P0218🔧 Automatic transmission temperature monitoringStop and fix promptly

P0218: Transmission Fluid Over Temperature (Meaning, Causes, Fixes)

Reviewed 2026-10-26 · Based on 2 cited source(s)

What P0218 means

A transmission fluid temperature sensor tells the engine computer (PCM) how hot the transmission fluid is. RepairPal says that when the fluid gets too hot, the PCM sets P0218 and may put the vehicle into limp home mode, limiting engine power to protect the transmission. OBD-Codes.com says P0218 sets when fluid temperature goes above about 290 degrees F on the vehicles it describes and that many vehicles also turn on a transmission over-temperature light in the instrument cluster; the exact limit varies by vehicle, and RepairPal does not give a number. The code is generic to OBD-II vehicles with a transmission fluid temperature sensor, but repair steps vary by make and model. Search interest shows people look it up mostly for Allison transmissions, Dodge, Ford and Jeep, so check technical service bulletins (TSBs) for your vehicle. If you have a sensor circuit code such as P0710 to P0714 at the same time, the reading itself may be wrong.

Severity: can I keep driving?

Stop and fix promptly

Stop and let it cool before driving on. RepairPal rates P0218 'Urgent', meaning it can cause severe damage, and OBD-Codes.com says overheated fluid is the number one cause of transmission failure. If you are towing, pull over safely, let the transmission cool with the engine idling or off, and don't keep towing until the cause is found. Hot transmission fluid can spray or drip out of the vent and seals, so keep clear of hot parts.

Common symptoms

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

  1. Towing a trailer that is too heavy or exceeds the vehicle's towing rating (both sources)
  2. Long, hard towing uphill (RepairPal)
  3. Restricted transmission cooler or cooler lines, including debris in the cooler (both sources)
  4. Low transmission fluid level (both sources)
  5. Cooling fan or fan clutch not working (OBD-Codes.com)
  6. Missing or damaged front air dam or spoiler (OBD-Codes.com)
  7. Bad transmission fluid temperature sensor (OBD-Codes.com)
  8. Engine computer (PCM) software needing an update (RepairPal)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

  1. If you are towing, check the load against your vehicle's towing rating in the owner's manual. OBD-Codes.com says that if the load is too heavy, the transmission cooler may not be able to keep the fluid temperature down.
  2. Check the transmission fluid level the way your owner's manual describes (many need the engine running and the fluid warm). If it is low, top it up with the correct fluid and look for leaks.
  3. Check the color and smell of the fluid. OBD-Codes.com says that if it smells burnt or is dark, the fluid should be changed.
  4. Look at the transmission cooler (often in front of the radiator) for leaves, bugs or other debris, and check the cooler lines for kinks, pinches or leaks.
  5. Check that the radiator cooling fans or fan clutch work, and that the front air dam or spoiler is in place.
  6. Read all stored codes and write them down, and look up TSBs for your year, make and model.

Typical fixes

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

  • Compare the scan tool's transmission fluid temperature reading with the actual temperature (for example with an infrared thermometer on the pan) to tell a real overheat from a bad sensor reading.
  • OBD-Codes.com notes that an overheated transmission can push fluid out of the vent or the torque converter seal, so a leak found there may be a result of the overheat rather than its cause.
  • The sources differ: OBD-Codes.com gives a 290 degrees F trigger and lists the fan, air dam and temperature sensor as causes, while RepairPal gives no temperature and adds a PCM software update. RepairPal also lists limp mode as a symptom, while OBD-Codes.com lists the transmission not engaging and fluid leaks.
  • Repeated overheating can damage internal transmission parts, so a shop may need to inspect the transmission if it slips or shifts poorly after the cause is fixed.

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Can I drive with P0218?

Only gently, after the transmission has cooled, and not while towing until it's checked. RepairPal rates it 'Urgent', and OBD-Codes.com says overheated fluid is the number one cause of transmission failure.

What usually causes P0218?

Both sources point to towing too much weight, a restricted transmission cooler or cooler lines, and low transmission fluid. OBD-Codes.com also lists a bad cooling fan, a missing air dam and a bad temperature sensor, and RepairPal adds PCM software needing an update.

At what temperature does P0218 set?

OBD-Codes.com says above about 290 degrees F, but the exact limit depends on the vehicle, and RepairPal only says the code sets when the fluid gets too hot.

What codes are related to P0218?

The transmission fluid temperature sensor codes P0710 to P0714 can point to a bad reading instead of real overheating, and P0217 is the matching engine coolant over-temperature code.

Sources

  1. OBD-Codes.com: P0218 Transmission Over Temperature Condition
  2. RepairPal: P0218 Transmission Fluid Over Temperature Condition (rated Urgent)

Last reviewed 2026-10-26. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.