DTC P2146, P2149, P2152, or P2155. GMC Truck Sierra Denali 2009

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2009 🢒 Sierra Denali 🢒 Engine 🢒 Engine Controls and Fuel - 6.6L 🢒 DTC P2146, P2149, P2152, or P2155

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC P2146: Injector Positive Voltage Control Circuit Group 1

DTC P2149: Injector Positive Voltage Control Circuit Group 2

DTC P2152: Injector Positive Voltage Control Circuit Group 3

DTC P2155: Injector Positive Voltage Control Circuit Group 4

Diagnostic Fault Information

Fuel Injector Circuits	Short to Ground	High Resistance	Open	Short to Voltage
Fuel Injector Positive Voltage Control Group 1	P2146	P2146	P0201, P0204¹	P1233, P1224, P2146
Fuel Injector Positive Voltage Control Group 2	P2149	P2149	P0206, P0207¹	P1239, P1242, P2149
Fuel Injector Positive Voltage Control Group 3	P2152	P2152	P0202, P0205¹	P1227, P1236, P2152
Fuel Injector Positive Voltage Control Group 4	P2155	P2155	P0203, P0208¹	P122A, P1247, P2155
Fuel Injector 1 Control	P1233, P2146	P2146	P0201	P1224, P2146
Fuel Injector 2 Control	P1236, P2152	P2152	P0202	P1227, P2152
Fuel Injector 3 Control	P1247, P2155	P2155	P0203	P122A, P2155
Fuel Injector 4 Control	P1224, P2146	P2146	P0204	P1233, P2146
Fuel Injector 5 Control	P1227, P2152	P2152	P0205	P1236, P2152
Fuel Injector 6 Control	P1242, P2149	P2149	P0206	P1239, P2149
Fuel Injector 7 Control	P1239, P2149	P2149	P0207	P1242, P2149
Fuel Injector 8 Control	P122A, P2155	P2155	P0208	P1247, P2155
¹ Misfire DTCs may also set.

Circuit/System Description

The engine control module (ECM) supplies voltage to each fuel injector on the injector positive voltage control circuits. The ECM energizes each fuel injector by grounding the control circuit of that fuel injector. The ECM monitors the status of the injector positive voltage control circuits and the fuel injector control circuits. The injectors are separated into the following four groups:

•	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

When a fuel injector circuit condition is detected by the ECM, the fuel injectors in the affected group will be disabled and set the group DTC and may also set the fuel injectors DTCs.

Conditions for Running the DTC

•	The ignition is ON.

•	The charging system voltage is between 6-18 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 3 seconds for groups 1, 2, and 3.

•	The above condition is present for 5 seconds for group 4.

Action Taken When the DTC Sets

DTCs P2146, P2149, P2152 and P2155 are Type A DTCs.

Conditions for Clearing the MIL/DTC

DTCs P2146, P2149, P2152 and P2155 are Type A DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

Important: If you cannot duplicate the condition, operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Turn OFF the ignition.
Disconnect the ECM connector.
Connect a test lamp between the fuel injector positive voltage control circuit and battery voltage. The test lamp should not illuminate.

⇒	If the test lamp illuminates, test the fuel injector positive voltage control circuit and both injector control circuits for a short to ground.

Connect a test lamp between the affected fuel injector positive voltage control circuit and a ground. The test lamp should not illuminate.

⇒	If the test lamp illuminates, test the fuel injector positive voltage control circuit for a short to voltage.

Connect a test lamp between the affected fuel injector control circuit and battery voltage. The test lamp should not illuminate.

⇒	If the test lamp illuminates, test both fuel injector control circuits of the affected group for a short to ground.

Test the affected fuel injector positive voltage control circuit and the fuel injector control circuit for high resistance.
Test the affected fuel injector for high resistance. Refer to Component Testing in this diagnostic.

⇒	If all circuits test normal, replace the ECM.

Component Testing

Disconnect the connector of the fuel injector to be tested.
Connect a DMM between the terminals of the fuel injector and measure the resistance. The resistance should be 0.2-0.3 ohms.

⇒	If resistance is more than 0.2-0.3 ohms, replace the fuel injector.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Fuel Injector Replacement

•	Control Module References for ECM replacement, programing and setup