Key On Engine Running (KOER)

DESCRIPTION
Key On Engine Running (KOER) Self-Test is a functional test of the powertrain control system performed on-demand with the engine running and vehicle stopped. A check of the inputs and outputs is made during operating conditions and at normal temperature. A fault has to be present at the time of testing for the KOER Self-Test to detect the fault. When a fault is detected, a Diagnostic Trouble Code (DTC) will be output on the data link when requested by a scan tool. Technicians may be required to perform some action on certain vehicles during KOER in order to test some switches.

PROCEDURE - Generic Scan Tool in Enhanced Diagnostic Test Mode
A string of characters must be entered into the generic scan tool to perform KOER Self-Test. The generic keystroke entry for this specific function is provided below. Also, refer to the scan tool manufacturer's instructions for additional information.

Perform the necessary vehicle preparation and visual inspection.

Connect scan tool to DLC.

Turn ignition key to the ON position and start vehicle.

Verify tool is connected and communicating properly by entering the OBD II System Readiness Test.

Enter the following four strings separately and in the order shown to initiate KOER Self-Test:

All string ID numbers (first field) must match the order shown.

After the test begins, cycle BOO, 4X4L and TCS switches (if equipped).

- 08,3E,22,C4103382,,9E 00 445443287329 20 8042 20 8062 20 8082 A851 FF, 34

- 07,32,22FF,C410220202,,9E 00 434E54 20 8061 A961 00 08, F2

- 06,32,22,C410328200,,9E 00 57414954 20 8081 A181 61 07, 68

- 05,32,22,C4103182,,9E00 5354415254 20 8081 A181 00 06, 5D