Transmission Fluid Pressure Sensor/Switch Circuit Malfunction
The P0987 code indicates a problem in the electrical circuit of the transmission fluid pressure sensor or switch, which monitors hydraulic pressure inside the transmission. This sensor provides critical data to the powertrain control module (PCM) for proper shift timing and line pressure control. A fault can cause erratic shifting, slipping, or limp mode.
01. Most Common Causes
- Faulty transmission fluid pressure sensor
- Damaged wiring or connector in the sensor circuit
- Low or contaminated transmission fluid
- Internal transmission mechanical failure
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Erratic or harsh shifting
- Transmission slipping or delayed engagement
- Transmission stuck in limp mode
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and record freeze frame data.
Step 2: Inspect transmission fluid level and condition; top off or replace if necessary.
Step 3: Visually check the sensor wiring and connector for damage, corrosion, or loose pins.
Step 4: Test the sensor resistance and voltage with a multimeter per manufacturer specs.
Step 5: If sensor and wiring are OK, check for internal transmission issues (requires professional scan tool or disassembly).
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Driving with P0987 can cause transmission damage due to improper shifting or low fluid pressure. Have it diagnosed promptly.
How much does it cost to fix?▼
Repair costs vary: sensor replacement $150-$300, wiring repair $100-$200, transmission rebuild $1500-$4000. Diagnosis fee is typically $100-$150.