General Motors 4.3L GM Engine — ECM Removal/Installation
Repair & overhaul · Engine Control Module
For the General Motors 4.3L GM Engine, from the General Motors service manual.
Before you start
- The ECM is calibrated for each engine - verify correct controller by the P/N on the ECM label.
Procedure
- Disconnect negative battery cable.
- Push connector lock back to unlock connector, unplug the Wire Harness from ECM and remove.
- Remove four bolts mounting the controller to the mounting bracket.
- Installation: mount controller into mounting bracket with four screws; torque to 7.5 N·m (5.5 ft. lbs.).
- Plug connector into controller and push lock into place.
- Reconnect the negative battery cable.
- Install Diagnostic Service Tool; start engine and run to normal operating temperature.
- Check for any DTC codes and clear; verify engine in closed loop and no MIL light.
Tools required
- Diagnostic Service Tool (DST) Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- ECM mounting bolts 7.5 N·m (5.5 ft. lbs.)
Source: General Motors service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.