Engine Control Module Replacement

WARNING: This page is about a different car, the 2012 GMC Sierra, 2012 GMC Cab & Chassis Sierra, 2012 Chevrolet Silverado, and 2012 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Locating Engine Control Module Components

Courtesy of GENERAL MOTORS COMPANY

Callout	Component Name
1	Engine Control Module Cover NOTE: Release the tab on the rear of the cover while rotating the cover upward.
2	Engine Control Module Bracket
3	Engine Control Module CAUTION: Turn the ignition OFF when installing or removing the control module connectors and disconnecting or reconnecting the power to the control module (battery cable, powertrain control module (PCM)/engine control module (ECM)/transaxle control module (TCM) pigtail, control module fuse, jumper cables, etc.) in order to prevent internal control module damage. Control module damage may result when the metal case contacts battery voltage. DO NOT contact the control module metal case with battery voltage when servicing a control module, using battery booster cables, or when charging the vehicle battery. In order to prevent any possible electrostatic discharge damage to the control module, do no touch the connector pins or the soldered components on the circuit board. Remove any debris from around the control module connector surfaces before servicing the control module. Inspect the control module connector gaskets when diagnosing or replacing the control module. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the control module. The replacement control module must be programmed. Procedure Disconnect the engine control module harness connectors. Release the three tabs retaining the engine control module to the module bracket. If replacing, reprogram the engine control module. Refer to Control Module References . Relearn the turbocharger. Refer to Turbocharger Learn . Reprogram the glow plug control module. Refer to Glow Plug Control Module Programming and Setup (LGH or LML) . Perform the crankshaft position reluctor wheel learn procedure. Refer to Crankshaft Position Reluctor Wheel Learn . NOTE: Before removing the engine control module (ECM), use the scan tool to capture the ECM data. This captured data will then need to be restored into the NEW ECM. Refer to Control Module References .

Callout

Component Name

Engine Control Module Cover

NOTE:

Release the tab on the rear of the cover while rotating the cover upward.

Engine Control Module Bracket

Engine Control Module

CAUTION:

Turn the ignition OFF when installing or removing the control module connectors and disconnecting or reconnecting the power to the control module (battery cable, powertrain control module (PCM)/engine control module (ECM)/transaxle control module (TCM) pigtail, control module fuse, jumper cables, etc.) in order to prevent internal control module damage.
Control module damage may result when the metal case contacts battery voltage. DO NOT contact the control module metal case with battery voltage when servicing a control module, using battery booster cables, or when charging the vehicle battery.
In order to prevent any possible electrostatic discharge damage to the control module, do no touch the connector pins or the soldered components on the circuit board.
Remove any debris from around the control module connector surfaces before servicing the control module. Inspect the control module connector gaskets when diagnosing or replacing the control module. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the control module.
The replacement control module must be programmed.

Procedure

Disconnect the engine control module harness connectors.
Release the three tabs retaining the engine control module to the module bracket.
If replacing, reprogram the engine control module. Refer to Control Module References .
Relearn the turbocharger. Refer to Turbocharger Learn .
Reprogram the glow plug control module. Refer to Glow Plug Control Module Programming and Setup (LGH or LML) .
Perform the crankshaft position reluctor wheel learn procedure. Refer to Crankshaft Position Reluctor Wheel Learn .

NOTE:

Before removing the engine control module (ECM), use the scan tool to capture the ECM data. This captured data will then need to be restored into the NEW ECM. Refer to Control Module References .