The presence of a P0938 DTC means that the ECU thinks the hydraulic oil temperature sensor is not performing within its preprogrammed range. This could naturally lead to overheating and serious internal damage.
What Transmission Do I Have?
How Serious is the Code?
The hydraulic oil temperature sensor monitors how hot the hydraulic oil is getting, and relays this information to the ECU on a constant basis. The P0939 diagnostic trouble code means that this is not happening the way it should, so overheating and other serious damage can occur.
Symptoms
Symptoms of a P0938 include:
- Check engine light
- Overheating
- Erratic vehicle behavior
- Limp Mode
Causes
- Damaged/frayed wiring
- Connectors are corroded or broken
- Hydraulic oil temperature sensor has failed
- Low hydraulic fluid level
- Dirty hydraulic fluid and filter
How to Diagnose the Code?
To figure out what is causing a P0938 OBDII trouble code, a technician should check the condition of the hydraulic oil to see if it is dirty, low, burnt or contains metal shavings. If any of these conditions apply, the fluid should be changed immediately. The wiring and connectors along the hydraulic oil temperature circuit should also be checked for signs of damage and corrosion. If no problems have been found, then the hydraulic oil temperature sensor, and possibly the ECU will need to be tested.
What Repairs Will Fix P0938?
- Repair damaged wiring and/or connectors
- Replace hydraulic oil temperature sensor
- Change hydraulic fluid
- Reprogram or replace ECU
Related Codes
N/A
What Transmission Do I Have?
