P026A code meaning
Charge Air Cooler Efficiency Below Threshold
Powertrain system Generic code P02xx codes Check engine light
What P026A means
P026A means the charge air cooler is not cooling enough. The module compares the temperature drop across the cooler with the maximum possible (inlet minus ambient) or with a model: GM's 6.6 litre LML diesel sets it below 25 % efficiency, later GM diesels below 50 %, both after two trips; Ford's 6.7 and 3.0 diesels when the measured temperature is 18–35 °C (3.0: 35–65 °C) off the model over about 10 s. GM's 3.0 twin-turbo gasoline with a coolant-cooled charge air cooler sets it in the first trip when manifold air exceeds 110 °C or boost has been limited for a long time. Hot intake air costs power and raises NOx and soot.
P026A at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P026A
- Check engine light on
- Loss of power under load or in heat
- High intake air temperature in live data
Common causes of P026A
- Most likelyCharge air cooler clogged on the outside (insects, leaves, dirt) or fins damaged
- Most likelyCoolant-cooled cooler: pump faulty, air in the low-temperature circuit, low coolant
- PossibleCharge air or ambient temperature sensor inaccurate
- Less likelyCharge air cooler bypass stuck open
- Less likelySoftware or calibration
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Charge air coolerCharge air temperature sensorsCharge air cooler coolant pump
What each part of P026A 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). |
| 6A | The exact fault in that area. |
What to do next
- Note P026A 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 P026A
What does P026A mean?
P026A means "Charge Air Cooler Efficiency Below Threshold". P026A means the charge air cooler is not cooling enough. It is a generic code, so it means the same on every make.
Is it safe to drive with P026A?
Drive gently and only to a workshop. With P026A the car can go into limp mode (reduced power) to protect itself.
Will P026A fail an emissions test?
Yes, it can. P026A 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 P026A to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P026A 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.