Refer to
Injectors (5.0L/5.7L)
.
Refer to
Fuel Injector #1 -- #8 (7.4L)
.
Diagnostic Aids
The vehicle control module (VCM) has integrated circuits that are fault protected, therefore, if a circuit has failed, the integrated circuits may not be damaged. If this is the case, the ignition control (IC) will keep the circuit open until you have corrected the fault in the circuit. When you have corrected the fault, reinstall the VCM. Check the circuit. Replace the VCM only if the circuit is still inoperative.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step determines if the ignition feed circuit to the injectors are OK.
-
This step determines if the injector control circuits are OK.
-
This step determines if there is an internal VCM short to ground for an injector control circuit.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Important: Before clearing DTCs, use the scan tool in order to record freeze frame and the failure records for reference because the Clear Info function will lose the data. Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
Is the test lamp on for all the injector feed circuits? | -- | |||
Does the injector test lamp flash for each injector? | -- | |||
4 | Is the injector test lamp on steady for any injector circuit? | -- | ||
| -- | |||
6 | Check for an open or short to B+ for the affected injector control circuit. Was a problem found? | -- | ||
7 | Repair circuit as necessary. Refer to Wiring Repairs in Engine Electrical. Is the action complete? | -- | -- | |
8 | Repair short to ground in the injector control circuit. Refer to Wiring Repairs in Engine Electrical. Is the action complete? | -- | -- | |
9 | Check the terminal contact at the VCM. Was a problem found? | -- | ||
10 | Repair terminal contact as necessary. Is action complete? | -- | -- | |
11 | Repair the VCM. Important: If the VCM is faulty, reprogram the VCM. Refer to VCM Replacement/Programming (With KS Calibration PROM) . Is the action complete? | -- | -- | |
12 |
Does the engine start and continue to run? | -- | ||
13 |
Are any DTCs displayed that have not been diagnosed? | -- | Go to The Applicable DTC Table | |
14 | Using the scan tool, select the Capture Info and the Review Info. Are any DTCs displayed that have not been diagnosed? | -- | Go to The Applicable DTC Table | System OK |
