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 P0201: Fuel Injector 1 Control Circuit
DTC P0201 04: Fuel Injector 1 Control Circuit Open
DTC P0202: Fuel Injector 2 Control Circuit
DTC P0202 04: Fuel Injector 2 Control Circuit Open
DTC P0203: Fuel Injector 3 Control Circuit
DTC P0203 04: Fuel Injector 3 Control Circuit Open
DTC P0204: Fuel Injector 4 Control Circuit
DTC P0204 04: Fuel Injector 4 Control Circuit Open
DTC P1224: Fuel Injector 1 Control Circuit
DTC P1224 01: Fuel Injector 1 Control Circuit Short to Battery
DTC P1227: Fuel Injector 2 Control Circuit
DTC P1227 01: Fuel Injector 2 Control Circuit Short to Battery
DTC P122A: Fuel Injector 3 Control Circuit
DTC P122A 01: Fuel Injector 3 Control Circuit Short to Battery
DTC P1233: Fuel Injector 4 Control Circuit
DTC P1233 01: Fuel Injector 4 Control Circuit Short to Battery

### Diagnostic Fault Information

Fuel Injector Circuits | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance
--- | --- | --- | --- | --- | ---
Fuel Injector Positive Voltage Control Group 1 | P2146 | P2146 | P0201, P0204 | P2146 | --
Fuel Injector Positive Voltage Control Group 2 | P2149 | P2149 | P0202, P0203 | P2149 | --
Fuel Injector 1 Control | P0201 | P2146 | P0201 | P0201 | --
Fuel Injector 2 Control | P0202 | P2149 | P0202 | P0202 | --
Fuel Injector 3 Control | P0203 | P2149 | P0203 | P0203 | --
Fuel Injector 4 Control | P0204 | P2146 | P0204 | P0204 | --

### 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 fuel injectors are separated into the following two groups:

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

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

When a fuel injector circuit condition is detected by the ECM, the affected fuel injectors will be disabled and may disable the affected group of fuel injectors.

### Conditions for Running the DTC

• | The engine is operating.

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

### Conditions for Setting the DTC

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match.

### Action Taken When the DTC Sets

DTCs P0201, P0202, P0203, P0204, P1224, P1227, P122A, and P1233 are Type A DTCs.

### Conditions for Clearing the DTC

DTCs P0201, P0202, P0203, P0204, P1224, P1227, P122A, and P1233 are Type A DTCs.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

• | Engine Control Module Connector End Views

• | Engine Controls 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

• | Scan Tool Data List

• | Scan Tool Data Definitions

• | Scan Tool Output Controls

### Circuit/System Verification

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

⇒ | If DTC P2146, or P2149 is set, refer to DTC P2146 or P2149 .

2. Engine idling, observe the scan tool diagnostic trouble code (DTC) information. DTCs P0201, P0202, P0203, P0204, P1224, P1227, or P1233 should not be set.
3. 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 are captured in the Freeze Frame/Failure Records Data List.

### Circuit/System Testing

1. Disconnect the harness connector at the appropriate fuel injector.
2. Ignition ON, test for 3-4 volts between the low control circuit terminal 2 and ground.

⇒ | If less than the specified range, test the low control circuit for an open/high resistance or for a short to ground. If the circuits/connections test normal, replace the ECM.

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

3. Test for less than 1 volt between the high control circuit terminal 1 and ground.

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

4. Engine idling, test for 12.5-14 volts between the high control circuit terminal 1 and ground.

⇒ | If less than the specified range, test the high control circuit for an open/high resistance or for a short to ground. If the circuits/connections test normal, replace the ECM.

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

### Component Testing

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

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

2. Test for 0.3-0.6 ohms between the terminals of the fuel injector.

⇒ | 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 within the specified range, 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, programming, 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 .