P0942
Hydraulic Pressure Unit
The TCM detects a generic fault in the hydraulic pressure unit. Pump output, pressure regulation, or accumulator function impaired.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Common causes
Ordered by how often each turns out to be the cause.
- Hydraulic pump wornCommon
- Internal leakagePossible
Parts involved
- Hydraulic Pressure Unit
- TCM
P0942 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.