Exhaust Gas Temperature Sensor Circuit Bank 1 Sensor 1 Open (Generic)
The P4000 code means the vehicle's onboard diagnostic system has detected: Exhaust Gas Temperature Sensor Circuit Bank 1 Sensor 1 Open (Generic). This is a critical severity code.
- Keep driving?
- No -- stop driving
- DIY difficulty
- hard
- Estimated cost
- $80 - $350 (parts and labor)
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Common Symptoms
- Check Engine Light on
- Reduced engine power mode
- DPF regeneration disabled
- Increased exhaust emissions
- Turbo protection mode activated
Probable Causes (Ranked by Likelihood)
- Open circuit in EGT sensor 1 wiring Very High
- Faulty exhaust gas temperature sensor 1 High
- Corroded connector at EGT sensor Moderate
- PCM internal circuit failure Low
Step-by-Step Diagnostic Procedure
-
Check EGT sensor 1 resistance and compare to specifications
-
Inspect wiring harness between EGT sensor 1 and PCM
-
Verify connector integrity at sensor and PCM side
-
Swap sensor with known good unit and retest
Frequently Asked Questions
What is an EGT sensor?
An exhaust gas temperature sensor monitors how hot the exhaust gases are. This data is critical for diesel particulate filter regeneration and turbocharger protection.
Can I drive without the EGT sensor working?
No, the vehicle will likely enter reduced power mode. DPF regeneration will be disabled which can lead to a clogged DPF.
How much does an EGT sensor cost?
The sensor itself is typically $40-100. With labor, expect $150-350 as some sensors are difficult to access.
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