For 1990-2009 cars

### 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 Descriptors

DTC 2146: Injector Positive Voltage Control Circuit Group 1
DTC 2149: Injector Positive Voltage Control Circuit Group 2

### 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.

When the ECM detects a fuel injector circuit condition, the fuel injectors in the affected group will be disabled.

### Conditions for Running the DTC

• | The engine is running.

• | The ECM monitors for a condition once per camshaft revolution.

### Conditions for Setting the DTC

The ECM detects an open, short to ground, or a short to voltage on the voltage supply circuit of the fuel injector.

### Action Taken When the DTC Sets

DTCs P2146 and P2149 are Type A DTCs.

### Conditions for Clearing the DTC

DTCs P2146 and P2149 are Type A DTCs.

### Diagnostic Aids

The fuel injectors are separated into the following groups:

• | Group 1--DTC P2146 with injectors 1 and 4

• | Group 2--DTC P2149 with injectors 2 and 3

### 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 Verification

1. Ignition ON, observe the DTC information with a scan tool. DTCs P2146 or P2149 should not set.
2. 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.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate fuel injectors. Refer to diagnostic aids.
2. Verify a test lamp does not illuminate between any of the fuel injector circuits and B+.

⇒ | If the test lamp illuminates, test the appropriate circuit for a short to ground. If the circuit tests normal, replace the ECM.

3. Test for less than 1 volt on all of the fuel injector circuits.

⇒ | If greater than the specified range, test the circuit for a short to voltage. If the circuits test normal, replace the ECM.

4. Test for less than 1 ohm on all of the appropriate fuel injector circuits.

⇒ | If greater than the specified range, repair the appropriate circuit for a high resistance.

5. If all circuits test normal, test or replace the fuel injector.

### Component Testing

1. Disconnect the harness connector at the appropriate fuel injector.

Important: The DMM and test leads must be calibrated to 0 ohms in order to prevent misdiagnosis.

2. Test for 0.3-0.7 ohms between the low control terminal 1 and the high control terminal 2.

⇒ | If not within the specified range, replace the fuel injector.

3. Test for infinite resistance between each terminal of the fuel injector and ground.

⇒ | If not the specified value, 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

### Repair Verification

Ignition ON, observe the scan tool DPF soot mass parameter. The parameter should be less than 24 grams.

⇒ | If greater than the specified range, perform a DPF service regeneration. Refer to Exhaust Particulate Filter Cleaning.