DTC B1142: ESL authenticate error; DTC B1151 OSS authenticate timeout (ESL): Diagnosis

STEP 1. After turning the forced power supply output to "IG-ON" using the scan tool MB991958, check if the DTC B1161 is set.
Q: Is the DTC set?
1. YES: Carry out the troubleshooting for the DTC B1161. Refer to DTC B1159 VIN not programmed (OSS); DTC B1160 Key code not programmed (OSS); DTC B1164 VIN not programmed (ESL); DTC B1165 Key code not programmed (ESL) .
2. NO: Go to Step 2.
STEP 2. After performing the locking and unlocking operations of the electric steering lock, recheck the DTC.
Q: Is the DTC set?
1. YES: Replace the electric steering lock and register the VIN (Refer to CHECK OF ENGINE SWITCH REMINDER TONE ALARM ).
2. NO: Intermittent malfunction is suspected (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).