A/T - EEC Trouble Codes
TECHNICAL BULLETIN: # 088TRANSMISSION: N/A
SUBJECT: Trouble Codes
APPLICATION: Ford
Ford Electronic Engine Control Trouble Codes
IMPORTANT POINTS PARTICULAR TO FORD:
Fords Electronic Engine Control (EEC) system does not have the ability to be "read" as other systems do. (Example -- watching TPS voltage on a scan tool.) After the codes are retrieved, the system is best diagnosed with a tool called a break-out box. This ties into the computer system and checks the sensors and ground circuits using a DVOM.
BEFORE TEST PROCEDURES BEGIN:
1. Check all wiring connectors and vacuum hoses.
2. Check for non-OEM splices into wiring, IE: Car phones, CB radios, back up alarms, etc.
3. Engine radiator must be full and able to hold pressure.
4. Engine must be at operating temperature with all electrical accessories turned off.
THEN PROCEED:
Voltmeter hook-up
1. Locate the diagnostic connector and the Self Test Input (STI) gray connector.
2. Connect "Analog voltmeter as illustrated Figure 1. If the vehicle is an '83 - 1.6L the schematic in figure 2 must be used.
Typical STI Locations
(Always perform this test 1st)
KOEO - Key ON engine OFF test:
(After hook-up of analog voltmeter)
(STEP 1)
Turn the key ON... If diesel powered, depress the throttle to the floor for entire test! The processor will run its own self diagnostics and output "hard codes" on your voltmeter. (Figure 4)
(STEP 2)
Count the needle sweeps and write down the codes in order. Watch for separator code 11 and code 10. These are not faults but indicate "no codes" and divisions between processor memory. Figure 5 is an example of "No Codes". If there were codes present, they would be displayed in the 4 second pause location.
KOER - KEY ON ENGINE RUNNING TEST
Do this after KOEO tests. Start the engine, the first meter display will be the Engine I.D. code,
2 pulses - 4 cylinder
3 pulses - 6 cylinder
4 pulses - 8 cylinder
5 pulses - 7.3 diesel
(Verifies processor installed for proper engine.)
2nd output will be code 10 which is a single pulse on the meter.
This indicates it is time for the operator to complete the "Dynamic Tests". These tests check items listed as they are actuated.
(1st STEP) Perform WOT (Wide Open Throttle).
(2nd STEP)) Turn steering 1/2 turn.
(3rd STEP) Perform BOO (Brake On/Off).
(4th STEP) Cycle O.D. cancel switch if equipped (E4OD).
After completing steps 1 to 4, the analog voltmeter will present codes. (Figure 6)
E4OD - DRIVE CYCLE TEST
(STEP 1)
Erase all existing codes by disconnecting STI connector while codes are emitted.
(STEP 2)
Check transmission fluid level. Engine must be at operating temperature.
(STEP 3)
Transmission in "D" range ... Press O.D. cancel switch (light on)... moderately accelerate from 0 to 40 mph and allow 3rd gear shift. Hold speed and throttle steady for 15 seconds.
(STEP 4)
Press O.D. switch (light off). Moderately accelerate from 40 to 50 and allow 4th gear upshift. Hold speed and throttle steady for 15 seconds.
(STEP 5)
When transmission is in 4th gear... lightly apply and release the brake ... hold speed and throttle steady for 15 seconds.
(STEP 6)
Brake to a stop, stand stationary for 20 seconds in "D". Repeat steps 3 to 6 a minimum of 4 times.
(STEP 7)
PERFORM KOEO to retrieve any codes.
FOR ADDITIONAL INFORMATION:
Locate a Ford - H - Manual or diagnostic manual and Bulletin # 089