Transmission Fluid Pressure Sensor/Switch Circuit High
The P0873 code indicates that the Transmission Control Module (TCM) has detected a voltage signal from the transmission fluid pressure sensor that is higher than the expected range. This sensor monitors the hydraulic pressure inside the transmission to ensure proper shifting. A high voltage reading can be caused by a faulty sensor, wiring issues, or internal transmission problems. This condition can lead to harsh or erratic shifting, transmission slippage, or limp mode.
01. Most Common Causes
- Faulty transmission fluid pressure sensor
- Short to voltage in the sensor circuit
- Damaged wiring or connector
- Internal transmission malfunction
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Harsh or delayed shifting
- Transmission slipping
- Vehicle enters limp mode
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for other related codes.
Step 2: Inspect the transmission fluid level and condition; top off or replace if necessary.
Step 3: Visually inspect the wiring and connector for damage, corrosion, or loose connections.
Step 4: Test the sensor's voltage and resistance with a multimeter; compare to manufacturer specs.
Step 5: If sensor and wiring are okay, perform a transmission pressure test to rule out internal issues.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code as it can cause transmission damage or unsafe driving conditions. Have it diagnosed and repaired promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and sensor replacement, but may be higher if internal transmission repairs are needed.