Ranger 2WD V6-245 4.0L VIN X SFI (1997)
Multifunction Electronic Control Module: Testing and Inspection
Flow of Diagnosis
Inspection and Verification
The Generic Electronic Module (GEM) diagnostic system is composed of the New Generation STAR (NGS) tester, the GEM and all GEM-associated
components. They allow you to determine if a GEM subsystem has a fault and provides the capability to isolate the fault.
NOTE: This diagnostic information contains only on-demand self-test and functional test procedures for the GEM and GEM-related subsystems and
power and ground concern isolation pinpoint tests. Refer to the testing for the affected system for GEM subsystem diagnostic procedures.
Erasing Diagnostic Trouble Codes
Trouble codes are erased when either:
1. The ignition has been moved to the start position at any time during the diagnostic mode or
2. Power is removed from the Central Timer Module (CTM).
Interface
Central Timer Module Diagnostic Connector
The Central Timer Module (CTM) diagnostic mode is entered by grounding the dedicated diagnostic mode input. This one-pin connector is located
under the instrument panel. The diagnostic mode is exited (returned to normal operation) immediately upon removal of the ground on the diagnostic
mode input.
Retrieving Diagnostic Trouble Codes
The diagnostic mode is made up of the three following separate steps:
1. Tone and door ajar lamp test
2. Trouble code test
3. Input test
Step 1 is run immediately upon entry into the diagnostic mode.
Step 2 is run without the key in the ignition.
Step 3 is run with the key in the ignition.
The operator may switch between Steps 2 and 3 indefinitely until the diagnostic mode input is ungrounded.