P023B code meaning
Charge Air Cooler Coolant Pump A Control Circuit Low
Powertrain system Generic code P02xx codes Check engine light
What P023B means
Some engines cool the charge air with a coolant-to-air cooler in its own low-temperature circuit, driven by an electric pump – GM uses this on supercharged V8s such as the LT4 (Camaro ZL1, Corvette Z06, CTS-V) and LT5 (Corvette ZR1). P023B means GM's driver diagnosis has found a short to ground (0.5 Ω or less between output and ground with the driver off). Bundled conditions: main relay at least 11 V, ignition above 5 V; 50 of 63 samples set the code with the warning light in the first trip on 2018–2019 engines, older modules need two trips. Without the pump the charge air gets hot and boost is limited.
P023B at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P023B
- Check engine light on
- Loss of power under load or in heat (boost limited)
- Follow-up code P026A possible
Common causes of P023B
- Most likelyControl wire to the pump shorted to ground
- PossiblePump shorted internally
- PossibleMoisture or corrosion in the connector
- Less likelyDriver stage in the engine module faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Charge air cooler coolant pumpPump wiringEngine control module
What each part of P023B means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 2 | Area: fuel and air metering (injector circuit). |
| 3B | The exact fault in that area. |
What to do next
- Note P023B 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 P023B
What does P023B mean?
P023B means "Charge Air Cooler Coolant Pump A Control Circuit Low". Some engines cool the charge air with a coolant-to-air cooler in its own low-temperature circuit, driven by an electric pump – GM uses this on supercharged V8s such as the LT4 (Camaro ZL1, Corvette Z06, CTS-V) and LT5 (Corvette ZR1). It is a generic code, so it means the same on every make.
Is it safe to drive with P023B?
Drive gently and only to a workshop. With P023B the car can go into limp mode (reduced power) to protect itself.
Will P023B fail an emissions test?
Yes, it can. P023B 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 P023B to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P023B clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.