Transmission Fluid Temperature Too High

The computer measures the temperature of the transmission fluid. If it goes over about 220°F (104°C), it triggers a code, meaning the fluid is too hot and could damage the transmission.

The computer sees a transmission fluid temperature sensor reading above 220°F (104°C) for more than a prescribed duration, often around 5-15 seconds.

Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.

1. 1Check transmission fluid level. It should be within the marks on the dipstick, usually between the low and high marks. Is it low? If yes, add fluid and retest. If not, go to step 2.
2. 2Inspect the wiring and connector to the transmission fluid temperature sensor. Look for frayed wires or poor connections. Are they damaged? If yes, repair or replace as necessary. If not, go to step 3.
3. 3Test the transmission fluid temperature sensor with a multimeter. At normal operating temperatures, you should see readings between 175°F (79°C) and 220°F (104°C). Is the reading excessive? If yes, replace the sensor. If the sensor reads normal, go to step 4.
4. 4Check the transmission cooler for blockages or restrictions. Inspect hoses for kinks and the cooler itself for build-up. Is there a blockage? If yes, clean or replace the cooler. If all is clear, go to step 5.
5. 5Evaluate engine and transmission load. If the vehicle is regularly overloaded or heavily towed, this may cause elevated temperatures. Consider reducing load or optimizing driving conditions.

• Low transmission fluid level
• Faulty transmission fluid temperature sensor
• Blocked or restricted transmission cooler
• High engine load or towing overload
• Contaminated transmission fluid

$$ (100 to 800 dollars depending on sensor replacement or transmission service)