P23F1 code meaning
Camshaft B Position Signal Output Circuit High (Bank 2)
What P23F1 means
P23F1 means the camshaft B output for bank 2 sits at a high level that the ECM did not command. Its driver switches the line to ground to form the pulses; if the line stays high while switched, current is coming in from elsewhere – typically a short to a supply wire in a shared harness bundle, sometimes water bridging terminals. The GM bank 1 camshaft A analogue P2616 judges this at 0.5 ohm or less to power, with at least 11 V at the powertrain relay, and classes it as Type C. There is no published manufacturer description of P23F1. Measure the line with the receiver unplugged: if the voltage disappears, the receiving module is the source. Counterparts are P23EE for bank 1 and P23F0 for a line stuck low.
P23F1 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P23F1
- Code present, no change in engine behaviour
- Communication or plausibility faults in the receiving module
Common causes of P23F1
- Most likelyShort to a supply wire within a shared harness bundle
- PossibleWater bridging connector terminals
- Less likelyReceiving module feeding voltage back into the line
- Less likelyECM driver no longer switching
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Engine control moduleCam position signal b b2 outputWiring harness
What each part of P23F1 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 3 | Area: ignition system or misfire. |
| F1 | The exact fault in that area. |
What to do next
- Note P23F1 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P23F1
What does P23F1 mean?
P23F1 means "Camshaft B Position Signal Output Circuit High (Bank 2)". P23F1 means the camshaft B output for bank 2 sits at a high level that the ECM did not command. It is a generic code, so it means the same on every make.
Is it safe to drive with P23F1?
Drive gently and only to a workshop. With P23F1 the car can go into limp mode (reduced power) to protect itself.
Will P23F1 fail an emissions test?
P23F1 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is P23F1 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P23F1 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.