P2805 code meaning
Transmission Range Sensor A/B Correlation
Powertrain system Generic code P28xx codes Check engine light
What P2805 means
Both range sensor signals are valid on their own, yet they do not agree. Many designs output two complementary pulse-width signals whose duty cycles must add up to 100 %. GM reads signal A in the transmission module and signal B in the engine module and sets P2805 as Type A when the sum is off by more than 4.849 % (2020 table) or 5.2 % (2025) for 1 s of 1.5 s. Ford allows plus or minus 4 % on its six- and ten-speed automatics (2024) and used the same principle on the DPS6 (2012). Audi bulletin 2051686 for 2016-2017 A6 links P280500 with a no-start and a gearbox message, cured by a new drive position sensor G676 plus TCM. Single-signal faults are P0705-P0709 and P2800-P2804.
P2805 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2805
- MIL and gearbox warning on
- Engine will not start or selector position not accepted
- Substitute gear or limp operation
Common causes of P2805
- Most likelyRange sensor with one drifting output
- PossibleAdded resistance or poor ground in one of the two signal paths
- Less likelyFault in the reading control module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Transmission range sensor aTransmission range sensor bTCM
What each part of P2805 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. |
| 05 | The exact fault in that area. |
What to do next
- Note P2805 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 P2805
What does P2805 mean?
P2805 means "Transmission Range Sensor A/B Correlation". Both range sensor signals are valid on their own, yet they do not agree. It is a generic code, so it means the same on every make.
Is it safe to drive with P2805?
Drive gently and only to a workshop. With P2805 the car can go into limp mode (reduced power) to protect itself.
Will P2805 fail an emissions test?
Yes, it can. P2805 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 P2805 to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P2805 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.