Chart C-1 Electric Load Signal Check

Chart C-1:

Diode Module Circuit:

CIRCUIT DESCRIPTION:

The ECM receives a signal at terminals "A2" and "B12" depending on vehicle model. This signal is present whenever one or more of the following components is turned "ON."

^ Head lights.
^ Rear window defogger.
^ Brake lights.
^ Heater blower motor.
^ Radiator cooling fan. The engine rpm will slightly increase for the additional electrical load.

TEST DESCRIPTION: Numbers below refer to the numbers on the diagnostic chart.

1. Checking for electrical load signal.

2. This is checking for an open circuit to the ECM or a faulty ECM.