ECM Replacement Check

CHART C-1 ECM REPLACEMENT CHECK










Description:
Prior to replacing an ECM, the vehicle must be tested for:

1. Check connector terminals that they are properly seated and locked in the connector and terminal retainers are properly positioned and locked;

2. Check ECM ground at the generator and battery ground at the engine and chassis.

3. Check IGN 1-ISO fuse in the fuse block.

Notes On Fault Tree:

1. The ECM supplies power through a high side driver to the Cruise Control Vent and Vacuum Solenoids. An internal short in the servo causing a low resistance or short to ground in the wiring harness may damage the ECM or cause the servo to solenoids to fail.

2. The ECM supplies power to the fuel pump relay through a high side driver. An internal short in the relay winding causing a low resistance or short to ground in the wiring harness may cause damage to the EMC or the relay to fail.

3. The ECM supplies power to the ISC through an internal switching IC that will change the polarity of the circuit. An internal short in the ISC motor armature windings or short to ground in the wiring harness may cause damage to the ECM or the ISC motor to fail.

4. The ECM provides the ground for the EGR solenoid, Electric Switching Valve (ESV), Canister Purge solenoid, And Electric Divert Valve (EDV) through a quad driver IC. An internal short in the windings or resistor of the devices or a short to ground in the wiring harness may cause damage to the ECM or the Emission Control System (ESC) device.

5. The ECM provides the ground for the VCC solenoid in the transmission through a quad driver IC. An internal short in the winding or diode of the solenoid or a short to ground in the wiring harness may cause damage to ECM or the solenoid to fail.