Inspection Procedure 2: SOS switch/information switch indicator light does not illuminate.
caution
When replacing the ECU, always check that the communication circuit is normal.
TECHNICAL DESCRIPTION (COMMENT)
If the SOS switch/information switch indicator light does not illuminate, the SOS switch/information switch or the TCU may be defective.
TROUBLESHOOTING HINTS
The ECALL&BCALL switch may be defective
The TCU may be defective
DIAGNOSIS
Required Special Tools
MB991223: Wiring harness set
MB992006: Extra fine probe
STEP 1. Check the SOS switch/information switch indicator light.
Check that the SOS switch/information switch indicator light illuminates. Refer to .
Is the check result normal?
Go to Step 2.
Replace the ECALL&BCALL switch (Refer to ).
STEP 2. Retest the system.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).