refer to «KNOCK SENSOR»(ref-151892-S16389784292003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If KS is okay, go to next step. If KS is faulty, replace KS. Refer to «KNOCK SENSOR»(ref-151901-S30681157522003010900000) under ENGINE SENSORS & SWITCHES in REMOVAL & INSTALLATION article. After repair, go to step 9.
7. Inspect PCM Connector Terminal For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out pins, corrosion). If malfunction is not present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to next step.
8. Inspect KS Circuit For Open Circuit - Turn ignition off. Check continuity between following circuits: KS harness connector terminal "A" and PCM 104-pin harness connector terminal No. 4 (Green wire) KS harness connector terminal "B" and PCM 104-pin harness connector terminal No. 31 (Red wire) If continuity is present, go to next step. If continuity is not present, repair open circuit in suspected wire or replace wire harness. After repair, go to next step.
9. Verify Trouble Shooting Of DTC P0325 Is Completed - Make sure to reconnect all disconnected connectors. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Turn ignition on, engine off. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
10. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

If PCM does not receive input voltage from Crankshaft Position (CKP) sensor for 4.2 seconds while MAF is 0.36 lb./min. (2.7 grams/sec.) or more, PCM determines CKP sensor circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction conditions during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. CKP sensor is dirty
2. CKP sensor malfunction
3. CKP sensor pulse wheel malfunction
4. Connector or terminal malfunction
5. Open circuit between CKP sensor 2-pin harness connector terminal "A" (Brown/Blue wire) and PCM 104-pin harness connector terminal No. 22 (Green wire)
6. Open circuit between CKP sensor harness connector terminal "B" (White/Red wire) and PCM 104-pin harness connector terminal No. 21 (Blue wire)
7. PCM malfunction
8. Short circuit between CKP sensor harness connector terminal "A" (Brown/Blue wire) and terminal "B" (White/Red wire)
9. Short to ground circuit between CKP sensor harness connector terminal "A" (Brown/Blue wire) and PCM 104-pin harness connector terminal No. 22 (Green wire)
10. Short to ground circuit between CKP sensor harness connector terminal "B" (White/Red wire) and PCM 104-pin harness connector terminal No. 21 (Blue wire)

Scheme 66

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Verify CKP Sensor Voltage - Disconnect CKP sensor harness connector. Connect voltmeter between CKP sensor connector terminals. (Scheme 67) Check voltage in AC range while cranking engine. If voltage reading is present, go to next step. If voltage reading is not present, go to step 10.
4. Verify CKP Sensor Resistance - Measure CKP sensor resistance. Refer to «CRANKSHAFT POSITION SENSOR»(ref-151892-S03434950902003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If CKP sensor resistance reading is okay, check CKP sensor pulse wheel for damage. If any malfunction is present, replace CKP sensor pulse wheel. Refer to appropriate article in ENGINES. After repair, go to step 10. If CKP sensor resistance reading is zero, go to next step. If resistance reading is infinity, go to step 7.
5. Inspect CKP Sensor Circuit For Short To Ground - Turn ignition off. Check for continuity between following circuits: CKP sensor harness connector terminal "A" (Brown/Blue wire) and body ground CKP sensor harness connector terminal "B" (White/Red wire) and body ground If no continuity is present, go to next step. If continuity is present, repair short circuit to ground in suspected wire between CKP sensor harness connector and PCM 104-pin harness connector or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 10.
6. Inspect CKP Sensor Circuit For Short With Each Other - Turn ignition off. Disconnect CKP sensor harness connector. Check for continuity between CKP sensor harness connector terminal "A" (Brown/Blue wire) and terminal "B" (White/Red wire). (Scheme 67) If no continuity is present, go to next step. If continuity is present, repair short between CKP sensor circuits or replace wire harness. After repair, go to step 10.
7. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If connector terminals are okay, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 10.
8. Inspect CKP Sensor Circuit For Open Circuit - Turn ignition off. Check for continuity between following circuits: CKP sensor harness connector terminal "A" (Brown/Blue wire) and PCM 104-pin harness connector terminal No. 22 (Green wire) CKP sensor harness connector terminal "B" (White/Red wire) and PCM 104-pin harness connector terminal No. 21 (Blue wire) If continuity is present, go to next step. If continuity is not present, repair open circuit in suspected wire CKP sensor harness connector and PCM 104-pin harness connector or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 10.
9. Inspect CKP Sensor - Inspect CKP sensor. Refer to «CRANKSHAFT POSITION SENSOR»(ref-151892-S03434950902003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If CKP sensor is okay, go to next step. If CKP sensor is faulty, replace CKP sensor. After repair, go to next step.
10. Verify Trouble Shooting Of DTC P0335 Is Completed - Make sure to reconnect all disconnected connectors. Turn ignition on, engine off. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Start engine. Access MAF PID using WDS or equivalent. MAF PID should indicate 0.36 lb./min. (2.7 grams/sec.) or more during this test. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
11. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

The PCM monitors input voltage from right side Camshaft Position (CMP) sensor when engine is running. If PCM does not receive input voltage from right side CMP sensor while PCM receives input signal from Crankshaft Position (CKP) sensor, PCM determines CMP circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Open circuit between right side CMP sensor harness connector terminal "A" (White/Black wire) and PCM 104-pin harness connector terminal No. 85 (Black wire)
3. Open circuit between right side CMP sensor harness connector terminal "B" (Brown/Yellow wire) and PCM 104-pin harness connector terminal No. 86 (White wire)
4. PCM malfunction
5. Right side CMP sensor is dirty
6. Right side CMP sensor malfunction
7. Short to ground circuit between right side CMP sensor 2-pin harness connector terminal "A" (White/Black wire) and PCM 104-pin harness connector terminal No. 85 (Black wire)
8. Short to ground circuit between right side CMP sensor harness connector terminal "B" (Brown/Yellow wire) and PCM 104-pin harness connector terminal No. 86 (White wire)
9. Short each harness right side CMP sensor harness connector terminal "A" (White/Black wire) and terminal "B" (Brown/Yellow wire)

Scheme 67

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Verify Right Side CMP Sensor Voltage - Disconnect right side CMP sensor harness connector. Connect voltmeter between right side CMP sensor connector terminals. (Scheme 68) Check voltage in AC range while cranking engine. If voltage reading is present, go to next step. If voltage reading is not present, go to step 10.
4. Verify Right Side CMP Sensor Resistance - Measure right side CMP sensor resistance. Refer to «CAMSHAFT POSITION SENSOR»(ref-151892-S16315825052003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If CMP sensor resistance reading is okay, check right side CMP sensor pulse wheel for damage. If there is any malfunction, replace right side CMP sensor pulse wheel. Refer to appropriate article in ENGINES. After repair, go to step 10. If right side CMP sensor resistance reading is zero ohm, go to next step. If right side CMP sensor resistance reading is infinity, go to step 7.
5. Inspect Right Side CMP Sensor Circuit For Short To Ground - Turn ignition off. Check for continuity between following circuits: Right side CMP sensor harness connector terminal "A" (White/Black wire) and body ground Right side CMP sensor harness connector terminal "B" (Brown/Yellow wire) and body ground If no continuity is present, go to next step. If continuity is present, repair short circuit to ground in suspected wire between right side CMP sensor harness connector and PCM 104-pin harness connector or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 10.
6. Inspect Right Side CMP Sensor Circuit For Short With Each Other - Turn ignition off. Disconnect right side CMP sensor harness connector. Check for continuity between right side CMP sensor harness connector terminal "A" (White/Black wire) and terminal "B" (Brown/Yellow wire). (Scheme 68) If no continuity is present, go to next step. If continuity is present, repair short between right side CMP sensor circuits or replace wire harness. After repair, go to step 10.
7. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is found, go to next step. If any malfunction is present, repair or replace terminal or replace wire harness. After repair, go to step 10.
8. Inspect Right Side CMP Sensor Circuit For Open Circuit - Turn ignition off. Check for continuity between following circuits: Right side CMP sensor harness connector terminal "A" (White/Black wire) and PCM 104-pin harness connector terminal No. 85 (Black wire) Right side CMP sensor harness connector terminal "B" (Brown/Yellow wire) and PCM 104-pin harness connector terminal No. 86 (White wire) If continuity is present, go to next step. If no continuity is present, repair open circuit in suspected wire right side CMP sensor harness connector and PCM 104-pin harness connector or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 10.
9. Inspect Right Side CMP Sensor - Inspect right side CMP sensor. Refer to «CAMSHAFT POSITION SENSOR»(ref-151892-S16315825052003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If right side CMP sensor is okay, go to next step. If right side CMP sensor is faulty, replace right side CMP sensor. Refer to «CAMSHAFT POSITION SENSOR»(ref-151901-S26280287582003010900000) under ENGINE SENSORS & SWITCHES in REMOVAL & INSTALLATION article. After repair, go to next step.
10. Verify Trouble Shooting Of DTC P0340 Is Completed - Make sure to reconnect all disconnected connectors. Turn ignition on, engine off. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Start engine. Access MAF PID using WDS or equivalent. MAF PID should indicate 0.36 lb./min. (2.7 grams/sec.) or more during this test. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
11. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors input voltage from left side Camshaft Position (CMP) sensor when engine is running. If PCM does not receive input voltage from left side CMP sensor while PCM receives input signal from Crankshaft Position (CKP) sensor, PCM determines CMP circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Left side CMP sensor is dirty
3. Left side CMP sensor malfunction
4. Open circuit between left side CMP sensor harness connector terminal "A" (White/Green wire) and PCM 104-pin harness connector terminal No. 58 (Brown wire)
5. Open circuit between left side CMP sensor harness connector terminal "B" (Brown/White wire) and PCM 104-pin harness connector terminal No. 59 (Yellow wire)
6. PCM malfunction
7. Short between left side CMP sensor harness connector terminal "A" (White/Green wire) and terminal "B" (Brown/White wire)
8. Short to ground circuit between left side CMP sensor harness connector terminal "A" (White/Green wire) and PCM 104-pin harness connector terminal No. 58 (Brown wire)
9. Short to ground circuit between left side CMP sensor harness connector terminal "B" (Brown/White wire) and PCM 104-pin harness connector terminal No. 59 (Yellow wire)

Scheme 68

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Verify Left Side CMP Sensor Voltage - Disconnect left side CMP sensor harness connector. Connect voltmeter between left side CMP sensor connector terminals. Check voltage in AC range while cranking engine. If a voltage reading is present, go to next step. If a voltage reading is not present, go to step 9.
4. Verify Left Side CMP Sensor Resistance - Measure right side CMP sensor resistance. Refer to «CAMSHAFT POSITION SENSOR»(ref-151892-S16315825052003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If CMP sensor resistance reading is okay, check left side CMP sensor pulse wheel for damage. If there is any malfunction, replace left side CMP sensor pulse wheel. Refer to appropriate article in ENGINES. After repair, go to step 10. If left side CMP sensor resistance reading is zero ohm, go to next step. If left side CMP sensor resistance reading is infinity, go to step 7.
5. Inspect Left Side CMP Sensor Circuit For Short To Ground - Turn ignition off. Check for continuity between following circuits: Left side CMP sensor harness connector terminal "A" (White/Green wire) and body ground Left side CMP sensor harness connector terminal "B" (Brown/White wire) and body ground If no continuity is present, go to next step. If continuity is present, repair short circuit to ground in suspected wire between left side CMP sensor harness connector and PCM 104-pin harness connector or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 10.
6. Inspect Left Side CMP Sensor Circuit For Short With Each Other - Turn ignition off. Disconnect left side CMP sensor harness connector. Check for continuity between left side CMP sensor harness connector terminal "A" (White/Green wire) and terminal "B" (Brown/White wire). (Scheme 69) If no continuity is present, go to next step. If continuity is present, repair short between left side CMP sensor circuits or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 10.
7. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is found, go to next step. If any malfunction is present, repair or replace terminal or replace wire harness. After repair, go to step 10.
8. Inspect Left Side CMP Sensor Circuit For Open Circuit - Turn ignition off. Check for continuity between following circuits: Left side CMP sensor harness connector terminal "A" (White/Green wire) and PCM 104-pin harness connector terminal No. 58 (Brown wire) Left side CMP sensor harness connector terminal "B" (Brown/White wire) and PCM 104-pin harness connector terminal No. 59 (Yellow wire) If continuity is present, go to next step. If no continuity is present, repair open circuit in suspected wire or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 10.
9. Inspect Left Side CMP Sensor - Inspect left side CMP sensor. Refer to «CAMSHAFT POSITION SENSOR»(ref-151892-S16315825052003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If left side CMP sensor is okay, go to next step. If left side CMP sensor is faulty, replace left side CMP sensor. Refer to «CAMSHAFT POSITION SENSOR»(ref-151901-S26280287582003010900000) under ENGINE SENSORS & SWITCHES in REMOVAL & INSTALLATION article. After repair, go to next step.
10. Verify Trouble Shooting Of DTC P0340 Is Completed - Make sure to reconnect all disconnected connectors. Turn ignition on, engine off. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Start engine. Access MAF PID using WDS or equivalent. MAF PID should indicate 0.36 lb./min. (2.7 grams/sec.) or more during this test. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
11. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors difference in intake manifold pressures when EGR is operated and when it is stopped. If difference is too small, PCM determines EGR flow is insufficient. This is an intermittent monitor (EGR). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. EGR boost sensor malfunction
2. EGR boost sensor solenoid valve malfunction
3. EGR valve gasket malfunction
4. EGR valve malfunction
5. PCM malfunction

PCM monitors difference in intake manifold pressures when EGR is operated and when it is stopped. If difference is too large, PCM determines EGR flow is excessive. This is an intermittent monitor (EGR). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. EGR valve gasket has been damaged.
2. EGR valve gasket is not installed.
3. PCM malfunction

PCM monitors input voltages from EGR valve control signals. If voltage is less than or more than the specification, PCM determines EGR valve circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. EGR valve malfunction
3. Open circuit in Pink wire between EGR valve 6-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 72
4. Open circuit in Gray wire between EGR valve 6-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 46
5. Open circuit in Red/Green wire between EGR valve 6-pin harness connector terminal "E" and PCM 104-pin harness connector terminal No. 12
6. Open circuit in Yellow wire between EGR valve 6-pin harness connector terminal "F" and PCM 104-pin harness connector terminal No. 56
7. Open circuit in White wire between main relay harness connector terminal "C" and EGR valve 6-pin harness connector terminal "C"
8. Open circuit in White wire between main relay harness connector terminal "C" and EGR valve 6-pin harness connector terminal "D"
9. PCM malfunction
10. Short to ground circuit in Gray wire between EGR valve 6-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 46
11. Short to ground circuit in Pink wire between EGR valve 6-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 72
12. Short to ground circuit in Red/Green wire between EGR valve 6-pin harness connector terminal "E" and PCM 104-pin harness connector terminal No. 12
13. Short to ground circuit in Yellow wire between EGR valve 6-pin harness connector terminal "F" and PCM 104-pin harness connector terminal No. 56

Scheme 69

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Classify Intermittent Concern Or Continuous Concern - Turn ignition off, then on (engine off). If same DTC is present, go to next step. If same DTC is not present, problem is intermittent. Refer to «INTERMITTENT PROBLEM DIAGNOSIS»(ref-151888-S40451828582003010900000) in TROUBLE SHOOTING - NO CODES article.
4. Inspect EGR Valve Connector For Poor Connection - Turn ignition off. Disconnect EGR valve 6-pin harness connector. (Scheme 70) Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 10.
5. Inspect EGR Valve Power Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between following circuits: EGR valve 6-pin harness connector terminal "C" (White wire) and body ground EGR valve 6-pin harness connector terminal "D" (White wire) and body ground If battery voltage is present, go to next step. If battery voltage is not present, repair open circuit in suspected wire between EGR valve 6-pin harness and PCM 104-pin harness connector or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 10.
6. Inspect EGR Valve Control Circuit For Short To Ground - Turn ignition off. Check for continuity between following circuits: EGR valve 6-pin harness connector terminal "A" (Pink wire) and body ground EGR valve 6-pin harness connector terminal "B" (Gray wire) and body ground EGR valve 6-pin harness connector terminal "E" (Red/Green wire) and body ground EGR valve 6-pin harness connector terminal "F" (Yellow wire) and body ground If continuity is not present, go to next step. If continuity is present, repair short circuit to ground in suspected wire between EGR valve 6-pin harness connector and PCM 104-pin harness connector or replace wire harness. After repair, go to step 10.
7. Inspect EGR Valve - Inspect EGR valve. Refer to «EXHAUST GAS RECIRCULATION SYSTEM»(ref-151892-S39514123932003010900000) under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If EGR valve is okay, go to next step. If EGR valve is faulty, replace EGR valve. After repair, go to step 10.
8. Inspect PCM Connector Terminal For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out pins, corrosion). If malfunction is not present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 10.
9. Inspect EGR Valve Control Circuit For Open Circuit - Turn ignition off. Check for continuity between following circuits: EGR valve 6-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 72 (Pink wire) EGR valve 6-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 46 (Gray wire) EGR valve 6-pin harness connector terminal "E" and PCM 104-pin harness connector terminal No. 12 (Red/Green wire) EGR valve 6-pin harness connector terminal "F" and PCM 104-pin harness connector terminal No. 56 (Yellow wire) If continuity is present, go to next step. If continuity is not present, repair open circuit in suspected wire between EGR valve 6-pin harness connector and PCM 104-pin harness connector or replace wire harness. After repair, go to next step.
10. Verify Trouble Shooting Of DTC P0403 Is Completed - Make sure to reconnect all disconnected connectors. Turn ignition on, engine off. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
11. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM compares number of front HO2S and rear HO2S inversions for a predetermined time. PCM monitors number of inversions rear side performs while front side inverts for a specified number of times when following monitoring conditions are met. PCM detects inversion ratio. If inversion ratio is less than threshold, PCM determines catalyst system has deteriorated.

Monitoring Condition

1. Engine speed is 1250-2750 RPM
2. Calculated load is 15-44 percent, depending on engine speed

This is an intermittent monitor (catalyst). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Exhaust gas leakage
2. HO2S (RF, LF) malfunction
3. Looseness of HO2S (RF, LF, RR or LR)
4. PCM malfunction
5. WU-TWC deterioration or malfunction

PCM measures purge line pressure, which is vacuum, when following conditions are met. If vacuum between charcoal canister and intake manifold does not reach specification, PCM determines that EVAP system is clogged.

1. Engine speed: 1500-3550 RPM (MTX)
2. Engine speed: 1220-3000 RPM (ATX)
3. Throttle opening angle: 10.2-27.8 percent
4. Vehicle speed: 43.1-84.3 MPH (MTX)
5. Vehicle speed: 21.4-84.3 MPH (ATX)

This is an intermittent monitor (evaporative). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Catch tank malfunction
2. Charcoal canister malfunction
3. EVAP hose damaged or loose
4. EVAP pipe damaged
5. EVAP system leak detection pump malfunction
6. PCM malfunction
7. Purge solenoid valve malfunction

PCM measures pump load current (EVAP line pressure) when a certain period has passed after EVAP system is sealed when following monitoring conditions are met. If load does not reach reference current value within a certain period, PCM determines EVAP system has a small leak.

Monitoring Condition

1. Ignition off
2. IAT: 41-113°F (5-45°C)
3. Battery voltage: 11-14.6 volts
4. Atmospheric pressure: 21.3 in. Hg (72.2 kPa) or more
5. Fuel tank level: 15-85 percentage

This is an intermittent monitor (evaporative). MIL illuminates if PCM detects above malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Catch tank malfunction
2. Charcoal canister malfunction
3. EVAP hose damaged or loose
4. EVAP pipe damaged
5. EVAP system leak detection pump malfunction
6. Fuel filler cap malfunction
7. Fuel pump unit poor seal
8. Fuel tank malfunction
9. Purge solenoid valve malfunction

PCM monitors input voltages from purge solenoid valve. If voltage at PCM 104-pin harness connector terminal No. 18 remains low or high, PCM determines purge solenoid valve circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Open circuit in White wire between main relay harness connector terminal "C" and purge solenoid valve 2-pin harness connector terminal "A"
3. Open circuit in Blue/Yellow wire between purge solenoid valve harness connector terminal "B" and PCM 104-pin harness connector terminal No. 18
4. PCM malfunction
5. Purge solenoid valve malfunction
6. Short to ground in Blue/Yellow wire between purge solenoid valve harness connector terminal "B" and PCM 104-pin harness connector terminal No. 18
7. Short to power circuit in Blue/Yellow wire between purge solenoid valve harness connector terminal "B" and PCM 104-pin harness connector terminal No. 18

Scheme 70

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Classify Intermittent Concern Or Continuous Concern - Turn ignition off, then on (engine off). If same DTC is present, go to next step. If same DTC is not present, problem is intermittent. Refer to «INTERMITTENT PROBLEM DIAGNOSIS»(ref-151888-S40451828582003010900000) in TROUBLE SHOOTING - NO CODES article.
4. Classify Open Circuit Or Short To Ground Malfunction - Disconnect purge solenoid valve tube that is connected to intake manifold. Connect vacuum pump to purge solenoid valve. Pump vacuum pump several times and stop. Wait a few seconds. If vacuum is not maintained, go to next step. If vacuum is maintained, go to step 12.
5. Inspect Passage Control Of Purge Solenoid Valve - Turn ignition off. Disconnect purge solenoid valve harness connector. (Scheme 71) Pump vacuum pump several times and wait a few seconds. If vacuum is maintained, repair short circuit to ground in Blue/Yellow wire between purge solenoid valve harness connector terminal "B" and PCM 104-pin harness connector terminal No. 18 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 12. If vacuum is not maintained, replace purge solenoid valve. After repair, go to step 12.
6. Inspect Purge Solenoid Valve Connector For Poor Connection - Turn ignition off. Inspect for poor connection (damaged/pulled-out pins, corrosion, etc.). If terminals are okay, go to next step. If malfunction is present, repair or replace suspected terminal. After repair, go to step 12.
7. Inspect Purge Solenoid Valve Power Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage in White wire between purge solenoid valve harness connector terminal "A" and body ground. If battery voltage is present, go to next step. If battery voltage is not present, repair open circuit in White wire between purge solenoid valve harness connector terminal "A" and main relay harness connector terminal "C" or replace wire harness. After repair, go to step 12.
8. Inspect Purge Solenoid Valve Control Circuit For Short To Power - Turn ignition on, engine off. Measure voltage in Blue/Yellow wire between purge solenoid valve harness connector terminal "B" and body ground. (Scheme 71) If voltage reading is present, repair short circuit to power in Blue/Yellow wire between purge solenoid valve harness connector terminal "B" and PCM 104-pin harness connector terminal No. 18 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 12.
9. Inspect Purge Solenoid Valve - Perform Purge Solenoid Valve Inspection. Refer to «PURGE SOLENOID VALVE»(ref-151892-S07758970622003010900000) under RELAYS & SOLENOIDS in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If purge solenoid valve is okay, go to next step. If purge solenoid valve is faulty, replace purge solenoid valve. After repair, go to step 12.
10. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Check for poor connection (damaged/pulled-out pins, corrosion, etc.). If connection is okay, go to next step. If malfunction is present, repair or replace terminal. After repair, go to next step.
11. Inspect Purge Solenoid Valve Control Circuit For Open Circuit - Turn ignition off. Check for continuity in Blue/Yellow wire between purge solenoid valve harness connector terminal "B" and PCM 104-pin harness connector terminal No. 18. (Scheme 71) If continuity is present, go to next step. If continuity is not present, repair open circuit in Blue/Yellow wire between purge solenoid valve harness connector terminal "B" and PCM 104-pin harness connector terminal No. 18 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
12. Verify Trouble Shooting Of DTC P0443 Is Completed - Make sure to reconnect all disconnected connectors. Turn ignition on, engine off. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
13. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors pump load current (EVAP line pressure), while evaporative leak monitor is operating. When decrease in pump load current is less than specification after reference current value has been obtained, PCM determines Change Over Valve (COV) in EVAP system leak detection pump has a malfunction. This is a Continuous Monitor (Evaporative). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Change over valve (in EVAP system leak detection pump) malfunction.
2. PCM malfunction
3. Short to power circuit in Orange wire between EVAP system leak detection pump 4-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 6

PCM measures pump load current (EVAP line pressure) when a certain period has passed after EVAP system is sealed when following monitoring conditions are met. If load does not reach reference current value within a certain period, PCM determines EVAP system has a large leak.

Monitoring Condition

1. Ignition: OFF
2. IAT: 41-113°F (5-45°C)
3. Battery voltage: 11-14.6 volts
4. Atmospheric pressure: 21.3 in. Hg (72.2 kPa) or more
5. Fuel tank level: 15-85 percent

This is an intermittent monitor (Evaporative). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Catch tank malfunction
2. Charcoal canister malfunction
3. EVAP hose damaged or loose
4. EVAP system leak detection pump malfunction
5. Fuel tank malfunction
6. Loose, missing or defective fuel filler cap
7. PCM malfunction
8. Poor connection or damaged vacuum hose
9. Purge solenoid valve malfunction

PCM measures pump load current (EVAP line pressure) when a certain period has passed after EVAP system is sealed and after ignition is turned off. If load does not reach reference load value or a rate of load increase less than specified within a certain period, PCM determines EVAP system has a very small leak.

Monitoring Condition

1. Ignition: OFF
2. IAT: 41-113°F (5-45°C)
3. Battery voltage: 11-14.6 volts
4. Atmospheric pressure: 21.3 in. Hg (72.2 kPa) or more
5. Fuel tank level: 15-85 percent

This is an intermittent monitor (Evaporative). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for the same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Catch tank malfunction
2. Charcoal canister malfunction
3. EVAP hose damaged or loose
4. EVAP pipe damaged
5. EVAP system leak detection pump malfunction
6. Fuel cap malfunction
7. Fuel pump unit poor seal
8. Fuel tank malfunction
9. PCM malfunction
10. Purge solenoid valve malfunction

PCM monitors fuel gauge sender unit input voltage difference before and after PCM-calculated fuel consumption has reached 25.9 quarts (24.5 Liters). If fuel gauge sender unit operation reflects 5 percent less than PCM-calculated fuel consumption, PCM determines fuel gauge sender unit range/performance is in error. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Fuel gauge sender unit malfunction or substandard performance
2. PCM malfunction

PCM monitors fuel level signal and fuel gauge sender unit output voltage from instrument cluster. If PCM detects a fuel level or fuel gauge sender unit output voltage that is too low, PCM determines that fuel gauge sender unit circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Fuel gauge sender unit malfunction
2. Instrument cluster malfunction
3. PCM malfunction

PCM monitors fuel level signal and fuel gauge sender unit output voltage from instrument cluster. If PCM detects a fuel level or fuel gauge sender unit output voltage that is too high, PCM determines fuel gauge sender unit circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Fuel gauge sender unit malfunction
2. Instrument cluster malfunction
3. PCM malfunction

PCM monitors input voltages from fan control module. If voltage at PCM 104-pin harness connector terminal No. 44 remains low or high, PCM determines fan control circuit has a malfunction. This is a Continuous Monitor (other). MIL does not illuminate. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Fan control module malfunction
2. Connector or terminal malfunction
3. Open circuit in Red/Black wire between fan control module 3-pin harness connector terminal "1B" and PCM 104-pin harness connector terminal No. 44
4. Short to power circuit in Red/Black wire between fan control module 3-pin harness connector terminal "1B" and PCM 104-pin harness connector terminal No. 44
5. Short to ground circuit in Red/Black wire between fan control module 3-pin harness connector terminal "1B" and PCM 104-pin harness connector terminal No. 44
6. PCM malfunction

Scheme 71

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect Fan Control Module Connector For Poor Connection - Turn ignition off. Disconnect fan control module 3-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If connections are okay, go to next step. If malfunction is present, repair or replace terminal. After repair, go to step 9.
4. Inspect Fan Control Module Signal Circuit For Short To Power - Turn ignition on, engine off. Measure voltage between fan control module 3-pin harness connector terminal "1B" and body ground. (Scheme 72) If battery voltage is not present, go to next step. If battery voltage is present, repair short circuit to power in Red/Black wire between fan control module 3-pin harness connector terminal "1B" and PCM 104-pin harness connector terminal No. 44 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
5. Inspect Fan Control Module Signal Circuit For Short To Ground - Turn ignition off. Check for continuity between fan control module harness connector terminal "1B" and body ground. If continuity is not present, go to next step. If continuity is present, repair short circuit to ground in Red/Black wire between fan control module 3-pin harness connector terminal "1B" and PCM 104-pin harness connector terminal No. 44 or replace wire harness. After repair, go to step 9.
6. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If terminals are okay, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 9.
7. Inspect Fan Control Module Signal Circuit For Open Circuit - Turn ignition off. Check for continuity in Red/Black wire between fan control module 3-pin harness connector terminal "1B" and PCM 104-pin harness connector terminal No. 44. (Scheme 72) If continuity is present, go to next step. If continuity is not present, repair open circuit in Red/Black wire between fan control module 3-pin harness connector terminal "1B" and PCM 104-pin harness connector terminal No. 44 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
8. Inspect Fan Control Module - Check fan control module. See appropriate ELECTRIC COOLING FANS article in ENGINES. If fan control module is okay, go to next step. If fan control module is faulty, replace fan control module. After repair, go to next step.
9. Verify Trouble Shooting Of DTC P0480 Is Completed - Make sure to reconnect all disconnected connectors. Turn ignition on, engine off. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
10. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM determines Vehicle Speed Sensor (VSS) circuit has a malfunction when following conditions are detected

1. With ABS/TCS - Wheel speed signal from ABS/DSC HU/CM is less than 2.3 MPH when following conditions are met: Engine speed is 2000 RPM or more Load is more than 40 percent Neutral switch and clutch switch are off (MTX) Shift range in any position except P, N or R range (ATX)
2. ATX Without ABS/TCS - Vehicle speed signal from TCM is incorrect. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

With ABS/TCS

1. ABS/TCS HU/CM malfunction
2. Connector or terminal malfunction
3. PCM malfunction

MTX Without ABS/TCS

1. Connector or terminal malfunction
2. Open circuit in Yellow/Red wire between VSS 2-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 57
3. Open circuit in Gray/Red wire between VSS harness connector terminal "B" and PCM 104-pin harness connector terminal No. 84
4. PCM malfunction
5. Short to ground circuit in Gray/Red wire between VSS harness connector terminal "B" and PCM 104-pin harness connector terminal No. 84
6. Short to ground circuit in Yellow/Red wire between VSS harness connector terminal "A" and PCM 104-pin harness connector terminal No. 57
7. Short to power circuit in Gray/Red wire between VSS harness connector terminal "B" and PCM 104-pin harness connector terminal No. 84
8. Short to power circuit in Yellow/Red wire between VSS harness connector terminal "A" and PCM 104-pin harness connector terminal No. 57
9. VSS malfunction

ATX Without ABS/TCS

1. Connector or terminal malfunction
2. PCM malfunction
3. TCM malfunction

Scheme 72

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Verify Current Input Signal Status - Is Concern Intermittent Or Constant - Connect WDS or equivalent to DLC-2. Start engine. Access VSS PID using WDS or equivalent. Vehicle speed 12.4 MPH Vehicle speed 24.8 MPH If PID readings are within specification, go to intermittent concern troubleshooting procedure. Refer to «INTERMITTENTS»(ref-151888-S02099367392003010900000) in TROUBLE SHOOTING - NO CODES article. If PID readings are not within specification, go to next step.
4. Verify Vehicle Type - Verify vehicle type. If vehicle is equipped with a MTX without ABS/TCS, go to next step. If vehicle is equipped with a ATX without ABS/TCS, go to applicable DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If vehicle is equipped with ABS/TCS, go to applicable DTC inspection.
5. Inspect VSS Connector For Poor Connection - Verify VSS connector is connected securely. If connection is okay, go to next step. If connector is loose, reconnect VSS harness connector securely. After repair, go to step 11.
6. Inspect VSS Circuit For Short To Ground - Turn ignition off. Check continuity between following circuits: VSS harness connector terminal "A" (Yellow/Red wire) and body ground. (Scheme 73)VSS harness connector terminal "B" (Gray/Red wire) and body ground If continuity is not present, go to next step. If continuity is present in either terminal, repair short circuit to ground in suspected wire or replace wire harness. After repair, go to step 11.
7. Inspect VSS Circuit For Short To Power - Turn ignition off. Disconnect VSS harness connector. Turn ignition on, engine off. Measure voltage at following terminals: VSS harness connector terminal "A" (Yellow/Red wire) and body ground VSS harness connector terminal "B" (Gray/Red wire) and body ground If voltage reading is not present at either terminal, go to next step. If any voltage reading is present, repair short circuit to power in suspected wire or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 11.
8. Inspect VSS - Perform VSS inspection. Refer to «VEHICLE SPEED SENSOR»(ref-151892-S18953781802003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If VSS is okay, go to next step. If VSS is faulty, replace VSS. After repair, go to step 11.
9. Inspect PCM Connector For Poor Connection - Disconnect PCM 104-pin harness connector. (Scheme 73) Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If any malfunction is present, repair suspected terminal or replace wire harness. After repair, go to step 11.
10. Inspect VSS Circuit For Open Circuit - Turn ignition off. Check for continuity between following harnesses: VSS harness connector terminal "A" and PCM 104-pin harness connector terminal No. 57 VSS harness connector terminal "B" and PCM 104-pin harness connector terminal No. 84 If continuity is present, go to next step. If continuity is not present, repair open circuit in suspected wire or replace harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
11. Verify Trouble Shooting Of DTC P0500 Is Completed - Make sure to reconnect all disconnected connectors. Turn ignition on, engine off. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Warm up engine. Access RPM and LOAD PID using WDS or equivalent. Drive vehicle under following conditions for 18 seconds. Engine speed: 2000 RPM or more Gear Position: Gear is in position other than Neutral Load: 40 percent or more If PENDING CODE of same DTC is not present, go to next step. If PENDING CODE of same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
12. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

The PCM cannot control idle speed at target idle speed during self test.

Possible causes are

1. A/C relay control circuit malfunction
2. Air cleaner element clogged
3. Air intake passage clogged
4. Electronic throttle control system malfunction
5. Generator control circuit malfunction
6. Low engine compression (Over capacity of blow-by gas)
7. PCM malfunction

Note. If atmospheric pressure is 21.3 in. Hg (72.2 kPa) or less, or intake air temperature is 14°F (-10°C) or less, PCM cancels diagnosis of P0506.

Actual idle speed is less than expected by 100 RPM for 14 seconds when brake pedal is depressed (brake switch is on) and steering wheel is held straight ahead (power steering pressure switch is off). This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. A/C relay control circuit malfunction
2. Air cleaner element clogged
3. Air intake passage clogged
4. Electronic throttle control system malfunction
5. Generator malfunction
6. Low engine compression (Over capacity of blow-by gas)
7. PCM malfunction
8. Purge solenoid valve malfunction

The actual idle speed is higher than expected by 200 RPM for 14 seconds when brake pedal is depressed (brake switch is on) and steering wheel is held straight ahead (power steering pressure switch is off). This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Electronic throttle control system malfunction
2. PCM malfunction
3. Vacuum hose misconnection

The PCM monitors Power Steering Pressure (PSP) switch signal at PCM 104-pin harness connector terminal No. 14. If input voltage is low (switch stays on) for one minute when VSS is 37.2 MPH or more and ECT is 140°F (60°C) or more, PCM determines PSP switch circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. PCM malfunction
3. PSP switch malfunction
4. Short to ground circuit between PSP switch harness connector terminal "A" (Brown/Green wire) and PCM 104-pin harness connector terminal No. 14 (Black/Blue wire)

Scheme 73

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect PSP Switch Connector For Poor Connection - Turn ignition off. Disconnect PSP harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If there are no malfunctions, go to next step. If there are any malfunctions, repair or replace terminal. After repair, go to step 7.
4. Inspect PSP Switch Signal Circuit For Short To Ground - Turn ignition off. Check for continuity between PSP switch harness connector terminal "A" (Brown/Green wire) and body ground. (Scheme 74) If continuity is not present, go to next step. If continuity is present, repair short circuit to ground between PSP switch harness connector terminal "A" (Brown/Green wire) and PCM 104-pin harness connector terminal No. 14 (Black/Blue wire) or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 7.
5. Inspect PSP Switch - Inspect PSP switch. Refer to «POWER STEERING PRESSURE SWITCH»(ref-151892-S01306177172003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If PSP switch is okay, go to next step. If PSP switch is faulty, replace PSP switch. After repair, go to step 7.
6. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If terminals are okay, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to next step.
7. Verify Trouble Shooting Of DTC P0550 Is completed - Reconnect all connectors. Clear DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Drive vehicle at 37.2 MPH or more for one minute. Verify ECT PID is 140°F (60°C) or more using WDS or equivalent. If PENDING CODE of same DTC is not present, go to next step. If PENDING CODE of same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
8. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

The PCM monitors cruise control switch signal at PCM 104-pin harness connector terminal No. 15. If PCM detects any one of following switches (Main, CANCEL, SET/COAST, RESUME/ACCEL) remains on for 2 minutes, PCM determines cruise control switch circuit has a malfunction. This is a Continuous Monitor (other). MIL does not comes on. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Cruise control switch malfunction
3. Open circuit in Black wire between cruise control switch 8-pin harness connector terminal "C" and body ground
4. Open circuit in Black/Blue wire between cruise control switch 8-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 15
5. PCM malfunction
6. Short to ground circuit in Red/Blue wire between cruise control switch 8-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 15
7. Short to power circuit in Red/Blue wire between cruise control switch 8-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 15

Scheme 74

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect Cruise Control Switch Connector For Poor Connection - Turn ignition off. Disconnect cruise control switch 8-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If connections are okay, go to next step. If any malfunctions are present, repair or replace faulty terminal. After repair, go to step 10.
4. Inspect Cruise Control Switch Signal Circuit For Short To Power - Turn ignition on, engine off. Check for voltage between cruise control switch 8-pin harness connector terminal "B" (Red/Blue wire) and body ground. If battery voltage is not present, go to next step. If battery voltage is present, repair short circuit to power in Red/Blue wire between cruise control switch 8-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 15 or replace wire harness. After repair, go to step 10.
5. Inspect Cruise Control Switch Signal Circuit For Short To Ground - Disconnect cruise control switch 8-pin harness connector and PCM 104-pin harness connector. Check for continuity in Red/Blue wire between cruise control switch 8-pin harness connector terminal "B" and body ground. (Scheme 75) If continuity is not present, go to next step. If continuity is present, repair short circuit to ground in Red/Blue wire between cruise control switch 8-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 15 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 10.
6. Inspect Cruise Control Switch Ground Circuit For Open Circuit - Turn ignition off. Check for continuity between cruise control switch 8-pin harness connector terminal "C" (Black wire) and body ground. If continuity is present, go to next step. If continuity is not present, repair open circuit in Black wire between cruise control switch 8-pin harness connector terminal "C" and body ground or replace wire harness. After repair, go to next step.
7. Inspect Cruise Control Switch Operation - Inspect cruise control switch. Refer to appropriate CRUISE CONTROL SYSTEMS article in ACCESSORIES & EQUIPMENT. If cruise control switch is okay, go to next step. If cruise control switch is faulty, replace cruise control switch. After repair, go to step 10.
8. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If terminals are okay, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 10.
9. Inspect Cruise Control Switch Signal Circuit For Open Circuit - Turn ignition off. Check for continuity in Red/Blue wire between cruise control switch 8-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 15. (Scheme 75) If continuity is present, go to next step. If continuity is not present, repair open circuit in Red/Blue wire between cruise control switch 8-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 15 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
10. Verify Trouble Shooting Of DTC P0564 Is Completed - Reconnect all connectors. Clear DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Drive vehicle using cruise control for 2 minutes or more. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
11. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors changes in input voltage for brake switches No. 1 and No. 2. If PCM detects both brake switches No. 1 and No. 2 remain on or off for 15 seconds, PCM determines brake switch circuit has a malfunction. This is a Continuous Monitor (other). MIL does not come on. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Brake switch malfunction
2. Connector or terminal malfunction
3. Open circuit in Black/Orange wire between brake switch 4-pin harness connector terminal "C" and body ground
4. Short to ground circuit in Green/Orange wire between brake switch 4-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 7
5. Open circuit in Green/Orange wire between brake switch 4-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 7
6. PCM malfunction

Scheme 75

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect Brake Switch Connector For Poor Connection - Turn ignition off. Disconnect brake switch 4-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If there are no malfunctions, go to next step. If there are any malfunctions, repair or replace suspected terminal. After repair, go to step 9.
4. Inspect Brake Switch No. 2 Ground Circuit For Open Circuit - Check for continuity between brake switch 4-pin harness connector terminal "C" (Black/Orange wire) and body ground. (Scheme 76) If continuity is present, go to next step. If continuity is not present, repair open circuit in Black/Orange wire between brake switch 4-pin harness connector terminal "C" and ground terminal. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
5. Inspect Brake Switch No. 2 Signal Circuit For Short To Ground - Check for continuity between brake switch 4-pin harness connector terminal "A" (Green/Orange wire) and body ground. If continuity is not present, go to next step. If continuity is present, repair short circuit in Green/Orange wire between brake switch 4-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 7 or replace wire harness. After repair, go to step 9.
6. Inspect Brake Switch - Inspect brake switch. Refer to «BRAKELIGHT SWITCH»(ref-151892-S00360292682003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If brake switch is okay, go to next step. If brake switch is faulty, replace brake switch. After repair, go to step 9.
7. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If connections are okay, go to next step. If any malfunctions are present, repair or replace faulty terminal. After repair, go to step 9.
8. Inspect Brake Switch No. 2 Signal Circuit For Open Circuit - Check for continuity in Green/Orange wire between brake switch 4-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 7. (Scheme 76) If continuity is present, go to next step. If continuity is not present, repair open circuit in Green/Orange wire between brake switch 4-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 7 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
9. Verify Trouble Shooting Of DTC P0571 Is Completed - Make sure to reconnect all disconnected connectors. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Turn ignition on, engine off. Depress and release brake pedal 5 times or more. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
10. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

No configuration data in PCM. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Complete configuration has not been completed
2. PCM malfunction

PCM internal ROM/RAM malfunction. This is a Continuous Monitor (other). MIL does not come on. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible Cause

Possibly caused by PCM internal ROM/RAM malfunction.

PCM data configuration error. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Configuration procedure has not been completed
2. PCM malfunction

PCM monitors changes in input voltage from brake switch No. 1. If PCM does not detect voltage changes at PCM 104-pin harness connector terminal No. 32 while alternately accelerating and decelerating 8 times, PCM determines that brake switch No. 1 circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Brake switch malfunction
2. Connector or terminal malfunction
3. Open circuit between positive battery terminal and brake switch 4-pin harness connector terminal "B" (Green/White wire)
4. Open circuit in Green/Yellow wire between brake switch 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 32
5. PCM malfunction
6. Short to power circuit in Green/Yellow wire between brake switch 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 32

Scheme 76

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect Brake Switch Connector For Poor Connection - Turn ignition off. Disconnect brake switch 4-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If there are no malfunctions, go to next step. If there are any malfunctions, repair or replace suspected terminal. After repair, go to step 9.
4. Inspect Brake Switch No. 1 Power Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between brake switch 4-pin harness connector terminal "B" (Green/White wire) and body ground. (Scheme 77) If battery voltage is present, go to next step. If battery voltage is not present, repair open circuit in Green/White wire between positive battery terminal and brake switch 4-pin harness connector terminal "B" or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
5. Inspect Brake Switch No. 1 Signal Circuit For Short To Power - Turn ignition on, engine off. Measure voltage between brake switch 4-pin harness connector terminal "D" (Green/Yellow wire) and body ground. If battery voltage is not present, go to next step. If battery voltage is present, repair short circuit to power in Green/Yellow wire between brake switch 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 32 or replace wire harness. After repair, go to step 9.
6. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If connections are okay, go to next step. If any malfunctions are present, repair or replace faulty terminal. After repair, go to step 9.
7. Inspect Brake Switch No. 1 Signal Circuit For Open Circuit - Check for continuity in Green/Yellow wire between brake switch 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 32. (Scheme 77) If continuity is present, go to next step. If continuity is not present, repair open circuit in Green/Yellow wire between brake switch 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 32 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
8. Inspect Brake Switch No. 1 - Inspect brake switch No. 1. Refer to «BRAKELIGHT SWITCH»(ref-151892-S00360292682003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If brake switch is okay, go to next step. If brake switch is faulty, replace brake switch. After repair, go to next step.
9. Verify Trouble Shooting Of DTC P0703 Is Completed - Make sure to reconnect all disconnected connectors. Clear DTC from memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Drive vehicle at 18.6 MPH or more. Depress and release brake pedal more than 8 times while driving vehicle. If PENDING CODE of same DTC is not present, go to next step. If PENDING CODE of same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
10. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors changes in input voltage from clutch switch. If PCM does not detect voltage changes at PCM 104-pin harness connector terminal No. 17 while alternately accelerating and decelerating 8 times, PCM determines clutch switch circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Clutch switch malfunction
2. Connector or terminal malfunction
3. Open circuit between clutch switch 5-pin harness connector terminal "D" (Black wire) and ground
4. Open circuit in White/Green wire between clutch switch 5-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 17
5. PCM malfunction
6. Short to ground circuit in White/Green wire between clutch switch 5-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 17

Scheme 77

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Classify High Input Or Low Input - Connect WDS or equivalent to DLC-2. Access CPP PID. Verify CPP PID during clutch pedal operation. If CPP PID is always off, go to next step. If CPP PID is not always off, go to step 10.
4. Inspect Clutch Switch Connector For Poor Connection - Turn ignition off. Disconnect clutch switch 5-pin harness connector. Check for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair or replace faulty terminal. After repair, go to step 14.
5. Classify Clutch Switch Or Circuit - Connect WDS or equivalent to DLC-2. Access CPP PID. Connect a fused jumper wire between clutch switch 5-pin harness connector terminal "B" (White/Green wire) and terminal "D" (Black wire). (Scheme 78) If CPP PID is ON, go to next step. If CPP PID is not ON, go to step 7.
6. Inspect Clutch Switch - Perform clutch switch inspection. Refer to «CLUTCH SWITCH (M/T)»(ref-151892-S16884553252003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If clutch switch is okay, go to next step. If clutch switch is faulty, replace clutch switch. After repair, go to step 14.
7. Inspect Clutch Switch Ground Circuit For Open Circuit - Inspect continuity between clutch switch 5-pin harness connector terminal "D" (Black wire) and ground. If continuity is present, go to next step. If continuity is not present, repair open circuit in Black wire between clutch switch 5-pin harness connector terminal "D" and body ground or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 14.
8. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair terminal or replace wire harness. After repair, go to step 14.
9. Inspect Clutch Switch Signal Circuit For Open Circuit - Check for continuity in White/Green wire between clutch switch 5-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 17. (Scheme 78) If continuity is present, go to step 14. If continuity is not present, repair open circuit in White/Green wire between clutch switch 5-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 17 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 14.
10. Inspect Clutch Switch Connector For Poor Connection - Turn ignition off. Disconnect clutch switch 5-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair terminal or replace wire harness. After repair, go to step 14.
11. Classify Clutch Switch Or Circuit - Connect WDS or equivalent to DLC-2. Access CPP PID. Verify CPP PID changes from ON to OFF when clutch switch 5-pin harness connector is disconnected. If CPP PID changes from ON to OFF, go to next step. If CPP PID does not change from ON to OFF, go to step 14.
12. Inspect Clutch Switch - Perform clutch switch inspection. Refer to «CLUTCH SWITCH (M/T)»(ref-151892-S16884553252003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If clutch switch is okay, go to next step. If clutch switch is faulty, replace clutch switch. After repair, go to step 14.
13. Inspect Clutch Switch Signal Circuit For Short To Ground - Inspect continuity between clutch switch 5-pin harness connector terminal "B" and ground. (Scheme 78) If continuity is not present, go to next step. If continuity is present, repair short circuit in White/Green wire between clutch switch 5-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 17 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
14. Verify Trouble Shooting Of DTC P0704 Is Completed - Make sure to reconnect all disconnected connectors. Start engine. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Operate clutch pedal while driving vehicle at 18.6 MPH or less, 8 times alternately. If PENDING CODE of same DTC is not present, go to next step. If PENDING CODE of same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
15. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

The PCM monitors changes in input voltage from the neutral switch. If PCM does not detect voltage changes at PCM 104-pin harness connector terminal No. 64 when gears are shifted more than 14 times and vehicle speed is more than 18.6 MPH, PCM determines that neutral switch circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in 2 consecutive drive cycles. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available and DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Neutral switch malfunction
3. Open circuit in Black wire between neutral switch 2-pin harness connector terminal "A" and ground
4. Open circuit in Blue/Red wire between neutral switch harness connector terminal "B" and PCM 104-pin harness connector terminal No. 64
5. PCM malfunction
6. Short to ground circuit in Blue/Red wire between neutral switch harness connector terminal "B" and PCM 104-pin harness connector terminal No. 64

Scheme 78

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Classify High Input Or Low Input - Connect WDS or equivalent to DLC-2. Access CPP/PNP PID. Verify CPP/PNP PID when gear in neutral position. If CPP/PNP PID is always OFF, go to next step. If CPP/PNP PID is not always OFF, go to step 10.
4. Inspect Neutral Switch Connector For Poor Connection - Turn ignition off. Disconnect neutral switch harness connector. Check for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is present, repair or replace terminal. After repair, go to step 14.
5. Classify Neutral Switch Or Circuit - Connect WDS or equivalent to DLC-2. Access CPP/PNP PID. Connect fused jumper wire between neutral switch harness connector terminal "A" (Black wire) and terminal "B" (Blue/Red wire). If CPP/PNP PID is ON, go to next step. If CPP/PNP PID is not ON, go to step 7.
6. Inspect Neutral Switch - Perform Neutral Switch Inspection. Refer to «NEUTRAL SWITCH (M/T)»(ref-151892-S40222397452003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If neutral switch is okay, go to step 14. If neutral switch is faulty, replace Neutral switch. After repair, go to step 14.
7. Inspect Neutral Switch Ground Circuit For Open Circuit - Check for continuity between neutral switch harness connector terminal "A" (Black wire) and body ground. (Scheme 79) If continuity is present, go to next step. If continuity is not present, repair open circuit in Black wire between Neutral switch harness connector terminal "A" and body ground or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 14.
8. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair terminal or replace wire harness. After repair, go to step 14.
9. Inspect Neutral Switch Signal Circuit For Open Circuit - Check for continuity in Blue/Red wire between neutral switch harness connector terminal "B" and PCM 104-pin harness connector terminal No. 64. If continuity is present, go to step 14. If continuity is not present, repair open circuit in Blue/Red wire between neutral switch harness connector terminal "B" and PCM 104-pin harness connector terminal No. 64. After repair, go to step 14.
10. Inspect Neutral Switch Connector For Poor Connection - Turn ignition off. Disconnect neutral switch harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair terminal or replace wire harness. After repair, go to step 14.
11. Classify Neutral Switch Or Circuit - Connect WDS or equivalent to DLC-2. Access CPP/PNP PID. Ensure CPP/PNP PID changes from ON to OFF when neutral switch harness connector is disconnected. If CPP/PNP PID changes from ON to OFF, go to next step. If CPP/PNP PID does not change from ON to OFF, go to step 13.
12. Inspect Neutral Switch - Perform Neutral Switch Inspection. Refer to «NEUTRAL SWITCH (M/T)»(ref-151892-S40222397452003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If neutral switch is okay, go to step 14. If neutral switch is faulty, replace neutral switch. After repair, go to step 14.
13. Inspect Neutral Switch Signal Circuit For Short To Ground - Check for continuity in Blue/Red wire between neutral switch harness connector terminal "B" and body ground. (Scheme 79) If continuity is not present, go to next step. If continuity is present, repair short circuit in Blue/Red wire between neutral switch harness connector terminal "B" and PCM 104-pin harness connector terminal No. 64. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
14. Verify Trouble Shooting Of DTC P0850 Is Completed - Reconnect all connections. Start engine. Clear DTC from memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Start engine and let idle until normal operating temperature is reached. Drive vehicle at 18.6 MPH or more. Shift up or down 14 times during test drive. Monitor for DTCs. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION article. After repair, go to next step.
15. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

When Integrated Circuit (IC), which detects misfire, sends an extraordinary signal to the PCM, PCM determines IC has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possibly caused by IC which is detecting misfire malfunction.

PCM monitors Variable Air Duct (VAD) solenoid control signal at PCM 104-pin harness connector terminal No. 42. If PCM detects VAD solenoid control signal does not change when VAD solenoid valve is switched to ON or OFF, PCM determines VAD solenoid control circuit has a malfunction. This is a Continuous Monitor (other). MIL does not illuminate. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Open circuit in Green/White wire between VAD control solenoid valve 2-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 42
3. Open circuit in White wire between main relay harness connector terminal "C" and VAD control solenoid valve harness connector terminal "A"
4. PCM malfunction
5. Short to ground circuit in Green/White wire between VAD control solenoid valve terminal "B" and PCM 104-pin harness connector terminal No. 42
6. Short to power circuit in Green/White wire between VAD control solenoid valve harness connector terminal "B" and PCM 104-pin harness connector terminal No. 42
7. VAD control solenoid valve malfunction

Scheme 79

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Classify Power Circuit Or Control Circuit Malfunction - If same DTC is present or P0102, P0103 and P0403, repair power circuit (White wire) between main relay harness connector terminal "C" and appropriate component harness connector or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step. If same DTC is not present or P0102, P0103 and P0403, repair VAD control solenoid valve or control circuit (Green/White wire) between VAD harness connector terminal "B" and PCM 104-pin harness connector terminal No. 42 or replace wire harness. (Scheme 80) After repair, go to step 6.
4. Inspect VAD Control Solenoid Valve Connector For Poor Connection - Turn ignition off. Disconnect VAD control solenoid valve harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 12.
5. Inspect VAD Control Solenoid Valve Power Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between VAD control solenoid valve harness connector terminal "A" (White wire) and body ground. If battery voltage is present, inspect VAD control solenoid valve. Refer to «VARIABLE AIR DUCT CONTROL SOLENOID VALVE - MAZDA6»(ref-151892-S21080856102003052000000) under RELAYS & SOLENOIDS in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If VAD control solenoid valve is okay, go to step 13. If VAD control solenoid valve is faulty, replace VAD control solenoid valve. After repair, go to step 12. If battery voltage is not present, repair open circuit in White wire between VAD control solenoid valve harness connector terminal "A" and main relay harness connector terminal "C" or replace wire harness. After repair, go to step 12.
6. Inspect VAD Control Solenoid Valve Connector For Poor Connection - Turn ignition off. Disconnect VAD control solenoid valve harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If malfunction is present, repair or replace terminal. After repair, go to step 12.
7. Inspect VAD Control Solenoid Valve Control Circuit For Short To Power - Turn ignition on, engine off. Measure voltage between VAD control solenoid valve harness connector terminal "B" (Green/White wire) and body ground. (Scheme 80) If battery voltage is not present, go to next step. If battery voltage is present, repair short circuit to power in Green/White wire between VAD control solenoid valve harness connector terminal "B" and PCM 104-pin harness connector terminal No. 42 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 12.
8. Inspect VAD Control Solenoid Valve Control Circuit For Short To Ground - Turn ignition off. Check for continuity between VAD control solenoid valve terminal "B" (Green/White wire) and body ground. If no continuity is present, go to next step. If continuity is present, repair short circuit to ground in Green/White wire between VAD control solenoid valve terminal "B" and PCM 104-pin harness connector terminal No. 42 or replace wire harness. After repair, go to step 12.
9. Inspect VAD Control Solenoid Valve - Inspect VAD control solenoid valve. Refer to «VARIABLE AIR DUCT CONTROL SOLENOID VALVE - MAZDA6»(ref-151892-S21080856102003052000000) under RELAYS & SOLENOIDS in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If VAD control solenoid valve is okay, go to next step. If VAD control solenoid valve is faulty, replace VAD control solenoid valve. After repair, go to step 12.
10. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair terminal or replace wire harness. After repair, go to step 12.
11. Inspect VAD Control Solenoid Valve Control Circuit For Open Circuit - Turn ignition off. Check for continuity in Green/White wire between VAD control solenoid valve harness connector terminal "B" and PCM 104-pin harness connector terminal No. 42. (Scheme 80) If continuity is present, go to next step. If continuity is not present, repair open circuit in Green/White wire between VAD control solenoid valve harness connector terminal "B" and PCM 104-pin harness connector terminal No. 42 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
12. Verify Trouble Shooting Of DTC P1410 Is Completed - Make sure to reconnect all disconnected connectors. Turn ignition on, engine off. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Access RPM, ECT and TP_REL PIDs. Start engine and warm up until ECT PID is more than 158°F (70°C). Race engine a few times as follows: RPM PID: more than 5800 RPM TP_REL PID: more than 50 percent Retrieve DTCs. If same DTC is not present, go to next step. If PENDING CODE of same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
13. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors EGR boost sensor solenoid valve control signal. If PCM 104-pin harness terminal No. 47 voltage does not change when EGR boost sensor solenoid valve is switched to ON or OFF, PCM determines EGR boost sensor solenoid valve circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. EGR boost sensor solenoid valve malfunction
3. Open circuit in Green/Yellow wire between EGR boost sensor solenoid valve 2-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 47
4. Open circuit in White wire between main relay harness connector terminal "C" and EGR boost sensor solenoid valve harness connector terminal "A"
5. PCM malfunction
6. Short to ground circuit in Green/Yellow wire between EGR boost sensor solenoid valve harness connector terminal "B" and PCM 104-pin harness connector terminal No. 47
7. Short to power circuit in Green/Yellow wire between EGR boost sensor solenoid valve harness connector terminal "B" and PCM 104-pin harness connector terminal No. 47

Scheme 80

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Classify Intermittent Concern Or Continuous Concern - Turn ignition off. Clear DTC from memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Turn ignition off, then on (engine off). If same DTC is present, go to next step. If same DTC is not present, problem is intermittent. Refer to «INTERMITTENT PROBLEM DIAGNOSIS»(ref-151888-S40451828582003010900000) in TROUBLE SHOOTING - NO CODES article.
4. Classify Open Circuit Or Short To Ground Malfunction - Disconnect EGR boost sensor solenoid valve tube that is connected to intake manifold. Connect vacuum pump to EGR boost sensor solenoid valve. Pump vacuum pump several times. Wait a few seconds. If vacuum is not maintained, go to next step. If vacuum is maintained, go to step 6.
5. Inspect Passage Control Of EGR Boost Sensor Solenoid Valve - Turn ignition off. Disconnect EGR boost sensor solenoid valve harness connector. (Scheme 81) Pump vacuum pump several times and stop, then wait a few seconds. If vacuum is maintained, repair short circuit to ground in Green/Yellow wire between EGR boost sensor solenoid valve harness connector terminal "B" and PCM 104-pin harness connector terminal No. 47 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 12. If vacuum is not maintained, replace EGR boost sensor solenoid valve. After repair, go to step 12.
6. Inspect EGR Boost Sensor Solenoid Valve Connector For Poor Connection - Turn ignition off. Disconnect EGR boost sensor solenoid valve harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 12.
7. Inspect EGR Boost Sensor Solenoid Valve Power Circuit For Open Circuit - Turn ignition off. Measure voltage between EGR boost sensor solenoid valve terminal "A" (White wire) and body ground. If battery voltage is present, go to next step. If battery voltage is not present, repair open circuit in White wire between EGR boost sensor solenoid valve harness connector terminal "A" and main relay harness connector terminal "C" or replace wire harness. After repair, go to step 12.
8. Inspect EGR Boost Sensor Solenoid Valve Control Circuit For Short To Power - Turn ignition off. Measure voltage between EGR boost sensor solenoid valve harness connector terminal "B" (Green/Yellow wire) and body ground. If battery voltage is not present, go to next step. If battery voltage is present, repair short circuit to power in Green/Yellow wire between EGR boost sensor solenoid valve harness connector terminal "B" and PCM 104-pin harness connector terminal No. 47 or replace wire harness. After repair, go to step 12.
9. Inspect EGR Boost Sensor Solenoid Valve - Inspect EGR boost sensor solenoid valve. Refer to «EGR BOOST SENSOR SOLENOID VALVE»(ref-151892-S04297659122003010900000) under RELAYS & SOLENOIDS in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If EGR boost sensor solenoid valve is okay, go to next step. If EGR boost sensor solenoid valve is faulty, replace EGR boost sensor solenoid valve. After repair, go to step 12.
10. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair terminal or replace wire harness. After repair, go to step 12.
11. Inspect EGR Boost Sensor Solenoid Valve Control Circuit For Open Circuit - Turn ignition off. Check for continuity in Green/Yellow wire between EGR boost sensor solenoid valve harness connector terminal "B" and PCM 104-pin harness connector terminal No. 47. (Scheme 81) If continuity is present, go to next step. If continuity is not present, repair open circuit in Green/Yellow wire between EGR boost sensor solenoid valve harness connector terminal "B" and PCM 104-pin harness connector terminal No. 47 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
12. Verify Trouble Shooting Of DTC P1487 Is Completed - Make sure to reconnect all disconnected connectors. Turn ignition on, engine off. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Turn ignition on, engine off. If PENDING CODE of same DTC is not present, go to next step. If PENDING CODE of same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
13. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors voltage of back-up positive battery terminal at PCM 104-pin harness connector terminal No. 55. If PCM detects positive battery terminal voltage of 2.5 volts or less for 2 seconds, PCM determines that backup voltage circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Meltdown of MAIN fuse
3. Open circuit between positive battery terminal and PCM 104-pin harness connector terminal No. 55 (White/Black wire)
4. PCM malfunction
5. Short circuit to ground between positive battery terminal and PCM 104-pin harness connector terminal No. 55 (White/Black wire)

Scheme 81

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect MAIN Fuse - Turn ignition off. Inspect MAIN fuse for failure and proper installation. If MAIN fuse is melted, go to next step. If MAIN fuse is okay and installed properly, go to step 5. If MAIN fuse was improperly installed, reinstall MAIN fuse correctly. After repair, go to step 7.
4. Inspect Monitor Circuit For Short To Ground - Turn ignition off. Disconnect battery cables. Check for continuity between MAIN fuse terminals (harness-side) and body ground. (Scheme 82) If continuity is not present, go to next step. If continuity is present, repair short circuit to ground in suspected circuit or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, replace MAIN fuse. Go to step 7.
5. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair terminal or replace wire harness. After repair, go to step 7.
6. Inspect Monitor Circuit For Open Circuit - Turn ignition off. Disconnect battery cables. Disconnect PCM 104-pin harness connector. Check for continuity between positive battery terminal harness connector and PCM 104-pin harness connector terminal No. 55 (White/Black wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in White/Black wire between positive battery terminal harness connector and PCM 104-pin harness connector terminal No. 55 or replace wire harness. After repair, go to next step.
7. Verify Trouble Shooting Of DTC P1562 Is Completed - Make sure to reconnect all disconnected connectors. Turn ignition on, engine off. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Turn ignition off, start engine. If PENDING CODE of same DTC is not present, go to next step. If PENDING CODE of same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
8. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors right OCV voltage. If PCM detects right OCV control voltage (calculated from OCV) is less than threshold voltage (calculated from positive battery voltage), PCM determines that right OCV circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Open circuit between right OCV 2-pin harness connector terminal "A" (Brown wire) and PCM 104-pin harness connector terminal No. 81 (Blue/Yellow wire)
3. Open circuit between main relay harness connector terminal "C" (White wire) and right OCV harness connector terminal "B" (Green/Blue wire)
4. PCM malfunction
5. Right OCV malfunction
6. Short to ground circuit between right OCV harness connector terminal "A" (Brown wire) and PCM 104-pin harness connector terminal No. 81 (Blue/Yellow wire)

Scheme 82

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect Right OCV Connector For Poor Connection - Turn ignition off. Disconnect right OCV harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If malfunction is not present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 9.
4. Inspect Right OCV Power Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between right OCV harness connector terminal "B" (White wire) and body ground. (Scheme 83) If battery voltage is present, go to next step. If battery voltage is not present, repair open circuit between main relay harness connector terminal "C" (White wire) and right OCV harness connector terminal "B" (Green/Blue wire) or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
5. Inspect Right OCV Control Circuit For Short To Ground - Turn ignition off. Disconnect right OCV harness connector. Check for continuity between right OCV harness connector terminal "A" (Brown wire) and body ground. If continuity is not present, go to next step. If continuity is present, repair short circuit in suspected wire between right OCV harness connector terminal "A" (Brown wire) and PCM 104-pin harness connector terminal No. 81 (Blue/Yellow wire) or replace wire harness. After repair, go to step 9.
6. Inspect Right OCV - Perform OCV Inspection. Refer to «OIL CONTROL VALVE - MAZDA6 & MIATA ONLY»(ref-151892-S39070078312003010900000) under VARIABLE VALVE TIMING in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If right OCV is okay, go to next step. If right OCV is faulty, replace right OCV. After repair, go to step 9.
7. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair terminal or replace wire harness. After repair, go to step 9.
8. Inspect Right OCV Control Circuit For Open Circuit - Disconnect right OCV harness connector. Check for continuity between right OCV harness connector terminal "A" (Brown wire) and PCM 104-pin harness connector terminal No. 81 (Blue/Yellow wire). (Scheme 83) If continuity is present, go to next step. If continuity is not present, repair open circuit in suspected wire between right OCV harness connector terminal "A" (Brown wire) and PCM 104-pin harness connector terminal No. 81 (Blue/Yellow wire) or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
9. Verify Trouble Shooting Of DTC P2088 Is Completed - Make sure to reconnect all disconnected connectors. Turn ignition on, engine off. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Start engine and warm up completely. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
10. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors right OCV voltage. If PCM detects right OCV control voltage (calculated from OCV) is more than threshold voltage (calculated from battery positive voltage), PCM determines that right OCV circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. PCM malfunction
3. Right OCV malfunction
4. Short to power circuit between right OCV 2-pin harness connector terminal "A" (Brown wire) and PCM 104-pin harness connector terminal No. 81 (Blue/Yellow wire)

PCM monitors left OCV voltage. If PCM detects left OCV control voltage (calculated from OCV) is less than threshold voltage (calculated from battery positive voltage), PCM determines that OCV circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Left OCV malfunction
3. Open circuit between left OCV 2-pin harness connector terminal "A" (Brown/Blue wire) and PCM 104-pin harness connector terminal No. 102 (Brown/Yellow wire)
4. Open circuit between main relay harness connector terminal "C" (White wire) and left OCV harness connector terminal "B" (Green/Blue wire)
5. PCM malfunction
6. Short to ground circuit between left OCV harness connector terminal "A" (Brown/Blue wire) and PCM 104-pin harness connector terminal No. 102 (Brown/Yellow wire)

Scheme 83

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect Left OCV Connector For Poor Connection - Turn ignition off. Disconnect left OCV harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If malfunction is not present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 9.
4. Inspect Left OCV Power Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between left OCV harness connector terminal "B" (Green/Blue wire) and body ground. (Scheme 84) If battery voltage is present, go to next step. If battery voltage is not present, repair open circuit between main relay harness connector terminal "C" (White wire) and left OCV harness connector terminal "B" (Green/Blue wire) or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
5. Inspect Left OCV Control Circuit For Short To Ground - Turn ignition off. Disconnect left OCV harness connector. Check for continuity between left OCV harness connector terminal "A" (Brown/Blue wire) and body ground. If continuity is not present, go to next step. If continuity is present, repair short circuit in suspected wire between left OCV harness connector terminal "A" (Brown/Blue wire) and PCM 104-pin harness connector terminal No. 102 (Brown/Yellow wire) or replace wire harness. After repair, go to step 9.
6. Inspect Left OCV - Perform OCV Inspection. Refer to «OIL CONTROL VALVE - MAZDA6 & MIATA ONLY»(ref-151892-S39070078312003010900000) under VARIABLE VALVE TIMING in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If left OCV is okay, go to next step. If left OCV is faulty, replace left OCV. After repair, go to step 9.
7. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair terminal or replace wire harness. After repair, go to step 9.
8. Inspect Left OCV Control Circuit For Open Circuit - Disconnect left OCV harness connector. Check for continuity between left OCV harness connector terminal "A" (Brown/Blue wire) and PCM 104-pin harness connector terminal No. 102 (Brown/Yellow wire). (Scheme 84) If continuity is present, go to next step. If continuity is not present, repair open circuit in suspected wire between left OCV harness connector terminal "A" (Brown/Blue wire) and PCM 104-pin harness connector terminal No. 102 (Brown/Yellow wire) or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
9. Verify Trouble Shooting Of DTC P2092 Is Completed - Make sure to reconnect all disconnected connectors. Turn ignition on, engine off. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Start engine and warm up completely. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
10. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors left OCV voltage. If PCM detects left OCV control voltage (calculated from OCV) is more than threshold voltage (calculated from battery positive voltage), PCM determines that OCV circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects above malfunction condition during first drive cycle. PENDING CODE is available if PCM detects above malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Left OCV malfunction
3. Short to power circuit between left OCV 2-pin harness connector terminal "A" (Brown/Blue wire) and PCM 104-pin harness connector terminal No. 102 (Brown/Yellow wire)
4. PCM malfunction

PCM monitors throttle actuator motor current. If PCM detects throttle actuator motor current is less than threshold current, PCM determines that throttle actuator motor circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Open circuit between throttle body 6-pin harness connector terminal "A" (Black/Orange wire) and PCM 104-pin harness connector terminal No. 80 (Blue/White wire)
3. Open circuit between throttle body 6-pin harness connector terminal "B" (Green/Red wire) and PCM 104-pin harness connector terminal No. 54 (Blue/Black wire)
4. PCM malfunction
5. Short to ground circuit between throttle body 6-pin harness connector terminal "A" (Black/Orange wire) and PCM 104-pin harness connector terminal No. 80 (Blue/White wire)
6. Short to ground circuit between throttle body 6-pin harness connector terminal "B" (Green/Red wire) and PCM 104-pin harness connector terminal No. 54 (Blue/Black wire)
7. Short to power circuit between throttle body 6-pin harness connector terminal "A" (Black/Orange wire) and PCM 104-pin harness connector terminal No. 80 (Blue/White wire)
8. Throttle actuator malfunction

Scheme 84

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Classify Intermittent Concern Or Continuous Concern - Clear DTC using WDS or equivalent. Start engine and let idle. If same DTC is present, go to next step. If same DTC is not present, problem is intermittent. Refer to «INTERMITTENT PROBLEM DIAGNOSIS»(ref-151888-S40451828582003010900000) in TROUBLE SHOOTING - NO CODES article.
4. Inspect Throttle Body Connector For Poor Connection - Turn ignition off. Disconnect throttle body 6-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If malfunction is not present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 14.
5. Inspect Throttle Actuator - Inspect throttle actuator. Refer to «THROTTLE ACTUATOR»(ref-151892-S12915776162003061200000) under IDLE CONTROL SYSTEM in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If no malfunction is present, go to next step. If throttle actuator is faulty, replace throttle body. After repair, go to step 14.
6. Classify Malfunction At Power Supply Circuit Or Control Circuit - Turn ignition on, engine off. Measure voltage between throttle body 6-pin harness connector terminal "B" (Green/Red wire) and body ground. If battery voltage is not present, malfunction is in supply circuit. Go to next step. If battery voltage is present, malfunction is in control circuit. Go to step 10.
7. Inspect Throttle Actuator Power Circuit For Short To Ground - Turn ignition off. Check for continuity between throttle body 6-pin harness connector terminal "B" (Green/Red wire) and body ground. (Scheme 85) If continuity is not present, go to next step. If continuity is present, repair short circuit to ground in suspected wire between throttle body 6-pin harness connector terminal "B" (Green/Red wire) and PCM 104-pin harness connector terminal No. 54 (Blue/Black wire) or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 14.
8. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair terminal or replace wire harness. After repair, go to step 14.
9. Inspect Throttle Actuator Power Circuit For Open Circuit - Turn ignition off. Check for continuity between throttle body 6-pin harness connector terminal "B" (Green/Red wire) and PCM 104-pin harness connector terminal No. 54 (Blue/Black wire). If continuity is present, go to step 14. If continuity is not present, repair open circuit in suspected wire between throttle body 6-pin harness connector terminal "B" (Green/Red wire) and PCM 104-pin harness connector terminal No. 54 (Blue/Black wire) or replace wire harness. After repair, go to step 14.
10. Inspect Throttle Actuator Control Circuit For Short To Power - Turn ignition on, engine off. Measure voltage between throttle body 6-pin harness connector terminal "A" (Black/Orange wire) and body ground. (Scheme 85) If battery voltage is not present go to next step. If battery voltage is present, repair short circuit to power in suspected wire between throttle body 6-pin harness connector terminal "A" (Black/Orange wire) and PCM 104-pin harness connector terminal No. 80 (Blue/White wire) or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 14.
11. Inspect Throttle Actuator Control Circuit For Short To Ground - Turn ignition off. Check for continuity between throttle body 6-pin harness connector terminal "A" (Black/Orange wire) and body ground. If continuity is not present, go to next step. If continuity is present, repair short circuit to ground in suspected wire between throttle body 6-pin harness connector terminal "A" (Black/Orange wire) and PCM 104-pin harness connector terminal No. 80 (Blue/White wire) or replace wire harness. After repair, go to step 14.
12. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair terminal or replace wire harness. After repair, go to step 14.
13. Inspect Throttle Actuator Control Circuit For Open Circuit - Turn ignition off. Check for continuity between throttle body 6-pin harness connector terminal "A" (Black/Orange wire) and PCM 104-pin harness connector terminal No. 80 (Blue/White wire). (Scheme 85) If continuity is present, go to next step. If continuity is not present, repair open circuit in suspected wire between throttle body 6-pin harness connector terminal "A" (Black/Orange wire) and PCM 104-pin harness connector terminal No. 80 (Blue/White wire) or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
14. Verify Trouble Shooting Of DTC P2100 Is Completed - Make sure to reconnect all disconnected connectors. Turn ignition on, engine off. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Start engine and warm up completely. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
15. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

If PCM detects any of following conditions, PCM determines that throttle actuator motor circuit has a malfunction.

1. Fully closed throttle angle detected by each TP sensor No. 1 and No. 2 is one degree or larger than default throttle opening angle.
2. Difference in default throttle opening angle from fully closed throttle angle detected by TP sensor No. 1 is 1.5 times larger or more than that of No. 2.
3. Voltage from the ET control relay is too low or too high.
4. PCM detects large voltage differences from the ET control relay and from the main relay.

This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Main relay and related circuit malfunction
2. ET control relay and related circuit malfunction
3. Connector or terminal malfunction
4. PCM malfunction

Scheme 85

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Verify Related Pending Code Or Stored DTCs - Turn ignition off, then on (engine off). Verify pending code or stored DTCs using WDS or equivalent. If no other DTCs are present, go to next step. If any DTC is present, go to appropriate DTC trouble shooting procedure. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000).
4. Identify Trigger DTC For FREEZE FRAME DATA - If only DTC P2101 is on FREEZE FRAME DATA, go to next step. If any other DTC triggered FREEZE FRAME DATA, go to appropriate trouble shooting procedure for DTC that triggered FREEZE FRAME DATA. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000).
5. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair or replace terminal. After repair, go to step 17.
6. Inspect Main Relay Output Voltage - Turn ignition off. Connect PCM 104-pin harness connector. Turn ignition on, engine off. Measure voltage between following harnesses: PCM 104-pin harness connector terminal No. 71 (White/Blue wire) and body ground PCM 104-pin harness connector terminal No. 97 (White/Blue wire) and body ground (Scheme 86) If battery voltage is not present, go to next step. If battery voltage is present, go to step 11.
7. Inspect Main Relay Connector For Poor Connection - Turn ignition off. Disconnect main relay. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair or replace terminal. After repair, go to step 17.
8. Inspect Main Relay Power Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between following harnesses: Main relay harness connector terminal "A" (White/Green wire) and body ground Main relay harness connector terminal "D" and body ground If battery voltage is present, go to next step. If battery voltage is not present, repair open circuit between main relay and battery or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 17.
9. Inspect Main Relay - Inspect main relay. Refer to «MAIN RELAY»(ref-151892-S41194166442003010900000) under RELAYS & SOLENOIDS in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If no malfunction is present, go to next step. If main relay is faulty, replace main relay. After repair, go to step 17.
10. Inspect Main Relay Circuit For Open Circuit - Turn ignition off. Check for continuity between following harnesses: Main relay harness connector terminal "C" and PCM 104-pin harness connector terminal No. 71 (White/Blue wire) Main relay harness connector terminal "C" and PCM 104-pin harness connector terminal No. 97 (White/Blue wire) Main relay harness connector terminal "E" and PCM 104-pin harness connector terminal No. 28 (Black/Yellow wire) (Scheme 86) If continuity is present, go to next step. If continuity is not present, repair open circuit in suspected wire between main relay harness connector and PCM 104-pin harness connector or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 17.
11. Inspect ET Control Relay Output Voltage - Turn ignition on, engine off. Measure voltage between PCM 104-pin harness connector terminal No. 92 (Pink wire) and body ground. If battery voltage is not present, go to next step. If battery voltage is present, go to step 17.
12. Inspect ET Control Relay Connector For Poor Connection - Turn ignition off. Disconnect ET control relay harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace faulty terminal. After repair, go to step 17.
13. Inspect ET Control Relay Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between ET control relay harness connector terminal "D" and body ground. (Scheme 86) If battery voltage is present, go to next step. If is not present, repair open circuit between ET control relay and battery or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 17.
14. Inspect ET Control Relay Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between ET control relay terminal "A" (White/Blue wire) and body ground. If battery voltage is present, go to next step. If battery voltage is not present, repair open circuit in White/Blue wire between ET control relay harness connector terminal "A" and main relay harness connector terminal "C" or replace wire harness. After repair, go to step 17.
15. Inspect ET Control Relay - Inspect ET control relay. Refer to «MAIN RELAY»(ref-151892-S41194166442003010900000) under RELAYS & SOLENOIDS in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If no malfunction is present, go to next step. If ET control relay is faulty, replace ET control relay. After repair, go to step 17.
16. Inspect ET Control Relay Circuit For Open Circuit - Turn ignition off. Check for continuity between following harnesses: ET control relay harness connector terminal "C" and PCM 104-pin harness connector terminal No. 92 (Pink wire) ET control relay harness connector terminal "E" and PCM 104-pin harness connector terminal No. 19 (Blue wire) (Scheme 86) If continuity is present, go to next step. If continuity is not present, repair open circuit in suspected wire between ET control relay harness connector and PCM 104-pin harness connector or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
17. Verify Trouble Shooting Of DTC P2101 Is Completed - Make sure to reconnect all disconnected connectors. Turn ignition on, engine off. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Start engine and run at idle. If PENDING CODE of same DTC is not present, go to next step. If PENDING CODE of same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
18. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

If PCM detects any of following conditions, PCM determines that throttle actuator control system has a malfunction. Engine speed exceeds threshold value even if ET control relay is turned off. An internal malfunction of PCM. This is a Continuous Monitor (other). MIL does not illuminate. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. ET control relay stuck closed
3. PCM malfunction
4. Short to ground circuit in Blue wire between ET control relay harness connector terminal "E" and PCM 104-pin harness connector terminal No. 19
5. Short to power circuit in Pink wire between ET control relay harness connector terminal "C" and PCM 104-pin harness connector terminal No. 92

If PCM detects internal failure or an abnormal output signal for throttle actuator control system, PCM determines throttle actuator control module processor has a malfunction. This is an intermittent monitor. MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possibly caused by PCM malfunction.

If PCM detects failure to turn off the ET control relay (fail safe mode), PCM determines throttle actuator control system has a malfunction.

1. Accelerator Pedal Position (APP) sensor No. 1 output voltage is 1.19 volts or less, or 4.3 volts or more
2. Actual throttle opening angle is too large as compared to target opening angle (open too much)
3. APP sensor No. 1 signal value and APP sensor No. 2 signal value correlation is out of specification
4. APP sensor No. 2 output voltage is 0.54 volt or less, or 3.8 volts or more
5. Difference exists in APP sensor No. 1 or No. 2 voltage between PCM main CPU and sub-CPU
6. Difference in default throttle opening angle from fully closed throttle angle detected by TP sensor No. 1 is 1.5 times larger or more than that of No. 2
7. During dash pot correction, a difference exists between actual and target throttle valve opening angles
8. During normal driving, a difference exists between actual and target throttle valve opening angles
9. Fully closed throttle angle detected by each TP sensor No. 1 and No. 2 is one degree or larger than default throttle opening angle
10. PCM detects actual throttle opening angle is larger than target throttle opening angle by 2.5 degrees or more during closing throttle valve.
11. PCM detects actual throttle opening angle is smaller than target throttle opening angle by 2.5 degrees or more during closing throttle valve
12. PCM detects internal failure or an abnormal output signal for throttle actuator control system
13. PCM detects large voltage differences from ET control relay and main relay
14. PCM detects throttle opening angle signal voltage is higher than default throttle opening angle voltage after ignition is turned to off
15. Target throttle opening angle is too large as compared to actual opening angle (closed too much)
16. Throttle actuator motor current is less than threshold current
17. TP sensor No. 1 output voltage is 0.255 volt or less, or 4.72 volts or more
18. TP sensor No. 1 signal value and TP sensor No. 2 signal value correlation is out of specification
19. TP sensor No. 2 output voltage is 0.255 volt or less, or 4.72 volts or more
20. Voltage from ET control relay is too low or too high
21. When idling, a difference exists between actual and target idling speeds

This is an intermittent monitor. MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. APP sensor and related circuit malfunction
2. Connector or terminal malfunction
3. PCM malfunction
4. Throttle valve stuck
5. TP sensor and related circuit malfunction

1. DTC P2111: If PCM detects actual throttle opening angle is larger than target throttle opening angle by 2.5 degrees or more during closing throttle valve, PCM determines that throttle actuator control system has malfunction.
2. DTC P2112: If PCM detects actual throttle opening angle is smaller than target throttle opening angle by 2.5 degrees or more during closing throttle valve, PCM determines that throttle actuator control system has malfunction.

This is an intermittent monitor. MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. ET control relay and related circuit malfunction
3. PCM malfunction
4. Throttle actuator and related circuit malfunction
5. TP sensor and related circuit malfunction

If PCM detects that throttle opening angle signal voltage is higher than default throttle opening angle voltage after ignition is turned off, PCM determines throttle actuator has a malfunction. This is an intermittent monitor. MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. PCM malfunction
2. Throttle valve return spring (in throttle body) broken
3. Throttle valve stuck

PCM monitors Accelerator Pedal Position (APP) sensor No. 1 signal at PCM 104-pin harness connector terminal No. 9. If PCM detects APP sensor No. 1 voltage of 1.19 volts or less, PCM determines APP sensor No. 1 circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. APP sensor No. 1 malfunction
2. Connector or terminal malfunction
3. Open circuit in Gray wire between APP sensor 6-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 43
4. Open circuit in White wire between APP sensor 6-pin harness connector terminal "F" and PCM 104-pin harness connector terminal No. 9
5. PCM malfunction
6. Short to ground circuit in White wire between APP sensor 6-pin harness connector terminal "F" and PCM 104-pin harness connector terminal No. 9

Scheme 86

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect APP Sensor Connector For Poor Connection - Turn ignition off. Disconnect APP sensor 6-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If malfunction is not present, go to next step. If malfunction is present, repair or replace terminal. After repair, go to step 9.
4. Inspect APP Sensor No. 1 Power Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between APP sensor 6-pin harness connector terminal "D" (Gray wire) and body ground. (Scheme 87) If voltage reading is 4.5-5.5 volts, go to next step. If voltage reading is not 4.5-5.5 volts, repair open circuit in Gray wire between APP sensor 6-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 43 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
5. Verify APP Sensor No. 1 Signal Circuit For Short To Ground - Turn ignition off. Check for continuity between APP sensor 6-pin harness connector terminal "F" (White wire) and body ground. If no continuity is present, go to next step. If continuity is present, repair short circuit to ground in White wire between APP sensor 6-pin harness connector terminal "F" and PCM 104-pin harness connector terminal No. 9 or replace wire harness. After repair, go to step 9. NOTE: APP sensor is an integral part of the accelerator pedal and must be replaced as an assembly.
6. Inspect APP Sensor No. 1 - Inspect APP sensor No. 1. Refer to «ACCELERATOR PEDAL POSITION SENSOR»(ref-151892-S30951181632003050700000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If no malfunction is present, go to next step. If APP sensor No. 1 is faulty, replace accelerator pedal assembly. After repair, go to step 9.
7. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair or replace terminal. After repair, go to step 9.
8. Verify APP Sensor No. 1 Signal Circuit For Open Circuit - Turn ignition off. Check for continuity between APP sensor 6-pin harness connector terminal "F" (White wire) and PCM 104-pin harness connector terminal No. 9. (Scheme 87) If continuity is present, go to next step. If continuity is not present, repair open circuit in White wire between APP sensor 6-pin harness connector terminal "F" and PCM 104-pin harness connector terminal No. 9 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
9. Verify Trouble Shooting Of DTC P2122 Is Completed - Make sure to reconnect all disconnected connectors. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Turn ignition on, engine off. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
10. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors Accelerator Pedal Position (APP) sensor No. 1 signal at PCM 104-pin harness connector terminal No. 9. If PCM detects APP sensor No. 1 voltage of 4.3 volts or more, PCM determines APP sensor No. 1 circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. APP sensor No. 1 malfunction
2. Connector or terminal malfunction
3. Open circuit in Red/Green wire between APP sensor 6-pin harness connector terminal "E" and PCM 104-pin harness connector terminal No. 40
4. PCM malfunction
5. Short to power circuit in White wire between APP sensor 6-pin harness connector terminal "F" and PCM 104-pin harness connector terminal No. 9

PCM monitors Accelerator Pedal Position (APP) sensor No. 2 signal at PCM 104-pin harness connector terminal No. 10. If PCM detects APP sensor No. 2 voltage of 0.54 volt or less, PCM determines APP sensor No. 2 circuit has a malfunction. This is a continuous monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. APP sensor No. 2 malfunction
2. Connector or terminal malfunction
3. Open circuit between APP sensor 6-pin harness connector terminal "A" (Red/Black wire) and PCM 104-pin harness connector terminal No. 45 (Light Green/Red wire)
4. Open circuit in Blue/Yellow wire between APP sensor 6-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 10
5. PCM malfunction
6. Short to ground circuit in Blue/Yellow wire between APP sensor 6-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 10

Scheme 87

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect APP Sensor Connector For Poor Connection - Turn ignition off. Disconnect APP sensor 6-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If malfunction is not present, go to next step. If malfunction is present, repair or replace terminal. After repair, go to step 9.
4. Inspect APP Sensor No. 2 Power Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between APP sensor 6-pin harness connector terminal "A" (Red/Black wire) and body ground. (Scheme 88) If voltage reading is 4.5-5.5 volts, go to next step. If voltage reading is not 4.5-5.5 volts, repair open circuit between APP sensor 6-pin harness connector terminal "A" (Red/Black wire) and PCM 104-pin harness connector terminal No. 45 (Light Green/Red wire) or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
5. Inspect APP Sensor No. 2 Signal Circuit For Short To Ground - Turn ignition off. Check for continuity in between APP sensor 6-pin harness connector terminal "C" (Blue/Yellow wire) and body ground. If no continuity is present, go to next step. If continuity is present, repair, short circuit to ground in Blue/Yellow wire between APP sensor 6-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 10 or replace wire harness. After repair, go to step 9. NOTE: APP sensor is an integral part of the accelerator pedal and must be replaced as an assembly.
6. Inspect APP Sensor No. 2 - Inspect APP sensor No. 2. Refer to «ACCELERATOR PEDAL POSITION SENSOR»(ref-151892-S30951181632003050700000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If no malfunction is present, go to next step. If APP sensor No. 2 is faulty, replace accelerator pedal assembly. After repair, go to step 9.
7. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair or replace terminal. After repair, go to step 9.
8. Inspect APP Sensor No. 2 Signal Circuit For Open Circuit - Turn ignition off. Check for continuity in Blue/Yellow wire between APP sensor 6-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 10. (Scheme 88) If continuity is present, go to next step. If continuity is present, repair open circuit in Blue/Yellow wire between APP sensor harness connector terminal "C" and PCM 104-pin harness connector terminal No. 10 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
9. Verify Trouble Shooting Of DTC P2127 Is Completed - Make sure to reconnect all disconnected connectors. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Turn ignition on, engine off. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
10. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors Accelerator Pedal Position (APP) sensor No. 2 signal at PCM 104-pin harness connector terminal No. 10. If PCM detects APP sensor No. 2 voltage of 3.8 volts or more, PCM determines APP sensor No. 2 circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. APP sensor No. 2 malfunction
2. Connector or terminal malfunction
3. Open circuit between APP sensor 6-pin harness connector terminal "B" (Brown wire) and PCM 104-pin harness connector terminal No. 11 (Gray/Black wire)
4. PCM malfunction
5. Short to power circuit in Blue/Yellow wire) between APP sensor 6-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 10

PCM compares Throttle Position (TP) sensor No. 1 signal value and TP sensor No. 2 signal value. If signal correlation for both is out of specification, PCM determines TP sensor has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. PCM malfunction
2. TP sensor malfunction

PCM compares APP sensor No. 1 signal value and APP sensor No. 2 signal value. If correlation for both signals is out of specification, PCM determines APP sensor has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. APP sensor malfunction
2. PCM malfunction

PCM monitors differences between intake manifold vacuum and atmospheric pressure at idle, which EGR boost sensor detects by switching EGR boost sensor solenoid. If difference is 1.9 in. Hg (6.4 kPa) or less, PCM determines that there is a EGR boost sensor performance problem. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. EGR boost sensor malfunction or substandard performance
2. EGR boost sensor solenoid valve malfunction
3. Loose, damaged, misconnected, clogged or frozen moisture in vacuum hose from EGR boost sensor solenoid valve to EGR boost sensor
4. Loose, damaged, misconnected, clogged or frozen moisture in vacuum hose from EGR boost sensor solenoid valve to EGR pipe
5. PCM malfunction

PCM monitors input voltage from EGR boost sensor. If input voltage at PCM 104-pin harness connector terminal No. 34 is 0.35 volt or less, PCM determines EGR boost circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. EGR boost sensor malfunction
3. Open circuit in Pink wire between EGR boost sensor 3-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 34
4. Open circuit in Red/Black wire between EGR boost sensor 3-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 90
5. PCM malfunction
6. Short to ground circuit in Pink wire between EGR boost sensor 3-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 34

Scheme 88

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect EGR Boost Sensor Connector For Poor Connection - Turn ignition off. Disconnect EGR boost sensor 3-pin harness connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If malfunction is not present, go to next step. If malfunction is present, repair or replace terminal. After repair, go to step 9.
4. Inspect EGR Boost Sensor Power Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between EGR boost sensor 3-pin harness connector terminal "C" (Red/Black wire) and body ground. (Scheme 89) If voltage reading is present, go to next step. If no voltage is present, repair open circuit in Red/Black wire between EGR boost sensor 3-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 90 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 9.
5. Inspect EGR Boost Sensor Signal Circuit For Short To Ground - Turn ignition off. Check for continuity between EGR boost sensor 3-pin harness connector terminal "A" (Pink wire) and body ground. If no continuity is present, go to next step. If continuity is present, repair short circuit to ground in Pink wire between EGR boost sensor 3-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 34 or replace wire harness. After repair, go to step 9.
6. Inspect EGR Boost Sensor - Inspect EGR boost sensor. Refer to «EGR BOOST SENSOR»(ref-151892-S13781115562003010900000) under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If EGR boost sensor is okay, go to next step. If EGR boost sensor is faulty, replace EGR boost sensor. After repair, go to step 9.
7. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair or replace terminal. After repair, go to step 9.
8. Inspect EGR Boost Sensor Signal Circuit For Open Circuit - Turn ignition off. Check for continuity in Pink wire between EGR boost sensor 3-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 34. (Scheme 89) If continuity is present, go to next step. If continuity is not present, repair open circuit in Pink wire between EGR boost sensor 3-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 34 or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
9. Verify Trouble Shooting Of DTC P2228 Is Completed - Make sure to reconnect all disconnected connectors. Turn ignition on, engine off. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Start engine and run at idle. If PENDING CODE of same DTC is not present, go to next step. If PENDING CODE of same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
10. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors input voltage from EGR boost sensor. If input voltage at PCM 104-pin harness connector terminal No. 34 is 4.9 volts or more, PCM determines EGR boost sensor circuit has a malfunction. This is a Continuous Monitor (CM). MIL illuminates if PCM detects malfunction condition during first drive cycle. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. EGR boost sensor malfunction
3. Open circuit in Brown wire between EGR boost sensor 3-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 91
4. PCM malfunction
5. Short to power circuit in Pink wire between EGR boost sensor 3-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 34

PCM monitors pump load current (EVAP line pressure) while evaporative leak monitor is operating. If pump load current is less than specified, PCM determines EVAP system leak detection pump motor circuit has a malfunction. This is an intermittent monitor (other). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. EVAP system leak detection pump malfunction
3. Open circuit in Pink wire between EVAP system leak detection pump 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 67
4. Open circuit in White wire between main relay harness connector terminal "C" and EVAP system leak detection pump 4-pin harness connector terminal "A"
5. PCM malfunction
6. Short to ground circuit in Pink wire between EVAP system leak detection pump 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 67

Scheme 89

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Verify Related Pending Code Or Stored DTCs - Turn ignition off, then on (engine off). Verify pending code or stored DTCs using WDS or equivalent. If no other DTCs are present, go to next step. If any DTC is present, go to appropriate DTC trouble shooting procedure. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000).
4. Inspect EVAP System Leak Detection Pump Connector For Poor Connection - Turn ignition off. Disconnect EVAP System Leak Detection Pump 4-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair or replace terminal. After repair, go to step 10.
5. Inspect EVAP System Leak Detection Pump Power Circuit For Open Circuit - Turn ignition off. Disconnect main relay. Disconnect EVAP system leak detection pump 4-pin harness connector. Check for continuity in White wire between EVAP system leak detection pump 4-pin harness connector terminal "A" and main relay harness connector terminal "C". (Scheme 90) If continuity is present, go to next step. If continuity is not present, repair open circuit in White wire between EVAP system leak detection pump 4-pin harness connector terminal "A" and main relay harness connector terminal "C" or replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to step 10.
6. Inspect EVAP System Leak Detection Pump Signal Circuit For Short To Ground - Turn ignition off. Disconnect EVAP system leak detection pump 4-pin harness connector. Check for continuity between EVAP system leak detection pump 4-pin harness connector terminal "D" (Pink wire) and body ground. If continuity is not present, go to next step. If continuity is present, repair short circuit to ground in Pink wire between EVAP system leak detection pump 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 67 or replace wire harness. After repair, go to step 10.
7. Inspect EVAP System Leak Detection Pump - Perform EVAP System Leak Detection Pump Inspection. Refer to «FUEL EVAPORATIVE SYSTEM - EXCEPT PROTEGE & PROTEGE5»(ref-151892-S26634580692003010900000) under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If EVAP system leak detection pump is okay, go to next step. If EVAP system leak detection pump is faulty, replace EVAP system leak detection pump. After repair, go to step 10.
8. Inspect EVAP System Leak Detection Pump Signal Circuit For Open Circuit - Turn ignition off. Disconnect EVAP system leak detection pump 4-pin harness connector. Check for continuity in Pink wire between EVAP system leak detection pump 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 67. If continuity is present, go to next step. If continuity is not present, repair open circuit in Pink wire between EVAP system leak detection pump 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 67 or replace wire harness. After repair, go to step 10.
9. Inspect PCM Connector For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out terminals or corrosion). If malfunction is not present, go to next step. If malfunction is present, repair or replace terminal. After repair, go to next step.
10. Verify Trouble Shooting Of DTC P2401 Is Completed - Make sure to reconnect all disconnected connectors. Turn ignition on, engine off. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Run «MODE 1 - PCM ADAPTIVE MEMORY PRODUCE DRIVE MODE»(ref-151886-S16512332172003101600000), «MODE 2 - EGR SYSTEM REPAIR VERIFICATION DRIVE MODE»(ref-151886-S07990137762003101600000) and «MODE 3 - HO2S HEATER, HO2S & TWC REPAIR VERIFICATION DRIVE MODE»(ref-151886-S21328120192003101600000). Stop vehicle. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
11. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM monitors pump load current (EVAP line pressure) while evaporative leak monitor is operating. If pump load current is higher than specified, PCM determines that EVAP system leak detection pump motor circuit has a malfunction. This is an intermittent monitor (other). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. EVAP system leak detection pump malfunction
3. PCM malfunction
4. Short to power circuit in Pink wire between EVAP system leak detection pump 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 67

Detection Procedure

PCM monitors pump load current (EVAP line pressure) while evaporative leak monitor is operating. After obtaining reference current value, if the time in which pump load current reaches reference current value is less than specification, PCM determines air filter is clogged. This is an intermittent monitor (other). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Air filter clogging
2. EVAP hose bending
3. PCM malfunction

PCM monitors pump load current (EVAP line pressure) while evaporative leak monitor is operating. If current is lower than specification while the PCM obtains reference current value, PCM determines EVAP system leak detection pump orifice has fallen off. This is an intermittent monitor (other). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. EVAP system leak detection pump motor malfunction
2. EVAP system leak detection pump orifice has fallen off
3. PCM malfunction

PCM monitors pump load current (EVAP line pressure) while evaporative leak monitor is operating. If current is higher than specification while PCM obtains reference current value, PCM determines EVAP system leak detection pump orifice is clogged. This is an intermittent monitor (other). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. EVAP system leak detection pump motor malfunction
2. EVAP system leak detection pump orifice clogging
3. PCM malfunction

PCM monitors pump load current (EVAP line pressure) while evaporative leak monitor is operating. When either of following is detected 28 times or more successively, PCM determines EVAP system leak detection pump heater has a malfunction

1. While obtaining reference current value, change in pump load current exceeds specification
2. After obtaining reference current value, pump load current is kept lower than maximum pump load current for more than specified time

This is an intermittent monitor (other). MIL illuminates if PCM detects malfunction condition. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. EVAP system leak detection pump heater malfunction
2. PCM malfunction

PCM determines generator output voltage is 17 volts or more, or battery voltage is 11 volts or less while engine is running. This is a Continuous Monitor (other). MIL does not come on. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Battery malfunction
2. Open circuit between generator terminal "B" (Black/White wire) and positive battery terminal
3. PCM malfunction

Scheme 90

1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
2. Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
3. Inspect Battery - Turn ignition off. Inspect battery. If battery is okay, go to next step. If battery is faulty, replace battery. After repair, go to step 7.
4. Inspect Poor Installation Of Generator Terminal - Turn ignition off. Check for looseness of generator terminal "B" (Black/White wire) installation nut. (Scheme 91) If installation tight, go to next step. If installation nut is loose, tighten generator terminal "B" installation nut. After repair, go to step 7.
5. Inspect Poor Installation Of Positive Battery Terminal - Check for loose positive battery terminal. If positive battery terminal is tight, go to next step. If terminal is loose, connect positive battery terminal correctly. After repair, go to step 7.
6. Inspect Battery Charging Circuit - Start engine. Disconnect positive battery terminal. If engine does not stall, go to next step. If engine stalls, repair or replace wire harness between generator terminal "B" (Black/White wires) and positive battery terminal (Black/Red wire). See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL. After repair, go to next step.
7. Verify Trouble Shooting Of DTC P2502 Is Completed - Make sure to reconnect all disconnected connectors. Clear DTC from PCM memory using WDS or equivalent. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151886-S28720020882003010900000) under SELF-DIAGNOSTIC SYSTEM. Turn ignition off. Start engine. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see «POWERTRAIN CONTROL MODULE»(ref-151901-S39392855062003010900000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
8. Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See «AFTER REPAIR PROCEDURE»(ref-151886-S09792749392003101700000). If any DTCs are present, go to appropriate DTC inspection. Refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151886-S37188811592003010900000). If no DTCs are present, trouble shooting is complete.

PCM needs 20 amps or more from generator, and determines generator output voltage to be 8.5 volts or less while engine is running. This is a Continuous Monitor (other). MIL does not come on. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Drive belt cut off or drive belt came off
3. Generator malfunction: Rectifier circuit malfunction Brush abrasion
4. Open or short to ground circuit in Green wire between generator terminal "D" and PCM 104-pin harness connector terminal No. 53
5. Open or short to ground circuit in Yellow/Red wire between generator terminal "P" and PCM 104-pin harness connector terminal No. 30
6. PCM malfunction

PCM determines generator output voltage is 18.5 volts or more, or battery voltage is 16.0 volts or more while engine is running. This is a Continuous Monitor (other). MIL does not come on. PENDING CODE is available if PCM detects malfunction condition. FREEZE FRAME DATA is available. DTC is stored in PCM memory.

Possible causes are

1. Connector or terminal malfunction
2. Generator malfunction
3. PCM malfunction
4. Short to power circuit in Green wire between generator 3-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 53

1. CAN system related harness malfunction
2. Related module communication error

Possible causes are

1. ABS/TCS HU/CM malfunction
2. Instrument cluster malfunction
3. Malfunction of connectors between PCM, TCM, ABS/TCS HU/CM and instrument cluster
4. Open or short circuit in wiring harness
5. PCM malfunction
6. TCM malfunction

Scheme 91

1. Determining Location Of A Malfunction Determine malfunctioning part of CAN system. See «PROCEDURES FOR DETERMINING LOCATION OF A MALFUNCTION»(ref-151886-S10213597892003101700000) under SYSTEM TESTS. see scheme 39 If malfunction is not part of wire harness "E" or instrument cluster, go to next step. If malfunction is part of wire harness "E" or instrument cluster, go to step 6.
2. Determining Location Of A Malfunction If malfunction is not part of wire harness "D" or ABS/TCS HU/CM, go to next step. If malfunction is part of wire harness "D" or ABS/TCS HU/CM, go to step 12.
3. Determining Location Of A Malfunction If malfunction is not part of wire harness "C", go to next step. If malfunction is part of wire harness "C", go to step 14.
4. Determining Location Of A Malfunction If malfunction is not part of wire harness "B" or TCM, go to next step. If malfunction is part of wire harness "B" or TCM, go to step 17
5. Determining Location Of A Malfunction If malfunction is not part of wire harness "A" or PCM, trouble shooting is completed. If malfunction is part of wire harness "A" or PCM, go to step 19.
6. Inspect Instrument Cluster Connector Disconnect negative battery cable Disconnect instrument cluster 24-pin harness connector If instrument cluster 24-pin harness connector is okay, go to next step. If instrument cluster 24-pin harness connector is faulty, replace wire harness.
7. If vehicle is equipped with ABS/TCS, go to next step. If vehicle is not equipped with ABS/TCS, go to step 9.
8. Inspect Wire Harness Between ABS/TCS HU/CM & Instrument Cluster Disconnect ABS/TCS HU/CM harness connector. Inspect following wire harness between ABS/TCS HU/CM and instrument cluster harness connector terminals for short to ground, short to power supply, and open circuit: "R" - "2W" (CAN_L) "O" - "2X" (CAN_H) If wire harness is okay, replace instrument cluster. After repair, go to step 21. If wire harness is faulty, replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL.
9. If inspected vehicle has a automatic transaxle, go to next step. If inspected vehicle has a manual transaxle, go to step 11.
10. Inspect Wire Harness Between TCM & Instrument Cluster Disconnect TCM 24-pin harness connectors. Inspect following wire harness between TCM and instrument cluster harness connector terminals for short to ground, short to power supply, and open circuit: JA5A-EL "2J" - "2W" (CAN_L) "2M" - "2X" (CAN_H) If wire harness is okay, replace instrument cluster. After repair, go to step 21. If wire harness is faulty, replace wire harness.
11. Inspect Wire Harness Between PCM & Instrument Cluster Disconnect PCM 104-pin harness connector. Inspect following wire harness between PCM and instrument cluster harness connector terminals for short to ground, short to power supply, and open circuit: "49" - "2W" (CAN_L) "50" - "2X" (CAN_H) If wire harness is okay, replace instrument cluster. After repair, go to step 21. If wire harness is faulty, replace wire harness.
12. Inspect ABS/TCS HU/CM Connector Disconnect negative battery cable Disconnect ABS/TCS HU/CM 28-pin harness connector If ABS/TCS HU/CM 28-pin harness connector is okay, go to next step. If ABS/TCS HU/CM 28-pin harness connector is faulty, replace wire harness.
13. Inspect Wire Harness Between ABS/TCS HU/CM & Instrument Cluster Disconnect instrument cluster harness connector. Inspect following wire harness between ABS/TCS HU/CM and instrument cluster harness connector terminals for short to ground, short to power supply, and open circuit: "R" - "2W" (CAN_L) "O" - "2X" (CAN_H) If wire harness is okay, replace ABS/TCS HU/CM. After repair, go to step 21. If wire harness is faulty, replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL.
14. If inspected vehicle has a automatic transaxle, go to next step. If inspected vehicle has a manual transaxle, go to step 16.
15. Inspect Wire Harness Between TCM & ABS/TCS HU/CM Disconnect negative battery cable. Disconnect TCM 24-pin harness connectors. Disconnect ABS/TCS HU/CM 28-pin harness connector. Inspect following wire harness between TCM and ABS/TCS HU/CM harness connector terminals for short to ground, short to power supply, and open circuit: JA5A-EL "2J" - "K" (CAN_L) "2M" - "O" (CAN_H) If wire harness is okay, go to step 21. If wire harness is faulty, replace wire harness.
16. Inspect Wire Harness Between PCM & ABS/TCS HU/CM Disconnect negative battery cable. Disconnect PCM 104-pin harness connector. Disconnect ABS/TCS HU/CM 28-pin harness connector. Inspect following wire harness between PCM and ABS/TCS HU/CM harness connector terminals for short to ground, short to power supply, and open circuit: "49" - "K" (CAN_L) "50" - "O" (CAN_H) If wire harness is okay, go to step 21. If wire harness is faulty, replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL.
17. Inspect TCM Connector Disconnect negative battery cable Disconnect TCM 24-pin harness connectors If TCM 24-pin harness connectors are okay, go to next step. If TCM 24-pin harness connectors are faulty, replace wire harness.
18. Inspect Wire Harness Between TCM & Instrument Cluster Disconnect instrument cluster 24-pin harness connector. Inspect following wire harness between TCM and instrument cluster harness connector terminals for short to ground, short to power supply, and open circuit: JA5A-EL "2J" - "2W" (CAN_L) "2M" - "2X" (CAN_H) If wire harness is okay, replace TCM. After repair, go to step 21. If wire harness is faulty, replace wire harness.
19. Inspect PCM Connector Disconnect negative battery cable. Disconnect PCM 104-pin harness connector. If PCM 104-pin harness connector is okay, go to next step. If PCM 104-pin harness connector is faulty, replace wire harness.
20. Inspect Wire Harness Between PCM & Instrument Cluster Disconnect instrument cluster 24-pin harness connector. Inspect following wire harness between PCM and instrument cluster harness connector terminals for short to ground, short to power supply, and open circuit: "49" - "2W" (CAN_L) "50" - "2X" (CAN_H) If wire harness is okay, replace PCM. After repair, go to next step. If wire harness is faulty, replace wire harness. See ENGINE PERFORMANCE in «SYSTEM WIRING DIAGRAMS»(ref-159366) article in ELECTRICAL.
21. Check DTC Indicated Connect PCM 104-pin harness connector Connect TCM 24-pin harness connectors Connect ABS/TCS HU/CM 28-pin harness connector Connect instrument cluster 24-pin harness connector Clear DTC from module memory using scan tool Perform KOEO/KOER self-test If DTCs U0073, U1900 and/or U2516 are indicated, repeat step 1. If DTCs U0073, U1900 and/or U2516 are not indicated, trouble shooting is completed.

Transaxle Control Module (TCM)

1. Check display of DTC U0100, using scan tool. see scheme 40
2. Referring to TCM Malfunction Locator Table, determine malfunctioning part of CAN system. see scheme 39and (Scheme 93).

Scheme 92

ABS/TCS HU/CM

1. Access and monitor "PCM_MSG" and "TCM_MSG" of PID using scan tool.
2. Referring to PID/DATA MONITOR, confirm display status of the PID. see scheme 40
3. Referring to ABS/TCS HU/CM Malfunction Locator Table, determine malfunctioning part of CAN system. see scheme 39and (Scheme 94).

Scheme 93

Instrument Cluster

1. Access and monitor "PCM_MSG", "TCM_MSG" and "ABS_MSG" of PID using the SST (WDS or equivalent).
2. Referring to PID/DATA MONITOR, confirm display status of PID. see scheme 40
3. Referring to Instrument Cluster Malfunction Locator table, determine malfunctioning part of CAN system. see scheme 39and see scheme 44.

Scheme 94

When Idling Cannot Be Continued

1. Remove Oil Control Valve (OCV) and verify spool valve is at maximum retard position. If spool valve is stuck in advance direction, replace OCV. See «VARIABLE VALVE TIMING ACTUATOR»(ref-151901-S38245530762003010900000) under VARIABLE VALVE TIMING in REMOVAL & INSTALLATION article.
2. Connect OCV.
3. Turn ignition on.
4. Verify spool valve is at maximum retard position. If spool valve is stuck in advance direction, inspect for short circuit in harnesses or connectors between OCV and PCM.
5. Inspect Variable Valve Timing (VVT) actuator.

When Idling Can Be Continued

Right Bank

1. Disconnect right side Oil Control Valve (OCV) connector.
2. Warm up engine and let idle.
3. Apply battery voltage to OCV and verify engine idles roughly or stalls. If engine idles roughly or stalls, inspect timing belt component (valve timing deviation). If engine does not idle roughly or stalls, go to next step.
4. Remove right side OCV and perform spool valve operation inspection. Refer to «OIL CONTROL VALVE - MAZDA6 & MIATA ONLY»(ref-151892-S39070078312003010900000) under VARIABLE VALVE TIMING CONTROL in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If not as specified, inspect following: Right side OCV Harnesses and connectors between right side OCV and PCM for open or short circuit If as specified, inspect following hydraulic passages for clogging or leakage or both Oil pressure switch to OCV OCV to camshaft Camshaft internal passage
5. If all passages are okay, replace right side camshaft pulley (with built-in variable valve timing actuator).

Left Bank

1. Disconnect left side Oil Control Valve (OCV) connector.
2. Warm up engine and let idle.
3. Apply battery voltage to OCV and verify engine idles roughly or stalls. If engine idles roughly or stalls, inspect timing belt component (valve timing deviation). If engine does not idle roughly or stalls, go to next step.
4. Remove left side OCV and perform spool valve operation inspection. Refer to «OIL CONTROL VALVE - MAZDA6 & MIATA ONLY»(ref-151892-S39070078312003010900000) under VARIABLE VALVE TIMING CONTROL in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If not as specified, inspect following: Left side OCV Harnesses and connectors between left side OCV and PCM for open or short circuit If as specified, inspect following hydraulic passages for clogging or leakage or both Oil pressure switch to OCV OCV to camshaft Camshaft internal passage
5. If all passages are okay, replace camshaft pulley (with built-in variable valve timing actuator).

AFTER REPAIR PROCEDURE

Connect scan tool. Turn ignition off, then on (engine off). Record DTCs if present. Erase all diagnostic data with scan tool.