Exhaust Gas Temperature Sensor Circuit Bank 1 Sensor 1 High (Generic)
The P4002 code means the vehicle's onboard diagnostic system has detected: Exhaust Gas Temperature Sensor Circuit Bank 1 Sensor 1 High (Generic). This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $80 - $350 (parts and labor)
Best-selling code reader on Amazon. Reads and clears check engine codes on any 1996+ vehicle. Under $30.
Check Price on AmazonAffiliate link -- we earn a commission at no extra cost to you.
Essential for diagnosing sensor codes, checking voltage, and testing circuits. Under $15 and pays for itself on the first job.
Check Price on AmazonAffiliate link -- we earn a commission at no extra cost to you.
Common Symptoms
- Check Engine Light on
- False high temperature reading on scan tool
- Unnecessary DPF regeneration cycles
- Reduced engine power
- Poor fuel economy from excess regen
Probable Causes (Ranked by Likelihood)
- Short to voltage in EGT sensor circuit Very High
- Faulty EGT sensor reading high High
- Damaged wiring near exhaust manifold Moderate
- PCM reference voltage issue Low
Step-by-Step Diagnostic Procedure
-
Check EGT sensor signal voltage with scan tool
-
Inspect wiring for shorts to power or other circuits
-
Test sensor resistance and compare to temperature chart
-
Verify 5V reference circuit integrity
Frequently Asked Questions
What happens if EGT reads too high?
The PCM may trigger unnecessary DPF regeneration cycles which wastes fuel, or it may limit engine power to protect exhaust components from perceived overheating.
Can I drive with P4002?
You can drive short distances. The main risk is unnecessary DPF regeneration events or engine power reduction.
How do I test an EGT sensor?
Measure the sensor resistance with a multimeter and compare to the manufacturer temperature-resistance chart. The resistance should change smoothly as temperature changes.
Explore More
Was this helpful?
Share carcodefinder.com with a friend who needs to decode their check engine light.