Quick Test 3.0 (Key On Engine Off)

Follow the procedures as outlined in the "E40D Self Test Overview" section for performing the Key On Engine Off Self-Test.

Some special considerations:

Some 1991 E40D applications will utilize three digit self-test codes.

As indicated in the test procedure, treat rough engine idle as a separate symptom and service it first (gasoline engines).

On 7.3L diesel applications, the throttle pedal must be fully depressed (WOT) for the entire Key On Engine Off Test. DO NOT depress the throttle pedal for gasoline engline applications.

The Key On Engine Off test provides both "hard" failures (present at the time of testing) and continuous memory codes. Always service the hard failures first. These are displayed first on the tester. For E40D faults most codes are stored in memory. According to directions these will lead you to the proper diagnostic test steps.