P0218

DTC P0218 Transmission Fluid Over Temperature

Circuit Description
The Transmission Fluid Temperature (TFT) sensor is a thermistor that controls the signal voltage to the PCM. The PCM supplies a 5-volt reference to the sensor on circuit RED/BLK. When the transmission fluid is cold, the sensor resistance is high and the PCM will sense high signal voltage. As the fluid temperature warms to a normal transmission operating temperature of 100°C (212°F), the sensor resistance becomes less and the voltage decreases to 1.5 to 2.0 volts.
This DTC detects a high transmission temperature for a long period of time. This is a type "D" DTC.

Conditions For Setting The DTC
- No TFT DTCs P0712 or P0713.
- TFT is greater than 135°C (275°F).
- All conditions met for 21 seconds.

Action Taken When The DTC Sets
- Hot mode TCC Shift Pattern.
- The PCM will not illuminate the Malfunction Indicator Lamp (MIL) and CHECK TRAMS Lamp.
- ATF Lamp ON. (TFT is greater than 145°C (293°F).)
- Disable E-side TCC OFF request.

Conditions For Clearing The DTC
- The DTC can be cleared from the PCM history by using a scan tool.
- The DTC will be cleared from history when the vehicle has achieved 40 warm-up cycles without a failure reported.
- The PCM will cancel the DTC default actions when the fault no longer exists and the ignition is cycled "off" long enough to power down the PCM.

Diagnostic Aids
- Inspect the wiring for poor electrical connections at the PCM and at the transmission 16-way connector. Look for possible bent, backed out, deformed, or damaged terminals. Check for weak terminal tension as well.
Also check for a chafed wire that could short to bare metal or other wiring. Inspect for a broken wire inside the insulation.
- When diagnosing for a possible intermittent short or open condition, move the wiring harness while observing test equipment for a change.
- Check harness routing for a potential short to ground in circuit RED/BLK.
- Scan tool TFT sensor temperature should rise steadily to about 1OO°C (212°F), then stabilize.
- Check for a "skewed" (mix-scaled) sensor by comparing the TFT sensor temperature to the ambient temperature after a vehicle cold soak. A "skewed" sensor can cause delayed garage shifts or TCC complaints.
- Check for a possible torque converter stator problem.
- Verify customer driving habits, trailer towing, etc.

Test Description








DTC P0218 Transmission Fluid Over Temperature

The numbers below refer to the step numbers on the diagnostic chart.
3. This test checks for a "skewed" sensor or shorted circuit.
4. This test simulates a TFT DTC P0713.