OBD-II code · Powertrain (generic, extended)
P23C4 Engine Coolant Bypass Valve C Position Sensor Circuit Low
Same as P23C3 with the signal voltage below the plausible range. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Is it safe to drive with P23C4?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySignal shorted to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.8–2 h
- Emissions test
- Usually unaffected
- Parts involved
- Coolant Bypass Valve C Position Sensor
Related codes
- P26A6Engine Coolant Bypass Valve A Position Sensor Circuit Low
- P2AA9Engine Coolant Bypass Valve B Position Sensor Circuit Low
- P23C1NOx Sensor Sensing Element Bank 1 Sensor 3
- P23C2NOx Sensor Delayed Response High to Low Bank 1 Sensor 3
- P23C3Engine Coolant Bypass Valve C Position Sensor Circuit
- P23C5Engine Coolant Bypass Valve C Position Sensor Circuit High
- P23C6Engine Coolant Bypass Valve C Control Circuit Driver Current or Temperature Too High
- P23C7Fuel Heater Control Module Power Control Circuit Open
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.