P026A
Charge Air Cooler Efficiency Below Threshold
Charge air cooler efficiency dropped below diagnostic threshold — intake air not cooled enough after compression. Risk of knock and loss of power.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Intercooler airflow blocked or core damagedCommon
Parts involved
- Intercooler
- Cac Coolant Pump
P026A is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.