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. This sensor monitors hydraulic pressure within the transmission to ensure proper shift timing and line pressure. A fault can cause incorrect pressure readings, leading to erratic shifting, slippage, or limp mode. The issue may stem from a faulty sensor, damaged wiring, or a poor electrical connection.
1. Symptoms You Will Notice
- Check Engine Light illuminated
- Erratic or harsh shifting
- Transmission slipping or delayed engagement
- Vehicle enters limp mode
2. Most Common Causes
- Faulty transmission fluid pressure sensor
- Damaged or corroded wiring/connectors
- Low or contaminated transmission fluid
- Internal transmission mechanical failure
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Inspect transmission fluid level and condition.
Step 3: Visually check wiring and connectors for damage or corrosion.
Step 4: Test sensor resistance and voltage with a multimeter per manufacturer specs.
Step 5: If sensor and wiring are OK, check for internal transmission issues.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Driving with this code can cause transmission damage due to improper shifting or slipping. Have it diagnosed promptly.
How much does it cost to fix?▼
Repair costs vary from $150 to $400, depending on whether the sensor, wiring, or transmission fluid needs attention. Labor and parts may increase if internal transmission repairs are needed.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.