P06AC code meaning
Control Module Internal Temperature Sensor B Range/Performance
Powertrain system Generic code P06xx codes Check engine light
What P06AC means
Control modules can carry a second internal temperature sensor (B). In GM's 6T70/6T75 and related automatics, sensor A measures the circuit board (substrate) temperature, sensor B the 'power-up temperature' used as a reference and substitute; both sit inside the transmission module in the valve body, so repairs mean module or valve body. P06AC is the plausibility check of sensor B: GM compares the power-up temperature with the substrate temperature (sensor A) and the transmission fluid temperature and sets the code after two trips if they disagree beyond tabulated limits. Check the fluid temperature sensor (P0711) as comparison partner first.
P06AC at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 4 hours
- Clears after repairAfter a drive cycle
Symptoms of P06AC
- Warning or check engine light
- Changed shift quality (substitute value)
- Implausible module temperature in the scan tool
Common causes of P06AC
- Most likelyTransmission module or valve body (internal sensor) faulty
- PossibleTransmission fluid temperature sensor reads wrong
- Less likelyModule supply or software
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Transmission control moduleControl module internal temperature sensor
What each part of P06AC means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 6 | Area: computer (engine control module) and output circuits. |
| AC | The exact fault in that area. |
What to do next
- Note P06AC 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 P06AC
What does P06AC mean?
P06AC means "Control Module Internal Temperature Sensor B Range/Performance". Control modules can carry a second internal temperature sensor (B). It is a generic code, so it means the same on every make.
Is it safe to drive with P06AC?
Drive gently and only to a workshop. With P06AC the car can go into limp mode (reduced power) to protect itself.
Will P06AC fail an emissions test?
Yes, it can. P06AC 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 P06AC to fix?
Difficulty: hard. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will P06AC clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.