Transmission · Powertrain · generic (SAE-defined)
P0218: Transmission Fluid Over Temperature Condition
P0218 means the transmission control system detected automatic transmission fluid hotter than its allowed limit, which can quickly damage clutches, seals, and the fluid itself.
Standard title per SAE J2012 / ISO 15031-6 · Updated 2026-11-07 · By CarWhere Research
How P0218 sets
The transmission control module (TCM) or powertrain control module (PCM) monitors a transmission fluid temperature (TFT) sensor, usually located in the valve body or pan. If the fluid temperature exceeds a calibrated limit for a set time, the code sets. Many transmissions also change shift and torque converter lockup behavior to reduce heat. Limits vary by manufacturer.
Common causes of P0218
Roughly most likely first; the actual cause depends on the vehicle and needs testing to confirm.
- Towing, hauling, or extended hill climbing beyond the vehicle's capacity
- Low or degraded transmission fluid
- Restricted or damaged transmission fluid cooler or cooler lines
- Torque converter clutch not locking up, creating excess slip and heat
- Internal slipping from worn clutches or bands
- Faulty transmission fluid temperature sensor or wiring
P0218 symptoms
- Check engine light or transmission warning light on
- Transmission temperature warning message
- Harsh, delayed, or erratic shifts
- Burnt smell from the fluid
- Reduced power or limp mode in some vehicles
How P0218 is diagnosed
- Check freeze frame data for vehicle speed, load, and fluid temperature when the code set.
- Scan for other transmission codes, especially torque converter clutch or sensor codes.
- Check fluid level and condition using the manufacturer's procedure; look for dark or burnt fluid.
- Inspect the transmission cooler, lines, and airflow through the cooler for blockage or damage.
- Compare the fluid temperature reading on a scan tool to actual pan temperature.
- Monitor torque converter slip and lockup status on a road test.
Typical fixes for P0218
- Service the transmission fluid and filter with the correct fluid type
- Clean, repair, or replace the transmission cooler or lines
- Add an auxiliary transmission cooler for vehicles that tow regularly
- Repair torque converter clutch control faults
- Replace a faulty fluid temperature sensor or repair its wiring
Replace parts only after testing confirms the cause — a code names the circuit or condition that failed a check, not necessarily the faulty part. We don’t publish per-repair prices; for what households actually spend on upkeep, see car repair costs.
Related codes & warning lights
P0218 FAQ
What does code P0218 mean?
P0218 means the transmission control system detected automatic transmission fluid hotter than its allowed limit, which can quickly damage clutches, seals, and the fluid itself. The standard definition is "Transmission Fluid Over Temperature Condition."
Can I drive with a P0218 code?
Only briefly and gently. Stop and let the transmission cool, avoid towing or heavy loads, and have it inspected soon, because overheated fluid breaks down and can lead to slipping or transmission failure.
Why did P0218 appear only while towing?
Towing raises the load on the torque converter and clutches, generating far more heat. If it only happens under heavy load, the cooling capacity may be marginal and an auxiliary cooler or lighter loads may be needed.
Will changing the fluid fix P0218?
It can help if the fluid is old or burnt, but it will not fix a blocked cooler, a slipping converter, or a sensor fault. Fluid that has overheated repeatedly is a sign to look for the underlying cause.
Keep researching
More transmission codes
Sources
- SAE J2012 — Diagnostic Trouble Code Definitions (standard code titles)
- ISO 15031-6 — Road vehicles: communication between vehicle and external equipment for emissions-related diagnostics, Part 6: Diagnostic trouble code definitions
- U.S. EPA — Vehicle Emissions Inspection and Maintenance (I/M) programs
- U.S. EPA, 40 CFR 86.1806-17 — Federal onboard diagnostics requirements for light-duty vehicles
General information written by CarWhere Research, not a diagnosis of your vehicle. Manufacturers can add their own sub-definitions and test conditions; confirm with the factory service information for your year, make and model. Before paying for a repair, check NHTSA for open recalls and your warranty booklet: federal law requires an emissions warranty on major emission-control parts such as the catalytic converter and engine computer.