No Econo Light With Engine Off (Chart C-8-1)

Chart C-8-1:

ECONO Light Circuit:

CIRCUIT DESCRIPTION:

The Electronic Control Unit (ECU) controls the economy (ECONO) light by using a driver to supply a ground path for the circuit. There are two possible conditions that could cause the light to be "ON." If the economy mode is selected, the light will be illuminated or the light will flicker if malfunction codes are stored. The economy (ECONO) light is also used to flash out malfunction codes stored in the ECU's memory.

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

1. The ORN/BLK wire should be grounded with the key "ON."

2. B+ should be present at YEL wire at economy (ECONO) light.

DIAGNOSTIC AIDS:

An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation. Inspect ECU harness connector for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection and damaged harness.