Colorado 2WD L4-2.8L VIN 8 (2004)
Engine Control Module: Description and Operation
Antitheft Function
ENGINE CONTROL MODULE
The engine control module (ECM) contains the remainder of the logic of the theft deterrent system. If a serial data message containing a valid password
is received from the body control module (BCM), the ECM will continue to allow the fuel injectors to operate. The ECM will allow the fuel injectors to
operate until it decides there is no valid password coming from the BCM. If the ECM does not receive a serial data message, or receives a serial data
message with an incorrect password, the engine will crank and will not run or will start and stall immediately.