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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2000 🢒 Seville 🢒 DTC 🢒 DTC P0218 Transmission Fluid Overtemperature

Object Number: 25444 Size: MF
Automatic Transmission Components
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice

Circuit Description

The automatic transmission fluid temperature (TFT) sensor is a negative coefficient thermistor. When the transmission fluid is cold, the sensor resistance is high. As the transmission fluid warms up, the sensor resistance becomes lower. The PCM uses TFT information to control torque converter clutch (TCC) apply and release, line pressure, and shift time. The TFT range is from -40°C to +151°C (-40°F to +305°F).

If the PCM detects a high transmission fluid temperature for an extended period of time on the TFT sensor circuit, then DTC P0218 sets. DTC P0218 is a type C DTC.

Conditions for Running the DTC

The transmission fluid temperature is -38° to 143°C (-36° to 289°F)

Conditions for Setting the DTC

The transmission fluid temperature is greater than 132°C (270°F) for 10 minutes.

Action Taken When the DTC Sets
    • The PCM does not illuminate the malfunction indicator lamp (MIL).
    •  TRANSMISSION HOT message displays on the driver information center (DIC).
    • The PCM freezes transmission adapt functions.
    • The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Failure Records.
    • The PCM stores DTC P0218 in PCM history.

Conditions for Clearing the DIC/DTC
    • The PCM clears the DIC message when the condition no longer exists.
    • The transmission fluid temperature is less than 130°C (266°F) for 5 seconds.
    • A scan tool can clear the DTC .
    • The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
    • The PCM cancels the DTC default actions when the fault no longer exist and/or the ignition switch is OFF long enough in order to power down the PCM.

Diagnostic Aids
    • Ask the customer about overloading the vehicle, exceeding the trailer-towing limit, or towing in Overdrive.
    • Ensure that the transmission fluid is at the proper level.
    • Inspect the transmission cooling system for possible blockage and restrictions.

Test Description

The numbers below refer to the step numbers on the diagnostic table:

  1. This step ensures that the transmission fluid is at the proper level. A low fluid level may cause an overtemperature condition.

    2.

  2. This step inspects or repairs the following items:

    3. • Engine: Refer to the Cooling and Radiator Section.
    • Vehicle: Was the vehicle used to tow excessive weight?
    • Fluid: Refer to Transmission Fluid Check .
    • Filter: Replace the filter if the filter is cracked or not seated. Refer to Transmission Fluid Filter Replacement .
    • Scavenger Screens: Refer to Transmission Overhaul in the 4T80-E section of the Transmission Unit Repair Manual.
    • Low Line Pressure: Inspect cooler lines for any crimps or restrictions. Refer to Line Pressure Check .
    • Radiator: Refer to the Cooling and Radiator Section.

DTC P0218 Transmission Fluid Overtemperature

Step

Action

Value(s)

Yes

No

1

Did you perform the Powertrain Diagnostic System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

Did you perform the Transmission Fluid Checking Procedure?

--

Go to Step 3

Go to Transmission Fluid Check

3

  1. Inspect for the following conditions:
    2. • An overheated engine
    • An overloaded vehicle
    • Fluid that has become contaminated with antifreeze
    • A clogged filter or a filter that is not seated correctly
    • Clogged scavenger screens
    • Low line pressure caused by clogged or restricted cooler lines
    • A restricted radiator
  2. Repair any of the above conditions as necessary.

Is the repair complete?

--

Go to Step 4

--

4

Perform the following procedure in order to verify the repair:

  1. Install a Scan Tool
  2. Select DTC.
  3. Select Clear Info.
  4. Start and idle the engine until it reaches normal operating temperature.
  5. Select Engine Run Time and Trans. Fluid Temp. on the Scan Tool .
  6. Drive the vehicle for 15 minutes.
  7. Ensure that the transmission fluid temperature has stabilized and is less than 130°C (266°F).
  8. Select Specific DTC. Enter DTC P0218.

Has the test run and passed?

--

System OK

Go to Step 1