Ford OBD/OBD2 Codes >> EEC IV Self Test – Ford Fuel Injection and EEC IV Electronic Engine Control – EEC 4

• Code Types
  • Fast Codes
  • Hard Faults
  • Separator Pulse
  • Memory Codes
  • Engine ID
  • Goose Codes
• Code Formats
• Tests
  • Hookup
  • KOEO Test
  • KOER Test
  • Cylinder Balance Test
  • Wiggle Test
  • Memory Erase
  • Output State Test
• Ignition Timing Tests
• Intermittent Wiring Faults
  • Short to Ground
  • Short to Power
  • Open Circuit

• Transmission in Park or Neutral and the driven wheels off the ground or chocked when cranking/running the engine.
• Check fan blade for cracks and do not stand next to the fan when engine is running.
• Use caution when working on fuel systems, which can remain pressurized for a long period after the key is turned off.
• No smoking around fuel.
• Watch for electric fan which can come on at any time.
• Watch out for hot and/or moving parts.
• When working on a no-start vehicle, use a neon spark tester to check for spark and ground the coil wire to prevent accidental starting if spark should occur while testing.
• Watch out for high voltage secondary circuits.
• If you are not sure of the safety of any operation DO NOT DO IT. ASK SOMEONE!

CODE TYPES

• NOTE: Some people have problems distinguishing the different codes.
• READ THIS SECTION CAREFULLY.
• There are drawings of the code formats at the end of this section.

Fast Codes

• Fast codes contain the fault information output in the normal slow codes but are output about 100 times faster.
• These are the first things output on a Key On Engine Off test.

Hard Faults

• Hard faults are problems that the computer has located RIGHT NOW. Examples are a sensor out of range or a broken wire (open circuit).
• Hard faults are the FIRST set of slow codes output in a Key On Engine Off test. BEFORE the SEPARATOR pulse.
• In a Key On Engine Running test, there are ONLY HARD FAULT codes. These are output right after the fast codes.

Separator Pulse

• The separator pulse is a single pulse that indicates the END of hard fault codes and the BEGINNING of memory codes.
• It will show up as a code 10 on most digital testers.

Memory Codes

Memory codes are problems that the computer has noticed in the past. If for example there was a loose wire to a solenoid that only lost contact while driving but was making contact while testing the system there would be NO HARD FAULT CODE. The code would show up IN MEMORY. The same would happen for a sensor that only went out of range occasionally. Memory codes come out AFTER the separator pulse.

NOTE: The computer will erase the memory after a certain number of engine re-starts if the problem does not repeat itself. The number of re-starts varies from 20 to 80 depending on the year of the vehicle. The later models keep memory longer.

Engine ID

The engine ID in a running test is a series of pulses equal to one half the number of engine cylinders. A 4 cylinder engine ID is 2 pulses, a 6 cylinder ID is 3 pulses and an 8 cylinder ID is 4 pulses. A diesel ID is 5.

Goose Code

• A “GOOSE” code (also called a dynamic response test) is output during an engine running test. This is a single pulse to signal you to quickly move the throttle approximately 1/2 way down and release.
• NOTE: Not all engines give a “GOOSE” code.

CODE FORMATS

Codes are output as a series of pulses. The following charts show the (approximate) timing of the various code pulses.

NOTE: Two digit codes are shown. Three digit codes have similar timing. It just takes a little practice to distinguish between two and three digit types.

TESTS

NOTE: Vehicle should be fully warmed for all tests.

Hookup

See figure below. EEC IV vehicles have two connectors for self testing the system. They are located on the firewall or the left or right front fender. The large connector contains the self test output (STO) and ground (SIG RTN). The small pigtail is the self test input (STI).

Key On Engine Off (KOEO) Test

NOTE: On 4.9L trucks with a manual transmission hold the clutch pedal in during this test. On Diesel engine trucks hold the throttle to the floor during this test.

1. Make sure engine is fully warmed. If in doubt, run engine at 2000 rpm for 2 minutes.
2. Turn ignition off and wait 10 seconds for system to shut off. Make sure A/C is off and transmission is in Park (automatic) or Neutral (manual).
3. Hook up light and jumper (or a tester if you have one). Turn key to ON (do not start engine).
4. Fast Codes are output (ignore fast light flashes).
5. NOTE: Unhook self test input jumper (or tester if used) at any time during code output to erase memory.
6. Read hard faults.
7. Separator Pulse.
8. Read memory codes.
9. See code explanations and check components as necessary.
10. Use FIRST CODE OUTPUT and retest after any repairs are made.

Key On Engine Running (KOER) Test

1. Make sure engine is fully warmed. If in doubt, run engine at 2000 rpm for 2 minutes.
2. Turn ignition off and wait 10 seconds for system to shut off. Make sure A/C is off and transmission is in Park (automatic) or Neutral (manual).
3. Hook up light and jumper (or tester if you have one).
4. Make sure vehicle is safe to run and start engine.
5. Engine I.D. should be output.
6. Step on brake and turn steering wheel 1/4 turn.
7. If the vehicle has an overdrive cancel switch, push it.
8. If a “Goose” pulse is received, move throttle quickly 1/2 way down and release.
9. Fast Codes are output (ignore).
10. Read codes.
11. See code explanations and check components as necessary.
12. Use FIRST CODE OUTPUT and retest after any repairs are made.

Cylinder Balance Test

NOTE: This test is only available on Sequential Fuel Injection (SFI) Engines.

Start an engine running test and press the accelerator lightly within 2 minutes after the last code is output. The PCM will cancel each cylinder in turn and measure the RPM drop. If any weak cylinders are noted their number will be output as a multiple of 10 (e.g. 30, 40). The output is the actual cylinder number, not the number in the firing order. NOTE: Will not always pinpoint bad injectors.

Wiggle Test

Engine running or engine off tests

Hook up for a self test but do not hook up the self test trigger. Turn key to on. Hook up the trigger, wait 10 seconds and disconnect. Hook up trigger again . Tap suspected sensors (be careful if engine is running), wiggle the wiring harnesses etc. IF the PCM picks up a fault the self test output will pulse and a memory code will be stored (The value of this is questionable. I NEVER located a problem with it. – JT).

Memory Erase

To erase the memory disconnect the self test trigger while the codes are being output. You COULD also disconnect the battery but then the PCM forgets some important running characteristics.

Output State Test

NOTE: Do not perform on E4OD diesel.

Run the KOEO test all the way through and leave the test hooked up.

Cycle throttle 3/4 open and closed while watching tester, light or voltmeter. Self test output will switch with every throttle activation. On some testers (like my old pocket testers) the light will only pulse every other push. But the outputs still switch EVERY time.

Solenoids (EGR etc.) will switch on or off with every throttle activation (push throttle they’re on, push throttle they’re off). You should be able to hear clicks as the solenoids switch states. The test will work for most solenoids: AIRB, AIRD, BOOST, EGR, EVR (NOTE: EVR does not click but vacuum cycles). Below is a graphic example of Output State test.

IGNITION TIMING TESTS

NOTE: Timing is not adjustable on Electronic Ignition

Engine off. Unplug the SPOUT connector in the (usually) yellow wire coming from the distributor connector (either in-line or shorting plug see figure below).

Restart engine, and with a timing light, set to specifications on decal (usually 10 degrees BTDC). Shut off engine and reconnect SPOUT wire.

To check timing advance the SPOUT must be hooked up. Start a running EEC test and when test starts (RPM’s go up) check the timing.

It should be advanced about 20 degrees (plus or minus 3 degrees) more than the original base timing. Since base timing is usually 10 degrees BTDC then the advance is usually to 30 degrees BTDC.

INTERMITTENT WIRING FAULTS

The first thing to do for wiring faults is an inspection. Checking the wiring CAREFULLY can make a long job into a quick one. Get into the habit of doing a quick wire harness check first.

Typical bad spots are where wiring runs across engine brackets or body parts. If you see a harness that’s laying on any of these areas pick it up and look underneath for shiny metal showing through.

If you have a persistent problem that needs to be fixed, there are a few ways you can check for intermittent faults.

To Check For a Short to Ground:

Key OFF. Disconnect PCM and all other parts that the suspect wire hooks to (e.g. the EGR Vent (EGRV) solenoid). Hook a 12 volt test light clip to battery POSITIVE and the other end of the lamp to the suspect wire. Wiggle, bend and move the wire everywhere it runs. If it shorts to ground, the test light will light.

You can use a meter in the same way but a light is more attention getting.

To Check For a Short to Power:

Key OFF. Disconnect the PCM and all other parts that the suspect wire hooks to (e.g. the Constant Control Relay Module (CCRM)). Hook a 12 volt test light clip to battery NEGATIVE and the other end of the lamp to the suspect wire. Wiggle, bend and move the wire everywhere it runs. If it short to power, the test light will light.

Again, you can use a meter in the same way but a light is easier.

To Check For an Open Circuit:

1. Key OFF. Disconnect the PCM and all other parts that the suspect wire hooks to (e.g. the transmission).
2. ON THIS TEST IT IS VERY IMPORTANT YOU ARE SURE EVERYTHING IS DISCONNECTED.
3. Ground one end of the suspect wire. Whichever end is easier at the PCM end or the other.
4. Hook a 12 volt test light clip to battery POSITIVE and the other end of the lamp to the opposite end of the suspect wire from where you hooked the ground. The light should light. Wiggle, bend and move the wire everywhere it runs. If it opens, the test light will go out.
5. Again, you can use a meter in the same way but a light is easier.