Inspection Procedure 2

Communication with Scan Tool is Not Possible (Communication with ECM Only is Not Possible)

Data Link Connector Circuit Part 1:

CIRCUIT OPERATION
- A diagnostic output is made from the ECM (terminal No. 62) to the diagnostic output terminal (terminal No. 7) of the data link connector.

COMMENT
- No power supply to ECM.
- Defective ground circuit of ECM.
- Defective ECM.
- Improper communication line between ECM and scan tool.

TROUBLESHOOTING HINTS (The most likely causes for this case:)
- Malfunction of ECM power supply circuit.
- Malfunction of the ECM.
- Open circuit between ECM and data link connector.

DIAGNOSIS




STEP 1. Check connector C-117 at ECM for damage.

Q: Is the connector in good condition?

YES: Go to Step 2.

NO: Repair or replace it. Refer to 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-14 (terminal No. 7) and ECM connector C-117 (terminal No. 62).

NOTE: Check harness after checking intermediate connectors C-101, C-105 and C-124. If intermediate connectors are damaged, repair or replace them. Refer to Harness Connector Inspection. Then check that the malfunction is eliminated.

Q: Is the harness wire in good condition?

YES: Refer to, INSPECTION PROCEDURE 30 - Power Supply System and Ignition Switch - IG System.

NO: Repair it. Then confirm that the malfunction symptom is eliminated.