Inspection Procedure 2

Communication with Scan Tool Is Not Possible (Communication with PCM Only Is Not Possible)

Data Link Connector Circuit Part 1:

Data Link Connector Circuit Part 2:

CIRCUIT OPERATION
- A diagnostic output is made from the PCM (terminal No. 74) to the diagnostic output terminal (terminal No. 7) of the data link connector.

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

TROUBLESHOOTING HINTS (The most likely causes for this case: )
- Open or shorted data link connector circuit, harness damage or connector damage.

DIAGNOSIS




STEP 1. Check harness connector C- 112 at PCM for damage.

Q: Is the harness 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-18 (terminal No. 7) and PCM connector C-112 (terminal No. 74).

NOTE: Check harness after checking intermediate connectors C-118 and C-01. If the 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 29 - Power Supply System and Ignition Switch-IG System.

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