Transmission Fluid Pressure Sensor/Switch C Circuit Low
What does P0872 mean?
The P0872 code means the vehicle's onboard diagnostic system has detected: Transmission Fluid Pressure Sensor/Switch C Circuit Low. This is a moderate severity code.
Common Symptoms
- Check Engine Light illuminated
- Slipping in specific gear ranges
- Soft or delayed shifts
- Limp mode in some vehicles
Probable Causes (Ranked by Likelihood)
- Short to ground in pressure sensor C signal wire Very High
- Faulty pressure sensor C with low output High
- Corroded connector at sensor C Moderate
- Low transmission fluid level Moderate
Step-by-Step Diagnostic Procedure
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Check transmission fluid level
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Measure voltage at pressure sensor C connector
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Test for short to ground on the signal wire
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Replace sensor C if wiring and fluid checks are good
Frequently Asked Questions
Is P0872 the low voltage counterpart of P0873?
Yes, P0872 indicates the sensor C signal is too low while P0873 indicates it is too high. They represent opposite electrical faults.
Can road debris damage the sensor C wiring?
Yes, rocks and road debris can damage the wiring harness on the underside of the vehicle near the transmission, causing shorts to ground.
How do I find sensor C?
Sensor C is typically mounted on the transmission case or valve body. Consult your vehicle service manual for the exact location, as it varies by transmission model.