What does it mean?
C1401 is a Chassis (ABS, traction control, steering) fault code. It indicates: Transfer Case Range Select Switch Circuit Low .
Symptoms
- Service four wheel drive message and a warning lamp
- Range does not change when the selector is moved
- Indicator shows a range that was never selected
- Transfer case stays in the range it was in when the fault set
- Code sets as soon as the ignition is switched on, before the vehicle is driven
Likely causes
- Signal wire from the range select switch shorted to ground
- Chafed harness grounding against the console frame, a bracket or the floor pan
- Switch shorted internally or stuck in a closed position
- Water or spilled liquid inside the switch connector bridging the terminals
- Damaged or pushed-in pin making unintended contact with a ground pin
- Open circuit where a pull-up defines the level, so the module reads a low
- Control module input pulled low internally (least likely)
How to fix it
- Read the switch circuit voltage in live data with the ignition on and the selector in each position
- Unplug the switch and see whether the voltage rises to reference, which separates a faulty switch from a shorted harness
- With the switch unplugged, measure resistance from the signal circuit to ground; a low reading confirms the short
- Inspect the connector for moisture, corrosion and bent or pushed-in terminals
- Trace the harness along the console and floor for chafe points and repair the damaged section
- Replace the switch if it measures shorted internally
- Check the module connector and the module itself only after the switch and harness test good