Recommended Procedure

To perform self-test, turn ignition off. Ensure test equipment is properly attached. If vehicle is equipped with an auxiliary powertrain control system (RPM control), it must be turned off before performing self-test. Using scan tool, perform the following steps:

Perform the necessary vehicle preparation and visual inspection. See QUICK TEST in SELF-DIAGNOSTICS - 6.0L DIESEL article.
Refer to the scan tool manufacturer manual for scan tool instructions.
Record DTCs and perform appropriate system test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 6.0L DIESEL article.
After test has been completed, cycle ignition off before performing other self-tests or driving vehicle.
Continuous Memory DTCs must be cleared after repair.

NOTE: If performing repeated self-tests, it may be necessary to unplug GPCM to keep battery from going dead. Ignore any GPCM DTCs while GPCM is unplugged.