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.
| CAUTION | Continuous Memory Codes should be recorded when received during KOEO SELF-TEST. These codes may be used to identify intermittent problems that exist after all KOEO and KOER codes have been repaired, and a Code 11 or 111 (pass code) has been obtained in KOEO SELF-TEST and KOER SELF-TEST. Failure to follow this procedure may result in replacement of non-faulty components and unnecessary testing. Some Continuous Memory Codes faults may not be valid after KOEO and KOER codes are repaired. |
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
- Analog Volt-Ohmmeter (VOM)
- "Scan" Tool
- STAR Series Tester
- In-Dash "CHECK ENGINE" or "SERVICE ENGINE SOON" Light
| Application | Location |
|---|---|
| Aerostar | Left front inner fender panel |
| Ranger | Right front inner fender panel |
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.
| CAUTION | DO NOT disconnect vehicle battery to clear codes. This will erase stored operating information from the Keep-Alive Memory (KAM). To clear KAM, disconnect negative battery terminal for a minimum of 5 minutes. If KAM has been cleared, drive vehicle 10 miles or more to allow ECA to relearn operating conditions and driving style of vehicle. Driveability may be affected during relearning cycle. |
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 42
Scheme 43
Scheme 44
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 43) 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
- If engine starts and stalls, or stalls during self-test, go to TEST S, step 1).
- 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.
- 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.
- 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.
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.
SERVICE CODE DEFINITIONS
| Service Code | Test Condition(s) | Definition | |
|---|---|---|---|
| 11 | KOEO/KOER/ CONTINUOUS | System Pass | |
| 12 | KOER | Unable to control RPM during Self-Test high RPM check | |
| 13 | KOER | Unable to control RPM during Self-Test low RPM check | |
| 14 | |||
| 7.3L Diesel | CONTINUOUS | Engine RPM Sensor circuit failure | |
| All Others | CONTINUOUS | PIP circuit failure | |
| 15 | KOEO | ECA Read Only Memory (ROM) Test Failed | |
| 15 | CONTINUOUS | ECA Keep Alive Memory (KAM) Test Failed | |
| 16 | KOEO | IDM signal not received | |
| 18 | |||
| 2.3L | KOER | SPOUT circuit open | |
| 2.3L | CONTINUOUS | Erratic IDM input to processor | |
| 4.0L | KOER | SAW circuit failure | |
| 4.0L | CONTINUOUS | Loss of IDM input to processor/IDM circuit failure | |
| All Others | KOER | SPOUT circuit open | |
| All Others | CONTINUOUS | Loss of IDM input to processor/SPOUT circuit grounded | |
| 19 | KOEO | Failure in ECA internal voltage | |
| 21 | KOER/KOEO | ECT sensor out of Self-Test Range | |
| 22 | KOEO/KOER/ CONTINUOUS | MAP/BP sensor input is out of Self-Test Range | |
| 23 | |||
| 7.3L Diesel | KOEO/KOER | Fuel Injection Pump Lever (FIPL) circuit is out of Self-Test Range | |
| All Others | KOEO/KOER | TP sensor input is out of Self-Test Range | |
| 24 | KOER/KOEO | ACT sensor input is out of Self-Test Range | |
| 25 | KOER | Knock not sensed during Dynamic Response Test | |
| 26 | |||
| 2.9L/4.0L | KOEO/KOER | MAF sensor is out of Self-Test range | |
| All Others | KOEO/KOER | Transmission Oil Temperature (TOT) Sensor out of Self-Test range | |
| 28 | CONTINUOUS | Loss of IDM - Right Side | |
| 29 | CONTINUOUS | Insufficient input from VSS | |
| 31 | KOEO/KOER/ CONTINUOUS | EVP circuit below minimum voltage | |
| 32 | KOEO/KOER/ CONTINUOUS | EVP voltage below closed limit | |
| 33 | KOER/CONTINUOUS | EGR valve opening not detected | |
| 34 | KOEO/KOER/ CONTINUOUS | EVP voltage above closed limit | |
| 35 | KOEO/KOER/ CONTINUOUS | EVP circuit above maximum voltage | |
| 39 | CONTINUOUS | AXOD lock-up failed | |
| 41 | KOER | HEGO sensor circuit indicates lean | |
| 41 | CONTINUOUS | No HEGO switching detected | |
| 42 | KOER/CONTINUOUS | HEGO sensor circuit indicates rich | |
| 44 | KOER | Thermactor air system inoperative | |
| 45 | |||
| 4.0L | CONTINUOUS | Coil 1, 2 or 3 failure | |
| All Others | CONTINUOUS | Thermactor air upstream during Self-Test | |
| 46 | KOER | Thermactor air not bypassed during Self-Test | |
| 47 | KOEO | 4X4 switch is closed (E4OD) | |
| 48 | CONTINUOUS | Loss of IDM - Left Side | |
| 49 | CONTINUOUS | 1-2 shift error (E4OD) | |
| 51 | KOEO/CONTINUOUS | ECT indicated -40°F/sensor circuit open | |
| 52 | KOEO | PSPS circuit is always open | |
| 52 | KOER | PSPS circuit did not change states | |
| 53 | |||
| 7.3L Diesel | KOEO/CONTINUOUS | Fuel Inj. Pump Lever (FIPL) circuit is greater than maximum voltage | |
| All Others | KOEO/CONTINUOUS | TP sensor input is greater than maximum voltage | |
| 54 | KOEO/CONTINUOUS | ACT sensor -40°F circuit open | |
| 56 | |||
| 2.9L/4.0L | KOEO/CONTINUOUS | MAF circuit above maximum voltage | |
| All Others | KOEO/CONTINUOUS | Transmission Oil Temperature (TOT) indicated -40°F circuit open (E4OD) | |
| 57 | CONTINUOUS | AXOD Neutral Pressure Switch (NPS) circuit failed open | |
| 59 | CONTINUOUS | 2-3 shift error (E4OD) | |
| 61 | KOEO/CONTINUOUS | ECT indicated 254°F circuit grounded | |
| 62 | CONTINUOUS | Converter Clutch error (E4OD) | |
| 63 | |||
| 7.3L Diesel | KOEO/CONTINUOUS | Fuel Inj. Pump Lever (FIPL) circuit is below minimum voltage | |
| All Others | KOEO/CONTINUOUS | TP sensor input is less than minimum voltage | |
| 64 | KOEO/CONTINUOUS | ACT indicated 254°F circuit grounded | |
| 65 | KOER | Overdrive Cancel Switch (OCS) not changing state (E4OD) | |
| 66 | |||
| 2.9L/4.0L | KOEO/CONTINUOUS | MAF circuit below minimum voltage | |
| All Others | KOEO/CONTINUOUS | Transmission Oil Temperature (TOT) indicated 290°F circuit grounded (E4OD) | |
| 67 | |||
| All Models | KOEO | Neutral Drive Switch (NDS) circuit open; A/C on | |
| All Others | CONTINUOUS | Manual Lever Position (MLP) is out of range; A/C on (E4OD) | |
| 2.9/4.0L | CONTINUOUS | Clutch switch circuit failure | |
| 69 | CONTINUOUS | 3-4 shift error (E4OD) | |
| 72 | KOER | Insufficient MAF or MAP change during Dynamic Response Test | |
| 73 | KOER | Insufficient throttle position (TP) change during Dynamic Response Test | |
| 74 | KOER | Brake ON/OFF (BOO) switch circuit failure (not activated during Self-Test) | |
| 77 | KOER | Operator error during Dynamic Response/Cylinder Balance tests | |
| 79 | KOEO | A/C On/Defrost on during Self-Test | |
| 81 | KOEO | Air Management 2 (AM2) circuit failure | |
| 82 | KOEO | Air Management 1 (AM1) Ckt failure | |
| 84 | KOEO | EGR Vacuum Regulator (EVR) circuit failure | |
| 85 | KOEO | Canister Purge (CANP) circuit failure | |
| 86 | KOEO | Shift Solenoid (SS) circuit failure | |
| 87 | KOEO/CONTINUOUS | Primary Fuel Pump circuit failure | |
| 88 | KOEO | Loss of Dual Plug input control | |
| 89 | KOEO | Converter Clutch Override (CCO) circuit failure | |
| 91 | KOEO | Shift Solenoid 1 (SS1) circuit failure (E4OD) | |
| 92 | KOEO | Shift Solenoid 2 (SS2) circuit failure (E4OD) | |
| 93 | KOEO | Coast Clutch Solenoid (CCS) circuit failure (E4OD) | |
| 94 | KOEO | Converter Clutch Control (CCC) solenoid circuit failure (E4OD) | |
| 95 | KOEO/CONTINUOUS | Fuel pump circuit open; ECA to motor ground | |
| 96 | KOEO/CONTINUOUS | Fuel pump circuit open; Battery to ECA | |
| 97 | KOEO | Overdrive Cancel Light (OCIL) | |
| 98 | KOEO | Electronic Pressure Control (EPC) driver open in ECA (E4OD) | |
| 98 | KOER | Hard fault is present | |
| 99 | KOEO/CONTINUOUS | Electronic Pressure Control (EPC) circuit failure (E4OD) | |
| NO CODES | Unable to initiate Self-Test or unable to output Self-Test codes | ||
| CODES NOT LISTED | Service codes displayed are not applicable to vehicle being tested | ||
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.
MANIFOLD ABSOLUTE PRESSURE/BAROMETRIC PRESSURE (MAP/BP) SENSOR
Note. 3.0L Aerostar is equipped with a MAP sensor. 3.0L Ranger is equipped with a BP sensor.
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
- Faulty VSS
- Faulty ECA
- Open or shorted circuit
On all vehicles except 3.0L Aerostar, perform appropriate drive cycle procedure. See PRELIMINARY INSTRUCTIONS (A/T VEHICLES) or PRELIMINARY INSTRUCTIONS (M/T VEHICLES). On 3.0L Aerostar vehicles, ensure driveability complaint can be verified. If Code 29/452 is still present or driveability complaint can be verified (3.0L 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 45
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.
No Starts
- Inertia switch not reset or electrically open
- Open circuit in or between ECA and fuel pump
- Faulty ground connection at fuel pump
Vehicle Starts
- Fuel pump secondary circuit shorted to power
- Fuel pump relay contacts always closed
- Open in Fuel Pump Monitor (FPM) circuit between ECA and connection to POWER-to-PUMP circuit
- HEGO short to power (dual HEGO applications)
- 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 (No. 19 on Escort, Tracer, Mustang, 5.0L Crown Victoria and 5.0L Grand Marquis) 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 46
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 (on Escort and Tracer, measure resistance between GND pin and FP pin). 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
- Open circuit between BATT (+) supply and FPM connection to POWER-to-PUMP circuit
- Fuel pump relay contacts are always open
Engine Starts
- HEGO short to power (Dual HEGO vehicles)
- 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.