GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2008 🢒 Express 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC P0218

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provide an overview of each diagnostic category.

DTC Descriptors

DTC P0218: Transmission Fluid Overtemperature

Circuit/System Description

Transmission fluid is drawn from the bottom pan through the filter, case assembly, channel plate assembly, control valve body assembly, and into the oil pump assembly. The pump is mounted on the control valve body assembly. Fluid pressure leaving the pump is controlled by the pressure regulator valve and becomes the main supply of line pressure to the various components and hydraulic circuits. Hot fluid from the torque converter flows through the torque converter clutch (TCC) control valve into the cooler lines to the oil cooler located in the vehicle radiator and auxiliary cooler, if equipped. Cool fluid then returns to lubricate the final drive assembly and other components along the output shaft.

Conditions for Running the DTC
    • The ignition voltage is between 8 and 18-volts.
    • The transmission fluid temperature (TFT) is between -39 and +149°C (-38 and +300°F) for 5 seconds.

Conditions for Setting the DTC

The TFT is greater than 130°C (267°F) for 60 seconds (1 minute).

Action Taken When the DTC Sets

DTC P0218 is a type C DTC.

Conditions for Clearing the DTC

DTC P0218 is a type C DTC.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Transmission General Description

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

    • J 35616 GM Terminal Test Kit
    • J 44152 Jumper Harness (20 Pins)

Circuit/System Verification

Ensure the transmission fluid level is at the proper level by performing the Transmission Fluid Check .

Circuit/System Testing
  1. Perform the Transmission Fluid Check .
    2. ⇒ If the level is not within specifications, repair as necessary.
  2. Inspect for the following conditions:
    3. • Transmission line pressure low
    • Refer to Line Pressure Check .
    • Transmission fluid flow through cooler and/or auxiliary cooler, if equipped, is restricted due to the following conditions:
       - Transmission fluid level low
       - A clogged filter
       - A leaking filter or seal
       - Plugged, kinked, or damaged transmission cooler pipes
    • Air flow through the transmission fluid cooler and/or auxiliary cooler, if equipped, is restricted due to the following conditions:
       - Damaged fins
       - Debris
    • Engine overheating due to the following conditions:
       - Low coolant level
       - Inspect coolant temperature, coolant level, and hoses.
       - Restricted air flow
       - Restricted coolant flow

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for transmission control module (TCM) replacement, setup, and programming.

Valve Body and Pressure Switch Replacement .