Transmission Over Temperature Condition (P0218)
Code P0218 indicates that the transmission control module (TCM) has detected the transmission fluid temperature has exceeded a safe operating threshold, typically above 270°F (132°C). This can be caused by low fluid level, degraded fluid, a faulty transmission cooler, a stuck torque converter clutch, or excessive load on the transmission. Prolonged overheating can lead to internal damage and transmission failure.
1. Most Common Causes
- Low transmission fluid level due to leaks or poor maintenance
- Degraded, contaminated, or incorrect type of transmission fluid
- Faulty transmission cooling system (clogged cooler, restricted hoses, stuck bypass)
- Defective transmission fluid temperature (TFT) sensor or open/short circuit
- Vehicle overload (excessive towing, severe driving on grades)
- Internal mechanical failure (slipping clutches, faulty torque converter, damaged oil pump) generating excessive heat
- Inoperative engine or transmission cooling fan
2. Symptoms You Will Notice
- Check Engine Light or Transmission Warning Light on
- Transmission slipping, harsh shifting, or delayed engagement
- Burning smell from transmission fluid
- Transmission goes into limp mode or fails to shift
3. Step-by-Step Diagnosis
Step 1: Check transmission fluid level and condition; top off or replace if burnt or low.
Step 2: Inspect transmission cooler and lines for blockages or leaks; flush if necessary.
Step 3: Scan for additional codes and monitor transmission temperature with a scan tool.
Step 4: Test torque converter clutch operation and inspect wiring/sensor for the temperature circuit.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
No, driving with an overheated transmission can cause severe internal damage. Pull over and let the transmission cool down. Have the vehicle towed to a shop for diagnosis.
How much does it cost to fix?▼
Diagnosis typically costs $50-$150. Repairs vary: fluid change $100-$250, cooler replacement $200-$600, or sensor replacement $150-$300. Major transmission repairs can exceed $2,000.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.