For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle

• | Review Strategy Based Diagnosis

• | Diagnostic Procedure Instructions

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Ignition voltage - fuse to splice | 1 | 2 | -- | --
Ignition voltage - splice to injector | 1 | P0201 00, P0202 00, P0203, 00 or P0204 00 | -- | --
Fuel injector 1 control | P0261 00 | P0201 00 | P026 00 | --
Fuel injector 2 control | P0264 00 | P0202 00 | P0265 00 | --
Fuel injector 3 control | P0267 00 | P0203 00 | P026 00 | --
Fuel injector 4 control | P0270 00 | P0204 00 | P0271 00 | --
1. Open fuse, cranks no start 2. Cranks no start

### Circuit/System Description

The engine control module (ECM) enables the appropriate fuel injector pulse for each cylinder. Ignition voltage is supplied to the fuel injectors. The ECM controls each fuel injector by grounding the control circuit via a solid state device called a driver.

### 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

#### Scan Tool Reference

Control Module References

#### Special Tools

EL-35616-E M-Approved Terminal Test Kit includes J-35616-200 Test Light -Probe Kit

For equivalent regional tools, refer to LINK.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate fuel injector listed below:

• | Q17A Fuel Injector 1

• | Q17B Fuel Injector 2

• | Q17C Fuel Injector 3

• | Q17D Fuel Injector 4

2. Ignition ON, verify that a test lamp illuminates between the appropriate Q17 Fuel Injector ignition circuit terminal 1 or circuit terminal A and ground.

⇒ | If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test or replace the Q17A Fuel Injector.

3. Ignition OFF, connect a J-35616-200 Test Light -Probe Kit between the K20 Engine Control Module (ECM) control circuit terminal 2 or B and the ignition circuit terminal 1 or circuit terminal A of each Q17 Fuel Injector one at a time.
4. Engine cranking, the test lamp should flash for each injector.

⇒ | If the test lamp is always ON, test the appropriate K20 Engine Control Module (ECM) control circuit for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

⇒ | If the test lamp is always OFF, test the appropriate K20 Engine Control Module (ECM) control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

5. If all circuits test normal, test or replace the appropriate Q17D Fuel Injector. Refer to Fuel Injector Diagnosis

### Repair Instructions

Perform the Diagnostic Repair Verification

• | Link (Fuel Injector Replacement)

• | Control Module References