Transmission Fluid Pressure Sensor/Switch "A" Circuit Low
The DURAMAX-P0842 (Duramax) diesel fault code means: Transmission Fluid Pressure Sensor/Switch "A" Circuit Low. This is a moderate severity code.
- Keep driving?
- Yes, with caution
- DIY difficulty
- intermediate
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What Are the Symptoms of DURAMAX-P0842?
- Check Engine Light on
- Harsh, delayed or erratic shifts
- Transmission may hold a single gear
What Causes DURAMAX-P0842? (Most Likely First)
- Signal wire shorted to ground High
- Failed pressure sensor or switch High
- Low fluid pressure from low fluid level Moderate
Can I Still Drive with DURAMAX-P0842?
Yes, with caution. DURAMAX-P0842 is rated moderate severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.
Frequently Asked Questions
What does P0842 mean on a Duramax?
P0842 means Transmission Fluid Pressure Sensor/Switch "A" Circuit Low. The transmission fluid pressure sensor or switch "A" signal is below its normal range.
Is P0842 a Duramax-specific code?
No. P0842 is a generic OBD-II code defined by SAE J2012, so it means the same thing on any vehicle that sets it. The exact conditions GM uses to set it on its diesels are in GM service information.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose DURAMAX-P0842?
Check the transmission fluid level.
Inspect the transmission harness and connector.
Check the sensor circuit for a short to ground.
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines P0842 as a generic OBD-II code)
P0842 on Other Platforms
The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown:
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