P23F0 code meaning
Camshaft B Position Signal Output Circuit Low (Bank 2)
What P23F0 means
P23F0 is stored when the bank 2 camshaft B output stays at ground potential while the ECM expects it to float high. A low reading can come from insulation damage near the exhaust side, where heat makes harness sleeves brittle, or from a receiving module whose input has failed shorted. Following GM's published logic for P2615, the module samples every 100 ms and sets the fault after 40 bad samples out of 50; an open beyond about 200 kOhm is caught by the same test. These values are borrowed, since no maker publishes P23F0. A dead output leaves the downstream unit without engine phase information, so it may fall back to substitute values, which drivers notice as harsher shifts or disabled features.
P23F0 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 P23F0
- Code stored, engine itself unaffected
- Harsher shifts or delayed gear changes
- Features such as start-stop disabled
Common causes of P23F0
- Most likelyHeat-damaged insulation on the exhaust side grounding the wire
- PossibleReceiving module input failed short to ground
- Less likelyDefective output stage in the ECM
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 P23F0 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. |
| F0 | The exact fault in that area. |
What to do next
- Note P23F0 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 P23F0
What does P23F0 mean?
P23F0 means "Camshaft B Position Signal Output Circuit Low (Bank 2)". P23F0 is stored when the bank 2 camshaft B output stays at ground potential while the ECM expects it to float high. It is a generic code, so it means the same on every make.
Is it safe to drive with P23F0?
Drive gently and only to a workshop. With P23F0 the car can go into limp mode (reduced power) to protect itself.
Will P23F0 fail an emissions test?
P23F0 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 P23F0 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P23F0 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.