Inspection Procedure 1

INSPECTION PROCEDURE 1: The scan tool cannot communicate with the shift lever-ECU.

CAUTION:
Whenever the ECU is replaced, ensure that the CAN bus lines are normal.

COMMENTS ON TROUBLE SYMPTOM

The CAN bus line, shift lever-ECU power supply circuit, or shift lever-ECU may have a problem.

PROBABLE CAUSES

- Wrong scan tool wiring harness
- The CAN bus line is defective.
- Malfunction of the shift lever-ECU power supply circuit
- Malfunction of the shift lever-ECU
- ECU malfunction of other system

DIAGNOSTIC PROCEDURE

STEP 1. Scan tool CAN bus diagnostics

Using scan tool MB991958, diagnose the CAN bus lines.

Q. Is the check result normal?

YES Check and repair the shift lever-ECU power supply circuit. (Refer to Inspection Procedure 6.)
NO Repair the CAN bus lines. CAN Bus Diagnostics Chart.)