P2B83 code meaning
Charge Air Cooler Coolant Pump A Overspeed/Air In System
Powertrain system Generic code P2Bxx codes Check engine light
What P2B83 means
P2B83 concerns the electric pump that keeps coolant moving through a water-cooled charge air cooler. When the impeller runs in air instead of liquid, load vanishes and the motor spins up. GM documents this in its 2025 diesel table 25OBDG04B: a reported pump speed of 8,500 rpm or more in 8 of 10 one-second samples sets the code, provided the pump is fitted and enabled, the engine is not cranking and relay voltage is at least 11 V; Type B, MIL after two trips. GM's 3.0-litre Duramax uses such a pump (M10, bulletin 23-NA-102). GM's bulletin 18-NA-291 for the supercharged LT4 notes that this pump switches off once it draws air, so the loop must be vacuum filled. Too little speed is P2B84, the B pump has P2CB1. Hot charge air can cut power.
P2B83 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2B83
- Check engine light after two drives with the fault
- Reduced power under load because the intake air gets hot
- Falling level in the charge air cooler coolant reservoir
Common causes of P2B83
- Most likelyAir pocket in the charge air cooler loop after service or a leak
- PossibleLow coolant level in the separate low-temperature loop
- Less likelyImpeller loose or broken on the pump shaft
- Less likelyPump electronics reporting an implausible speed
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Cac coolant pump aCac coolant loop
What each part of P2B83 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| B | Area: hybrid propulsion. |
| 83 | The exact fault in that area. |
What to do next
- Note P2B83 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 P2B83
What does P2B83 mean?
P2B83 means "Charge Air Cooler Coolant Pump A Overspeed/Air In System". P2B83 concerns the electric pump that keeps coolant moving through a water-cooled charge air cooler. It is a generic code, so it means the same on every make.
Is it safe to drive with P2B83?
Drive gently and only to a workshop. With P2B83 the car can go into limp mode (reduced power) to protect itself.
Will P2B83 fail an emissions test?
Yes, it can. P2B83 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 P2B83 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P2B83 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.