Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2008 Mitsubishi Eclipse L4-2.4L (4G69)FACTORY OEM SERVICE PROCEDURE
Inspection Procedure 2
INSPECTION PROCEDURE 2: Scan Tool Communication with ECM [M/T] or PCM [A/T] Is Not Possible.
CIRCUIT OPERATION
- A diagnostic output is made from the ECM [M/T] or the PCM [A/T] (terminal No. 15) to the diagnostic output terminal (terminal No. 7) of the data link connector.
COMMENT
- No power supply to ECM [M/T] or PCM [A/T].
- Defective ground circuit of ECM [M/T] or PCM [A/T].
- Defective ECM [M/T] or PCM [A/T].
- Improper communication line between ECM [M/T] or PCM [A/T] and scan tool.
TROUBLESHOOTING HINTS (The most likely causes for this case:)
- Malfunction of ECM [M/T] or PCM [A/T] power supply circuit.
- Malfunction of the ECM [M/T] or the PCM [A/T].
- Open circuit between ECM [M/T] or PCM [A/T] and data link connector.
DIAGNOSIS
STEP 1. Check harness connector B-18 at ECM [M/T] or PCM [A/T] for damage.
Q: Is the harness connector in good condition?
YES : Go to Step 2.
NO : Repair or replace it. Refer to general (electrical), Harness Connector Inspection. Then confirm that the malfunction symptom is eliminated.
STEP 2. Check for open circuit, short circuit to ground and harness damage between data link connector C-125 (terminal No. 7) and ECM [M/T] or PCM [A/T] connector B-18 (terminal No. 15).
NOTE: Check harness after checking intermediate connectors C-21. If intermediate connector C-21 is damaged, repair or replace it. Refer to general (electrical), Harness Connector Inspection. Then check that the malfunction is eliminated.
Q: Is the harness wire in good condition?
YES : Refer to MFI, INSPECTION PROCEDURE 28 -Power Supply System and Ignition Switch-IG System. Inspection Procedure 28
NO : Repair it. Then confirm that the malfunction symptom is eliminated.
Data Link Connector Circuit (Part 1):
Data Link Connector Circuit (Part 2):
CIRCUIT OPERATION
- A diagnostic output is made from the ECM [M/T] or the PCM [A/T] (terminal No. 15) to the diagnostic output terminal (terminal No. 7) of the data link connector.
COMMENT
- No power supply to ECM [M/T] or PCM [A/T].
- Defective ground circuit of ECM [M/T] or PCM [A/T].
- Defective ECM [M/T] or PCM [A/T].
- Improper communication line between ECM [M/T] or PCM [A/T] and scan tool.
TROUBLESHOOTING HINTS (The most likely causes for this case:)
- Malfunction of ECM [M/T] or PCM [A/T] power supply circuit.
- Malfunction of the ECM [M/T] or the PCM [A/T].
- Open circuit between ECM [M/T] or PCM [A/T] and data link connector.
DIAGNOSIS
STEP 1. Check harness connector B-18 at ECM [M/T] or PCM [A/T] for damage.
Q: Is the harness connector in good condition?
YES : Go to Step 2.
NO : Repair or replace it. Refer to general (electrical), Harness Connector Inspection. Then confirm that the malfunction symptom is eliminated.
STEP 2. Check for open circuit, short circuit to ground and harness damage between data link connector C-125 (terminal No. 7) and ECM [M/T] or PCM [A/T] connector B-18 (terminal No. 15).
NOTE: Check harness after checking intermediate connectors C-21. If intermediate connector C-21 is damaged, repair or replace it. Refer to general (electrical), Harness Connector Inspection. Then check that the malfunction is eliminated.
Q: Is the harness wire in good condition?
YES : Refer to MFI, INSPECTION PROCEDURE 28 -Power Supply System and Ignition Switch-IG System. Inspection Procedure 28
NO : Repair it. Then confirm that the malfunction symptom is eliminated.
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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