Engine Controls - Tests W/codes - Eec-Iv (1.9L): Other Ford Escort V facelift

SERVICE CODES

All models use 3-digit codes. When CIRCUIT TEST procedures apply to both 2-digit codes and 3-digit codes, the applicable codes will be separated by a diagonal mark (example: Code 31/327).

During QUICK TEST, 3 types of service codes are retrieved: KOEO, KOER and Continuous Memory codes. See QUICK TEST for self-test procedures. Codes may be cleared from PCM memory after they have been recorded or repaired. See CLEARING CODES.

KOEO & KOER Codes (Hard Faults)

These codes indicate faults are present at time of testing. A hard fault may cause Malfunction Indicator Light (MIL) to go on and remain on until fault is repaired. If KOEO or KOER codes are retrieved during KOEO SELF-TEST or KOER SELF-TEST, use SERVICE CODE-TO-TEST MENUS to find correct testing and repair procedures.

Continuous Memory Codes (Soft Faults)

These codes indicate a fault that may or may not be present at time of testing. These codes are used to diagnose intermittent problems. Continuous Memory Codes are retrieved after KOEO SELF-TEST. Some codes may turn on MIL light. Corresponding soft fault trouble code will be retained in PCM memory. If fault does not reoccur within 40 warm-up cycles (80 cycles on some models), PCM will automatically clear code.

Technician may clear service codes from memory. See CLEARING CODES. Intermittent faults may be caused by a sensor, connector or wiring-related problem. See INTERMITTENTS in TESTS W/O CODES article in this section.

RETRIEVING CODES

Service codes are retrieved from EEC-IV system through Data Link Connector (DLC). Various methods and test equipment may be used to access these codes

1. Analog Volt-Ohmmeter (VOM).
2. Scan tester.
3. In-Dash Malfunction Indicator Light (MIL) light.

DATA LINK CONNECTOR (DLC) LOCATIONS

Separator Pulse

Single 1/2-second separator pulse is issued 6-9 seconds after last KOEO code. Continuous Memory Codes (soft faults) are then displayed 6-9 seconds after 1/2-second separator pulse. Some digital test equipment may display separator code as "10" instead of "1".

Pass Codes

A Code 11 or 111 indicates no service codes were recorded in that portion of test; system passes that portion of test. If Code 11 or 111 is not retrieved in KOEO SELF-TEST, codes retrieved during KOER SELF-TEST may not be valid. Code 11 or 111 (pass code) must be obtained in KOEO SELF-TEST. A Code 11-1-11or 111-1-111 output during KOEO SELF-TEST indicates no KOEO code or Continuous Memory Code was recorded.

Continuous Memory Codes

These codes result from information stored by PCM during continuous self-test monitoring. Codes are displayed after separator pulse code in KOEO SELF-TEST. Use these codes for diagnosis only when KOEO SELF-TEST and KOER SELF-TEST result in Code 11 or 111 (pass code) and all steps under QUICK TEST are successfully completed. (A few codes are exceptions which may be checked after KOEO codes have been repaired). These codes indicate faults recorded within last 40 engine starts (80 engine starts on some models). Fault may or may not be currently present. See SERVICE CODE-TO-TEST MENUS.

Fast Codes

At start of KOEO SELF-TEST and after Wide Open Throttle (WOT) request in KOER SELF-TEST, PCM outputs short bursts of information, known as FAST CODES, which were used by manufacturer during assembly. With most equipment, these code bursts are not visible; an entire code sequence lasts less than 1/2 second. If this fluctuation is visible on test equipment, ignore it.

Scheme 132

CLEARING CODES

To clear codes from PCM memory, start KOEO SELF-TEST. When service codes appear on test equipment or MIL light, disconnect jumper wire from Self-Test Input (STI) connector. If using STAR Series Tester, unlatch center button. This procedure erases Continuous Memory Codes from PCM memory. If problem has not been corrected or fault is still present, hard code will immediately be reset in PCM memory.

VISUAL CHECK & EQUIPMENT HOOKUP

Complete all steps in BASIC TESTING article in this section before proceeding to self-diagnostic tests. Ensure vacuum hoses and EEC-IV wiring harnesses are properly connected.

Apply parking brake, and place shift lever in Park (A/T) or Neutral(M/T) position. Block drive wheels. Turn off all electrical accessories. Connect appropriate test equipment to vehicle as follows

Analog Volt-Ohmmeter (VOM)

1) Turn ignition switch to OFF position. Set VOM at 0-15V DC range. Connect positive lead of VOM to positive battery terminal.

2) Connect negative VOM lead to Self-Test Output (STO) terminal of Data Link Connector (DLC). (Scheme 133) Connect timing light, and go to KOEO SELF-TEST. Activate KOEO SELF-TEST by connecting jumper wire from Self-Test Input (STI) pigtail to signal return terminal of Data Link Connector (DLC) with ignition on.

Scan Tester

Follow manufacturer's instructions to hook up equipment and record service codes.

STAR Series Tester

Turn ignition switch to OFF position. Connect color-coded adapter cable leads to diagnostic tester. Connect 2 service connectors of adapter cable to vehicle Data Link Connector (DLC) and STI pigtail connector. Connect timing light. Go to KOEO SELF-TEST.

Malfunction Indicator Light (MIL)

Turn ignition on. Connect a jumper wire between Self-Test Input (STI) pigtail and signal return terminal of Data Link Connector (DLC). (Scheme 133) Go to KOEO SELF-TEST.

Scheme 133

ADDITIONAL SYSTEM FUNCTIONS

Additional diagnostic system features are available to help diagnose driveability problems and service EEC-IV systems.

The MIL is intended to alert driver of certain malfunctions in EEC-IV system. Light may also be used to retrieve service codes stored in PCM. When hooked up for KOEO SELF-TEST or KOER SELF-TEST, light will display all codes which turn on light during vehicle operation.

Light should come on when ignition is turned on and go out when engine is started. If light comes on and then goes off during vehicle operation, code causing light to come on will be stored in PCM memory as a Continuous Memory Code. If light comes on during vehicle operation, vehicle should be inspected as soon as possible. Immediately turning off engine is not necessary; vehicle can be driven with light on.

OUTPUT STATE CHECK

OUTPUT STATE CHECK is used as an aid in servicing output actuators associated with EEC-IV system. It allows technicians to energize and de-energize most system output actuators on command. This mode is entered from KOEO SELF-TEST after all codes have been retrieved.

Disconnect cruise control servo (if equipped). With DVOM on 20-volt scale, connect DVOM negative lead to STO terminal at Diagnostic Link Connector (DLC). Connect positive lead to positive battery terminal. Using jumper wire, connect STI to SIG RTN at Diagnostic Link Connector (DLC).

Perform KOEO SELF-TEST until continuous memory test is complete. DVOM will read less than 1.0 volt when test is complete. Depress and release throttle. If voltage increases, OUTPUT STATE CHECK has been entered. If voltage does not increase, depress throttle to WOT and release. If STO voltage still does not increase, go to CIRCUIT TEST QC.

Failure Mode Effects Management (FMEM), Code 98 Or 998

FMEM mode allows system operation when sensors fail or transmit signals that are out of normal operating range. During FMEM mode, PCM substitutes a mid-range signal for defective sensor while continuing to monitor sensor. If faulty sensor's signals return to normal operating range, PCM will use those signals. A Code 98 or 998 will be displayed when FMEM mode is in effect.

SUMMARY

If no service code is present but driveability problem still exists, proceed to TESTS W/O CODES article in this section for symptom diagnosis or intermittent diagnosis procedures.

3-DIGIT SERVICE CODE REFERENCE CHART TABLE (CODE 111-175). Scheme 134

3-DIGIT SERVICE CODE REFERENCE CHART TABLE (CODE 176-222). Scheme 135

3-DIGIT SERVICE CODE-TO-TEST MENU TABLE (CODE 223-543). Scheme 136

3-DIGIT SERVICE CODE-TO-TEST MENU TABLE (CODE 551-625). Scheme 137

3-DIGIT SERVICE CODE-TO-TEST MENU TABLE (CODE 626-638). Scheme 138

CIRCUIT TESTS

Note. A breakout box, connected to vehicle harness at PCM, is necessary to perform most circuit tests. References to Test Pin No. found in CIRCUIT TEST steps refer to test terminals on manufacturer's breakout box. Circuit diagrams at beginning of each test identify circuit and wire colors.

HOW TO USE CIRCUIT TESTS

1) Ensure all non-EEC related faults found while performing steps in BASIC TESTING article have been corrected. DO NOT perform any CIRCUIT TEST unless specifically instructed by a QUICK TEST procedure. Follow each test step in order until fault is found. DO NOT replace any part unless directed to do so. When more than one code is retrieved, start with first code displayed.

2) CIRCUIT TESTS ensure electrical circuits are okay before sensors or other components are replaced. Always test circuits for continuity between sensor and PCM. Test all circuits for short to power, opens or short to ground. Voltage Reference (VREF) and Voltage Power (VPWR) circuits should be tested with ignition on or as specified in CIRCUIT TESTS.

3) DO NOT measure voltage or resistance at PCM. DO NOT connect any test light unless specified in testing procedure. All measurements are made by probing rear of connector. Isolate both ends of a circuit and turn ignition off when checking for shorts or continuity, unless instructed otherwise.

4) Disconnect solenoids and switches from harness before measuring continuity and resistance or applying voltage. After each repair, check all component connections and repeat QUICK TEST.

5) An open circuit is defined as a resistance reading of greater than 5 ohms. This specification tolerance may be too high for some items in EEC-IV system. If resistance approaches 5 ohms, always clean suspect connector and coat it with protective dielectric silicone grease. A short is defined as a resistance reading of less than 10,000 ohms to ground, unless stated otherwise in CIRCUIT TEST.

Preliminary Instructions (A/T)

Record and clear continuous memory codes. Warm engine to normal operating temperature. Place gear selector in Drive position. Accelerate hard to 35 MPH and coast down to a stop. Shut off engine. Perform KOEO SELF-TEST. Go to step 1).

Preliminary Instructions (M/T)

Record and clear continuous memory codes. Warm engine to normal operating temperature. Accelerate moderately to 40 MPH. Start in first gear, shifting no higher than second gear. Coast down to idle, and stop. Shut engine off. Perform KOEO SELF-TEST, and record continuous memory codes. Go to step 1).

1) Continuous Memory Code 29/452 Code 29/452 indicates PCM detected incorrect output from VSS sometime during vehicle operation. Possible causes for this code are

1. Faulty VSS.
2. Open or shorted circuit.
3. Faulty PCM.

Perform appropriate drive cycle procedure. See PRELIMINARY INSTRUCTIONS (A/T) or PRELIMINARY INSTRUCTIONS (M/T). Ensure driveability complaint can be verified. If Code 29/452 is still present or driveability complaint can be verified, go to step 2). If code is not present or complaint cannot be verified, fault cannot be duplicated at this time. Clear codes, and see SYMPTOMS TESTS W/O CODES article in this section

2) Check VSS Circuit Continuity Turn ignition off. Disconnect VSS sensor. Remove PCM 60-pin connector. Inspect terminals, and repair if damaged. Install EEC-IV Breakout Box (T83L-50-EEC-IV). Measure resistance between VSS (+) terminal at VSS wiring harness connector and test pin No. 3 at breakout box. Measure resistance between VSS (-) terminal at VSS wiring harness connector and test pin No. 6 at breakout box. If any resistance reading is more than 5 ohms, service open circuit in VSS wiring harness and repeat step 1). If both resistance readings are 5 ohms or less, go to step 3).

3) Check VSS Circuits For Shorts To Power Or Ground Turn ignition off. Ensure PCM and VSS are disconnected. Measure resistance between test pin No. 3 and test pins No. 6, 37 and 40 at breakout box. If all readings are greater than 500 ohms, go to step 4). If any reading is less than 500 ohms, repair shorts in VSS wiring harness and repeat step 1).

4) Check VSS Resistance Turn ignition off, and wait 10 seconds. Disconnect VSS wiring harness connector. Measure resistance across VSS terminals. If reading is not 190-250 ohms, replace VSS and repeat step 1). If resistance is 190-250 ohms, replace PCM and repeat step 1).

Engine Starts

1. Fuel pump secondary circuit shorted to power.
2. Fuel pump relay contacts always closed.
3. Open FPM circuit between PCM and junction to POWER-TO-PUMP circuit.
4. Left/front HO2S short to power (dual HO2S applications).
5. Faulty PCM.

No Start

1. IFS switch circuit open or not reset.
2. Open circuit in or between PCM and fuel pump.
3. Faulty ground connection at fuel pump.
4. Faulty fuel pump.

If engine starts, go to step 11). If engine does not start, go to step 15).

11) Check Fuel Pump Operation Turn ignition on. Wait 5 seconds. Listen for fuel pump operation. If fuel pump is off, go to step 13). If fuel pump is on, go to step 12).

12) Check For Fuel Pump Relay Always Closed Turn ignition off. Disconnect fuel pump relay. Turn ignition on. If fuel pump is off with relay disconnected, replace fuel pump relay and repeat QUICK TEST. If fuel pump is on with relay disconnected, repair short to power in POWER-TO-PUMP or FPM circuit. (For models with relay block, also check fuel pump prime plug circuit). Repeat QUICK TEST.

13) Check Continuity Of Fuel Pump Monitor (FPM) Circuit Turn ignition off. Disconnect PCM 60-pin connector. Inspect and repair any damaged terminals. Install EEC-IV Breakout Box (T83L-50-EEC-IV), leaving PCM disconnected. Disconnect fuel pump relay. Measure resistance between test pin No. 8 (No. 19 on Escort, and Tracer) at breakout box and POWER-TO-PUMP circuit at fuel pump relay wiring harness connector. If resistance is less than 5 ohms, go to step 25) (dual HO2S) or replace PCM and repeat QUICK TEST (single HO2S). If resistance is 5 ohms or more, repair open circuit and repeat QUICK TEST.

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 13) to step 15). No test procedures have been omitted.

15) Check IFS Switch Turn ignition off. Disconnect fuel pump IFS switch. Ensure switch is reset. Measure resistance of IFS switch (between GND pin and FP pin on Escort and Tracer). If resistance is less than 5 ohms, check for open in POWER-TO-PUMP circuit, poor fuel pump ground or faulty fuel pump. If resistance is 5 ohms or more, reset or replace IFS switch. Repeat QUICK TEST.

IFS Switch (Escort & Tracer). Scheme 139

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 15) to step 20). No test procedures have been omitted.

20) Code 96/543 Code 96/543 indicates fuel pump secondary circuit failure between B+ circuit and FPM connection to POWER-TO-PUMP circuit. Following are possible causes

1. Open circuit between B+ and FPM connection to POWER-TO-PUMP circuit.
2. Fuel pump relay contacts are always open.

1. HO2S short to power (dual HO2S models).
2. Faulty PCM.

If engine starts, go to step 25) (dual HO2S) or replace PCM and repeat QUICK TEST (single HO2S). If engine does not start, go to step 21).

21) Check For B+ To Fuel Pump Relay Turn ignition off. Disconnect fuel pump relay. Measure voltage between B+ terminal at fuel pump relay wiring harness connector and negative battery terminal. If voltage is 10.5 volts or more, go to step 22). If voltage is less than 10.5 volts, check fuse/fusible link. If fuse/fusible link is okay, repair open circuit in B+ circuit. Repeat QUICK TEST.

22) Check POWER-TO-PUMP Circuit Continuity Turn ignition off. Leave fuel pump relay disconnected. Measure resistance between POWER-TO-PUMP terminal at fuel pump relay wiring harness connector and negative battery terminal. If resistance is less than 10 ohms, replace fuel pump relay and repeat QUICK TEST. If resistance is 10 ohms or more, repair open circuit in POWER-TO-PUMP circuit between FPM junction and fuel pump relay. Repeat QUICK TEST.

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 22) to step 25). No test procedures have been omitted.

1. Fuel Pump Secondary Circuit Short To Power
2. Fuel Pump Relay Contacts Always Closed
3. Open In FPM Circuit Between PCM And Power To Pump Circuit Connection
4. Left/Front HO2S Short To Power (Dual HO2S System)
5. Faulty PCM

Engine Does Not Start

1. Open Circuit In Fuel Pump Or Between Fuel Pump And FPM Circuit
2. Poor Fuel Pump Ground Connection
3. Fuel Pump Internal Circuit Open
4. IFS Switch Not Reset Or Internal Circuit Open

If engine starts, go to step 81). If engine does not start, go to step 85).

81) Verify Fuel Pump Is Off Turn ignition on. Wait 5 seconds. Listen for fuel pump operation. If pump is on, go to step 82) for models with flexible fuel systems or step 83) for models with gasoline fuel systems.

82) Check For LFP Relay Always Closed Turn ignition off. Disconnect LFP relay. Turn ignition on. Wait 5 seconds. Listen for fuel pump operation. If pump goes off when relay is disconnected, replace LFP relay and repeat QUICK TEST. If pump does not go off when relay is disconnected, go to step 83).

83) Check For Fuel Pump Relay Always Closed Turn ignition off. Disconnect CCRM. Turn ignition on. Wait 5 seconds. Listen for fuel pump operation. If pump goes off when relay is disconnected, replace CCRM and repeat QUICK TEST. If pump does not go off when CCRM is disconnected, repair short to power in POWER-TO-PUMP/FPM circuit.

84) Check Continuity Of FPM Circuit Turn ignition off. Disconnect PCM 60-pin connector. Inspect connector for damaged pins, corrosion and loose wires. Repair as necessary. Install breakout box, leaving PCM disconnected. Disconnect CCRM. Measure resistance between test pin No. 8 at breakout box and pin No. 5 of CCRM wiring harness connector. If resistance is less than 5 ohms, go to step 86) (dual HO2S models) or replace PCM and repeat QUICK TEST (except dual HO2S models). If resistance is 5 ohms or more, repair open circuit and repeat QUICK TEST.

85) Check Inertia Fuel Shutoff (IFS) Switch Turn ignition off. Disconnect IFS switch. Measure resistance at IFS switch terminals "C" and NC. If resistance is 5 ohms or less, fault is in fuel pump electrical system. If resistance is more than 5 ohms, replace or reset IFS switch and repeat QUICK TEST.

86) Check Left/Front HO2S Sensor For Short To Power Turn ignition off. Disconnect left/front HO2S sensor. Measure resistance between HO2S SIGNAL terminal and KEY POWER terminal at HO2S sensor connector. see scheme 83 If resistance is 10,000 ohms or more, go to step 87). If resistance is less than 10,000 ohms, replace HO2S sensor and repeat QUICK TEST.

87) Check HO2S Circuit For Short To Power Leave ignition off and left/front HO2S sensor disconnected. Disconnect PCM 60-pin connector. Inspect for damage and repair as necessary. Install breakout box, leaving PCM disconnected. Turn ignition on. Measure voltage between HO2S SIGNAL terminal at sensor wiring harness connector and chassis ground. see scheme 84 If voltage is one volt or less, replace PCM and repeat QUICK TEST. If voltage is more than one volt, repair short circuit and repeat QUICK TEST.

88) Code 524 If KOEO Code 543 is present, go to step 90). Code 524 indicates LFP secondary circuit failure. Following are possible causes for this fault.

1. Open B(+) Circuit To LFP Relay
2. Open POWER-TO-PUMP Circuit
3. Faulty Fuel Pump Dropping Resistor

Turn ignition off. Disconnect LFP relay. Measure voltage between B(+) terminal of relay wiring harness connector and negative battery terminal. If less 10.5 volts is present, repair open in B(+) circuit. If 10.5 volts or more is present, go to next step.

89) Check POWER-TO-PUMP Circuit Continuity Leave ignition off and LFP relay disconnected. Disconnect CCRM. Measure resistance between terminal No. 5 of CCRM wiring harness connector and POWER-TO-PUMP terminal of LFP relay wiring harness connector. If resistance is less than 10 ohms, replace LFP relay. If resistance is 10 ohms or more, measure resistance across fuel pump dropping resistor terminals. If resistance is not approximately one ohm, replace fuel pump dropping resistor. If resistance is approximately one ohm, repair open in POWER-TO-PUMP circuit.

Checking POWER-TO-PUMP Circuit Continuity. Scheme 140

90) Code 543 Code 543 indicates one of the following conditions.

1. Left/Front HO2S Short To Power (Dual HO2S Systems)
2. Faulty PCM

1. Open Circuit In Fuel Pump Or Between Fuel Pump And FPM Circuit
2. Fuel Pump Relay Contacts Always Open

If engine does not start, go to step 91). If engine starts, replace PCM and repeat QUICK TEST.

91) Check B(+) To Fuel Pump Relay(s) Turn ignition off. Disconnect CCRM relay. Measure voltage between CCRM wiring harness connector terminal No. 12 and negative battery terminal. If voltage is 10.5 volts or less, repair open in B(+) circuit to CCRM and repeat QUICK TEST. If voltage is more than 10.5 volts, go to next step.

92) Check POWER-TO-CIRCUIT Continuity Leave ignition off and CCRM relay disconnected. Measure resistance between CCRM wiring harness connector terminal No. 5 and negative battery terminal. If resistance is more than 10 ohms, repair open in POWER-TO-PUMP circuit. If resistance is 10 ohms or less, replace CCRM and repeat QUICK TEST.

93) Check B(+) To HFP Relay Turn ignition off. Disconnect CCRM relay. Measure voltage between CCRM wiring harness connector terminal No. 12 and negative battery terminal. If voltage is 10.5 volts or less, repair open in B(+) circuit to CCRM and repeat QUICK TEST. If voltage is more than 10.5 volts, go to step 94).

94) Check POWER-TO-PUMP Circuit Continuity Leave ignition off and CCRM relay disconnected. Disconnect Inertia Fuel Shutoff (IFS) switch. Measure resistance between CCRM wiring harness connector terminal No. 5 and POWER-TO-PUMP circuit at IFS switch wiring harness connector. If resistance is more than 5 ohms, repair open in POWER-TO-PUMP circuit and repeat QUICK TEST. If resistance is 5 ohms or less, go to next step.

95) Check PCM Ability To Monitor FPM Leave ignition off and IFS switch disconnected. Reconnect CCRM relay. Perform KOEO SELF-TEST. If Code 542 is present, replace CCRM and repeat QUICK TEST. If Code 542 is not present, replace PCM and repeat QUICK TEST.

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 95) to step 98). No test procedures have been omitted.

98) Code 524 If KOEO Code 543 is present, go to step 90). Code 524 indicates LFP secondary circuit failure. Following are possible causes for this fault.

1. Open B(+) Circuit To LFP Relay
2. Faulty CCRM

Turn ignition off. Disconnect CCRM. Measure voltage between terminal No. 10 of CCRM wiring harness connector and negative battery terminal. If less than 10.5 volts is present, repair open in B(+) circuit between CCRM and splice to HFP and LFP relays. Repeat QUICK TEST. If 10.5 volts or more is present, replace CCRM and repeat QUICK TEST.

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 98) to step 105). No test procedures have been omitted.

105) Continuous Memory Code 542; Check EEC-IV Wiring Harness Continuous Memory Code 542 indicates one of following intermittent conditions has occurred.

1. Open Circuit In Or Between Fuel Pump And FPM Circuit In PCM
2. Poor Fuel Pump Ground
3. IFS Switch Reset
4. FPM Or POWER-TO-PUMP circuit short to power
5. Fuel Pump Relay Contacts Stuck Closed
6. Left/Front HO2S Circuit Short To Power
7. Engine Stall Due To Excessive Load

Start engine. Check for engine stall and stumble and listen for fuel pump shutting off while performing following

1. Shake, wiggle and bend POWER-TO-PUMP circuit between CCRM pin No. 5 and fuel pump.
2. Shake and bend fuel pump ground circuit from fuel pump to ground.
3. Lightly tap inertia switch and fuel pump to simulate road shock.

On all vehicles, turn ignition off. Inspect fuel pump wiring harness connector and fuel pump ground for corrosion or other damage. If fault is found, isolate and repair as necessary and repeat QUICK TEST. If fault is not found, go to step 106).

106) Check FPM Circuit Turn ignition off. Disconnect PCM 60-pin connector. Inspect for damaged and repair as necessary. Install breakout box, leaving PCM disconnected. Turn ignition on. Connect test light between test pin No. 8 and test pin No. 37. Test light should be on. Observe test light while shaking and bending FPM circuit between PCM and splice in POWER-TO-PUMP circuit. Test light will turn off if fault is found. If fault is indicated, isolate and repair as necessary and repeat QUICK TEST. If no fault is found, go to step 107).

107) Check For Short To Power Leave PCM disconnected. Turn ignition on. Connect test light between test pin No. 8 and test pin No. 40. Test light should be off. Observe test light while shaking and bending FPM and POWER-TO-PUMP circuit. If no fault is found, check individual sensor values. See the PIN VOLTAGE CHART S article in this section. If all sensor values are okay, go to step 120).

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 107) to step 110). No test procedures have been omitted.

110) Continuous Memory Code 524 Or 543: Check For Code 557 Or 556 If Continuous Memory Code 556 or Code 557 is also present, go to step 115). If codes are not present, go to step 111).

111) Check EEC-IV Wiring Harness Continuous Memory Code 524 or 543, without Continuous Memory Code 557 or 556, indicates one of following intermittent conditions has occurred.

1. Fuel Pump Relay Contacts Open
2. Open In B(+) Circuit To Fuel Pump Relay
3. Open In POWER-TO-PUMP Circuit Between CCRM Or LFP Relay And FPM Splice
4. Left/Front HO2S Sensor Short To Power

Start engine. Check for engine stall and stumble and fuel pump shutting off while performing following

1. Shake and bend POWER-TO-PUMP circuit between CCRM/LFP relay and FPM splice.
2. Shake and bend B(+) circuit to CCRM/LFP relay.
3. Lightly tap CCRM/LFP relay to simulate road shock.

Turn ignition off. Inspect CCRM/LFP relay connectors for corrosion and other damage. If fault is indicated, isolate and repair as necessary. Repeat QUICK TEST. If fault is not indicated, fault cannot be duplicated or identified at this time.

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 111) to step 115). No test procedures have been omitted.

115) Continuous Memory Code 556 Or 557: Check EEC-IV Wiring Harness Continuous Memory Code 556 or 557 indicates that a fuel pump primary circuit fault has occurred. The following are possible causes for fault.

1. Open VPWR Circuit In CCRM
2. Open In Fuel Pump Primary Circuit (PCM Pin No. 22, 32 Or 41)

Start engine. Check for engine stall or stumble and fuel pump shutting off while performing one of following

1. Shake and bend EEC-IV harness fuel pump circuit (pin No. 22 or 32) between PCM and CCRM.
2. Lightly tap CCRM to simulate road shock.

Turn ignition off. Inspect PCM 60-pin connector and fuel pump relay connectors for corrosion and other damage. If fault is indicated, isolate and repair as necessary. Repeat QUICK TEST. If fault is not indicated on single HO2S models, fault cannot be duplicated or identified at this time. If fault is not indicated on dual HO2S models, go to next step.

Note. An intermittent left/front HO2S signal short to power could produce Continuous Memory Code 524, 542 or 543.

116) Check Left/Front HO2S Circuit For Short To Power Turn ignition off. Disconnect 60-pin PCM connector. Inspect terminals, and repair if damaged. Install EEC-IV Breakout Box (T83L-50-EEC-IV), leaving PCM disconnected. Connect test light between left/front HO2S test pin and test pin No. 40. Turn ignition on. Wiggle and tap HO2S sensor and circuitry. If fault is detected, test light will turn on brightly. If fault is indicated, isolate and repair as necessary. If fault is not indicated, fault cannot be duplicated or identified at this time.

1. Short To Power In Fuel Pump/FPM Circuit
2. High Speed Fuel Pump (HFP) Relay Contacts Stuck Closed
3. Short To Ground In HFP Circuit (VCRM terminal No. 10)
4. Open FPM Circuit Between PCM And Power-To-Fuel Pump Splice
5. Short To Power In Left Heated Oxygen Sensor (HO2S)
6. Damaged VCRM
7. Damaged PCM

Check if engine will start and idle for one minute. If engine starts and idles for one minute, go to step 121). If engine does not start or starts but does not idle for one minute, go to step 130).

121) Verify Fuel Pump Is Off Turn ignition on, and wait 5 minutes. Listen for motor noise from fuel pump. If fuel pump is off, go to step 126). If fuel pump is on, go to step 122).

122) Check VCRM Turn ignition off. Disconnect and inspect VCRM connector. Clean or repair connector as necessary. Turn ignition on. Listen for fuel pump noise. If fuel pump is off, turn ignition off. Replace VCRM. Reconnect all components. Repeat QUICK TEST. If fuel pump is on, turn ignition off and go to step 123).

123) Check HFP Relay & Circuits Turn ignition off. Ensure VCRM is disconnected. Disconnect HFP relay. Relay is located in engine compartment fuse block. Turn ignition on. Listen to fuel pump. If fuel pump is off, go to step 124). If fuel pump is on, turn ignition off. Repair short to power in power-to-fuel pump/FPM circuit. Reconnect all components. Repeat QUICK TEST.

124) Check For Short To Ground In HFP Circuit Turn ignition off. Ensure VCRM and HFP relay are disconnected. Measure resistance between negative battery post and terminal No. 10 (Brown/White wire) at VCRM connector. If resistance is more than 10,000 ohms, replace HFP relay. Reconnect all components. Repeat QUICK TEST. If resistance is 10,000 ohms or less, repair short to ground in HFP circuit. Reconnect all components. Repeat QUICK TEST.

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 124) to step 126). No test procedures have been omitted.

126) Check FPM Circuit Continuity Turn ignition off. Disconnect and inspect PCM connector. Clean or repair connector as necessary. Install breakout box. Leave PCM disconnected. Disconnect HFP relay. Measure resistance between test pin No. 8 at breakout box and power-to-fuel pump terminal (Pink/Black wire) at HFP relay connector. (Scheme 141) If resistance is less than 5 ohms, go to step 127). If resistance is 5 ohms or more, repair open in FPM circuit between PCM and splice to power-to-fuel pump circuit. Remove breakout box, and reconnect all components. Repeat QUICK TEST.

High Speed Fuel Pump (HFP) Relay Connector Terminals. Scheme 141

127) Check For Short To Power In Left HO2S Turn ignition off. Disconnect left HO2S. Measure resistance between HO2S SIGNAL terminal and KEY POWER terminal at HO2S connector. (Scheme 142) If resistance is more than 10,000 ohms, to step 128). If resistance is 10,000 ohms or less, replace HO2S. Reconnect all components. Repeat QUICK TEST.

Identifying Heater Oxygen Sensor (HO2S) Terminals. Scheme 142

128) Check For Short To Power In Left HO2S Circuit Turn ignition off. Ensure left HO2S is disconnected. Disconnect and inspect PCM connector. Clean or repair connector as necessary. Turn ignition on. Measure voltage between negative battery post and HO2S SIGNAL terminal at HO2S connector. (Scheme 142) If voltage is less than 2 volts, replace PCM. Reconnect all components. Repeat QUICK TEST. If voltage is 2 volts or more, repair short to power in left HO2S circuit.

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 128) to step 130). No test procedures have been omitted.

130) Check Inertia Fuel Shutoff (IFS) Switch Turn ignition off. Disconnect IFS switch. IFS switch is located in left front of trunk. Ensure IFS switch button is in the down (set) position. Measure resistance between IFS switch terminals. If resistance is less than 5 ohms, reconnect IFS switch. Check for open in power-to-fuel pump circuit, open in fuel pump or poor fuel pump ground. Repair wiring as necessary. Repeat QUICK TEST. If resistance is 5 ohms or more, replace IFS switch. Reconnect all components. Repeat QUICK TEST.

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 130) to step 135). No test procedures have been omitted.

135) Code 524, 543 & Continuous Memory Code 583 KOEO Code 524 or 543 indicates that when PCM commanded fuel pump on, voltage was not detected on Fuel Pump Monitor (FPM) circuit (PCM terminal No. 8). Code 524 refers to low speed output (VCRM terminal No. 24; Pink/Black wire). Code 543 refers to high speed output. It is not possible to distinguish between circuits due to vehicle wiring and fuel pump operating strategy. Continuous Memory Code 583 indicates that when fuel pump was activated, power-to-fuel pump exceeded normal current draw. This could be due to a hard fault or an intermittent condition. Following are possible causes for these faults.

Without Continuous Memory Code 583

1. Open In Power-To-Fuel Pump Circuit Between VCRM And FPM Splice
2. Open In B (+) Supply To VCRM (Terminals No. 4 And 5)
3. Short To Power In Left HO2S

With Continuous Memory Code 583

1. Short To Ground In Power-To-Fuel Pump/FPM Circuit

If Continuous Memory Code 583 is present, go to step 136). If Continuous Memory Code 583 is not present, go to step 144).

136) Attempt To Re-Generate Continuous Memory Code 583 Turn ignition off. Clear continuous memory. See CLEARING CODES under SELF-DIAGNOSTIC SYSTEM. Start engine. If engine will not start, crank engine for 5 seconds. Repeat KOEO SELF-TEST. If Continuous Memory Code 583 is present, code is a hard fault. Go to step 139). If Continuous Memory Code 583 is not present, code is intermittent. Go to step 137).

137) Was KOEO Code 524 Or 543 Present In Step 136) If KOEO Code 524 and/or 543 was present in step 136), an over current condition (short to ground) was present sometime during last 80 warm-up cycles. Go to step 144). If KOEO Code 524 and/or 543 was not present in step 136), go to step 147).

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 137) to step 139). No test procedures have been omitted.

139) Attempt To Isolate Short To Ground Turn ignition off. Clear continuous memory. Disconnect Inertia Fuel Shutoff (IFS) switch. IFS switch is located in left front of trunk. Crank engine for 5 seconds. Repeat KOEO SELF-TEST. If Continuous Memory Code 583 is present (disregard other codes), go to step 140). If Continuous Memory Code 583 is not present, check for short to ground in power-to-fuel pump circuit. Repair wiring as necessary. After repair is complete, repeat QUICK TEST.

140) Check For Short To Ground In Power-To-Fuel Pump/FPM Circuit Turn ignition off. Ensure IFS switch is disconnected. Disconnect and inspect PCM and VCRM connectors. Clean or repair connectors as necessary. Install breakout box. Leave PCM and VCRM disconnected. Measure resistance between test pins No. 8 and 40 at breakout box. If resistance is more than 10,000 ohms, go to step 141). If resistance is 10,000 ohms or less, repair short to ground in power-to-fuel pump/FPM circuit. Remove breakout box, and reconnect all components. Clear continuous memory. Start engine and wait 5 seconds. Turn ignition off. Repeat QUICK TEST.

141) Check VCRM Turn ignition off. Ensure IFS switch is disconnected. Install breakout box. Leave PCM disconnected. Reconnect VCRM connector. Connect a jumper wire between test pins No. 22 and 40 at breakout box. Turn ignition on. Measure voltage between test pins No. 8 and 60 at breakout box. If voltage is more than 8.5 volts, replace PCM. Remove breakout box, and reconnect all components. Clear continuous memory. Start engine and wait 5 seconds. Turn ignition off. Repeat QUICK TEST. If voltage is 8.5 volts or less, replace VCRM. Remove breakout box, and reconnect all components. Clear continuous memory. Start engine and wait 5 seconds. Turn ignition off. Repeat QUICK TEST.

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 141) to step 144). No test procedures have been omitted.

144) Check If Engine Starts With High Speed Fuel Pump (HFP) Relay Disconnected Turn ignition off. Disconnect HFP relay. Relay is located in engine compartment fuse block. Attempt to start engine. If engine does not start or starts but runs for less than one minute, go to next step. If engine starts and runs for one minute, reconnect HFP relay. Go to step 127).

145) Check for B (+) To VCRM Turn ignition off. Ensure HFP relay is disconnected. Disconnect and inspect VCRM connector. Clean or repair connector as necessary. Connect negative lead of DVOM to negative battery post. Using positive lead of DVOM, measure voltage at terminals No. 4 (Yellow wire) and No. 5 (Yellow wire) at VCRM connector. If both voltage readings are more than 10.5 volts, go to step 146). If any reading is 10.5 volts or less, repair open in B (+) supply to VCRM. Ensure all related fuses are okay. Reconnect all components. Repeat QUICK TEST.

146) Check Power-To-Fuel Pump Circuit Continuity Turn ignition off. Disconnect HFP relay. Measure resistance between terminal No. 24 (Pink/Black wire) and power-to-fuel pump terminal at HFP relay. see scheme 90 If resistance is less than 10 ohms, replace VCRM. Reconnect all components. Repeat QUICK TEST. If resistance is 10 ohms or more, repair open in power-to-fuel pump circuit between VCRM and Fuel Pump Monitor (FPM) splice. Reconnect all components. Repeat QUICK TEST.

147) Check For Intermittent Short To Ground In Power-To-Fuel Pump Circuit Turn ignition off. Visually inspect power-to-fuel pump circuit between VCRM and fuel pump. Also, inspect Fuel Pump Monitor (FPM) circuit to PCM and power-to-fuel pump circuit at High Speed Fuel Pump (HFP) relay. Repair wiring as necessary. Install a fuel gauge or listen to fuel pump to check if fuel pump quits while performing wiggle test. Start engine. Shake, wiggle and bend Pink/Black wire (power-to-fuel pump circuit) between VCRM, fuel pump, PCM and HFP relay. To simulate road shock, lightly tap on Inertia Fuel Shutoff (IFS) switch, fuel pump, HFP relay, VCRM and fuel pump. If fuel pump stops, fuel pressure drops or engine stalls or stumbles, a short to ground in power-to-fuel pump circuit has been detected. Isolate fault and repair as necessary. Clear continuous memory (Code 583 should have been set). Start engine and wait 5 seconds. Turn ignition off. Repeat QUICK TEST. If no fault is detected, go to step 148).

148) Again, Check For Intermittent Short To Ground In Power-To-Fuel Pump Turn ignition off. Disconnect PCM, VCRM and fuel pump. Inspect connectors. Clean or repair connectors as necessary. Install breakout box. Leave PCM, VCRM and fuel pump disconnected. Connect a test light between test pins No. 1 (KAPWR) and No. 8 (FPM) at breakout box. Observe test light, and shake, wiggle and bend Pink/Black wire (power-to-fuel pump circuit) between VCRM, fuel pump, PCM and HFP relay. To simulate road shock, lightly tap on Inertia Fuel Shutoff (IFS) switch, fuel pump, HFP relay and VCRM. If a fault is detected, test light will turn on, indicating a short to ground. If a short to ground is detected, isolate fault and repair wiring as necessary. Start engine and wait 5 seconds. Turn ignition off. Repeat QUICK TEST. If a short to ground is not detected, fault is intermittent and cannot be duplicated at this time. Testing is complete. Reconnect all components. For further diagnosis, see TESTS W/O CODES article in this section.

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 148) to step 150). No test procedures have been omitted.

150) Continuous Memory Code 524, 543 Or 556 Continuous Memory Code 524 or 543 indicates that when PCM commanded fuel pump on, voltage was not detected at the power-to-fuel pump circuit. Code 524 refers to low speed output (VCRM terminal No. 24; Pink/Black wire). Code 543 refers to high speed output. It is not possible to distinguish between circuits due to vehicle wiring and fuel pump operating strategy. Following are possible causes for these faults.

1. Open In Power-To-Fuel Pump Circuit Between VCRM And FPM Splice
2. Open In B (+) Supply To VCRM (Terminals No. 4 And 5)
3. Left HO2S Short To Power

Continuous Memory Code 556 indicates that sometime during vehicle operation, fuel pump primary circuit failure occurred. Possible cause for this fault is an open or short in fuel pump circuit (PCM terminal No. 22). If Continuous Memory Code 583 is also present, go to step 136). If Continuous Memory Code 583 is not present, go to step 151).

151) Check Power-To-Fuel Pump & Fuel Pump Circuits Start engine. Disconnect High Speed Fuel Pump (HFP) relay. Relay is located in engine compartment fuse block. Connect a test light between ground and power-to-fuel pump terminal at HFP relay connector. If a fault is detected, test light will turn on, indicating a short to ground. Also, listen for engine stall/stumble or fuel pump turning off. Observe test light and perform the following

1. For Code 524 or 543, shake, wiggle and bend Pink/Black wire (power-to-fuel pump circuit) between terminal No. 24 at VCRM and Fuel Pump Monitor (FPM) splice. Also shake, wiggle and bend Yellow wire (B (+) circuit) between terminals No. 4 and 5 at VCRM.
2. For Code 556, shake, wiggle and bend Light Blue/Orange wire (fuel pump circuit) between terminals No. 22 at PCM and No. 18 at VCRM.

If a short to ground is detected, isolate fault and repair wiring as necessary. Clear continuous memory. Repeat QUICK TEST. If Code 556 is present and a short to ground is not detected, go to step 152). If Code 556 is not present and a short to ground is not detected, go to step 158).

152) Check For Intermittent Short To Ground In Fuel Pump Circuit Turn ignition off. Disconnect and inspect PCM and VCRM connectors. Clean or repair connectors as necessary. Connect ohmmeter between terminals No. 18 (Light Blue/Orange wire) and No. 1 (Black wire) at VCRM connector. Observe ohmmeter, and shake, wiggle and bend Light Blue/Orange wire (fuel pump circuit) between VCRM and PCM connectors. Also check fuel pump circuit to Data Link Connector (DLC). If a fault is detected, ohmmeter will show continuity, indicating a short to ground. If continuity exist, isolate fault and repair wiring as necessary. Clear continuous memory. Repeat QUICK TEST. If no continuity exists, fault is intermittent and cannot be duplicated at this time. Testing is complete. Reconnect all components. For further diagnosis, see TESTS W/O CODES article in this section.

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 152) to step 155). No test procedures have been omitted.

155) Continuous Memory Code 542 Continuous Memory Code 542 indicates that one of the following conditions has occurred.

1. Fuel Pump Circuit Activated When PCM Expected Circuit To Be Off
2. Open In Fuel Pump Monitor (FPM) Circuit, Power To Fuel Pump, Fuel Pump Or Fuel Pump Ground Circuit
3. Short To Power In FPM Or Power-To-Fuel Pump Circuits
4. VCRM Output Driver Or High Speed Fuel Pump (HFP) Relay Contacts Stuck Closed
5. Short To Ground In HFP Circuit
6. Short To Power In Left HO2S Signal Circuit
7. Engine Stall Due To Excessive Load

Start engine. Check for engine stall/stumble while performing the following (if possible, listen for fuel pump turning off). Shake, wiggle and bend Pink/Black wire (power-to-fuel pump circuit) between fuel pump and FPM splice. To simulate road shock, lightly tap on fuel pump, Inertia Fuel Shutoff (IFS) switch and VCRM. If engine stalls or stumbles, isolate fault and repair wiring as necessary. Clear continuous memory. Repeat QUICK TEST. If engine does not stall or stumble, go to step 156).

156) Check For Intermittent Open Or Short In FPM, Power-To-Fuel Pump & Fuel Pump Ground Circuits Turn ignition off. Disconnect and inspect PCM connector. Clean or repair connector as necessary. Install breakout box. Leave PCM disconnected. Connect a test light between test pins No. 8 and 37 at breakout box. Turn ignition on. Observe test light, and shake, wiggle and bend the following circuits.

1. Fuel Pump Monitor (FPM) Circuit
2. Power-To-Fuel Pump Circuit
3. Fuel Pump Ground And HFP Relay Circuits Between HFP Relay And VCRM

To simulate road shock, lightly tap on Inertia Fuel Shutoff (IFS) switch, VCRM and HFP relay. If a fault is detected, test light will turn off indicating an open circuit. Test light will also turn off and fuel pump will run, if a short to power or HFP circuit short to ground is detected. If a fault is detected, isolate fault and repair wiring as necessary. Remove breakout box. Reconnect all components. Repeat QUICK TEST. If a fault is not detected, go to step 158).

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 156) to step 158). No test procedures have been omitted. Due to internal circuitry of PCM, an intermittent short to power in left HO2S signal may produce a Continuous Memory Code 524, 542 or 543.

158) Check For Short To Power In Left HO2S Turn ignition off. Install breakout box. Leave PCM disconnected. Connect test light between test pins No. 43 and 40 at breakout box. Turn ignition on. Observe test light and shake, wiggle and bend Red/Black wire between left HO2S and PCM connector. To simulate road shock, lightly tap on left HO2S. If a fault is detected, test light will turn on bright, indicating a short to power. If a short to power is detected, isolate fault and repair wiring as necessary. Remove breakout box. Reconnect all components. Repeat QUICK TEST. If a short to power is not detected, fault is intermittent and cannot be duplicated at this time. Testing is complete. Reconnect all components. For further diagnosis, see TESTS W/O CODES article in this section.

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 158) to step 160). No test procedures have been omitted.

160) Lack Of Power/Hard Start; Check HFP Relay Operation Turn ignition off. Disconnect HFP relay. Relay is located in engine compartment fuse block. Measure voltage between negative battery post and B (+) terminal at HFP relay connector. see scheme 90 Turn ignition on. Measure voltage between IGN START/RUN terminal at HFP relay connector and negative battery post. If both voltage readings are more than 10.5 volts, go to step 161). If any reading is 10.5 volts or less, repair open in B (+) or IGN START/RUN circuit. Also, ensure all related fuses are good. After repair is completed, reconnect all components. Recheck system operation.

161) Check Power-To-Fuel Pump Circuit Continuity Turn ignition off. Disconnect HFP relay connector. Measure resistance between negative battery post and POWER-TO-FUEL PUMP terminal at HFP relay connector. see scheme 90 If resistance is less than 10 ohms, go to step 162). If resistance is 10 ohms or more, repair open in power-to-fuel pump circuit between HFP relay and splice to main power-to-fuel pump circuit. After repair is completed, reconnect all components. Recheck system operation.

162) Check VCRM & HFP Circuit Operation Turn ignition off. Reconnect HFP relay. Start engine. Run engine until normal operating temperature is reached. Turn ignition off. Disconnect HFP relay. Connect DVOM between terminals B (+) and HFP at HFP relay connector. see scheme 90 Ensure all accessories are off. Observe DVOM and start engine. Within 10 seconds of start, record DVOM voltage. Observe DVOM and allow engine to idle for 2 minutes. If voltage reading taken at 10 seconds decreases a minimum of 0.4 volt within 2 minutes of running engine, VCRM and HFP circuits are okay. Turn ignition off. Check HFP relay. Go to step 163). If voltage reading taken at 10 seconds does not decrease a minimum of 0.4 volt within 2 minutes of running engine, turn ignition off. Go to step 165).

163) Check HFP Relay Turn ignition off. Disconnect HFP relay. Connect a jumper wire between positive battery post and IGN START/RUN terminal at HFP relay. (Scheme 143) Connect one end of another jumper wire to HFP terminal at HFP relay. Listen to HFP relay and touch remaining end of jumper wire to negative battery post. If relay clicks, relay is working properly. Remove jumper wires and reconnect HFP relay. If relay does not click, replace relay. Reconnect all components. Recheck system operation.

Identifying High Speed Fuel Pump (HFP) Relay Terminals. Scheme 143

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 163) to step 165). No test procedures have been omitted.

165) Check HFP Circuit Continuity Turn ignition off. Disconnect HFP relay. Disconnect and inspect VCRM connector. Clean or repair connector as necessary. Measure resistance between terminal No. 10 (Brown/White wire) at VCRM connector and HFP terminal at HFP relay connector. (Scheme 143) If resistance is less than 5 ohms, go to step 166). If resistance is 5 ohms or more, repair open in HFP circuit (Brown/White wire). Reconnect all components. Recheck system operation.

166) Check For Short To Power In HFP Circuit Turn ignition off. Ensure VCRM and HFP relay are disconnected. Turn ignition on. Measure voltage between negative battery post and HFP terminal at HFP relay connector. (Scheme 143) If voltage is less than one volt, go to step 167). If voltage is one volt or more, repair short to power in HFP circuit. Reconnect all components. Recheck system operation.

167) Check For Short To Ground In HFP Circuit Turn ignition off. Ensure VCRM and HFP relay are disconnected. Measure resistance between negative battery post and HFP terminal at HFP relay connector. (Scheme 143) If resistance is more than 10,000 ohms, replace VCRM. Reconnect all components. Recheck system operation. If resistance is 10,000 ohms or less, repair short to ground in HFP circuit. Reconnect all components. Recheck system operation.

Note. A break in step numbering sequence occurs at this point. Procedure skips from step 167) to step 170). No test procedures have been omitted.

170) KOEO & Continuous Memory Code 587: Check Wiring Harness Code 587 indicates a Data Link Connector (DLC) failure between PCM and VCRM. DLC includes data (+) and data (-) circuits. Following are possible causes for this fault.

1. Open Or Short In Data (+) Or Data (-) Circuits
2. Damaged VCRM
3. Damaged PCM Check wiring harness containing data (+) (Tan/Orange wire) and data (-) (Pink/Light Blue wire) circuits between VCRM and PCM connectors for proper installation, location (not close to high voltage wires) and for aftermarket modifications.

Relocate or repair wiring as necessary. Clear continuous memory. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST. If KOEO Code 587 is present and wiring is okay, go to step 171). If Continuous Memory Code 587 is present and wiring is okay, go to step 180).

171) Check Data (+) & Data (-) Circuit Continuity Turn ignition off. Disconnect any test equipment connected to Data Link Connector (DLC). Leave equipment disconnected throughout procedure unless otherwise instructed. Disconnect and inspect VCRM and PCM connectors. Clean or repair connectors as necessary. Install breakout box. Leave PCM disconnected. Measure resistance between test pin No. 18 at breakout box and terminal No. 21 (Tan/Orange wire) at VCRM connector. Also, measure resistance between test pin No. 19 at breakout box and terminal No. 23 (Pink/Light Blue wire) at VCRM connector. If both resistance readings are less than 5 ohms, go to step 172). If any reading is 5 ohms or more, repair open in Tan/Orange and/or Pink/Light Blue wire. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST.

172) Check For Short To Power In Data (+) & Data (-) Circuits Ensure breakout box is installed, and PCM and VCRM are disconnected. Measure voltage between test pins No. 18 and 40, and pins No. 19 and 40 at breakout box. If both readings are less than one volt, go to step 173). If any reading is one volt or more, repair short to power in data (+) (Tan/Orange wire) and/or data (-) (Pink/Light Blue wire) circuits. Remove breakout box. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST.

173) Check For Short To Ground Or Short To Each Other In Data (+) & Data (-) Circuits Turn ignition off. Ensure breakout box is installed, PCM and VCRM are disconnected. Measure resistance between test pins No. 18 and 40, pins No. 18 and 19, and pins No. 19 and 40 at break-out box. If all readings are more than 10,000 ohms, go to step 174). If any reading is 10,000 ohms or less, repair short to ground as necessary. Remove breakout box. Reconnect all components. Start engine. TurnA/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST.

174) Check Data Link Connector (DLC) To VCRM Turn ignition off. Ensure all test equipment is disconnected from DLC. Ensure breakout box is installed and PCM is disconnected. Reconnect VCRM connector. Turn ignition on. Measure voltage between test pins No. 18 (data (+) circuit) and No. 19 (data (-) circuit) at breakout box. If voltage is 3.5-5.3 volts, go to step 175). If voltage is not 3.5-5.3 volts, turn ignition off. Replace VCRM. Remove breakout box. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST.

175) Check Data (-) Circuit In VCRM Turn ignition off. Ensure all test equipment is disconnected from Data Link Connector (DLC), breakout box is installed and PCM is disconnected. With VCRM connected, measure resistance between test pins No. 19 (data (-) circuit) and No. 40 (GND) at breakout box. If resistance is 1500-2500 ohms, go to step 176). If resistance is not 1500-2500 ohms, turn ignition off. Replace VCRM. Remove breakout box. Reconnect all components. Start engine. TurnA/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST.

176) Verify That PCM Can Communicate With DLC The purpose of this test is to verify that PCM can communicate with DLC. A scan tool is required for this test step. Follow manufacturer instructions to hook up equipment. Turn ignition off. Remove breakout box. Reconnect PCM. Connect scan tool to DLC. Start engine. While in DLC display, view RPM Parameter Identification (PID). Monitor RPM, and change engine speed. If RPM PID is displayed and changes with engine speed, go to step 177). If RPM PID is not displayed or is displayed but does not change with engine speed, go to step 179).

177) Verify DLC In VCRM Turn ignition off. Ensure PCM and VCRM are connected. Turn A/C off. Enter Output State Diagnostic Test Mode (OS DTM). See OUTPUT STATE CHECK procedure under ADDITIONAL SYSTEM FUNCTIONS. Depress and hold throttle near Wide Open Throttle (WOT) until Malfunction Indicator Light (MIL) flashes once (about 10 seconds). Release throttle. Cooling fan should turn on. Depress throttle to turn cooling fan off. If cooling fan turns on and off as requested, exit OS DTM. Go to step 178).

Note. Cooling fan can only be cycled once during OS DTM. To retest, exit and re-enter OS DTM.

If cooling fan does not turn on and off as requested, ensure OS DTM is operating properly. MIL should flash when throttle is depressed and released. If MIL does not flash, check throttle linkage and DLC connections. If OS DTM is operating properly, replace VCRM. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST.

178) Check DLC In VCRM Turn ignition off. Ensure PCM and VCRM are connected. Disconnect cooling fan. Ensure A/C and defroster are off. Perform KOEO SELF-TEST. If KOEO Code 582 is present, reconnect cooling fan. No problem is indicated at this time. Data (+) and data (-) circuits test okay and DLC is operational in PCM. Reconnect all components. If KOEO Code 582 is not present, allow time for engine to cool down to verify that cooling fan does to come on. After engine is cooled, start engine and wait 10 seconds. Turn ignition off. Repeat KOEO SELF-TEST. If KOEO Code 582 is still not present, replace VCRM. Reconnect cooling fan. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST.

179) Check Data (+) & Data (-) Circuit Continuity To DLC Turn ignition off. Install breakout box. Leave PCM disconnected. Disconnect scan tool from DLC. Measure resistance between test pin No. 18 at breakout box and data (+) terminal (Tan/Orange wire) at DLC. see scheme 92 Also measure resistance between pin No. 19 at breakout box and data (-) terminal (Pink/Light Blue wire) at DLC. If both readings are less than 5 ohms, replace PCM. Remove breakout box. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST. If any reading is 5 ohms or more, repair open circuit as necessary. After repair is complete, return to step 176).

180) Check For Intermittent In Data (+) & Data (-) Circuits Perform test while cooling fan is off. Start engine. Ensure A/C is off. Observe cooling fan (for turning on for other than normal operation) and shake, wiggle and bend data (+) (Tan/Orange wire) and data (-) (Pink/Light Blue wire) circuits between PCM and VCRM connectors. To simulate road shock, lightly tap on VCRM. VCRM will turn fan on if DLC fault is detected. If cooling fan turns on, for other than normal operation, isolate fault and repair wiring as necessary. Clear continuous memory. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST. If cooling fan does not turn on, go to step 181).

181) Check For Intermittent Short In Data (+) & Data (-) Ckts Turn ignition off. Disconnect test equipment from Data Link Connector (DLC). Disconnect and inspect PCM and VCRM connectors. Clean or repair connectors as necessary. Install breakout box. Leave PCM and VCRM disconnected. Connect a jumper wire between data (+) (Tan/Orange wire) and data (-) (Pink/Light Blue wire) circuits at DLC see scheme 92 Connect test light between test pins No. 19 and 37 at breakout box. Observe test light, and shake, wiggle and bend data (+) (Tan/Orange wire) and data (-) (Pink/Light Blue wire) circuits between PCM and VCRM connectors. If a fault is detected, test light will turn on, indicating a short to power. Disconnect jumper wire. Reconnect test light between test pins No. 19 and 40 at breakout box. Observe test light, and shake, wiggle and bend data (+) (Tan/Orange wire) and data (-) (Pink/Light Blue wire) circuits between PCM and VCRM connectors. If a fault is detected, test light will turn on, indicating a short to ground. If a short is detected, isolate fault and repair wiring as necessary. Remove breakout box, and reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST. If a short is not detected, go to step 182).

182) Check For Intermittent Open In Data (+) & Data (-) Ckts Turn ignition off. Ensure breakout box is installed and PCM and VCRM are disconnected. Connect a jumper wire between terminals No. 21 (Tan/Orange wire) and No. 23 (Pink/Light Blue wire) at VCRM connector. Ensure jumper wire does not contact other terminals at VCRM connector. Using an ohmmeter, measure resistance between test pins No. 18 and 19 at breakout box. Observe ohmmeter, and shake, wiggle and bend data (+) (Tan/Orange wire) and data (-) (Pink/Light Blue wire) circuits between PCM and VCRM connectors. If reading increases to more than 5 ohms at any time, isolate and repair open circuit and repair wiring as necessary. Remove jumper wire and breakout box. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST. If reading stays at 5 ohms or less, fault is intermittent and cannot be duplicated at this time. Testing is complete. Remove jumper wire and breakout box. Reconnect all components.

EEC-IV Wiring Diagram (Escort/Tracer 1.9L - 1 of 2). Scheme 144

EEC-IV Wiring Diagram (Escort/Tracer 1.9L - 2 of 2). Scheme 145