P280B code meaning
Transmission Range Sensor B Circuit Not Learned
Powertrain system Generic code P28xx codes Check engine light
What P280B means
P280B flags missing or invalid adaptation values for the second range sensor signal. Where a design reads A and B in different modules, as GM does with sensor A in the TCM and sensor B in the engine module, a replaced or reprogrammed engine controller can lose the B reference while A is still learned. No maker documents P280B publicly, and CARB 13 CCR 1968.2 gives only the general duty to monitor transmission inputs. GM's correlation check P2805 shows how closely both paths are compared afterwards: their duty cycles must add up to 100 % within about 5 %. Without a valid B reference the plausibility checks against A cannot run. Perform the learn with a scan tool once circuit codes P2800-P2804 are cleared.
P280B at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.3 to 1.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P280B
- Warning lamp after module replacement
- Gear position checks disabled, possible start refusal
Common causes of P280B
- Most likelyModule reading sensor B replaced or reprogrammed without learn
- PossibleLearn procedure interrupted
- Less likelyOpen circuit faults on sensor B preventing the learn
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Transmission range sensor bTCM
What each part of P280B means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 8 | Area: transmission. |
| 0B | The exact fault in that area. |
What to do next
- Note P280B 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 P280B
What does P280B mean?
P280B means "Transmission Range Sensor B Circuit Not Learned". P280B flags missing or invalid adaptation values for the second range sensor signal. It is a generic code, so it means the same on every make.
Is it safe to drive with P280B?
Drive gently and only to a workshop. With P280B the car can go into limp mode (reduced power) to protect itself.
Will P280B fail an emissions test?
Yes, it can. P280B is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P280B to fix?
Difficulty: medium. A typical repair takes 0.3 to 1.5 hours of work. This is a job for a workshop.
Will P280B clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.