P0218 Transmission fluid temperature too high

Transmission over temperature condition

P0218 in short

P0218 means the transmission fluid got hotter than the maker allows, often around 290 F. Towing, low fluid, a blocked cooler or a failing transmission are common causes, and a bad temperature sensor is also possible. Stop and let it cool if a warning shows, and get it checked soon.

The transmission computer watches fluid temperature through a sensor. If the reading goes above the maker's limit, it sets P0218 and may add a warning message, limit shifting or put the car into limp mode.

Heat comes from towing, low or worn fluid, a restricted cooler or cooler lines, a cooling fan problem, or a transmission that is slipping and making its own heat. A faulty temperature sensor can also report a false high reading.

Several makers have bulletins linking the code to a specific failure: torque converter clutch material coming off on some GM and Isuzu trucks, and a failed thrust washer on 2024 Ram 2500 and 3500 trucks.

Most likely causes

  1. Fluid overheating from towing, low fluid or a restricted cooler

    Common general cause
    Why it ranks here
    Reference pages list heavy towing, low or contaminated fluid, a leak, and debris or restriction in the cooler or lines as the main causes of fluid reaching the limit.
    What would change this
    Rises if the code appeared while towing or climbing, fluid is low or burnt, or the cooler flow is poor. Falls if fluid and cooling are fine.

  2. Torque converter clutch or internal transmission damage

    Supported by vehicle data
    Why it ranks here
    GM and Isuzu bulletins for 2006-2009 trucks tie slipping, overheating and P0218 to friction material coming off the torque converter clutch, and a 2024 Ram bulletin lists P0218 for a failed rear thrust washer.
    What would change this
    Rises if there is slipping, metal in the fluid or a matching bulletin. Falls if the transmission shifts normally and cooling is poor.

  3. Faulty fluid temperature sensor or wiring

    Common general cause
    Why it ranks here
    TroubleCodes.net lists wiring, the temperature sensor and the computer as probable causes, and PartsAvatar lists the sensor, so a false reading is possible.
    What would change this
    Rises if the fluid is not actually hot, or sensor voltage or resistance is out of range. Falls if a real temperature reading is high.

  4. Engine cooling or airflow problem (fan, air dam, radiator)

    Possible — needs testing
    Why it ranks here
    PartsAvatar lists a broken cooling fan or clutch and a missing front air dam as causes, because the cooler often depends on the same airflow.
    What would change this
    Rises if the engine also runs hot or the air dam is missing. Falls if engine temperature is normal.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Note when the code set (towing, hill climb, hot day) and look for any transmission temperature message or limp mode. Read all codes.

    Low riskTool: scan tool

    • IfIt set while towing or in heavy load, and the car shifts normally once cool

      It meansFluid temperature is likely the issue; check fluid and cooler.

      Go to step 2

    • IfSlipping, harsh shifts or limp mode too

      It meansInternal damage is possible.

      Go to step 4

  2. Have a shop check fluid level and condition, cooler lines for restriction, cooling fan, and a leak at the pan, cooler or seal.

    Best left to a shopTool: scan tool, infrared thermometer

    Warning:A hot transmission and its lines can cause burns. Let it cool, and have a shop do it.

  3. Compare the scan-tool fluid temperature with the real temperature after a cool-down, and check sensor voltage and wiring.

    Best left to a shopTool: scan tool, multimeter

    Warning:Have a qualified shop do this step.

  4. Ask a dealer whether your VIN has a bulletin for P0218, and have the transmission checked for slipping and debris.

    Best left to a shop

    Warning:Internal transmission work is shop work.

Symptoms

  • Transmission over-temperature message or check engine light
  • Slipping, late or harsh shifts
  • Limp mode or reduced power Gets more serious: stop and have it checked.
  • Burning smell or fluid leak under the car Gets more serious: stop and have it checked.

How to fix

  1. Stop driving and let the vehicle cool if an over-temperature message shows, and book a check.

  2. Ask a dealer whether your VIN has a bulletin for P0218.

Parts and cost context

  • Transmission control module (TCM):The temperature sensor is usually inside the transmission, so a shop decides whether it is the sensor or the transmission. Labor varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Isuzu

  • 2006–2009 · NPR

    Supported by vehicle data

    Isuzu bulletin SB-09-K-001 ties P0218 or P0894 with slipping or overheating to torque converter clutch friction material coming off. Whether the bulletin is still current is not verified.

  • SB-09-K-001Status unverified

    Transmission slips or overheats; P0894 or P0218

    2006–2009npr · NHTSA 10032488

    Names torque converter clutch friction material coming off as the cause.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Ram

  • 2024 · 2500

    Supported by vehicle data

    A Ram bulletin names P0218 among the codes for a failed rear selective thrust washer. Only the NHTSA summary was read. Whether the bulletin is still current is not verified.

  • 21-012-25 REV.AStatus unverified

    Rear selective thrust washer failure

    20242500, 3500 · NHTSA 11013157

    Lists P0218 among codes for a failed rear selective thrust washer; the NHTSA summary was read only in part.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • P0741Torque converter clutch not engaging as commanded

    Same system Supported by vehicle data

    A GM bulletin for the Allison LCT 1000 lists P0218 with P0741 and P0742 for overheat; a slipping converter clutch can set both.

  • P0700Transmission module requests the check engine light

    Same system Possible — needs testing

    P0700 may be stored when the transmission computer logs the over-temperature fault.

All Transmission codes

P0218 questions

Can I drive with P0218?

Not if a warning shows or the car slips. If it was a one-off while towing and everything feels normal, let it cool and get it checked soon.

Does P0218 always mean a bad transmission?

No. Low fluid, a restricted cooler or heavy towing can set it, and a bad temperature sensor can give a false reading.

Sources and review

  1. P0218 Code: Transmission Fluid Temperature Sensor A Over Temperature Condition — Kelley Blue Book
  2. OBD II error code P0218: Transmission Over Temperature Condition — PartsAvatar
  3. Isuzu SB-09-K-001: slipping or overheating, P0894 or P0218 — Isuzu (via NHTSA flat file)
  4. GM 08-07-30-016: slipping or overheating transmission, P0218 and P0894 — General Motors (via NHTSA flat file)
  5. Ram 21-012-25 Rev A: rear selective thrust washer failure — Stellantis (via NHTSA flat file)
  6. P0218 Trouble Code: Transmission Over Temperature Condition — TroubleCodes.net
Last reviewed
Written by
Saurabh K.
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