OEM Buick Terraza Engine Control Module

Buick Terraza Engine Control Module Parts Questions & Experts Answers

• PCM
  12678511
  Q: What should the service of the engine control module (ECM) normally consist of on Buick Terraza?

  A:

  The service procedure for engine control modules (ECM) can be fulfilled with either new ecm installation or eeprom programming. You must inspect the ecm before replacement but only when diagnostic tests indicate an ecm switch is needed. Replace the new service ecm as the first step after confirming the faulty ecm condition. You must close the engine through ignition shutdown before any task involving control module connectors or power disconnection to stop internal module destruction. The control module suffers damage when its metal frame comes into direct contact with battery electrical charge so avoid this situation in service operations and with battery booster cables and vehicular battery charging. Touching the circuit board's connector pins or soldered components will result in electrostatic damage therefore avoid doing so. Before servicing the control module connector you must remove all debris then verify that the installed gaskets are correct since they block contaminant entry. A programming process applies to the new control module and the broadcast code along with production ecm number must transfer onto the service ecm label for complete vehicle identification from start to end. A new unprogrammed service ecm shows dtc p0602 when the ecm fails to program correctly or malfunctions. All internal parts in this ecm should remain unaddressed by users and it should be avoided to open it. The replacement process requires documenting remaining engine oil life because lack of proper programming at the new module will reset it to 100 percent performing an oil change within 5000 km (3,000 mi) since the last maintenance. The removal process begins by using a scan tool to record the current engine oil life percentage then disconnecting the battery cable followed by removal of the left sheet metal diagonal brace and loose air cleaner cover from the air cleaner assembly before disconnection of engine harness electrical connectors from the ecm and ecm extraction from the air cleaner cover. The engine harness electrical connectors must be connected to the ecm before setting the ecm on top of the air cleaner cover and installing the air cleaner assembly cover. Replace the air cleaner cover onto the air cleaner assembly and tighten its cover screws to 4 n.m (35 lb in). Reinstall the left sheet metal diagonal brace followed by reconnecting the negative battery cable. Programming of the eeprom is necessary when installing a new ecm.