What does it mean?
C1948 is a Chassis (ABS, traction control, steering) fault code. It indicates: Seat Track Position Switch Circuit Resistance Out of Range .
Symptoms
- SRS/airbag warning lamp lit
- Fault that comes and goes with weather, humidity or seat movement
- Seat position input treated as unreliable, so deployment force adaptation is disabled
- Code returns after a short time even though the wiring looks intact
- Occasional intermittent SRS lamp before it becomes permanent
Likely causes
- Corroded or oxidised terminals under the seat adding resistance to the circuit
- Wire strands partly broken inside the insulation from repeated seat movement
- Dirty, worn or pitted switch contacts
- Poor crimp or a twisted-and-taped repair splice instead of a proper joint
- Non-original switch or seat assembly with a different resistance value
- Moisture in the connector changing the circuit resistance as it dries and wets
- Drifted input or reference circuit inside the restraint control module
How to fix it
- Disconnect the battery and wait the specified time before probing any restraint circuit
- Measure the circuit resistance at the restraint module connector and compare it with specification
- Measure the switch on its own at the seat connector to separate switch resistance from harness resistance
- Clean and inspect all terminals for green corrosion, spreading and poor tension
- Perform a voltage drop check across any repair splice in the circuit
- Replace poor splices with correctly crimped joints using the specified repair leads
- Replace the switch if its resistance is out of range with a good harness, then clear the codes and verify the SRS lamp goes out