P0004 - FUEL QUANTITY CONTROL CIRCUIT HIGH
For a complete wiring diagram Refer to Section 8W
Theory of Operation
The Fuel Quantity Solenoid (FQS) is a solenoid operated valve designed to regulate fuel volume to the fuel injection pump. The FQS valve is positioned in the inlet side of the fuel injection
pump assembly. The solenoid receives 12–volt power and a duty-cycle ground signal from the ECM. When the solenoid is not actuated (no ground signal from the ECM), the fuel injection pump inlet passage
is open allowing full fuel flow to the pump chamber. When the ECM grounds the FQS control signal the solenoid valve closes the fuel inlet passage, preventing fuel from entering the pump chamber.
Possible Causes
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INTERMITTENT DTC
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(K365) FUEL QUANTITY SOLENOID CONTROL CIRCUIT SHORTED TO VOLTAGE
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(K365) FUEL QUANTITY SOLENOID CONTROL CIRCUIT OPEN OR HIGH RESISTANCE
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FUEL QUANTITY SOLENOID
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ENGINE CONTROL MODULE (ECM)
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Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
(Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
Diagnostic Test
1.
DTC IS ACTIVE
Ignition on, engine not running.
With the scan tool, Clear DTCs in the Engine Control Module (ECM).
With the scan tool, actuate the Fuel Quantity Solenoid at 100%.
Monitor the scan tool for at least two minutes.
With the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
No
2.
(K365) FUEL QUANTITY SOLENOID CONTROL CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the Fuel Quantity Solenoid harness connector.
Disconnect the Engine Control Module (ECM) harness connector.
Remove the ASD Relay from the TIPM.
Connect a jumper wire between cavity 30 and cavity 87 of the ASD Relay connector.
Turn the ignition on.
Measure the voltage of the (K365) Fuel Quantity Solenoid Control circuit in the Fuel Quantity Solenoid harness connector.
Is there any voltage present?
Yes
No
3.
(K365) FUEL QUANTITY SOLENOID CONTROL CIRCUIT SHORTED TO (K366) FUEL QUANTITY SOLENOID 12 VOLT SUPPLY CIRCUIT
Turn the ignition off.
Remove the jumper wire and install the ASD Relay
Measure the resistance between the (K365) Fuel Quantity Solenoid Control circuit and the (K366) Fuel Quantity Solenoid 12 Volt Supply circuit in the Fuel Quantity Solenoid harness connector.
Is the resistance above 1000 ohms?
Yes
No
-
Repair the (K365) Fuel Quantity Solenoid Control circuit for a short to the (K366) Fuel Quantity Solenoid 12 Volt Supply circuit.
-
Perform the ECM Verification Test Ver. 1.
(Refer to 9 - ENGINE - STANDARD PROCEDURE)
4.
(K365) FUEL QUANTITY SOLENOID CONTROL OPEN OR HIGH RESISTANCE
Measure the resistance of the (K365) Fuel Quantity Solenoid Control circuit between the Fuel Quantity Solenoid harness connector and the Engine Control Module (ECM) harness connector.
Is the resistance below 10.0 ohms?
Yes
No
5.
FUEL QUANTITY SOLENOID
Connect the Engine Control Module (ECM) harness connector.
Turn the ignition on.
With the scan tool, actuate the Fuel Quantity Solenoid (CP3 Metering Pump) to 100%.
Using a 12 volt test light connected to 12 volts, check the (K365) Fuel Quantity Solenoid Control circuit in the Fuel Quantity Solenoid harness connector.
NOTE:
The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
NOTE:
The circuit will remain actuated by the controller for 30 seconds. Be certain the actuation is active when checking the circuit.
Is the test light illuminated and bright with the actuation at 100%?
Yes
No
6.
ENGINE CONTROL MODULE (ECM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Quantity Solenoid and the Engine Control Module (ECM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Refer to any Technical Service Bulletins that may apply.
Were any problems found?
Yes
No