What it means
The multiple EGT sensors on bank 1 disagree by more than the diagnostic tolerance under stable conditions - one of them has drifted relative to the others.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Exhaust gas temperature sensors on bank 1 report temperatures at different points in the exhaust, allowing the control module to assess exhaust and aftertreatment operation. P24C2 sets when readings from multiple bank 1 sensors disagree beyond the allowed correlation while conditions are stable.
Common causes
Most likely first.
- Exhaust gas temperature sensor drift or failure
- Damaged sensor wiring
- Loose or corroded connector
- Exhaust leak affecting a sensor reading
Symptoms
- Check-engine light on
- Aftertreatment or exhaust warning
- Reduced engine power
- Emissions inspection failure
How to diagnose it
- Save freeze-frame data and compare live readings from all bank 1 exhaust temperature sensors under the same stable operating conditions.
- Inspect each bank 1 sensor connector and harness along the exhaust for heat damage, loose pins, corrosion, or contact with hot or moving parts.
- Check for exhaust leaks near the bank 1 sensor locations that could make one sensor read differently from the others.
- Compare each sensor's response during warm-up or a supported scan-tool test to identify a reading that is biased or does not change plausibly.
- Test the suspect sensor and its wiring against the manufacturer's specification before replacing parts.
Common fixes
- Repair damaged or heat-exposed wiring to a bank 1 temperature sensor.
- Clean or repair a loose or corroded sensor connector.
- Repair an exhaust leak near the affected bank 1 sensor.
- Replace the bank 1 temperature sensor shown by testing to have drifted.
Can I keep driving?
You may be able to drive, but reduced power or an aftertreatment warning can occur and emissions performance may be affected. Avoid heavy loads if power is reduced, and stop if the exhaust warning is accompanied by overheating or other urgent warnings.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.