GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2008 🢒 Escalade ESV 🢒 DTC 🢒 DTC P0A2F

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 provides an overview of each diagnostic category.

DTC Descriptor

DTC P0A2F: Drive Motor 1 Overtemperature

Circuit/System Description

The transmission contains two electric motor generators. The drive motor generators are cooled by the transmission fluid. Hot fluid exits the drive motor generator housing and flows to the transmission cooler supply line. The supply line connects to the cooler. From the cooler, the fluid returns through the oil cooler return line and enters the lubrication circuits. After lubricating the internal components, the fluid returns to the oil pan. A non-serviceable motor temperature sensor (MTS) is located in each drive motor generator assembly.

Conditions for Running the DTC

DTC P0A2B is not set.

Conditions for Setting the DTC

The MTS is greater than 200°C (392°F) for 3 seconds and has not fallen below 135°C (275°F).

Action Taken When the DTC Sets
    • DTC P0A2F is a Type B DTC.
    • The hybrid powertrain control module (HPCM) commands the battery energy control module (BECM) to open the high voltage contactor relays.

Conditions for Clearing the DTC

DTC P0A2F is a Type B DTC.

Diagnostic Aids
    • The driver information center (DIC), if equipped, will display 'TRANSMISSION HOT- Idle Engine' when the transmission fluid temperature (TFT) is more than 132°C (270°F) for 10 minutes.
    • Ask about the customer's driving habits, trailer towing, etc.
    • Ensure the engine cooling system is functioning normally.
    • The HPCM will reduce drive motor generator torque at temperatures greater than 160°C (320°F). Drive motor generator torque is reduced to zero if the temperature reaches 190°C (374°F).

Reference Information

Schematic Reference

Hybrid Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification
  1. Review the Failure Records when the DTC set.
    2. ⇒If the engine coolant temperature (ECT) was above 125°C (257°F) when the DTC set, go to Symptoms - Engine Cooling and correct that concern first.
  2. Perform the Transmission Fluid Cooler Flushing and Flow Test .

Circuit/System Testing
  1. Review the Failure Records when the DTC set.
  2. Compare the MTS values for each drive motor generator.
    3. ⇒If both MTS values were not at or near 200°C (392°F) , test the MTS signal circuit for a low resistance to ground condition.
    ⇒If the circuit tests normal, replace the drive motor generator.
  3. Inspect the transmission cooling system for restrictions or damage.
    4. ⇒If a concern is found, repair or replace the restricted or damaged components as necessary.
  4. Perform the Transmission Fluid Cooler Flushing and Flow Test .
    5. ⇒If a concern is found, repair or replace the damaged components as necessary.
  5. Perform the automatic transmission Line Pressure Check .
    6. ⇒If a concern is found repair or replace the damaged components as necessary.

Component Testing
    • Perform the Fluid Leak Diagnosis .
    • Perform the Transmission Fluid Check procedure.
    • Perform the Line Pressure Check procedure.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Drive Motor with Generator Assembly Removal - 1st Position .
    •  Transmission Control Wiring Harness Extension Harness Removal .