2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 951

2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 951

* The control module detects an internal checksum malfunction.

Action Taken When the DTC Sets

* The affected system warning indicator/warning message will activate.

* The affected system will be disabled.

Conditions for Clearing the DTC

* A current DTC clears when the malfunction is no longer present.

* A history DTC clears when the control module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Circuit/System Verification

1. With a scan tool, clear DTC C0550. The DTC should clear.

瀚慖f the DTC will not clear, replace the control module.

2. Ignition OFF, remove the scan tool, open and close the drivers door.

3. Wait 60 seconds, ignition ON, then recheck for DTCs. DTC C0550 should not set.

瀚慖f DTC C0550 sets, replace the module.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, setup, and programming

MP 3010-NP0 - Transfer Case

DTC C0550

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions) provides an overview of each diagnostic category.

DTC Descriptor

DTC C0550 37

- Electronic Control Unit (ECU) Performance Watchdog Failure

DTC C0550 39

- Electronic Control Unit (ECU) Internal Electronic Failure

Diagnostic Fault Information

Circuit/System Description

This is an internal fault detection of the transfer case shift control module (TCCM). This fault is handled inside the TCCM. No external circuits are

involved.

At each power-up, the TCCM runs a self-test on the following:

* EEPROM Checksum

* ROM Checksum

* RAM Checksum

* RAM Malfunction

Conditions for Running the DTC