The engine control module (ECM) supplies a high voltage supply circuit and a high voltage control circuit for each fuel injector. The injector high voltage supply circuit and the high voltage control circuit are both controlled by the ECM. The ECM energizes each fuel injector by grounding the control circuit and supplying each fuel injector with up to 250 V and 20 amps on the voltage supply circuit to activate the piezo type fuel injectors. This is controlled by boost capacitors in the ECM. During the 250 V boost phase, the capacitor is used to charge the injector piezo stack, allowing for injector opening. The injector is then held open with this high voltage. At the end of the injection event the ECM closes the injector by discharging the injector piezo stack.
The ECM monitors the status of the voltage supply and voltage control circuits. The injectors are separated into the following four groups:
Group 1– injectors 1 and 4
Group 2– injectors 6 and 7
Group 3– injectors 2 and 5
Group 4– injectors 3 and 8
When a fuel injector circuit fault condition is detected by the ECM, the specific fuel injector, or the two fuel injectors in the affected group may be disabled. DTCs for the injector and/or group may set.
Conditions for Running the DTC
DTC P0606, P1224, P1227, P1233, P1236, P1239, P1242, P1247, or P122A is not set.
The ignition is ON.
The charging system voltage is between 10–18 volts.
Conditions for Setting the DTC
The ECM injector output driver detects an incorrect current on a fuel injector circuit.
The above condition is present for less than 1 second.
Action Taken When the DTC SetsDTCs P2146, P2149, P2152 and P2155 are Type A DTCs.
Conditions for Clearing the MIL/DTCDTCs P2146, P2149, P2152 and P2155 are Type A DTCs.
Diagnostic Aids
-The electronic control module (ECM) is sensitive to resistance on the injector circuits.
-Inspect each connector terminal for loose terminal fit or signs of fretting
-Testing for Intermittent Conditions and Poor Connections
DTC Type Reference Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference Control Module References for scan tool information
Circuit/System Verification
Engine Running.
Observe the following scan tool parameters:
Cylinder 1 Injector Circuit Status
Cylinder 2 Injector Circuit Status
Cylinder 3 Injector Circuit Status
Cylinder 4 Injector Circuit Status
Cylinder 5 Injector Circuit Status
Cylinder 6 Injector Circuit Status
Cylinder 7 Injector Circuit Status
Cylinder 8 Injector Circuit Status Each parameter should display OK or Not Run.
If any parameter does not display OK or Not Run Refer to Circuit/System Testing.
If all parameters display OK or Not Run
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
If DTC resets Refer to Circuit/System Testing.
If DTC does not reset
All OK.
Circuit/System Testing Danger: In order to reduce the risk of personal injury, loss of high voltage isolation to ground and higher system impedance, do not attempt to repair any HV wiring, connector, or terminal that is damaged. High voltage coaxial type cables are not repairable. Never attempt to repair a coaxial type cable. The entire cable/harness or component must be replaced. In order to maintain system integrity and personal safety, never attempt to repair any high voltage wiring, cables, or terminals. Performing this procedure on high voltage circuits may result in serious injury or death.
Danger: Before working on any high voltage fuel injection system, be aware of the following procedures:
Do not make contact with the fuel injection harness, engine control module (ECM), or fuel injectors while the ignition is ON or RUN positions.
Wait 5 minutes after key OFF to allow the electronic control module (ECM) to discharge before attempting to disconnect or test engine control components.
Do not use the electronic control module (ECM) case as a ground while jump starting.
Failure to follow the procedure exactly as written may result in serious injury or death.
Note: The following diagnostics must be performed to each injector in the group that the DTC was set.
Group 1–DTC P2146 with injectors 1 and 4
Group 2–DTC P2149 with injectors 6 and 7
Group 3–DTC P2152 with injectors 2 and 5
Group 4–DTC P2155 with injectors 3 and 8
Ignition OFF.
Disconnect the appropriate harness connectors at each of the Q17 Fuel Injectors in the group that the DTC set.
Ignition ON.
Test for less than 1 V between the appropriate Direct Fuel Injector (DFI) High Voltage Supply circuit terminal 1 and ground.
If greater than 1 V Repair the short to voltage in the appropriate Direct Fuel Injector (DFI) High Voltage Supply circuit.
If less than 1 V
Ignition OFF.
Disconnect the X1, X2 and X3 harness connector at the K20 Engine Control Module.
Test for 0.0 V between the appropriate Direct Fuel Injector (DFI) High Voltage Supply circuit terminal 1and B+.
If greater than 0.0 V Repair the short to ground in the appropriate Direct Fuel Injector (DFI) High Voltage Supply circuit.
If less than or equal to 0.0 V
Test for 0.0 V between the appropriate Direct Fuel Injector (DFI) High Voltage Control circuit terminal 2 and B+.
If greater than 0.0 V Repair the short to ground in the appropriate Direct Fuel Injector (DFI) High Voltage Control circuit.
If less than or equal to 0.0 V
Test for 150K-210K Ω between terminal 1 and terminal 2 of the appropriate Q17 Fuel Injector.
If the not between 150K-210K Ω Replace the appropriate Q17 Fuel Injector.
If between 150K-210K Ω
Test for infinite resistance between each terminal and the Q17 Fuel Injector housing/case.
If not infinite resistance Replace the Q17 Fuel Injector .
If infinite resistance
Replace the K20 Engine Control Module.
Component Testing
Ignition OFF.
Disconnect the harness connector at the appropriate Q17 Fuel Injector.
Test for 150K-210K ohms between terminal 1 and terminal 2 of the Q17 Fuel Injector.
If not within 150K to 210K ohms Replace the appropriate Q17 Fuel Injector.
If within 150K to 210K ohms
Test for infinite resistance between each terminal and the Q17 Fuel Injector housing/case.
If not infinite resistance Replace the Q17 Fuel Injector.
If infinite resistance
All OK.
Fuel Injector Replacement
Perform the Fuel Injector Flow Rate Programming procedure after replacement of a fuel injector.
