Exhaust Gas Temperature Sensor Circuit Bank 2 Sensor 2 Open (Generic)
The P4012 code means the vehicle's onboard diagnostic system has detected: Exhaust Gas Temperature Sensor Circuit Bank 2 Sensor 2 Open (Generic). This is a critical severity code.
- Keep driving?
- No -- stop driving
- DIY difficulty
- hard
- Estimated cost
- $120 - $450 (parts and labor)
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Common Symptoms
- Check Engine Light on
- DPF regeneration disabled on bank 2
- Reduced engine power mode
- High soot accumulation warning
- Service exhaust system message
Probable Causes (Ranked by Likelihood)
- Open circuit in bank 2 EGT sensor 2 wiring Very High
- Failed bank 2 post-DPF temperature sensor High
- Melted connector from DPF regen heat Moderate
- Wiring break from vibration fatigue Low
Step-by-Step Diagnostic Procedure
-
Check EGT sensor 2 bank 2 resistance
-
Inspect wiring near DPF on bank 2 side
-
Check connector for thermal damage
-
Verify continuity from sensor to PCM
Frequently Asked Questions
Can a clogged DPF cause P4012?
No, P4012 is an electrical circuit fault, not a DPF efficiency code. However, if P4012 prevents regeneration, the DPF may become clogged as a secondary issue.
How much does a DPF replacement cost if it gets clogged?
DPF replacement typically costs $2000-5000 depending on the vehicle. This is why addressing EGT sensor codes promptly is important.
Can I drive with P4012?
The vehicle will likely be in reduced power mode. Driving is not recommended as DPF regeneration is disabled.
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