Charge Air Cooler Temperature Sensor Circuit High
What does DURAMAX-P007D mean?
The DURAMAX-P007D (Duramax) diesel fault code means: Charge Air Cooler Temperature Sensor Circuit High. This is a moderate severity code.
Common Symptoms
- Sluggish acceleration / loss of power
- Excessive black smoke or white smoke
- Whining or fluttering noise from turbo
- Check Engine Light / reduced power message
- Turbo may exhibit surging under load
Probable Causes (Ranked by Likelihood)
- CAC temperature sensor open circuit Very Likely
- Soot buildup locking VGT vanes (chronic Duramax issue) Likely
- Cracked intercooler boot or charge pipe leak Possible
- Damaged turbo bearing / worn turbo Possible
- Failed boost pressure sensor Less Likely
Step-by-Step Diagnostic Procedure
Pressure-test the charge air (intercooler) system to rule out boot leaks first
Command VGT vane position with scan tool and watch actual vs. commanded response
Perform a VGT unstick procedure (if supported by scanner) — cycles vanes through full range
Remove VGT actuator and inspect vanes for soot lockup; clean with BG 44K or remove for decarbonization
Replace VGT solenoid ($250) before condemning the whole turbo ($2,500+)
Frequently Asked Questions
What is P007D on a Duramax?
Duramax code P007D (Charge Air Cooler Temperature Sensor Circuit High) is a moderate-severity diagnostic trouble code triggered by the engine control module when it detects a problem in the associated system. On LLY/LMM, a VGT service every 100K miles (decarbonize vanes) dramatically extends turbo life.
Is a Duramax P007D safe to drive?
No. Underboost from stuck vanes causes excessive EGT and can damage the turbo, exhaust manifold, or head if driven hard.
How much does it cost to fix P007D on a Duramax?
Solenoid $250, actuator $450, full turbo $2,500-$4,500 installed.