Quick Test 3.0 - Key ON, Engine OFF (KOEO)

Some special considerations for Key ON, Engine OFF Quick Test include the following:
- The KOEO test provides both "hard" Diagnostic Trouble Codes (DTCs) (present at the time of testing) and continuous memory DTCs.
- Always service the "hard" DTCs first. These are displayed first on the tester.

Performing KOEO Diagnostic Test

Note: If SUPER STAR Tester II or equivalent is unavailable, refer to Computers and Controls for alternate methods for running On-Board Diagnostic tests.

1. Activate Diagnostic Test by pressing center button on SUPER STAR II Tester (grounding Self-Test Input STI).
2. Turn ignition switch to RUN position.
3. Powertrain control module will run Diagnostic Test Mode and then output "hard" DTCs (or Code 111-pass test). "Hard" DTCs are repeated to make it easier to verify sequence. After "hard" DTCs have been repeated (or Code 111 repeated) a single pulse occurs to signal that next set of DTCs will be from continuous test (or Code 111-pass).
4. To display DTCs, unlatch center button and use memory buttons to scroll through codes.