Engine Controls - Tests W/codes - 4.0L: Other Ford Aerostar I

SERVICE CODES

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

KOEO & KOER CODES (HARD FAULTS)

These codes indicate faults are present at time of testing. See appropriate chart under CODE-TO-TEST MENU(S) tables for definitions of codes. A hard fault may cause "CHECK ENGINE" or "SERVICE ENGINE SOON" light to illuminate and remain on until fault is repaired. If KOEO or KOER codes are retrieved during KOEO SELF-TEST or KOER SELF-TEST, use appropriate KOEO SELF-TEST CODES or KOER SELF-TEST CODES chart under CODE-TO-TEST MENU(S) to select the correct CIRCUIT TEST for testing and repair.

CONTINUOUS MEMORY CODES (SOFT FAULTS)

These codes indicate a fault that may or may not be present at the time of testing, and are used to diagnose intermittent problems. See appropriate charts under CODE-TO-TEST MENU(S) for definitions of codes. Continuous Memory Codes are retrieved during the KOEO SELF-TEST. Some codes may illuminate the "CHECK ENGINE" or "SERVICE ENGINE SOON" light. The corresponding soft trouble code will be retained in the ECA memory. If the fault does not reoccur within 40 warm-up cycles (80 cycles on some models), ECA will automatically clear the code.

Service codes may be cleared from memory by the technician. See CLEARING CODES in this article. Intermittent faults may be caused by a sensor, connector or wiring-related problems. See INTERMITTENTS in the TESTS W/O CODES article.

RETRIEVING CODES

Service codes are retrieved from the EEC-IV system through the self-test connector. Various methods and test equipment may be used to access these codes. The following test equipment may be used

1. Analog Volt-Ohmmeter (VOM)
2. "Scan" Tool
3. STAR Series Tester
4. In-Dash "CHECK ENGINE" or "SERVICE ENGINE SOON" Light

SELF-TEST CONNECTOR LOCATIONS

CLEARING CODES

To clear codes from ECA memory, start KOEO SELF-TEST. When service codes appear on test equipment or "CHECK ENGINE" 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 ECA memory. If problem has not been corrected, or fault is still present, hard code will immediately be reset in ECA memory.

SEPARATOR PULSE

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

PASS CODES

A Code 11 or 111 indicates there are no service codes recorded in that portion of the test, and system passes that portion of the test. If Code 11 or 111 is not received in KOEO SELF-TEST, codes received during KOER SELF-TEST may not be valid. It is very important that Code 11 or 111 (pass code) be observed in KOEO SELF-TEST. A Code 11-1-11 or 111-1-111 output during KOEO SELF-TEST indicates there is no KOEO code or Continuous Memory Code recorded. The separator code may appear as a 10 instead of a 1 on some test equipment.

CONTINUOUS MEMORY CODES

These codes result from information stored by ECA during continuous self-test monitoring. Codes are displayed in KOEO SELF-TEST, after separator pulse code. 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. (There are few exceptions which may be checked after KOEO codes have been repaired). These codes indicate faults recorded within the last 40 engine starts. The fault may or may not be currently present. See appropriate chart under CODE-TO-TEST MENU(S) for definitions of codes.

FAST CODES

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

Scheme 86

Scheme 87

Scheme 88

VISUAL CHECK & VEHICLE PREPARATION

Complete all steps in BASIC TESTING article before proceeding to next test step. Ensure vacuum hoses are connected correctly and EEC-IV wiring harnesses are connected.

EQUIPMENT HOOKUP

Apply parking brake, and place shift lever in Park (A/T) or Neutral (M/T). Block drive wheels. Turn off all electrical loads. 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, and connect positive lead of VOM to positive battery terminal.

2) Connect negative VOM lead to Self-Test Output (STO) terminal of self-test connector. (Scheme 87) 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 self-test connector with ignition on.

"Scan" Tool

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

STAR Series Tester

Turn ignition to OFF position. Connect color-coded adapter cable leads to diagnostic tester. Connect 2 service connectors of adapter cable to vehicle self-test connector and STI pigtail connector. Connect timing light. Go to KOEO SELF-TEST.

"CHECK ENGINE" Or "SERVICE ENGINE SOON" Light (MIL)

With ignition on, connect a jumper wire between Self-Test Input (STI) pigtail and signal return terminal of self-test connector. No additional special equipment hookup is required.

COMPUTED TIMING CHECK

Turn ignition off and wait 10 seconds. Using jumper wire or test equipment, activate KOER SELF-TEST. Start engine and check for the following

1. If engine starts and stalls, or stalls during self-test, go to TEST S, step 1).
2. If Code 98 or 998 is displayed, it indicates EEC-IV system is operating in Failure Mode Effects Management (FMEM). Vehicle cannot be diagnosed in KOER SELF-TEST; rerun KOEO SELF-TEST.
3. Check computed timing after the last service code has been displayed. The timing will remain fixed for 2 minutes after the last code has been received, unless self-test is deactivated.
4. Computed timing, at the crankshaft, should equal the base timing (see vehicle emission decal) plus 20 degrees BTDC. This timing may vary 3 degrees (+/-). If computed timing is within specification, perform KOER SELF-TEST. If timing is not within specification, go to step 2) of TEST PC (vehicles with EDIS), or step 2) of TEST PA (vehicles with TFI).

ADDITIONAL SYSTEM FUNCTIONS

A number of additional diagnostic system features are available to help technicians diagnose driveability problems and test EEC-IV systems.

"CHECK ENGINE"/"SERVICE ENGINE SOON" - Malfunction Indicator Light (MIL)

The MIL is intended to alert driver of certain malfunctions in the EEC-IV system.

The light may also be used to retrieve service codes stored in ECA. When hooked up for KOEO SELF-TEST or KOER SELF-TEST, light will retrieve all codes, not just Continuous Memory Codes which turn on light during vehicle operation.

If the light comes on during vehicle operation, it should be serviced and inspected as soon as possible. It is not necessary to immediately turn off engine; vehicle can still be driven and does not need to be towed.

If the light comes on then goes off while in operation, the code causing light to illuminate will be stored in ECA memory as a Continuous Memory Code.

Light should come on when ignition is turned on and go out when engine is started. If hard fault codes are not present, ECA turns out the light when it receives a Profile Ignition Pick-Up (PIP) signal. If light never comes on, see SYMPTOMS in the TESTS W/O CODES article.

Output State Check

The 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 of the system output actuators on command. This mode is entered from the KOEO SELF-TEST, after all codes have been received. Leave self-test activated and depress throttle to initiate test sequence. Each time throttle is depressed and released, the output actuators will change state (from on to off, or off to on).

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

The FMEM mode allows system operation when sensor(s) fails or transmits signals which are out of normal operating range. When this happens, ECA substitutes a mid-range signal for the defective sensor(s) while continuing to monitor the sensor(s). If the faulty sensor's signals return to normal operating range, the ECA will use those signals. A Code 98 or 998 will be displayed when the FMEM mode is in effect.

SERVICE CODE DEFINITIONS

SERVICE CODE DEFINITIONS

HOW TO USE CIRCUIT TESTS

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

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 received, start with the first code displayed.

2) CIRCUIT TESTS check electrical circuits to make sure they are okay before replacing sensors or any other components. Always test circuits for continuity between sensor and ECA. Test all circuits for short to power, opens, or short to ground. Voltage Reference (VREF) and Voltage Power (VPWR) circuits should be tested with KOEO, or as specified in CIRCUIT TESTS.

3) DO NOT measure voltage or resistance at ECA, or 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 whenever checking for shorts or continuity, unless stated otherwise.

4) Disconnect solenoids and switches from harness before measuring continuity, resistance, or applying voltage. After each repair, check all component connections and repeat CIRCUIT 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 the EEC-IV system. If resistance approaches 5 ohms, always clean the suspected connector and coat with protective dielectric silicone grease. A short is defined as a resistance reading of less than 10 k/ohms to ground, unless stated otherwise in the CIRCUIT TEST.

6) On CIRCUIT TEST H and CIRCUIT TEST J (Fuel Control), to prevent replacement of good components, be aware that the following non-EEC related areas may also be the cause of problem. These areas include ignition coil, distributor cap and rotor, spark plug wires, fouled spark plugs, canister purge problems, EGR valve and gasket, air filter, poor power and ground circuits, fuel pressure, intake and exhaust manifold leaks, engine not at normal operating temperature, and problems with PCV valves or fuel-contaminated engine oil.

(RANGER & EXPLORER, NAVAJO)

4.0L SPFI-MA TEST PIN WIRE COLOR I.D.

4.0L TPS SPECIFICATIONS

4.0L SPFI-MA TEST PIN WIRE COLOR I.D.

Preliminary Instructions (A/T Vehicles)

Record and clear Continuous Memory Codes. Warm engine to normal operating temperature. In Low gear, accelerate hard to 25 MPH and coast down to a stop. Shut off engine. Perform KOEO SELF-TEST. Go to step 1).

Preliminary Instructions (M/T Vehicles)

Record and clear Continuous Memory Codes. Warm engine to normal operating temperature. Start in first gear, shift to second gear and accelerate moderately to 40 MPH. 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 there is insufficient input to ECA from VSS. Possible causes for this code are as follows

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

On all vehicles except 3.0L PFI Aerostar, perform appropriate drive cycle procedure. See PRELIMINARY INSTRUCTIONS (A/T VEHICLES) or PRELIMINARY INSTRUCTIONS (M/T VEHICLES). On 3.0L PFI Aerostar vehicles, ensure driveability complaint can be verified. If Code 29/452 is still present or driveability complaint can be verified (3.0L PFI Aerostar), go to next step. If code is not present or complaint cannot be verified, fault cannot be duplicated at this time. Clear codes and see INTERMITTENTS in the TESTS W/O CODES article in this section.

2) Check VSS Circuit Continuity Turn ignition off and wait 10 seconds. Remove ECA 60-pin connector and inspect for damaged pins, corrosion, or loose wires. Repair as necessary. Install breakout box. With ECA and VSS disconnected, set DVOM on 200-ohm scale. Measure resistance between test pin No. 3 at breakout box and VSS DIF (+) circuit at VSS vehicle harness connector. Also measure resistance between test pin No. 6 at breakout box and VSS DIF (-) circuit vehicle harness connector. If both readings are 5 ohms or less, go to next step. If readings are 5 ohms or more, service open circuit in VSS wiring harness. After repairs, reconnect all components and repeat step 1).

Checking VSS Circuits. Scheme 89

3) Check VSS Circuits For Shorts To Power Or Ground Turn ignition off. With ECA and VSS disconnected, install breakout box. Set DVOM on 200-k/ohm scale. Measure resistance between test pin No. 3 and test pins No. 37, 40 and 6. If all readings are greater than 500 ohms, remove breakout box and reconnect components; go to step 4). If any reading is less than 500 ohms, repair short(s) in VSS wiring harness and reconnect components. After repairs, repeat step 1).

4) Checking VSS Resistance Turn ignition off and wait 10 seconds. Disconnect VSS. Set DVOM on 2-k/ohm scale. Measure resistance across vehicle speed sensor. If reading is 190-250 ohms, replace ECA. Remove breakout box, reconnect components and repeat step 1). If reading is NOT 190-250 ohms, replace vehicle speed sensor and repeat appropriate drive cycle procedure.

4.0L SPFI-MA TEST PIN WIRE COLOR I.D.

To prevent replacement of good components, be aware that the following non-EEC related areas may be at fault: excessive blow-by, PCV malfunction, vacuum leak, fuel pressure or throttle linkage sticking or binding.

1) Throttle Position Sensor Integrity Code 121 indicates TPS is inconsistent with MAF value. Code 124 indicates TPS value is higher than expected. Code 125 indicates TPS value is lower than expected.

Turn ignition off. Disconnect ECA 60-pin connector. Inspect connector for damaged pins, corrosion, or loose wires. Install breakout box and connect ECA. Set DVOM on 20-volt scale. Connect DVOM to test pins No. 47 and 46. Operate throttle slowly to WOT, and slowly release to closed position. See TEST DH for schematics and specific engine values. If there are any sudden voltage variations, ensure TPS is properly installed on throttle body. If TPS is properly installed, replace TPS; remove breakout box, reconnect all components and rerun QUICK TEST. If there are no sudden voltage variations, go to step 6) (for a Continuous Code 121), or go to next step (all other codes).

2) Check Throttle Body Check throttle and/or speed control linkage for binding and smooth operation. Inspect throttle body for contamination. Check engine vacuum hoses. Refer to VECI decal for proper vacuum hose routing. Check for air leak between ISC solenoid and MAF sensor. If all checks reveal no problems, go to next step. If problems are found, repair as necessary; remove breakout box, reconnect all components and rerun QUICK TEST.

3) Check MAP/BP Sensor Output Refer to TEST DF for schematic. With MAP/BP tester connected and ignition on, measure sensor output voltage. If voltage output is within range at specific altitude, remove MAP/BP tester and go to next step. See MAP SENSOR VOLTAGE OUTPUT table for specification. If output reading is outside range, replace MAP/BP sensor; remove tester, reconnect all components and rerun QUICK TEST.

4.0L SPFI-MA TEST PIN WIRE COLOR I.D.

1) No Fuel Pump Pressure: Check Fuel Pump Electrical Operation Turn ignition from OFF to RUN position several times (DO NOT turn to START position). If fuel pumps run briefly each time ignition is turned to RUN position, fuel pump circuit is okay. If fuel pumps do not run, go to next step.

2) Check For VPWR To ECA With ignition off, install breakout box and reconnect ECA. Set DVOM on 20-volt scale. Turn ignition on, leaving engine off. Measure voltage between test pins No. 37 and 40 at breakout box. Measure voltage between test pins No. 57 and 60 at breakout box. If both voltage readings are greater than 10.5 volts, go to step 3). If voltage is not greater than 10.5 volts, go to TEST B, step 1).

3) Check Voltage To POWER-TO-PUMP(s) Circuit With Key On Engine Off (KOEO), breakout box installed and ECA connected, set DVOM on 20-volt scale. Measure voltage between chassis ground and POWER-to-PUMP circuit at fuel pump relay while cranking engine. If reading is less than 8 volts, go to next step. If reading is 8 volts or more, check the following: open in POWER-to-PUMP circuit, open in fuel pump, and open fuel pump ground circuit.

4) Checking BATT (+) Circuit To Fuel Pump Relay Turn ignition on, leaving engine off. Leave breakout box installed and ECA connected. Locate fuel pump relay. Set DVOM on 20-volt scale. Measure voltage between chassis ground and BATT (+) circuit at fuel pump relay. If reading is less than 10.5 volts, repair open in BATT (+) circuit between fuel pump relay and battery positive post. Repeat QUICK TEST. If reading is 10.5 volts or greater, go to next step.

5) Check Voltage At POWER-TO-PUMP(s) Circuit With ignition off, breakout box installed and ECA connected, set DVOM on 20-volt scale. Connect jumper wire from test pin No. 22 to test pin No. 40 or 60 at breakout box. Turn ignition on, leaving engine off. Measure voltage between chassis ground and POWER-to-PUMP circuit at fuel pump relay. If voltage is greater than 10.5 volts, replace ECA. Remove breakout box and rerun QUICK TEST. If voltage is less than 10.5 volts, replace fuel pump relay. Remove breakout box, reconnect ECA and rerun QUICK TEST.

Note. There is a break in the step numbering sequence at this point, skipping from step 5) to step 7). Break is due to previous chart references to these testing procedures. No test procedures have been omitted.

7) Code 87/556: Checking VPWR Circuit To Fuel Pump Relay Code 87/556 indicates a fuel pump primary circuit failure. Possible causes for this fault are as follows

1. Inertia switch not reset or electrically open
2. Faulty ECA
3. Open or shorted circuit
4. Faulty fuel pump relay

Turn ignition on, leaving engine off. Set DVOM on 20-volt scale. Disconnect fuel pump relay. Measure voltage between chassis ground and VPWR circuit at the fuel pump relay. If reading is 10.5 volts or more, go to next step. If reading is less than 10.5 volts, ensure inertia switch is on. If inertia switch will not reset, replace switch. If switch is okay, repair open in VPWR circuit between the EEC power relay and the fuel pump relay. Reconnect fuel pump relay and repeat QUICK TEST.

8) Check Fuel Pump Relay Turn ignition off and wait 10 seconds. Disconnect fuel pump relay. With DVOM on 200-ohm scale, measure resistance between VPWR pin and Fuel Pump circuit pin at fuel pump relay. Resistance should be 40-85 ohms.

Set DVOM to 20-k/ohm scale. Measure resistance between Fuel Pump circuit pin and both POWER-to-PUMP and BATT (+) pins at fuel pump relay. Both resistances should be greater than 10 k/ohms. If all resistances are as specified, go to next step. If resistances are not as specified, replace fuel pump relay and rerun QUICK TEST.

Fuel Pump Relay Connector. Scheme 90

9) Check For Short To Power With ignition off, disconnect 60-pin ECA connector and fuel pump relay. Install breakout box and leave ECA disconnected. Set DVOM on 20-volt scale. Turn ignition on. Measure voltage between test pin No. 22 and battery negative terminal. If voltage is less than one volt, go to next step. If voltage is not less than one volt, repair short circuit. Reconnect ECA and attempt to start vehicle. If vehicle fails to start, replace ECA. Rerun QUICK TEST.

10) Check For Shorts To Ground Turn ignition off and wait 10 seconds. Leave breakout box installed and ECA disconnected. Disconnect fuel pump relay. With DVOM on 200-k/ohm scale, measure resistance between test pin No. 22 and test pins No. 40 and 60. If reading is less than 10 k/ohms, repair short in FUEL PUMP circuit. Remove breakout box and reconnect all components. Repeat QUICK TEST. If reading is 10 k/ohms or more, go to next step.

11) Check Fuel Pump Circuit Continuity Turn ignition off. Leave breakout box installed and ECA disconnected. Set DVOM to 200-ohm scale. Disconnect fuel pump relay. Measure resistance between fuel pump circuit at fuel pump relay vehicle harness connector and test pin No. 22 at breakout box. If resistance is less than 5 ohms, replace ECA. Reconnect fuel pump relay and rerun QUICK TEST. If resistance is greater than 5 ohms, repair open circuit. Remove breakout box, reconnect all components and rerun QUICK TEST.

Note. There is a break in the step numbering sequence at this point, skipping from step 11) to step 20). Break is due to previous chart references to these testing procedures. No test procedures have been omitted.

20) Code 95/542: Does Engine Start? A KOEO Code 95/542 indicates one of the following conditions has occurred

No Starts

1. Inertia switch not reset or electrically open
2. Open circuit in or between ECA and fuel pump
3. Faulty ground connection at fuel pump

Vehicle Starts

1. Fuel pump secondary circuit shorted to power
2. Fuel pump relay contacts always closed
3. Open in Fuel Pump Monitor (FPM) circuit between ECA and connection to POWER-to-PUMP circuit
4. HEGO short to power (dual HEGO applications)
5. Faulty ECA

If engine starts, go to next step. If engine does not start, go to step 25).

21) Verify Fuel Pump Is Off Turn ignition on and wait 5 seconds. Listen for fuel pump noise. If fuel pump is off, go to step 23). If fuel pump is on, go to next step.

22) 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 rerun QUICK TEST. If Fuel pump is on with relay disconnected, repair short to power in POWER-to-PUMP/FPM circuit. (For vehicles with relay block, also check fuel pump prime plug circuit.) Rerun QUICK TEST.

23) Check Continuity Of Fuel Pump Monitor (FPM) Circuit Turn ignition off and wait 10 seconds. Disconnect ECA 60-pin connector. Inspect connector for damaged pins, corrosion, or loose wires. Install breakout box and leave ECA disconnected. Disconnect fuel pump relay. Set DVOM on 200-ohm scale and measure resistance between test pin No. 8 at breakout box and POWER-to-PUMP circuit at fuel pump relay vehicle harness connector. If resistance is less than 5 ohms, go to step 35) (dual HEGO vehicles), or replace ECA, remove breakout box, reconnect fuel pump relay and rerun QUICK TEST (all other vehicles). If resistance is greater than 5 ohms, repair open circuit; remove breakout box, reconnect all components and rerun QUICK TEST.

Fuel Pump Relay Vehicle Harness Connector. Scheme 91

Note. There is a break in the step numbering sequence at this point, skipping from step 23) to step 25). Break is due to previous chart references to these testing procedures. No test procedures have been omitted.

25) Check Inertia Switch Turn ignition off and wait 10 seconds. Locate and disconnect fuel pump inertia switch. Ensure switch is reset. Set DVOM on 200-ohm scale. Measure resistance of fuel pump inertia switch. If resistance is less than 5 ohms, reconnect switch and check for open in POWER-to-PUMP circuit, poor fuel pump ground or open in fuel pump. If resistance is not less than 5 ohms, replace or reset inertia switch. Repeat QUICK TEST.

Note. There is a break in the step numbering sequence at this point, skipping from step 25) to step 30). Break is due to previous chart references to these testing procedures. No test procedures have been omitted.

30) Code 96/543: Engine Does Not Start Code 96/543 indicates fuel pump secondary circuit failure between BATT (+) supply and FPM connection to POWER-to-PUMP circuit. The following are possible causes for this fault.

No Start

1. Open circuit between BATT (+) supply and FPM connection to POWER-to-PUMP circuit
2. Fuel pump relay contacts are always open

Engine Starts

1. HEGO short to power (Dual HEGO vehicles)
2. Faulty ECA

If engine starts, go to step 35) (for dual HEGO vehicles) or replace ECA and rerun QUICK TEST (for all other vehicles). If engine does not start, go to next step.

31) Check For BATT (+) To Fuel Pump Relay With ignition off, set DVOM on 20-volt scale. Connect DVOM between BATT (+) circuit at fuel pump relay and battery negative post. If voltage is greater than 10.5 volts, go to next step. If voltage is less than 10.5 volts, check integrity of fuse/fusible link for BATT (+) supply to fuel pump relay. If fuse/fusible is okay, repair open circuit in BATT (+) circuit. Rerun QUICK TEST.

32) Check For Voltage At POWER-TO-PUMP Circuit Turn ignition off and wait 10 seconds. Set DVOM to 20-volt scale. Connect DVOM between POWER-to-PUMP circuit at fuel pump relay and battery negative terminal. Observe DVOM while activating fuel pump relay (turn ignition to RUN position for one second, then turn ignition off for 10 seconds; repeat 5 times). If voltage is greater than 10.5 volts for about one second after key is turned to RUN position, go to next step. If voltage is not as specified, disconnect fuel pump relay. Inspect for damaged pins, corrosion, loose pins or other damage. Repair as necessary. If okay, replace fuel pump relay and rerun QUICK TEST.

33) Check POWER-To-PUMP Circuit Continuity Turn ignition off and wait 10 seconds. Set DVOM to 200-ohm scale. Disconnect fuel pump relay. Measure resistance between POWER-to-PUMP circuit at fuel pump relay vehicle harness connector and battery negative terminal. If resistance is less than 10 ohms, replace ECA. Reconnect relay and rerun QUICK TEST. If resistance is greater than 10 ohms, repair open circuit in POWER-to-PUMP circuit between FPM splice and fuel pump relay. Rerun QUICK TEST.

Note. There is a break in the step numbering sequence at this point, skipping from step 33) to step 35). Break is due to previous chart references to these testing procedures. No test procedures have been omitted.

4.0L SPFI-MA TEST PIN WIRE COLOR I.D.

1) Check System Function Enter OUTPUT STATE CHECK; see ADDITIONAL SYSTEM FUNCTIONS. Use only VOM or DVOM for this step; DO NOT use diagnostic tester. Turn ignition off and wait 10 seconds. Set DVOM on 20-volt scale. Connect DVOM negative test lead to STO and positive test lead to positive battery terminal. Using jumper wire, connect STI circuit to SIG RTN at self-test connector. Perform KOEO SELF-TEST until end of Continuous Memory Codes (DVOM reads zero volt). Depress and release throttle. DVOM should change to a high-voltage reading. If reading changes, remain in OUTPUT STATE CHECK and go to next step. If reading does not change, depress throttle to WOT and release. If STO voltage does not increase, leave test equipment hooked up and go to TEST QC, step 1).

2) Check CANP Solenoid Electrical Function With Key On Engine Off (KOEO), set DVOM on 20-volt scale. Disconnect CANP solenoid. Connect DVOM positive test lead to VPWR circuit and negative test lead to CANP output circuit on harness connector. While observing DVOM, depress and release throttle several times to cycle output on and off. If CANP circuit does not cycle on and off, remove jumper wire and go to step 6). If CANP circuit cycles, remain in OUTPUT STATE CHECK and go to next step.

3) Check Solenoid For Vacuum Leaks Turn ignition on. Leave CANP solenoid disconnected. Disconnect vacuum hose at CANP solenoid from manifold vacuum side of solenoid. Apply 16 in. Hg vacuum to manifold vacuum side of CANP solenoid. If CANP solenoid does not hold vacuum for 20 seconds, replace solenoid and repeat QUICK TEST. If fault is still present, service fuel evaporation canister. If CANP holds vacuum for 20 seconds, remain in OUTPUT STATE CHECK, leave vacuum pump attached and go to next step.

4) Check Solenoid Mechanical Operation While still in OUTPUT STATE CHECK, cycle CANP circuit off (no voltage). Reconnect CANP solenoid connector. Apply 16 in. Hg vacuum to the CANP solenoid as in step 3). Depress and release throttle. If vacuum is released, check hose from CANP solenoid to canister for leaks or cracks; if hose is okay, remove jumper wire from STI to SIG RTN and go to next step. If vacuum is not released, check hose from CANP solenoid to canister for leaks or cracks; if hose is okay, replace CANP solenoid and repeat QUICK TEST.

5) Check Vacuum Supply To CANP Solenoid Disconnect vacuum hose from CANP solenoid on manifold vacuum (PCV) side. Start engine. If vacuum is present at vacuum hose, EEC system is okay; check evaporative canister. If vacuum is not present at hose, check vacuum hose for proper routing, kinks or blockage; if hose is okay, check engine for cause of low vacuum.

6) Code 85/565 Or 569: Check CANP Solenoid Resistance Code 85/565 or 569 indicates fault in CANP solenoid circuit. For vehicles with dual CANP systems, Code 565 refers to CANP 1 while Code 569 refers to CANP 2. Possible causes for this fault are as follows

1. Faulty CANP solenoid
2. Open in harness circuit
3. Faulty ECA
4. Shorted harness circuit (power to ground)

Turn ignition off and wait 10 seconds. Set DVOM on 200-ohm scale. Disconnect appropriate CANP solenoid connector and measure CANP solenoid resistance. If resistance is 40-90 ohms, go to next step. If reading is NOT 40-90 ohms, replace CANP solenoid. Repeat QUICK TEST.

7) Check Voltage Of VPWR Circuit With KOEO and appropriate CANP solenoid disconnected, set DVOM on 20-volt scale. Measure voltage between VPWR circuit at CANP solenoid harness connector and battery negative terminal. If reading is 10.5 volts or greater, go to next step. If reading is less than 10.5 volts, repair open in circuit and repeat QUICK TEST.

8) Check Continuity Of CANP Circuit Turn ignition off and wait 10 seconds. Disconnect appropriate CANP solenoid and ECA 60-pin connector. Inspect connector for damaged pins, corrosion, or loose wires. Repair as necessary. Connect breakout box, leaving ECA disconnected. Set DVOM on 200-ohm scale. Measure resistance between test pin No. 11, 31 or 54 (refer to schematic at beginning of this circuit test) and CANP harness connector. If reading is less than 5 ohms, go to next step. If reading is 5 ohms or more, repair open circuit; remove breakout box, reconnect components. Repeat QUICK TEST.

9) Check CANP Circuit For Short To Ground Turn ignition off and wait 10 seconds. Install breakout box, leaving ECA disconnected. Set DVOM on 200-k/ohm scale and disconnect appropriate CANP solenoid. Measure resistance between test pin No. 11, 31 or 54 (refer to schematic at beginning of this circuit test) and test pins No. 40, 46 and 60. If all readings are 10 k/ohms or more, go to next step. If any reading is less than 10 k/ohms, repair short to ground. Remove breakout box, reconnect components and repeat QUICK TEST.

10) Check CANP Circuit For Short To Power Turn ignition off and wait 10 seconds. Disconnect appropriate CANP solenoid. Install breakout box, leaving ECA disconnected. Set DVOM on 200-k/ohm scale. Measure resistance between test pin No. 11, 31 or 54 (refer to schematic at beginning of this circuit test) and test pins No. 37 and 57. If all reading are 10 k/ohms or more, remove breakout box. Replace ECA and repeat QUICK TEST. If any reading is less than 10 k/ohms, repair short to power; remove breakout box, reconnect components and rerun QUICK TEST. If code is repeated, replace ECA. Rerun QUICK TEST.

4.0L SPFI-MA TEST PIN WIRE COLOR I.D.

1) Code 12/412: Check For RPM Drop Code 12/412 indicates that during KOER SELF-TEST, engine RPM could not be controlled within the upper RPM limit of self-test. Possible causes for this fault are as follows

1. Open or shorted circuit
2. Sticking or binding throttle linkage
3. Incorrect idle adjustment
4. Throttle body or ISC solenoid contaminated
5. Faulty ISC solenoid
6. Faulty ECA
7. Non-ECC mechanical faults that could affect RPM

Turn ignition off. Connect engine tachometer and start engine. Disconnect Idle Speed Control (ISC) harness. If RPM drops or engine stalls, go to next step. If RPM doesn't drop or engine doesn't stall, go to step 3).

2) Check For EGR Codes If EGR service codes 31/327, 32/326/328, 33/332 or 34/336/334 are displayed, reconnect ISC solenoid. Go to appropriate KOER SELF-TEST CODES chart under CODE-TO-TEST MENU(S), and perform appropriate CIRCUIT TEST. If these codes are not displayed, go to next step.

3) Check For Other EEC-IV Codes If Codes 22/126, 41/172, 42/173, 91/136 or 92/137 are displayed, reconnect ISC solenoid. Go to appropriate KOER SELF-TEST CODES chart under CODE-TO-TEST MENU(S), and perform appropriate CIRCUIT TEST. If these codes are not displayed, go to next step.

4) Measure ISC Solenoid Resistance Turn ignition off. Disconnect ISC solenoid. Set DVOM on 200-ohm scale, and measure resistance of ISC solenoid. Connect DVOM positive (+) lead to VPWR terminal and DVOM negative lead to ISC terminal, as ISC solenoid is equipped with a diode. If resistance is 7-13 ohms, go to next step. If resistance is NOT 7-13 ohms, replace ISC solenoid and repeat QUICK TEST.

ISC Solenoid Connector. Scheme 92

5) Check For Internal Short To ISC Solenoid Case With ignition off and ISC solenoid disconnected, set DVOM on 200-k/ohm scale. Measure resistance from either ISC terminal pin to ISC solenoid housing. If reading is greater than 10 k/ohms, go to next step. If reading is 10 k/ohms or less, replace ISC solenoid. Repeat QUICK TEST.

6) Check VPWR Circuit Voltage Leave ISC harness disconnected. With KOEO, set DVOM on 20-volt scale. Measure voltage between VPWR circuit at ISC harness connector and battery ground terminal. If reading is less than 10.5 volts, repair open in circuit and repeat QUICK TEST. If reading is 10.5 volts or more, go to next step.

7) Check ISC Circuit Continuity Turn ignition off and wait 10 seconds. Leave ISC solenoid disconnected. Disconnect ECA 60-pin connector. Inspect connector for damaged pins, corrosion, or loose wires. Repair as necessary. Install breakout box, leaving ECA disconnected. With DVOM on 200-ohm scale, measure resistance between test pin No. 21 and ISC circuit at ISC vehicle harness connector. If reading is greater than 5 ohms, repair open circuit; remove breakout box, reconnect all components and repeat QUICK TEST. If reading is less than 5 ohms, go to next step.

8) Check ISC Circuit For Short To Ground Turn ignition off and wait 10 seconds. Leave ISC solenoid disconnected. Install breakout box, leaving ECA disconnected. Set DVOM on 200-k/ohm scale. Measure resistance between test pin No. 21 and test pins No. 40, 46 and 60. If any reading is less than 10 k/ohms, repair short to ground and repeat QUICK TEST. If all readings are 10 k/ohms or more, go to next step.

9) Check ISC Circuit For Short To Power Turn ignition off and wait 10 seconds. Leave breakout box installed. Leave ECA and ISC solenoid disconnected. Set DVOM on 200-k/ohm scale. Measure resistance by connecting DVOM negative lead to test pin No. 21 and positive lead to test pin No. 37. If reading is greater than 10 k/ohms, go to next step. If reading is 10 k/ohms or less, repair short circuit and remove breakout box. Reconnect all components and repeat QUICK TEST. If code or symptom is still present, replace ECA.

10) Check ISC Signal From ECA With ignition off, reconnect ECA and ISC. Leave breakout box installed and set DVOM on 20-volt scale. Connect DVOM between test pins No. 21 and 40. Start engine and observe DVOM while slowly increasing RPM to 3000 RPM. If DVOM voltage reading is 3.0-11.5 volts, go to next step. If DVOM voltage reading does not vary, replace ECA and repeat QUICK TEST.

11) Check Base Idle Verify base idle speed. See the ADJUSTMENTS article. If base idle speed is within specifications, remove ISC solenoid and inspect for contamination; service as necessary. Rerun QUICK TEST. If code or symptom is still present, replace ISC solenoid. If curb idle speed is incorrect, reset idle speed to specification. Rerun QUICK TEST. If unable to set idle to specification, go to next step.

12) Check Faults Which Affect Idle Speed Check the following mechanical items for faults

1. Throttle linkage and/or cruise control linkage (sticking or binding)
2. Throttle body (contamination)
3. Vacuum hoses (check emission decal)
4. Check for leaks around ISC solenoid (gaskets, etc.)

If all of these items are okay, remove ISC solenoid and inspect for contamination. Service as necessary and rerun QUICK TEST. If code or symptom is still present, replace ISC. If any of these items are faulty, service as necessary. Remove breakout box. Reconnect components and rerun QUICK TEST.

Note. There is a break in the step numbering sequence at this point, skipping from step 12) to step 15). Break is due to previous chart references to these testing procedures. No test procedures have been omitted.

15) Code 13/411: Verify Idle Speed Is Within Specification Code 13/411 indicates that during KOER SELF-TEST, engine RPM could not be controlled within the lower RPM limit of self-test. Possible causes for this fault are as follows

1. Incorrect idle setting
2. Vacuum leaks
3. Sticking or binding throttle linkage
4. Throttle plates open
5. Incorrect ignition timing (TFI ignition only)
6. Throttle body or ISC solenoid contamination
7. ISC circuit shorted to ground
8. Faulty ISC solenoid

If all of the mentioned components are okay and idle is set to specification, remove ISC solenoid and inspect for contamination; service as necessary and rerun QUICK TEST. If code or symptom is still present, replace ISC solenoid. If idle speed is not set to specification, reset and rerun QUICK TEST. If idle speed cannot be reset to specification, go to next step.

16) Check For Conditions Affecting Idle Speed Check the following mechanical components

1. Engine vacuum hoses (refer to emission decal)
2. Throttle linkage and/or cruise control linkage (sticking or binding)
3. Ensure throttle plates are fully closed
4. Induction system (vacuum leaks)
5. Throttle body (contamination)
6. Ensure base ignition timing is to specification on emission decal (TFI vehicles only)

If everything check okay, go to next step. If fault is found, service as necessary and rerun QUICK TEST.

17) Check For Internal Short To ISC Solenoid Case With ignition off and ISC solenoid disconnected, set DVOM on 200-k/ohm scale. Measure resistance from either ISC terminal pin to ISC solenoid housing. If reading is greater than 10 k/ohms, go to next step. If reading is 10 k/ohms or less, replace ISC solenoid. Repeat QUICK TEST.

18) Check ISC Circuit For Short To Ground Turn ignition off and wait 10 seconds. Leave ISC solenoid disconnected. Disconnect ECA 60-pin connector. Inspect for damaged or corroded terminal pins; service as necessary. Install breakout box, leaving ECA disconnected. Set DVOM on 200-k/ohm scale. Measure resistance between test pin No. 21 and test pins No. 40, 46 and 60. If any reading is less than 10 k/ohms, repair short to ground and remove breakout box. Reconnect components and repeat QUICK TEST. If all readings are 10 k/ohms or more, go to next step.

19) Check ISC Signal From ECA With ignition off, connect ECA and ISC. Leave breakout box installed and set DVOM on 20-volt scale. Connect DVOM between test pins No. 21 and 40. Start engine and observe DVOM while slowly increasing and decreasing engine RPM. If DVOM voltage reading varies, remove ISC solenoid and inspect for contamination; service as necessary and rerun QUICK TEST. If code or symptom is still present, replace ISC solenoid. If DVOM voltage does not vary, replace ECA and rerun QUICK TEST.

AEROSTAR

4.0L SPFI-MA TEST PIN WIRE COLOR I.D.

4.0L SPFI-MA TEST PIN WIRE COLOR I.D.

1) No A/C: Check For Voltage At A/C Clutch Check all A/C related fuses in fuse panel before proceeding with this test. Use only DVOM for this step; DO NOT use diagnostic tester. With ignition off, disconnect A/C clutch harness connector. Turn A/C switch to A/C position. Set DVOM on 20-volt scale. Start engine and wait 10 seconds. Measure voltage between power side of A/C clutch vehicle harness connector and negative battery terminal. If voltage is greater than 10.5 volts, EEC-IV system is okay; diagnose A/C system. If voltage is less than 10.5 volts, go to next step.

2) Check Continuity Of POWER-To-CLUTCH Circuit Turn ignition off and wait 10 seconds. Set DVOM on 200-ohm scale. Disconnect A/C clutch harness and harness from WAC relay or A/C fan controller. Measure resistance between power side of A/C clutch vehicle harness connector and POWER-to-CLUTCH circuit terminal pin at WAC relay or A/C fan controller vehicle harness connector. If resistance is less than 5 ohms, reconnect A/C clutch and go to next step. If resistance is more than 5 ohms, service open circuit and retest system.

3) Check For Power On A/C Demand Circuit With KOEO and WAC relay or A/C fan controller disconnected, turn on A/C switch. Set DVOM to 20-volt scale. Perform the following procedure as applicable

1. Measure voltage between A/C demand input terminal pin at WAC relay or A/C fan controller vehicle harness connector and chassis ground.

If voltage is greater than 10.5 volts, go to step 5). If voltage is less than 10.5 volts, verify operation of A/C clutch cyclic pressure switch and A/C demand switch. If components are okay, repair open circuit and reconnect all components. Recheck system.

4) Check Continuity Between WAC Relay & A/C Relay With ignition off, disconnect WAC and A/C relays. Set DVOM on 200-ohm scale. Measure resistance between A/C relay output to WAC relay circuit (at A/C relay vehicle harness connector) and A/C relay input (at WAC relay vehicle harness connector). If resistance is less than 5 ohms, reconnect WAC relay; diagnose A/C system. If resistance is greater than 5 ohms, repair open circuit; reconnect relays and recheck system operation.

5) Check WAC Circuit For Short To Ground Turn ignition off and wait 10 seconds. Disconnect ECA 60-pin connector and WAC relay or A/C fan controller. Inspect and repair any damaged wiring. Leaving ECA disconnected, set DVOM on 200-k/ohm scale. Measure resistance between WAC circuit at WAC relay or A/C fan controller and chassis ground. If resistance is greater than 10 k/ohms, go to next step. If resistance is less than 10 k/ohms, repair short; reconnect all components and recheck system operation.

6) Check For Voltage At ACCS Input To ECA Turn ignition off and wait 10 seconds. Disconnect WAC relay and A/C fan controller. Disconnect ECA and install breakout box, leaving ECA disconnected. Set A/C switch to A/C position. Set DVOM to 20-volt scale. With KOEO, measure voltage between test pin No. 10 and test pin No. 40 at breakout box. If voltage is greater than 10.5 volts, go to step 9). If voltage is less than 10.5 volts, repair open circuit; remove breakout box, reconnect all components and recheck system operation.

7) Check For Ground To A/C Fan Controller With ignition off and A/C fan controller disconnected, set DVOM on 200-ohm scale. Install breakout box, leaving ECA disconnected. Measure resistance between ground circuit at A/C fan controller harness connector and chassis ground. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open circuit and retest system.

8) Check For Voltage To A/C Fan Controller With ignition on and ECA and A/C fan controller disconnected, set DVOM on 20-volt scale. Measure voltage between ignition switch RUN circuit at A/C fan controller vehicle harness connector and chassis ground. Measure voltage between BATT (+) circuit at A/C fan controller vehicle harness connector and chassis ground. If voltage is greater than 10.5 volts, go to next step. If voltage is less than 10.5 volts, repair open circuit. Reconnect ECA and A/C controller. Recheck system operation.

9) Check WAC Relay Or A/C Fan Controller Turn ignition off and wait 10 seconds. Leave ECA disconnected and reconnect WAC relay or A/C fan controller. Disconnect A/C clutch. Set DVOM on 20-volt scale. With KOEO and A/C on, measure voltage between power side of A/C clutch vehicle harness connector and battery negative terminal. If voltage is greater than 10.5 volts, replace ECA; reconnect A/C clutch and retest system. If voltage is less than 10.5 volts, replace WAC relay or fan controller; reconnect all components and recheck system.

Note. There is a break in the step numbering sequence at this point, skipping from step 9) to step 15). Break is due to previous chart references to these testing procedures. No test procedures have been omitted.

15) No A/C Output At WOT Enter OUTPUT STATE CHECK; see ADDITIONAL SYSTEM FUNCTIONS. Use a VOM or DVOM for this test. Turn ignition off and wait 10 seconds. Disconnect speed control servo electrical connector (if equipped). Set DVOM on 20-volt scale. Connect DVOM negative test lead to STO at self-test connector and positive lead to positive battery terminal. Jumper STI to SIGNAL RETURN at self-test connector. Perform KOEO SELF-TEST until Continuous Memory Code output is completed. Meter will indicate less than one volt when test is complete. Depress and release throttle. If voltage increases to greater than 10.5 volts, remain in OUTPUT STATE CHECK and go to the next step. If voltage does not increase to 10.5 volts, depress throttle to WOT and release. If STO voltage does not go high, leave test equipment connected and go to TEST QC, step 2).

16) Check For VPWR To Relay With vehicle in OUTPUT STATE CHECK, disconnect harness from WAC relay and set DVOM on 20-volt scale. Measure voltage between VPWR circuit and chassis ground. If voltage is greater than 10.5 volts, go to next step. If voltage is less than 10.5 volts, repair open circuit between power relay and WAC relay. Remove test equipment and retest system.

17) Check WAC System For Cycling With vehicle in OUTPUT STATE CHECK, reconnect WAC relay and set DVOM on 20-volt scale. Connect positive test lead to VPWR circuit and negative test lead to WAC circuit at WAC relay vehicle harness connector. Check DVOM while depressing and releasing throttle several times to cycle output on and off. If voltage cycles from high to low, replace WAC relay; remove jumper and retest system. If voltage does not cycle, remove test leads; reconnect speed control servo and go to next step.

18) Check Resistance Of WAC Relay Coil Turn ignition off and wait 10 seconds. Disconnect WAC relay. Set DVOM to 200-ohm scale. Measure resistance between WAC pin and VPWR pin on WAC relay. If resistance is 40-100 ohms, go to next step. If resistance is NOT 40-100 ohms, replace WAC relay and retest system.

19) Check Continuity Of WAC Circuit Turn ignition off and wait 10 seconds. Disconnect ECA 60-pin connector. Inspect and repair any damaged wiring. Install breakout box, leaving ECA and WAC relay disconnected. Set DVOM on 200-ohm scale. Measure resistance between test pin No. 54 and WAC circuit at WAC relay vehicle harness connector. If reading is 5 ohms or more, repair open circuit; remove breakout box, reconnect all components and retest system. If reading is less than 5 ohms, go to next step.

20) Check WAC Circuit For Short To Power Turn ignition off and wait 10 seconds. Leave breakout box installed and ECA and WAC relay disconnected. Set DVOM on 200-k/ohm scale. Measure resistance between test pin No. 54 and test pins No. 37 and 57. If all readings are 10 k/ohms or more, replace ECA; reconnect WAC relay and retest system. If any reading is less than 10 k/ohms, repair short circuit. Reconnect all components and retest system. If symptom is still present, replace ECA.

21) Check WAC Cycling With vehicle in OUTPUT STATE CHECK, disconnect A/C fan controller and set DVOM on 20-volt scale. Connect DVOM positive test lead to ignition run circuit and negative test lead to WAC circuit at A/C fan controller harness connector. Check DVOM while depressing and releasing throttle several times to cycle system. If voltage does not cycle, remove jumper; reconnect components and go to next step. If voltage cycles from high to low, replace A/C fan controller. Reconnect components and retest system.

22) Check Continuity Of WAC Circuit Turn ignition off and wait 10 seconds. Disconnect ECA 60-pin connector. Inspect and repair any damaged wiring. Install breakout box, leaving ECA and fan controller disconnected. Set DVOM on 200-ohm scale. Measure resistance between test pin No. 54 and WAC circuit at WAC relay vehicle harness connector. If reading is less than 5 ohms, go to next step. If reading is 5 ohms or more, repair open in harness; remove breakout box, reconnect all components and retest system.

23) Check WAC Circuit For Short To Power Turn ignition off and wait 10 seconds. Install breakout box, leaving ECA and A/C fan controller disconnected. Set DVOM on 200-k/ohm scale. Measure resistance between test pin No. 54 and test pins No. 37 and 57 at breakout box. If all readings are greater than 10 k/ohms, replace ECA; reconnect A/C fan controller and retest system. If any reading is 10 k/ohms or less, repair short to power and retest system; if symptom is still present, replace ECA.

Note. There is a break in the step numbering sequence at this point, skipping from step 23) to step 30). Break is due to previous chart references to these testing procedures. No test procedures have been omitted.

30) Cycle A/C Demand Switch Turn ignition off and wait 10 seconds. Disconnect ECA 60-pin connector. Inspect for corroded or damaged connector pins and repair as necessary. Install breakout box, leaving ECA disconnected. Set DVOM on 20-volt scale. With KOEO, connect DVOM positive test lead to test pin No. 43 and negative test lead to test pin No. 40. If voltage goes high and low as switch is cycled, go to step 44). If voltage does not cycle, go to next step.

31) Check Continuity Of A/C Demand (ACD) Circuit Turn ignition off and wait 10 seconds. Install breakout box, leaving ECA disconnected. Set DVOM on 200-ohm scale. Measure resistance between test pin No. 43 at breakout box and A/C demand switch. If resistance is greater than 5 ohms, repair open in ACD circuit and rerun QUICK TEST. If resistance is less than 5 ohms, EEC-IV system is okay. Remove breakout box and reconnect components. Diagnose A/C system.

Note. There is a break in the step numbering sequence at this point, skipping from step 31) to step 35). Break is due to previous chart references to these testing procedures. No test procedures have been omitted.

35) Check A/C Demand (ACD) Circuit For Short To Power With ignition off, disconnect WAC relay or A/C fan controller. Disconnect ECA 60-pin connector. Inspect for corroded or damaged connector pins and repair as necessary. Install breakout box, leaving ECA disconnected.

With A/C demand switch in OFF position, set DVOM on 20-volt scale. With KOEO, measure voltage between test pin No. 43 at breakout box and chassis ground. If voltage is less than one volt, EEC-IV system is okay; remove breakout box, reconnect all components and diagnose A/C system. If voltage is greater than one volt, check operation of A/C demand switch. If switch operation is okay, repair short circuit. Remove breakout box, reconnect all components and retest system.

Note. There is a break in the step numbering sequence at this point, skipping from step 35) to step 40). Break is due to previous chart references to these testing procedures. No test procedures have been omitted.

4.0L SPFI-MA TEST PIN WIRE COLOR I.D.

4.0L SPFI-MA TEST PIN WIRE COLOR I.D.

The purpose of the Octane Adjust Shorting Bar is to provide optimum spark advance for the fuel used. If vehicle engine detonates (spark knock), remove Octane Shorting Bar. This retards spark advance about 3 to 4 degrees. If vehicle continues to detonate, use fuel with a higher octane rating.

1) Code 57/341: Inspect Octane Adjust In-Line Connector Code 57/431 indicates Octane Adjust Shorting Bar is not in, or OCT ADJ circuit is open. Turn ignition off and wait 10 seconds. Inspect Octane Adjust in-line connector. If shorting bar has been removed, return to QUICK TEST for complete diagnosis. If shorting bar is in place, go to next step.

2) Check Octane Adjust Circuit Continuity There should be continuity from OCT ADJ circuit, through in-line connector and shorting bar, to SIG RTN circuit. Turn ignition off and wait 10 seconds. Disconnect ECA 60-pin connector; inspect for corroded or damaged connector pins and repair as necessary. Install breakout box, leaving ECA disconnected. Set DVOM to 200-ohm scale. Measure resistance between test pin No. 46 and OCT ADJ test pin at breakout box. If resistance is less than 5 ohms, replace ECA. Remove breakout box and rerun QUICK TEST. If resistance is greater than 5 ohms, repair open OCT ADJ circuit, shorting bar or SIG RTN circuit. Remove breakout box and rerun QUICK TEST.

3) Check For Code 11 Start engine and let idle at operating temperature. Turn ignition off and wait 10 seconds. Enter KOEO SELF-TEST. If Code 11 or 111 is present, go to next step. If Code 11 or 111 is not present, use higher octane fuel or check for other possible causes for Code 57/341; for all other codes, return to QUICK TEST.

4) Verify In-Line Shorting Bar Is Installed Turn ignition off and wait 10 seconds. Inspect Octane Adjust in-line connector. If shorting bar is installed, go to next step. If shorting bar is not installed, go to step 7).

5) Verify Drive Concern Turn ignition off and wait 10 seconds. Locate and remove shorting bar. Test drive vehicle to verify complaint. If symptom is present, go to next step. If symptom is not present, EEC is okay; testing is complete.

6) Rerun KOEO SELF-TEST Verify engine is at normal operating temperature. Turn ignition off and wait 10 seconds. Enter KOEO SELF-TEST. If Code 57 or 341 is present, use higher octane fuel; testing is complete. If Code 57 or 341 is not present, go to next step.

7) Check Octane Adjust Circuit For Short To Ground Turn ignition off and wait 10 seconds. Install breakout box and leave ECA disconnected. Set DVOM to 200-k/ohm scale. Measure resistance between OCT ADJ circuit at in-line connector and test pins No. 40 and 60 at breakout box.

If resistance is less than 10 k/ohms, repair short circuit; remove breakout box and rerun QUICK TEST. If each resistance is greater than 10 k/ohms, use higher octane fuel. If fuel is okay, replace ECA, remove breakout box and rerun QUICK TEST.

Instrument Cluster circuit failure

If vehicle does not start, go to TEST A, step 1). If vehicle starts, clear Continuous Memory codes. Wait 5 minutes then rerun KOEO SELF-TEST. If result is Code 11-10-11 (pass code), repair fault in electronic message center Data Communications Link (DCL). If pass code is not displayed, service codes as described in self-test procedures.

4.0L SPFI-MA TEST PIN WIRE COLOR I.D.

4.0L SPFI-MA TEST PIN WIRE COLOR I.D.

1) KOER Code 18/213: Check Computed Spark Timing Code 18/213 indicates SAW circuit is open or shorted to ground or VBAT. Possible causes for this fault are as follows

1. Faulty ECA
2. Faulty EDIS module
3. Open or shorted harness circuit

Activate KOER SELF-TEST. Check and record timing while in KOER SELF-TEST. Self-test mode locks timing during testing, and during 2 minutes after last code is displayed. Computed timing during these 2 minutes is equal to base timing plus 20 degrees (+/-3 degrees). If computed timing is correct, restart KOER SELF-TEST. If timing is not to specification, go to next step.

2) Check Base Timing Turn ignition off and wait 10 seconds. Locate in-line SAW connector, and open connection. Start engine and check base timing. Use specification on VECI decal. If base timing is correct, reconnect SAW and go to next step. If base timing is incorrect, diagnose ignition system, as base timing is not adjustable. See the I - SYS/COMP TESTS article in this section.

3) Check For Power To ECA Turn ignition off and wait 10 seconds. Disconnect ECA 60-pin connector. Inspect connector for damaged pins, corrosion, or loose wires. Repair as necessary. Install breakout box, leaving ECA disconnected. With KOEO and DVOM on 20-volt scale, measure voltage between test pins No. 37 and 40, and between test pins No. 57 and 60 at breakout box. If either reading is less than 10.5 volts, go to TEST B, step 1). If both readings are 10.5 volts or more, go to next step.

4) Check SAW Circuit For Continuity Turn ignition off and wait 10 seconds. Install breakout box. Disconnect ECA and EDIS module. With DVOM on 200-ohm scale, measure resistance between test pin No. 36 at breakout box and SAW terminal at EDIS module vehicle harness connector. If resistance is 5 ohms or less, go to next step. If resistance is greater than 5 ohms, repair open circuit. Reconnect all components and check timing as described in step 1).

Module Connector. Scheme 93

5) Check SAW Circuit For Shorts To Power (Except VREF Circuit) With ignition off, install breakout box. Disconnect ECA and EDIS module. Measure voltage between test pin No. 36 and test pins No. 40 and 60. To check for short to VBAT, turn ignition off. To check for short to VPWR, turn ignition on.

If voltage is less than 10.5 volts, go to next step. If any reading is greater than 10.5 volts, repair short circuit. Remove breakout box and reconnect all components. Rerun QUICK TEST.

6) Check SAW Circuit For Shorts To VREF, GROUND And PIP Turn ignition off and wait 10 seconds. Set DVOM to 200-k/ohm scale. Install breakout box, leaving ECA and EDIS module disconnected.

To check for shorts to ground, measure resistance between test pin 36 and test pins No. 16, 20, 40, 46 and 60. To check for shorts to VREF, measure resistance between test pin 36 and test pin No. 26. To check for shorts to PIP circuit, measure resistance between test pin No. 36 and test pin No. 56.

If each resistance is greater than 10 k/ohms, go to next step. If resistance is less than 10 k/ohms, repair short circuit. Remove breakout box, reconnect all components and rerun QUICK TEST.

4WD LOW CIRCUIT

Measure voltage between test pin No. 12 and test pins No. 40 and 60 at the breakout box while cycling the Overdrive Cancel Switch (OCS). Move transfer case lever between 4WD and 2WD positions several times. If voltage cycles, remove breakout box. Replace ECA and rerun QUICK TEST. If voltage does not cycle, go to step 9) for driveability faults or next step for other faults.

OVERDRIVE CANCEL SWITCH (OCS) CIRCUIT

Measure voltage between test pin No. 41 and test pins No. 40 and 60 at the breakout box while cycling the Overdrive Cancel Switch. Toggle the switch on the dash several times. If voltage cycles, remove breakout box. Replace ECA and rerun QUICK TEST. If voltage does not cycle, go to step 9) for driveability faults or next step for other faults.

7) Checking Circuits For Shorts To Ground Ensure key is off, breakout box is installed and ECA is disconnected. Set DVOM on 200-k/ohm scale.

Disconnect 4WD LOW switch. Measure resistance between test pin No. 12 and test pins No. 40 and 60 at the breakout box. If resistance(s) is greater than 10 k/ohms, go to step 10) for Code 47 or 65. Go to next step for Code 97. If resistance is not greater than 10 k/ohms, for Code 47, repair short circuit and rerun KOEO Self-Test; for Code 65, repair short circuit and rerun KOER Self-Test, if Code 65 is still present, go to step 9). For Code 97, repair short circuit and rerun KOEO Self-Test.

Disconnect Overdrive Cancel Switch. Measure resistance between test pin No. 41 and test pins No. 40 and 60 at the breakout box. If resistance(s) is greater than 10 k/ohms, go to step 10) for Code 47 or 65. Go to next step for Code 97. If resistance is not greater than 10 k/ohms, for Code 47, repair short circuit and rerun KOEO Self-Test; for Code 65, repair short circuit and rerun KOER Self-Test, if Code 65 is still present, go to step 9). For Code 97, repair short circuit and rerun KOEO Self-Test.

8) Checking Key Power Through OCIL Circuit With KOEO, ensure breakout box is installed and ECA is disconnected. Set DVOM on 20-volt scale. Measure voltage between test pin No. 32 and test pins No. 40 and 60 at the breakout box. If voltage is greater than 10.5 volts, remove the breakout box, replace ECA and rerun QUICK TEST. If voltage is less than 10.5 volts, go to next step.

9) Checking Continuity Of LED Harness (4WD LOW Or Overdrive Cancel) With KOEO, disconnect ECA 60-pin connector and inspect for corroded or damaged pins. Service or repair as necessary. Install breakout box, leaving ECA disconnected. Disconnect 4WD LOW or Overdrive Cancel Switch. Set DVOM on 200-ohm scale.

Measure resistance between Key Power Circuit at the fuse panel (+ probe) and test pin No. 12 (- probe) at the breakout box. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, check for a faulty indicator bulb (4WD LOW LED or OCIL) or defective fuse in fuse panel. If fuse is okay, repair open circuit, remove breakout box and reconnect ECA. Rerun QUICK TEST.

OCS-OCIL CIRCUIT

Measure resistance between Key Power Circuit at the fuse panel (+ probe) and test pin No. 32 (- probe) at the breakout box. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, check for a faulty indicator bulb (4WD LOW LED or OCIL) or defective fuse in fuse panel. If fuse is okay, repair open circuit, remove breakout box and reconnect ECA. Rerun QUICK TEST.

Fuse Panel. Scheme 94

10) Checking Continuity Of The 4WD LOW Or Overdrive Cancel Switch Harness With key off, breakout box installed and ECA disconnected, disconnect appropriate switch. Set DVOM on 200-ohm scale.

Measure resistance between test pin No. 12 at the breakout box and 4WD LOW circuit at the 4WD LOW switch vehicle harness. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open circuit(s) as necessary, remove breakout box, reconnect components and rerun QUICK TEST.

4WD LOW Circuit. Scheme 95

Measure the resistance between KEY PWR at the fuse panel (shown in step 14), ohmmeter positive lead) and the power side of the OCS harness connector (ohmmeter negative probe). Measure the resistance between test pin No. 41 at the breakout box and the signal side of the OCS harness connector. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open circuit(s) as necessary, remove breakout box, reconnect components and rerun QUICK TEST.

OCS-OCIL Circuit. Scheme 96

11) Checking Circuit(s) For Shorts To Power With key off, ensure breakout box is installed and ECA is disconnected. Set DVOM on 200-k/ohm scale.

Disconnect 4WD LOW switch. Measure resistance between test pin No. 12 and test pins No. 37 and 57 at the breakout box. If resistance(s) are greater than 10 k/ohms, remove breakout box, replace appropriate switch and rerun QUICK TEST. If resistance(s) are not greater than 10 k/ohms, repair short circuit(s), remove breakout box, reconnect ECA and rerun QUICK TEST.

Disconnect OCS switch. Measure resistance between test pin No. 41 and test pins No. 37 and 57 at the breakout box. Measure resistance between test pin No. 32 and test pins No. 37 and 57 at the breakout box. If resistance(s) are greater than 10 k/ohms, remove breakout box, replace appropriate switch and rerun QUICK TEST. If resistance(s) are not greater than 10 k/ohms, repair short circuit(s), remove breakout box, reconnect ECA and rerun QUICK TEST.

12) Service Code 91, 92, 93, 94, 98 And 99 Circuit Identification These service codes indicate that the appropriate On/Off solenoid is out of Self-Test range. This may cause harsh, early or late shifting. Reading should be 9-14.5 volts when ON and less than 1.0 volt when OFF. Code 98 indicates Electronic Pressure Control (EPC) solenoid may have a faulty driver in the ECA. Code 99 indicates a faulty EPC circuit which may cause harsh shifting and clutch wear. Possible causes for these codes are: solenoid resistance is out of limits, harness circuit is open or grounded, faulty ECA.

SOLENOID & CIRCUIT IDENTIFICATION CHART

If any of the listed codes are present, go to step 15) for 7.3L diesel vehicles or next step for all others. If codes are not present, go to KOEO Self-Test procedures.

13) Enter Output State Check Turn key off and wait 10 seconds, set DVOM on 20-volt scale. A VOM or DVOM MUST be used for this test.

Connect DVOM negative (-) test lead to STO circuit at Self-Test connector and positive (+) test lead to battery positive. Jumper STI circuit to SIGNAL RETURN at the Self-Test connector. Perform KOEO Self-Test until all Continuous Codes have been displayed. DVOM will indicate less than 1.0 volt when test is complete. Depress and release throttle. If voltage increases, remain in Output State Check and go to next step. If voltage does not increase, depress throttle to WOT and release. If STO voltage does not increase, go to TEST D16, step 1), leave test equipment hooked up.

14) Check Suspect E4OD Solenoid Electrical Operation With KOEO, disconnect transmission solenoid bulkhead connector. Use a mirror to inspect both ends of connector for damage or corrosion. Service or repair as necessary. Connect DVOM positive test lead to VPWR circuit and negative test lead to ECA signal test pin at the bulkhead connector (see step 12). Set DVOM on 20-volt scale. While observing DVOM, depress and release the throttle several times to cycle output on and off. If suspected solenoid output circuit voltage change is greater than 1.0 volt, service or repair solenoid. If voltage change is not greater than 1.0 volt, remove jumper and go to next step.

15) Checking E4OD Transmission Solenoid Resistance Turn key off and wait 10 seconds. Disconnect ECA 60-pin connector and inspect for corroded or damaged pins. Service or repair as necessary. Install breakout box, leave ECA disconnected. Connect transmission bulkhead connector. Set DVOM on 200-ohm scale. Measure resistance between test pins No. 37 and 57 and ECA signal test pin at the breakout box (see step 12). If resistance is within specification, go to step 17). See SOLENOID RESISTANCE CHART. If resistance is not as specified, go to next step.

SOLENOID RESISTANCE CHART

16) Checking Continuity Of E4OD Solenoid Harness Turn key off and wait 10 seconds. Install breakout box, leaving ECA disconnected. Disconnect transmission bulkhead connector. Set DVOM on 200-ohm scale. Measure resistance between the ECA signal test pin at the breakout box and transmission bulkhead connector (see step 12). Measure resistance between test pins No. 37 and 57 (test pin No. 35 on 7.3L diesel) at the breakout box and EPCPWR and VPWR pins at the E4OD transmission bulkhead connector (refer to circuit diagram at start of test). If all resistances are less than 5 ohms, go to next step. If resistance is greater than 5 ohms, remove breakout box, repair open circuit and reconnect ECA and solenoids. Rerun QUICK TEST.

17) Checking E4OD Solenoid Harness For Short To Ground Turn key off and wait 10 seconds. Install breakout box, leaving ECA disconnected. Ensure transmission bulkhead connector is disconnected. Set DVOM on 200-k/ohm scale. Measure resistance between ECA signal test pin (see table in step 12) and test pins No. 40, 46 and 60 at the breakout box. Measure resistance between the ECA signal test pin at the breakout box and chassis ground. If all resistances are greater than 10 k/ohms, go to next step. If resistances are less than 10 k/ohms, repair short circuit(s), remove breakout box, reconnect ECA and solenoid(s). Rerun QUICK TEST.

18) Checking E4OD Solenoid Harness For Short To Power Turn key off and wait 10 seconds. Install breakout box, leaving ECA disconnected. Ensure transmission bulkhead connector is disconnected. Set DVOM on 200-k/ohm scale. Measure resistance between ECA signal test pin (see table in step 12) ) and test pins No. 37 and 57 at breakout box. If all resistances are greater than 10 k/ohms, go to next step. If resistances are less than 10 k/ohms, repair short circuit(s), remove breakout box, reconnect ECA and solenoid(s). Rerun QUICK TEST.

19) Checking Voltage Of VPWR To E4OD Solenoids Turn key off and wait 10 seconds. Install breakout box, ensure ECA is connected. Ensure transmission bulkhead connector is disconnected. Set DVOM on 20-volt scale. With KOEO, measure voltage between test pins No. 37 and 57 at the bulkhead connector and chassis or battery ground. If voltage is greater than 10.5 volts, go to next step. If voltage is less than 10.5 volts, replace ECA, reconnect components and rerun QUICK TEST.

20) Check Solenoid Driver Signal With key off, install breakout box and leave ECA connected. Disconnect transmission bulkhead connector. Connect a test light between test pin No. 37 or 57 and the ECA signal test pin (refer to table in step 12)) at the breakout box. With KOEO, wait 10 seconds. Initiate KOEO Self-Test. If test light flashes momentarily and then stays off, repair transmission solenoids as necessary, driver signal is okay. If test light does not flash, replace ECA, reconnect solenoid(s) and rerun QUICK TEST. If test light is always on, solenoid driver is shorted to ground in ECA. Replace ECA, reconnect solenoid(s) and rerun QUICK TEST.

21) Code 26: Check Transmission Oil Operating Temperature Code 26 indicates Transmission Oil Temperature (TOT) sensor is out of Self-Test range. Correct voltage is 0.21-3.50. Possible causes for this fault are: TOT resistance is out of range or ECA is faulty. Drive vehicle normally in city traffic for 20-30 minutes to bring transmission oil temperature to at least 50° F (10°C). In extremely cold weather a longer warm-up drive may be necessary. Rerun QUICK TEST. If code 26 is still present, go to next step. If code 26 is no longer present, service or repair other codes as necessary.

22) Checking For VREF At Throttle Position Sensor (TPS) Refer to wiring circuit diagrams in TESTS B8 and B17. Turn key off and wait 10 seconds. Disconnect ECA 60-pin connector and inspect for corroded or damaged pins. Service or repair as necessary. Install breakout box and connect ECA to breakout box. Disconnect TPS (FIPL on 7.3L diesel) and set DVOM on 20-volt scale. With KOEO, measure voltage between VREF and SIGNAL RETURN at the TPS (or FIPL) vehicle harness connector. If voltage is 4.0-6.0 volts, reconnect TPS (or FIPL) and go to next step. If voltage is not as specified, go to TEST A3.

23) Checking Resistance Of TOT Sensor Ensure transmission temperature is 50° F (10°C), if transmission has cooled down, repeat test drive. Turn key off and wait 10 seconds. Ensure breakout box is installed and ECA is disconnected. Ensure bulkhead connector is connected at transmission. Set DVOM on 200-k/ohm scale. With KOEO, ensure transmission oil pan is "warm to touch" on side away from exhaust manifold. Measure resistance between test pin No. 42 (test pin No. 7 on 7.3L diesel) and test pin No. 46 at the breakout box. If resistance is within specification, go to next step. See TOT RESISTANCE CHART. If resistance is not as specified, repair or replace TOT sensor.

TRANSMISSION OIL TEMPERATURE (TOT) SENSOR RESISTANCE

24) Checking TOT Sensor Resistance In Relation To Oil Temperature Change TOT sensor may be within specification range (.8-100 k/ohms) and not correspond to temperature. Ensure transmission fluid is at operating temperature. Measure TOT resistance again and compare to resistance recorded in step 23). If resistance increased or decreased due to temperature change, replace ECA. If resistance did not change, replace breakout box, reconnect ECA, and replace temperature sensor.

25) Code 56: Attempt To Generate Code 66 Code 56 indicates TOT signal is greater than Self-Test maximum value of 4.80 volts. Possible causes for this fault are: faulty TOT sensor, open harness circuit, faulty ECA. Turn key off and wait 10 seconds. Disconnect transmission bulkhead connector from TOT sensor. Inspect for corroded or damaged pins. Service or repair as necessary. Insert a jumper wire at the bulkhead connector between TOT SIGNAL and SIGNAL RETURN. Run KOEO Self-Test. If Code 66 is present, remove jumper wire and service or replace TOT sensor. If Code 66 is not present, remove jumper wire and go to next step.

26) Check Continuity Of TOT SIGNAL And SIGNAL RETURN Circuit Turn key off and wait 10 seconds. Ensure bulkhead connector is disconnected at transmission. Disconnect ECA 60-pin connector and inspect for corroded or damaged pins. Service or repair as necessary. Install breakout box, leave ECA disconnected. Set DVOM on 200-ohm scale. Measure resistance between TOT SIGNAL at the bulkhead connector and test pin No. 42 (test pin No. 7 on 7.3L diesel) at the breakout box. Measure the resistance between SIGNAL RETURN at the bulkhead connector and test pin 46 at the breakout box. If both resistances are less than 5 ohms, replace ECA, remove breakout box, reconnect ECA and bulkhead connector. Rerun QUICK TEST. If resistances are not less than 5 ohms, repair open circuits, remove breakout box and reconnect ECA. Rerun QUICK TEST.

27) Code 66: Attempt To Generate Code 56 Code 66 indicates that TOT signal is less than 0.15 volt (Self-Test minimum value). Possible causes for this fault are: faulty TOT sensor, grounded harness or faulty ECA. Turn key off and wait 10 seconds, disconnect transmission connector from bulkhead connector. Inspect for corroded or damaged pins. Service or repair as necessary. Run KOEO Self-Test. If Code 56 is present, service or replace TOT sensor. If Code 56 is not present, go to next step.

28) Checking VREF At TPS Refer to wiring circuit diagrams in TESTS B8 and B17. Turn key off and wait 10 seconds. Disconnect ECA 60-pin connector and inspect for corroded or damaged pins. Service or repair as necessary. Install breakout box and connect ECA to breakout box. Disconnect TPS (FIPL on 7.3L diesel) and set DVOM on 20-volt scale. With KOEO, measure voltage between VREF and SIGNAL RETURN at the TPS (or FIPL) vehicle harness connector. If voltage is 4.0-6.0 volts, reconnect TPS (or FIPL) and go to next step. If voltage is not as specified, go to TEST A3.

29) Checking TOT Signal For Short To Ground Turn key off and wait 10 seconds. Ensure bulkhead is disconnected at transmission. With breakout box installed and ECA disconnected, set DVOM on 200-k/ohm scale. Measure resistance between test pin No. 42 (test pin No. 7 on 7.3L diesel) and test pins No. 40, 46 and 60 at the breakout box. If all resistances are greater than 10 k/ohms, replace ECA and remove breakout box. Reconnect components and rerun QUICK TEST. If resistances are not greater than 10 k/ohms, repair short circuit, remove breakout box and reconnect components. Rerun QUICK TEST.

30) Checking MLP, TOT Sensor And E4OD Solenoid Drive Cycle Bring engine to operating temperature. Verify transmission fluid level and that all components are connected. Run KOEO Self-Test and record Continuous Memory Codes. If Codes 49, 59 or 69 are present, go to step 36). If Codes are not present, record and clear Continuous Memory Codes.

Select "D" range and enable "OD". Drive vehicle in city traffic using moderate acceleration. Hold throttle opening steady while transmission is shifting through all four gears and hold throttle steady for an additional 15 seconds.

Apply brakes on coming to a stop and remained stopped for 20 seconds. Repeat previous drive step. Rerun KOEO Self-Test and record Continuous Memory Codes. If a Code 11 is present, go to next step. If Code 29 is present, go to TEST B12. For Codes 56, 62, 66, 67 or 99, go to step 32).

31) Attempt To Generate Continuous Memory Code 56, 62, 66, 67 & 99 Before performing any procedures in this step, complete the drive cycle test. Drive vehicle approximately 15 minutes over a rough road to simulate road shock. Observe MIL LED while driving for indication of a fault. If MIL flashes ON and OFF, go to next step. If light does not flash, fault may not be duplicated at this time. Testing is complete.

32) Check Circuit Using KOEO Continuous Monitor Mode Enter KOEO Continuous Monitor Mode. Observe VOM or STAR LED for indication of a fault while performing the following.

MLP SENSOR (CODE 67)

Lightly tap on MLP sensor to simulate road shock. Wiggle connector at MLP sensor.

TRANS SOLENOIDS (CODES 62/99) & TOT SENSOR (CODES 56/66)

Wiggle transmission bulkhead connector. If a fault is indicated, isolate fault and service or repair as necessary. Clear Continuous Memory Codes and rerun QUICK TEST. If a fault is not indicated, go to step 35).

33) Checking EEC-IV Harness Ensure vehicle is still in KOEO Continuous Monitor Mode. Observe VOM for an indication of a fault while performing the following: using illustration in step 34), grasp harness close to sensor or transmission connector and perform "Wiggle" test while working from transmission to dash panel and ECA. If a fault is indicated, isolate fault and service as necessary. Clear Continuous Memory Codes and rerun QUICK TEST. If no fault is indicated, go to step 35).

34) Circuit Diagram For Continuous Monitor Mode Refer to E4OD Vehicle Harness Circuit Diagram.

E4OD Vehicle Harness Circuit. Scheme 97

35) Checking ECA & Harness Connectors Turn key off and wait 10 seconds. Disconnect ECA 60-pin connector. Disconnect ECA 60-pin connector and inspect for corroded or damaged pins. Service or repair as necessary. If connectors and terminals are okay, fault may not be duplicated at this time. Clear Continuous Memory Codes. If connectors or terminals are faulty, service or repair as necessary. Clear codes and rerun QUICK TEST.

36) Isolating Faults For Continuous Memory Codes 49, 59, & 69 Codes 49, 59 and 69 indicate that the transmission went through 4 consecutive incorrect shifts in an upward or downward shift sequence. When changing a gear the SS1 or SS2 solenoid remained ON or OFF an extended amount of time. Possible causes for these faults are: intermittent harness continuity, stuck shift solenoid. Rerun KOEO Self-Test. If any other codes appear during the KOEO Self-Test in addition to Codes 49, 59 or 69, service other codes first. If other codes do not appear, go to next step.

37) Checking Circuits Using KOEO Continuous Monitor Mode Enter KOEO Continuous Monitor Mode. Observe VOM or STAR LED for indication of a fault while performing the following: wiggle, shake or bend a small section of system harness while working from dash panel and ECA to transmission bulkhead connector. If a fault is indicated, disconnect connectors and inspect connectors and harness for damage. Clear codes and rerun QUICK TEST. If a fault is not indicated, service or replace SS1 and SS2 solenoids as necessary.

SUMMARY

If no service code (or pass code 11-1-11 or 111-1-111) is present, but driveability problem still exists, proceed to the TESTS W/O CODES article for diagnosis by symptom (i.e. ROUGH IDLE, NO START, etc.), or intermittent diagnosis procedures.