Diagnostic Aids
Perform this test when directed by QUICK TEST. This test is intended to diagnose only the EEC-IV portion of ignition system. For additional information on ignition system and component testing, see SYSTEM/COMPONENT TESTS article in this section.
To prevent replacing good components, be aware that the following non-EEC related areas may be the cause of problem:
- TFI ignition module
- Ignition coil
- Spark plugs and/or high tension cables
- Distributor
- Secondary ignition component arcing
This test is intended to diagnose the following circuits and components:
- IDM Harness circuit
- ECA assembly
| Application | Location |
|---|---|
| All Models | Distributor |
| Application | Wire Color |
|---|---|
| Pin 3 (VSS DIF +) | Black/Red |
| Pin 4 (IDM) | Green |
| Pin 16 (IGN GND) | White |
| Pin 36 (SPOUT) | Red/White |
| Pin 40 (PWR GND) | Black/White |
| Pin 46 (SIG RTN) | Light Green/Yellow |
| Pin 60 (PWR GND) | Black/Yellow |
| Application | Wire Color | |
|---|---|---|
| Pin 3 (VSS DIF +) | Dark Green/White | |
| Pin 4 (IDM) | ||
| California | White/Pink | |
| 49 States & Canada | Dark Green/Yellow | |
| Pin 16 (IGN GND) | Orange/Red | |
| Pin 36 (SPOUT) | Yellow/Light Green | |
| Pin 40 (PWR GND) | Black/Light Green | |
| Pin 46 (SIG RTN) | Gray/Red | |
| Pin 60 (PWR GND) | Black/Light Green | |
1) Continuous Memory Code 14/211: Erratic Ignition Code 14/211 indicates 2 successive erratic Profile Ignition Pick-Up (PIP) pulses occurred, resulting in a possible engine miss or stall. Check for the following possible causes of fault:
- Loose wires or connectors
- Arcing secondary ignition components
- On-board transmitter equipment (2-way radio)
Repair any problems in listed items as necessary; clear code and rerun QUICK TEST. If problem is not found in listed items, go to next step for vehicles with Computer-Controlled Dwell (CCD), or go to step 3) for all others.
2) Code 18/212: Check IDM Circuit Continuity Continuous Memory Code 18/212 indicates loss of IDM input to ECA. Possible causes for this fault are as follows:
- Open harness
- Shorted Harness
- Faulty TFI module
- Faulty 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. Disconnect TFI module. Set DVOM to 200-ohm scale. Measure and record resistance between test pin No. 4 at breakout box and pin No. 3 at TFI vehicle harness connector. Measure and record resistance between pin No. 5 at TFI vehicle harness connector and ignition coil harness connector or negative terminal. If each resistance is less than 5 ohms, go to step 5). If any resistance is greater than 5 ohms, repair open circuit. Remove breakout box and reconnect all components. Clear codes and rerun QUICK TEST.
3) Code 18/212: Check IDM Circuit Continuity Continuous Memory Code 18/212 indicates loss of IDM input to ECA. Possible causes for this fault are as follows:
- Open harness
- Shorted Harness
- Faulty TFI module
- Faulty 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. Set DVOM to 200-k/ohm scale. Disconnect "E" core ignition coil and TFI module. Measure resistance between test pin No. 4 at breakout box and ignition coil harness connector negative terminal. If resistance is 20-24 k/ohms, go to next step. If resistance is NOT 20-24 k/ohms, repair open circuit. Remove breakout box and reconnect all components. Clear codes and rerun QUICK TEST.
4) Check IDM Circuit Continuity Turn ignition off and wait 10 seconds. Set DVOM to 200-ohm scale. With breakout box installed and ECA disconnected, measure resistance between pin No. 5 at TFI vehicle harness connector and ignition coil harness connector negative terminal. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, repair open circuit. Remove breakout box and reconnect all components. Clear codes and rerun QUICK TEST.
5) Check IDM Circuit For Short To Ground Turn ignition off and wait 10 seconds. Install breakout box and leave ECA disconnected. Disconnect "E" core coil on vehicles without CCD. Set DVOM to 200-k/ohm scale. Measure resistance between test pin No. 4 and test pins No. 40, 46 and 60 at breakout box. If each resistance is greater than 10 k/ohms, go to next step. If any resistance is less than 10 k/ohms, remove breakout box and repair short to ground in IDM circuit. Reconnect all components, clear codes and rerun QUICK TEST.
6) Check ECA For Short To Ground Turn ignition off and wait 10 seconds. Install breakout box and connect ECA to breakout box. Disconnect ignition coil and TFI module. Set DVOM to 200-k/ohm scale. Measure voltage between test pin No. 4 and test pins. No. 40 and 60 at breakout box. If resistance is greater than 10 k/ohms, reconnect all components and go to next step. If resistance is less than 10 k/ohms, replace ECA. Remove breakout box, reconnect all components and rerun QUICK TEST.
7) Check TFI Module Turn ignition off and wait 10 seconds. Enter CONTINUOUS MONITOR MODE (WIGGLE TEST). Observe VOM or diagnostic tester for indication of fault while lightly tapping on TFI module to simulate road shock. Wiggle all TFI harness connectors. If fault is indicated, go to next step. If fault is not indicated, disconnect and inspect TFI harness connectors and terminals for damage. If connector and terminals are okay, check ignition system. See SYSTEM/COMPONENT TESTS article in this section. If ignition is okay, replace ECA.
8) Check EEC-IV Harness Remain in CONTINUOUS MONITOR MODE (WIGGLE TEST). Wiggle, shake or bend small sections of harness, working from TFI connectors to firewall. Observe VOM or diagnostic tester for indication of fault. Repeat process from firewall to ECA. This test checks for the following circuit faults:
- PIP Open/Shorted to Ground (check at test pin No. 56)
- SPOUT Shorted to Ground (check at test pin No. 36)
- Ignition Ground Open (check at test pin No. 16)
- IDM Open to Ground (check at test pin No. 4)
- IDM Shorted to Power (check at test pin No. 4)
Perform CONTINUOUS MONITOR MODE (WIGGLE TEST) on these circuits, one at a time, to isolate fault. If fault is indicated, isolate fault and repair harness. Repeat QUICK TEST. If no fault is indicated, go to next step.
9) Check ECA & Harness Connectors Turn ignition off and wait 10 seconds. Disconnect ECA 60-pin connector. Inspect connector for damaged pins, corrosion or loose wires. If connector is damaged, repair as necessary; clear codes and repeat QUICK TEST. If connector is okay, perform the appropriate procedure listed as follows, based on the Continuous Memory Code displayed.
- Code 14/211: Erratic ignition fault in EEC system cannot be duplicated. Remove breakout box and reconnect all components. Diagnose TFI ignition system.
- Code 18/212: Replace ECA, remove breakout box and reconnect all components. Start and run engine for about one minute, then rerun QUICK TEST.