Engine Controls - Tests W/codes - 2.5L: Other Mazda Millenia I

SERVICE PRECAUTIONS

Before proceeding with diagnosis, following precautions must be observed

1. Ensure vehicle has a fully charged battery and function charging system.
2. Visually inspect connectors and circuit wiring being worked on.
3. DO NOT cause short circuits when performing electrical tests. This will set additional DTCs, making diagnosis of original problem more difficult.
4. DO NOT use a test light in place of a voltmeter.
5. When a vehicle has multiple DTCs, always repair lowest number DTC first.

MALFUNCTION INDICATOR LIGHT (MIL)

If DTCs are present, MIL is illuminated when malfunction is detected after 2 consecutive drive cycles. One exception is if a misfire malfunction is detected that may damage catalytic converter, the MIL will illuminate or flash immediately and DTC will be set. If malfunction is no longer present, MIL will go off between 3 to 4 drive cycles. DTC will be erased from memory after 41 engine warm-ups.

RETRIEVING CODES

Connect scan tool to data link connector. (Scheme 29) Start engine. Select DIAGNOSTIC TEST MODE and press trigger. If NO CODES RECEIVED/SYSTEM PASSED is displayed, all monitored systems is okay. If DTCs are present, see DIAGNOSTIC TROUBLE CODE IDENTIFICATION. See applicable CIRCUIT TEST. If LINK MONITOR ERROR is displayed, check scan tool connection. Once all repairs have been completed, go to CLEARING CODES (POST-REPAIR PROCEDURE).

Scheme 29

CLEARING CODES (POST-REPAIR PROCEDURE)

Note. DTCs may also be cleared by disconnecting battery, but learned values for mass airflow sensor and throttle position sensor will be erased.

Once repairs are completed, connect scan tool to DLC. Select CLEAR function and erase DLCs from memory. Perform drive cycle procedure twice. See appropriate DRIVE CYCLE PROCEDURE . Start engine and retrieve DTCs. If DTCs are present, see applicable CIRCUIT TEST. If no DTCs are present, repair is complete.

DRIVE CYCLE PROCEDURE

Note. Disconnecting battery will reset memory. DO NOT disconnect battery during and after drive cycle procedure. Vehicle speed and engine speed detected by ECM/PCM may differ from that indicated by speedometer and tachometer. Check vehicle speed and engine speed during drive cycle procedure using scan tool. If OBD-II system check is not completed during a drive cycle procedure, OBD-II system detects a malfunction or drive cycle procedure was not completed correctly.

1. Connect scan tool. Start engine. Select GENERIC OBDII FUNCTIONS. Select ON BOARD SYSTEM READINESS mode. Check OBDII system check condition. If scan tool displays ALL TESTS ARE COMPLETE, drive cycle procedure does not need to be performed. If scan tool does not display ALL TESTS ARE COMPLETE, go to next step.
2. Select PID/DATA MONITOR. Select RFCFLAG and press START. If RFCFLAG status is YES, go to next step. If status is NO, perform DRIVE CYCLE-MODE 1.
3. Select ON BOARD SYSTEM READINESS mode. If EVAPORATIVE PURGE SYSTEM check status is YES, go to next step. If check status is NO, perform DRIVE CYCLE-MODE 4.
4. Select ON BOARD SYSTEM READINESS mode. If EGR SYSTEM check status is YES, go to next step. If check status is NO, perform DRIVE CYCLE-MODE 2.
5. Select ON BOARD SYSTEM READINESS mode. If OXYGEN SENSOR HEATER check status is YES, go to next step. If check status is NO, perform DRIVE CYCLE-MODE 3.
6. Select ON BOARD SYSTEM READINESS mode. If OXYGEN SENSOR check status is YES, go to next step. If check status is NO, perform DRIVE CYCLE-MODE 3.
7. Select ON BOARD SYSTEM READINESS mode. If CATALYST check status is YES, no further procedure is required. If check status is NO, perform DRIVE CYCLE-MODE 3.

Drive Cycle-Mode 1

Start engine and warm to normal operating temperature. Ensure all electrical and A/C loads are off. Ensure ignition timing and idle speed are within specification. Adjust as necessary. See BASIC TESTING - 2.5L article. Ensure no jumper wires are connected to DLC. Increase engine RPM to specified speed. (Scheme 30) Operate engine at specified RPM for minimum of 15 seconds. Idle engine for more than 20 seconds with cooling fan disabled.

Scheme 30

Drive Cycle-Mode 2

Start engine and warm to normal operating temperature. Ensure all electrical and A/C loads are off. Drive vehicle at specified speed for one minute. (Scheme 31)

Scheme 31

Drive Cycle-Mode 3

Start engine and warm to normal operating temperature. Ensure all electrical and A/C loads are off. Idle engine for additional 5 minutes. Drive vehicle at specified speed (V1) for one minute. Lower vehicle speed to specified speed (V2) for 3 minutes. (Scheme 32)

Scheme 32

Drive Cycle-Mode 4

Ensure following conditions are met

1. Engine coolant temperature is 32-95 °F (0-35 °C).
2. Intake air temperature is 50-140 °F (10-60 °C).
3. Barometric pressure is 72 kPa.
4. Fuel gauge needle points within 15-85 percent.

Start and operate engine at 3500 RPM for 200 seconds. Within next 40 seconds, accelerate vehicle to 40-60 MPH (65-96 km/H). Maintain vehicle speed for 6 minutes.

CIRCUIT TESTS

Condition

DTC is set when input voltage from MAF sensor is less than .64 volts or greater than 4.9 volts once engine has operated (idle) for 3 seconds. Possible causes are

1. MAF sensor malfunction.
2. Open or short circuit between terminal 3E on Powertrain Control Module (PCM) and terminal "B" on MAF sensor.
3. Open or short circuit between terminal 4A on Powertrain Control Module (PCM) and terminal "C" on MAF sensor.
4. Open or short circuit between terminal 4D on Powertrain Control Module (PCM) and terminal "A" on MAF sensor.
5. Throttle Position (TP) sensor malfunction.

Conditions

DTC is set if input voltage from IAT sensor is less than .14 volts or greater than 4.8 volts when engine is started. Intake air temperature is 104° F (40° C) greater than engine coolant temperature. Possible causes are

1. IAT sensor malfunction.
2. Open or short circuit between terminal "A" on MAF sensor and terminal No. 3V on Powertrain Control Module (PCM).
3. Open or short circuit between terminal 3AB on Powertrain Control Module (PCM) and terminal "B" on MAF sensor.

DTC is set if input voltage from ECT sensor is less than .2 volts or greater than 4.9 volts when ignition is turned on. Possible causes are

1. ECT sensor malfunction.
2. Open or short circuit between terminal "A" on ECT sensor and terminal No. 3Q on Powertrain Control Module (PCM).
3. Open or short circuit between terminal 3AB on Powertrain Control Module (PCM) and terminal "B" on ECT sensor.

DTC is set when input voltage from TP sensor is less than .1 volts or greater than 4.8 volts when ignition is turned on. Possible causes are

1. TP sensor malfunction.
2. Open or short circuit between terminal 3A on Powertrain Control Module (PCM) and terminal "A" on TP sensor.
3. Open or short circuit between terminal 3B on Powertrain Control Module (PCM) and terminal "B" on TP sensor.
4. Open or short circuit between terminal 3AB on Powertrain Control Module (PCM) and terminal "D" on TP sensor.
5. Mass Air Flow (MAF) sensor malfunction.

DTC is set when engine coolant temperature has not increased after engine is started and default period of time has passed with closed position switch in OFF position. Possible causes are

1. Powertrain coolant temperature sensor malfunction.
2. Thermostat malfunction.
3. Engine cooling fan system malfunction.
4. Water pump malfunction.
5. Powertrain coolant passage clogged or leaks.
6. Powertrain coolant level or mixture incorrect.

DTC is set when right front oxygen sensor signal fluctuates at intervals of 3.4 seconds or longer during normal driving conditions. Possible causes are

1. Right front oxygen sensor.
2. Exhaust system leakage.

DTC is set when right front oxygen sensor signal voltage does not exceed .55 volts after engine is started, or stays below .55 volts for 99 seconds after engine has reached normal operating temperature. Engine speed at 1150 RPM or greater. Possible causes are

1. Right front oxygen sensor.
2. Open or short circuit between terminal 3I on Powertrain Control Module (PCM) and terminal "A" (Red wire) on right front oxygen sensor.
3. Intake air system, fuel system and/or ignition system malfunction.

DTC is set when PCM voltage is greater than 11.5 volts when voltage is supplied to right front oxygen sensor heater. When PCM voltage is less than 5.8 volts when no voltage is supplied to right front oxygen sensor heater. Possible causes are

1. Right front heated oxygen sensor.
2. Open or short circuit between main relay and terminal "C" (Red/Black wire) on right front oxygen sensor.
3. Open circuit between terminal 4E on Powertrain Control Module (PCM) and terminal "D" (Brown wire) on right front oxygen sensor.

DTC is set when middle heated oxygen sensor signal fluctuates at intervals of 4 seconds or longer during normal driving conditions. Possible causes are

1. Middle heated oxygen sensor.
2. Exhaust system leakage.

DTC is set when middle heated oxygen sensor signal voltage does not exceed .55 volts after engine is started, or stays below .55 volts for 99 seconds after engine has reached normal operating temperature. Engine speed at 1150 RPM or greater. Possible causes are

1. Middle heated oxygen sensor.
2. Open or short circuit between terminal 3D on Powertrain Control Module (PCM) and terminal "A" (White wire) on middle oxygen sensor.
3. Open circuit between terminal 3AB on Powertrain Control Module (PCM) and terminal "B" on middle oxygen sensor.
4. Intake air system, fuel system and/or ignition system malfunction.

DTC is set when PCM voltage is greater than 11.5 volts when voltage is supplied to middle oxygen sensor heater. When PCM voltage is less than 5.8 volts when no voltage is supplied to middle oxygen sensor heater. Possible causes are

1. Middle heated oxygen sensor.
2. Open or short circuit between main relay and terminal "C" (Red/Black wire) on middle oxygen sensor.
3. Open circuit between terminal 3C on Powertrain Control Module (PCM) and terminal "D" (Black/Red wire) on middle oxygen sensor.

DTC is set when rear heated oxygen sensor signal voltage does not exceed .60 volts after engine is started, or stays below .60 volts for 80 seconds after engine has reached normal operating temperature. Engine speed at 1150 RPM or greater. Possible causes are

1. Rear heated oxygen sensor.
2. Open or short circuit between terminal 3H on Powertrain Control Module (PCM) and terminal "A" (Green wire) on rear oxygen sensor.
3. Intake air system, fuel system and/or ignition system malfunction.

DTC is set when PCM voltage is greater than 11.5 volts when voltage is supplied to rear oxygen sensor heater. When PCM voltage is less than 5.8 volts when no voltage is supplied to rear oxygen sensor heater. Possible causes are

1. Rear heated oxygen sensor.
2. Open or short circuit between main relay and terminal "C" (Red/Black wire) on rear oxygen sensor.
3. Open circuit between terminal 3G on Powertrain Control Module (PCM) and terminal "D" (Black/Blue wire) on rear oxygen sensor.

DTC is set when left front heated oxygen sensor signal fluctuates at intervals of 4 seconds or longer during normal driving conditions. Possible causes are

1. Left front heated oxygen sensor.
2. Exhaust system leakage.

DTC is set when left front heated oxygen sensor signal voltage does not exceed .55 volts after engine is started, or stays below .55 volts for 99 seconds after engine has reached normal operating temperature. Engine speed at 1150 RPM or greater. Possible causes are

1. Left front heated oxygen sensor.
2. Open or short circuit between terminal 3M on Powertrain Control Module (PCM) and terminal "A" (Yellow wire) on left front oxygen sensor.
3. Intake air system, fuel system and/or ignition system malfunction.

DTC is set when PCM voltage is greater than 11.5 volts when voltage is supplied to left front oxygen sensor heater. When PCM voltage is less than 5.8 volts when no voltage is supplied to left front oxygen sensor heater. Possible causes are

1. Left front heated oxygen sensor.
2. Open or short circuit between main relay and terminal "C" (Red/Black wire) on left front oxygen sensor.
3. Open circuit between terminal 4I on Powertrain Control Module (PCM) and terminal "D" (White/Blue wire) on left front oxygen sensor.

DTC is set when fuel injection closed loop correction and learning correction are above specified value because of system malfunction. Possible causes are

1. Fuel pressure regulator malfunction.
2. Fuel injector malfunction.
3. Fuel pump malfunction.
4. Engine Coolant Temperature (ECT) sensor malfunction.
5. Mass Air Flow (MAF) sensor malfunction.
6. Right front heated oxygen sensor malfunction.
7. Purge solenoid valve malfunction.
8. Intake air system leakage.
9. Powertrain Control Module (PCM) malfunction.
10. Open or short in circuit between fuel injectors and PCM terminals 4Q, 4Y, 4AG.
11. Intake Air Temperature (IAT) sensor malfunction.
12. EGR boost sensor malfunction.
13. PCV valve malfunction.

DTC is set when fuel injection closed loop correction and learning correction are above specified value because of system malfunction. Possible causes are

1. Fuel pressure regulator malfunction.
2. Fuel injector malfunction.
3. Fuel pump malfunction.
4. Engine Coolant Temperature (ECT) sensor malfunction.
5. Mass Air Flow (MAF) sensor malfunction.
6. Left front heated oxygen sensor malfunction.
7. Purge solenoid valve malfunction.
8. Intake air system leakage.
9. Powertrain Control Module (PCM) malfunction.
10. Open or short in circuit between fuel injectors and PCM terminals 4U, 4AC, 4AK.
11. Intake Air Temperature (IAT) sensor malfunction.
12. EGR boost sensor malfunction.
13. PCV valve malfunction.

DTC is set when PCM input signal from Crankshaft Position (CKP) sensor signal is irregular. Possible causes are

1. Ignition system malfunction.
2. Low fuel level.
3. Low battery voltage.
4. Fuel system malfunction.
5. Insufficient compression.
6. Incorrect CKP sensor air gap.
7. EGR system malfunction.

DTC is set when PCM input signal from Crankshaft Position (CKP) sensor signal is irregular. Possible causes are

1. Ignition system malfunction on cylinder No. 1.
2. Low fuel level.
3. Low battery voltage.
4. Fuel system malfunction.
5. Insufficient compression on cylinder No. 1.
6. Incorrect CKP sensor air gap.
7. EGR system malfunction.

DTC is set when PCM input signal from Crankshaft Position (CKP) sensor signal is irregular. Possible causes are

1. Ignition system malfunction on cylinder No. 2.
2. Low fuel level.
3. Low battery voltage.
4. Fuel system malfunction.
5. Insufficient compression on cylinder No. 2.
6. Incorrect CKP sensor air gap.
7. EGR system malfunction.

DTC is set when PCM input signal from Crankshaft Position (CKP) sensor signal is irregular. Possible causes are

1. Ignition system malfunction on cylinder No. 3.
2. Low fuel level.
3. Low battery voltage.
4. Fuel system malfunction.
5. Insufficient compression on cylinder No. 3.
6. Incorrect CKP sensor air gap.
7. EGR system malfunction.

DTC is set when PCM input signal from Crankshaft Position (CKP) sensor signal is irregular. Possible causes are

1. Ignition system malfunction on cylinder No. 4.
2. Low fuel level.
3. Low battery voltage.
4. Fuel system malfunction.
5. Insufficient compression on cylinder No. 4.
6. Incorrect CKP sensor air gap.
7. EGR system malfunction.

DTC is set when PCM input signal from Crankshaft Position (CKP) sensor signal is irregular. Possible causes are

1. Ignition system malfunction on cylinder No. 5.
2. Low fuel level.
3. Low battery voltage.
4. Fuel system malfunction.
5. Insufficient compression on cylinder No. 5.
6. Incorrect CKP sensor air gap.
7. EGR system malfunction.

DTC is set when PCM input signal from Crankshaft Position (CKP) sensor signal is irregular. Possible causes are

1. Ignition system malfunction on cylinder No. 6.
2. Low fuel level.
3. Low battery voltage.
4. Fuel system malfunction.
5. Insufficient compression on cylinder No. 6.
6. Incorrect CKP sensor air gap.
7. EGR system malfunction.

DTC is set when input voltage knock sensor is less than 1.25 volts or greater than 3.75 volts after engine is started. Possible causes are

1. Knock sensor malfunction.
2. Incorrect sensor installation.
3. Open or short circuit between terminal "A" of knock sensor and terminal 3S on Powertrain Control Module (PCM).

DTC is set when there is no NE signal input from Crankshaft Position (CKP) sensor while engine is running. Possible causes are

1. CKP sensor malfunction.
2. Open or short circuit between terminal No. 4AH on Powertrain Control Module (PCM) connector and terminal "A" on CKP connector.
3. Open or short circuit between terminal No. 4AL on Powertrain Control Module (PCM) connector and terminal "B" on CKP connector.

DTC is set when difference in intake manifold pressure is not within preset value during EGR operation. Possible cause is any component of EGR system.

DTC is set when EGR valve does not achieve target position during EGR solenoid valve operation. Possible causes are

1. EGR solenoid valve (vent) malfunction.
2. Open or short circuit between terminal No. 4G on Powertrain Control Module (PCM) connector and terminal "B" (Yellow wire) on EGR solenoid valve.

DTC is set when rear heated oxygen sensor value difference becomes closer to value of middle heated oxygen sensor. Possible causes are

1. 3-way catalytic converter deterioration.
2. Exhaust system operation.

DTC is set when evaporative emission control system does not function normally because of mechanical malfunction. Possible causes are

1. Fuel tank components improperly installed.
2. Clogs or leakage in system hoses.

DTC is set when PCM voltage is greater than 11.5 volts when voltage is supplied to purge solenoid valve. When PCM voltage is less than 5.8 volts when no voltage is supplied to purge solenoid valve. Possible causes are

1. Purge solenoid valve malfunction.
2. Open or short circuit between terminal "A" on purge solenoid valve and terminal "D" on main relay.
3. Open or short circuit between terminal "B" on purge solenoid valve and terminal No. 4O on Powertrain Control Module (PCM).

DTC is set when fuel tank pressure sensor is less than .2 volts or greater than 4.9 volts with ignition switch on and engine at normal operating temperature. Possible causes are

1. Fuel tank pressure sensor malfunction.
2. Open or short circuit between terminal "C" on fuel tank pressure sensor and terminal No. 3A on Powertrain Control Module (PCM).
3. Open or short circuit between terminal "A" on fuel tank pressure sensor and terminal No. 3U on Powertrain Control Module (PCM).
4. Open circuit between terminal "B" on fuel tank pressure sensor and terminal No. 3AB on Powertrain Control Module (PCM).

DTC is set when evaporative emission control system does not function normally because of mechanical malfunction. Possible causes are

1. Fuel tank components improperly installed.
2. Clogs or leakage in system hoses.

DTC is set when vehicle speed signal is less than 1.9 MPH for more than 33 second while driving vehicle with engine speed is greater than 2000 RPM . Possible causes are

1. Speedometer sensor malfunction.
2. Open or short between ignition switch and instrument cluster.
3. Open or short circuit between ground and speedometer.
4. Open or short circuit between VSS and speedometer sensor.
5. Open or short circuit between VSS and terminal No. 1C on Powertrain Control Module (PCM).

DTC is set when actual engine speed is excessively higher or lower than target speed preset in PCM for more than 14 seconds. Possible causes are

1. Idle Air Control (IAC) valve malfunction.
2. Leakage in intake air system.
3. Open or short circuit between terminal "A" on IAC valve and main relay.
4. Open or short circuit between terminal "B" on IAC valve and terminal No. 4M on Powertrain Control Module (PCM).

DTC is set when PCM has not received closed throttle position switch ON/OFF signal while vehicle is operating. Condition must occur at least 10 consecutive times. Possible causes are

1. Closed throttle position switch malfunction.
2. Open or short circuit between terminal "C" on Throttle Position (TP) sensor and terminal No. 3X on Powertrain Control Module (PCM).
3. Open or short circuit between terminal "D" on Throttle Position (TP) sensor and terminal No. 3AB on Powertrain Control Module (PCM).

DTC is set when PCM has not received brake switch signal while vehicle is operating. Possible causes are

1. Brake switch malfunction.
2. Open or short circuit between brake switch terminal and terminal No. 1O on Powertrain Control Module (PCM).
3. Open or short in power supply circuit.

DTC is set when middle heated oxygen sensor signal voltage exceeds .45 volts and remains unchanged for 42 seconds after engine is started and has reached normal operating temperature. Engine speed at 1150 RPM or greater. Possible causes are

1. Middle heated oxygen sensor.
2. Open or short circuit between terminal 3D on Powertrain Control Module (PCM) and terminal "A" (White wire) on middle oxygen sensor.
3. Intake air system, fuel system and/or ignition system malfunction.

DTC is set when right front heated oxygen sensor signal voltage exceeds .45 volts and remains unchanged for 42 seconds after engine is started and has reached normal operating temperature. Engine speed at 1150 RPM or greater. Possible causes are

1. Right front oxygen sensor.
2. Open or short circuit between terminal 3I on Powertrain Control Module (PCM) and terminal "A" (Red wire) on right front oxygen sensor.
3. Intake air system, fuel system and/or ignition system malfunction.

DTC is set when left front heated oxygen sensor signal voltage exceeds .45 volts and remains unchanged for 42 seconds after engine is started and has reached normal operating temperature. Engine speed at 1150 RPM or greater. Possible causes are

1. Left front oxygen sensor.
2. Open or short circuit between terminal 3M on Powertrain Control Module (PCM) and terminal "A" (Yellow wire) on left front oxygen sensor.
3. Intake air system, fuel system and/or ignition system malfunction.

DTC is set when input voltage from EGR boost sensor is less than .4 volts or greater than 4.5 volts. Possible causes are

1. EGR boost sensor malfunction.
2. Damaged or clogged EGR boost sensor vacuum hose.
3. Open or short circuit between terminal "A" on EGR boost sensor and terminal No. 3F on Powertrain Control Module (PCM).
4. Open or short circuit between terminal "C" on EGR boost sensor and terminal No. 3A on Powertrain Control Module (PCM).
5. Open circuit between terminal "B" on EGR boost sensor and terminal No. 3AB on Powertrain Control Module (PCM).

DTC is set when input signal from starter to PCM continues for maore than 20 seconds with engine speed greater than 2000 RPM. Possible causes are

1. Starter malfunction.
2. Open or short circuit between starter terminal "S" and terminal 1H on Powertrain Control Module (PCM).

DTC is set when open or short circuit is detected in PRC solenoid valve when ignition is on. Possible causes are

1. PRC solenoid valve malfunction.
2. Open or short circuit between terminal "A" on PRC solenoid valve and main relay.
3. Open or short circuit between terminal "B" on PRC solenoid valve and terminal No. 1B on Powertrain Control Module (PCM).

DTC is set when there is no SGC signal input from Camshaft Position (CMP) sensor while engine is running. Possible causes are

1. CMP sensor malfunction.
2. Open or short circuit between main relay and terminal "B" on distributor connector.
3. Open or short circuit between terminal No. 4F on Powertrain Control Module (PCM) connector and terminal "D" on distributor connector.

DTC is set when input voltage from EGR valve position sensor is less than .2 volts or greater than 4.75 volts. Throttle valve is at closed throttle position and engine speed is less than 875. Possible causes are

1. EGR valve position sensor malfunction.
2. Open or short circuit between terminal No. 3A on Powertrain Control Module (PCM) connector and terminal "B" on EGR valve position sensor connector.
3. Open or short circuit between terminal No. 3R on Powertrain Control Module (PCM) connector and terminal "C" on EGR valve position sensor connector.
4. Open or short circuit between terminal No. 3AB on Powertrain Control Module (PCM) connector and terminal "A" on EGR valve position sensor connector.

DTC is set when PCM detects open or short circuit in CDCV system with ignition switch on. Possible causes are

1. CDCV malfunction.
2. Open or short circuit between terminal "A" on CDCV and main relay.
3. Open or short circuit between terminal "B" on CDCV and terminal No. 4R on Powertrain Control Module (PCM).

DTC is set when PCM detects malfunction in EVAP system. Possible causes are

1. Stuck Canister Drain Cut Valve (CDCV) malfunction.
2. Damage, leakage or clogging in EVAP system hoses.

DTC is set if fuel gauge sender unit operation range is minimal when fuel consumption is over 8 gallons. Possible causes are

1. Fuel gage sending unit malfunction.
2. Open or short circuit between fuel gauge sending unit and terminal No. 3K on Powertrain Control Module (PCM) connector.

DTC is set PCM detects open or short circuit in EGR boost sensor solenoid valve system when ignition switch is on. Possible causes are

1. EGR boost sensor solenoid valve malfunction.
2. Open or short circuit between EGR boost sensor solenoid valve and main relay.
3. Open circuit between terminal 4P on Powertrain Control Module (PCM) and terminal "B" (White/Green wire) on EGR boost sensor solenoid valve.

DTC is set when Powertrain Control Module (PCM) detects open or short circuit in VRIS No. 1 solenoid valve system with ignition switch on. Possible causes are

1. VRIS solenoid No. 1 malfunction.
2. Open or short circuit between terminal "B" on VRIS solenoid valve No. 1 and main relay.
3. Open or short circuit between terminal "A" on VRIS solenoid valve No. 1 and terminal 1AA on Powertrain Control Module (PCM).

DTC is set when Powertrain Control Module (PCM) detects open or short circuit in VRIS No. 2 solenoid valve system with ignition switch on. Possible causes are

1. VRIS solenoid No. 2 malfunction.
2. Open or short circuit between terminal "A" on VRIS solenoid valve No. 2 and main relay.
3. Open or short circuit between terminal "B" on VRIS solenoid valve No. 2 and terminal 1AE on Powertrain Control Module (PCM).

DTC is set when Powertrain Control Module (PCM) does not read DTCs from output devices. Cause is malfunctioning PCM. Replace PCM and erase any DTCs present. See CLEARING CODES under SELF-DIAGNOSTIC SYSTEM. Retest vehicle.

DTC is set when voltage at terminal No. 4I on Engine Control Module (PCM) harness connector is less than 1.4 volts (other than during starting). Possible causes are

1. Battery malfunction.
2. Open or short circuit between terminal No. 4B on PCM and positive battery cable.
3. Open MAIN fuse.

DTC is set under the following conditions

1. Powertrain Control Module (PCM) detects transmission range switch in "P" or "N" position with engine speed greater than 1810 RPM and vehicle speed greater than 50 MPH.

Possible causes are

1. Transmission range switch malfunction.
2. Open or short circuit between terminal "H" on transmission range switch and terminal No. 1F on PCM.

SUMMARY

If no diagnostic trouble code is present but driveability problem still exists, proceed to TESTS W/O CODES - 2.5L article for symptom diagnosis or intermittent diagnostic procedures.