B0402low severityBody
Tachometer Circuit Malfunction
on 2002 Audi A4 1.8L Turbo I4 · AWD
What this code means
The tachometer gauge is not functioning or displays incorrect RPM readings.
Symptoms
- Tachometer reads zero
- Tachometer needle erratic
- Tachometer bouncing at idle
- Gauge needle stuck
Common causes
- Instrument cluster stepper motor failure
- Cluster circuit board fault
- RPM signal issue from PCM
- Wiring problem
Diagnostic steps
- Check RPM signal from PCM with scan tool
- Test tachometer stepper motor
- Inspect cluster circuit board
- Check wiring from PCM to cluster
Repair notes
Replace instrument cluster stepper motor or circuit board.
Other Body codes on this vehicle
B0001
Driver Frontal Stage 1 Deployment Control
B0002
Driver Frontal Stage 2 Deployment Control
B0003
Passenger Frontal Stage 1 Deployment Control
B0004
Passenger Frontal Stage 2 Deployment Control
B0005
Driver Knee Airbag Deployment Circuit
B0006
Passenger Knee Airbag Deployment Circuit
B0010
Driver Side Airbag Deployment
B0011
Driver Side Airbag Deployment Circuit Open
B0012
Driver Side Airbag Deployment Circuit Short to Ground
B0013
Driver Side Airbag Deployment Circuit Short to Battery