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 NGS tester, perform the following steps:

Select VEHICLE & ENGINE SELECTION menu.
Select VEHICLE, YEAR & MODEL.
Select DIAGNOSTIC DATA LINK.
Select PCM - POWERTRAIN CONTROL MODULE.
Select DIAGNOSTIC TEST MODE.
Select RETRIEVE/CLEAR CONTINUOUS DTCs.
Turn ignition on.
Follow operating instructions from NGS tester menu.
Record DTCs and perform appropriate system test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 7.3L 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 disconnect glow plug relay to keep battery from going dead. Ignore any glow plug DTCs while glow plug relay is unplugged.