P0940: Hydraulic Oil Temperature Sensor Circuit High
Severity
High
System
Transmission
What Does P0940 Mean?
P0940 is a diagnostic trouble code indicating: Hydraulic Oil Temperature Sensor Circuit High. This code relates to the transmission system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.
Symptoms of P0940
- ⚠️ Check Engine Light (MIL) illuminated
- ⚠️ Hydraulic Oil Temperature Sensor reading stuck at maximum value
- ⚠️ Related system operating erratically or in default mode
- ⚠️ Harsh or delayed shifting
Common Causes
- 🔍 Short to voltage in Hydraulic Oil Temperature Sensor wiring harness
- 🔍 Corroded or water-damaged Hydraulic Oil Temperature Sensor connector
- 🔍 Faulty Hydraulic Oil Temperature Sensor outputting maximum voltage
- 🔍 Damaged wiring rubbing against metal components
- 🔍 ECM/PCM internal fault (rare)
Frequently Asked Questions
What does P0940 mean?
P0940 indicates: Hydraulic Oil Temperature Sensor Circuit High. The vehicle's computer has detected that the Hydraulic Oil Temperature Sensor is not operating within its expected parameters and stored this diagnostic trouble code.
Can I drive with code P0940?
Only short distances if absolutely necessary. P0940 affects a critical system and should be diagnosed within a few days to avoid further damage.
How much does it cost to fix P0940?
Repair costs for P0940 typically range from $20 to $500, depending on the root cause. Simple wiring or connector repairs are on the lower end, while component replacement costs more. A proper diagnosis ($80–$150 at most shops) will identify the exact cause before committing to expensive parts.
What To Do Next
Possible Fixes
- 🔧 Inspect and repair Hydraulic Oil Temperature Sensor wiring for short to voltage
- 🔧 Clean or replace corroded Hydraulic Oil Temperature Sensor connector
- 🔧 Replace faulty Hydraulic Oil Temperature Sensor
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1
Find your vehicle above
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Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
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3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.
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