Electric Load Sensor: Testing and Inspection

Electric Load Switch Circuit:

To test the electrical load switch located in the ECM, three separate switch circuits need to be checked. This verifies all inputs are working correctly.

1. Disconnect the ECM harness connector.
2. Turn "ON" the lighting switch. This activates the tail lamp relay.
3. Measure the input voltage between the ECM harness connector terminal 24 and ground.

Voltage
System Voltage

4. Turn "ON" the defogger switch, this activates the defogger relay.

5. Measure the input voltage between the ECM harness connector terminal 24 and ground.

Voltage
System Voltage

6. Depress the brake pedal, this activates the stop lamp switch.

7. Measure the input voltage between the ECM harness connector terminal 24 and ground.

Voltage
System Voltage

If any of the previous tests produce unsatisfactory results, the harness will need to be repaired or replaced, of switches adjusted. Once repairs have been completed, road test the vehicle to confirm that the repair has corrected the problem.
If the same problem reoccurs, it is possible that there is an intermittent failure of the component or the ECM. Check for looseness at all harness junctions and test for an intermittent failure.