U0404moderate severityNetwork
Invalid Data Received from Gear Shift Module
on 2002 Mercedes-Benz SL 3.0L I6 · RWD
What this code means
The data received from the gear shift position module is invalid or not within expected range.
Symptoms
- Incorrect gear display
- Shifter position not recognized
- Transmission defaulting to safe mode
- Cannot select some gears
Common causes
- Gear shift sensor fault
- Wiring issue to shift module
- Shift module calibration lost
- CAN bus noise
Diagnostic steps
- Check gear shift module for codes
- Test shift position sensor outputs
- Check CAN bus wiring to shift module
- Recalibrate shift module
- Inspect shift mechanism
Repair notes
Recalibrate or replace gear shift module. Check wiring to shifter assembly.
Other Network codes on this vehicle
U0001
High Speed CAN Communication Bus
U0002
High Speed CAN Communication Bus Performance
U0003
High Speed CAN Communication Bus (+) Open
U0004
High Speed CAN Communication Bus (+) Low
U0005
High Speed CAN Communication Bus (+) High
U0006
High Speed CAN Communication Bus (-) Open
U0007
High Speed CAN Communication Bus (-) Low
U0008
High Speed CAN Communication Bus (-) High
U0009
High Speed CAN Communication Bus Shorted Together
U0010
Medium Speed CAN Communication Bus