P1642high severityPowertrain
ECM Incorrect Coding MT/AT Mismatch
on 2002 Mercedes-Benz SL 3.0L I6 · RWD
What this code means
The ECU detected that the transmission type coding (manual vs automatic) does not match the actual transmission installed. This causes incorrect shift strategy, torque management, and idle speed parameters.
Symptoms
- Check Engine Light
- Incorrect idle speed
- Transmission control issues
- Torque reduction malfunction
- Starting difficulties
Common causes
- ECU replaced without proper coding
- Incorrect ECU installed
- Coding data corrupted during update
- Transmission swapped without ECU recoding
Diagnostic steps
- Read ECU coding for transmission type
- Compare coding to actual transmission installed
- Verify ECU part number matches vehicle
- Check for failed software updates
- Recode ECU with correct transmission type
Repair notes
Recode the ECU to match the installed transmission type using Mercedes Star Diagnosis.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1