DTC P0204 Injector 4 Control Circuit. Buick GL7 (Export) 2000

For 1990-2009 cars

### Circuit Description

The powertrain control module (PCM) controls the fuel injector control circuit with a multi-function driver (MFD). The MFD has the ability to detect an electrical malfunction. If an electrical malfunction is detected, the MFD signals the PCM to set DTC P0204.

### Conditions for Running the DTC

The ignition is ON.

### Conditions for Setting the DTC

• | An incorrect voltage level is detected on an injector driver circuit.

• | The above condition is present for more than 30 seconds.

### Action Taken When the DTC Sets

• | The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.

• | The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.

### Conditions for Clearing the MIL/DTC

• | The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.

• | The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

• | The DTC can be cleared by using the scan tool.

### Diagnostic Aids

Inspect for the following conditions:

• | A poor connection at the PCM. Inspect the harness connectors for the following conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems:

- | Backed-out terminals

- | Improper mating

- | Broken locks

- | Improperly formed or damaged terminals

- | Poor terminal-to-wire connections

• | A damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, observe the display on the scan tool while moving connectors and wiring harnesses related to the circuit. Refer to Wiring Repairs in Wiring Systems.

Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. If the scan tool indicates STUCK HIGH there is a short to B+ voltage on the fuel injector control circuit.

2. If the scan tool indicates STUCK LOW there is an open or a short to ground on the fuel injector control circuit.

3. When the multiple-way connector is disconnected, other DTCs will be set. These DTCs should be disregarded.

   If the scan tool indicates a STUCK HIGH while cranking, the short to B+ voltage is between the multiple-way connector and the PCM. If the scan tool indicates STUCK LOW while cranking the short to B+ voltage is between the multiple-way connector and the fuel injector.

   Important: While cranking the engine with the multiple-way connector disconnected, all of the other injector circuits should indicate STUCK LOW, this is a fault induced by disconnecting this connector. They will resume correct operation when the connector is reconnected.

4. This step tests for a short to ground in the circuit.

5. The fuel injector in this circuit will need to be tested after the short to ground is repaired or after the PCM is replaced.

6. This step tests the function of the PCM. If the test lamp flashes, the PCM is able to supply the ground.

7. This vehicle is equipped with a PCM which uses an electronically erasable programmable read-only memory (EEPROM). If the PCM is replaced, the new PCM must be programmed.

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 | Start and idle the engine. Does the scan tool indicate this DTC failed this ignition? | -- | Go to Step 4 | Go to Step 3

3

1. Turn ON the ignition.
2. Operate the vehicle within the Failure Records conditions.

Does the scan tool indicate this DTC failed this ignition?

--

Go to Step 4

Go to Diagnostic Aids

4 | With a scan tool, observe the Cyl. Injector Ckt. Status parameter for this injector. Does the scan tool indicate this parameter STUCK HIGH? | -- | Go to Step 6 | Go to Step 5
5 | Does the scan tool indicate this parameter STUCK LOW? | -- | Go to Step 9 | Go to Diagnostic Aids

6

Important: : While cranking the engine with the multiple-way connector disconnected, all of the other injector circuits should indicate STUCK LOW. This is a fault induced by disconnecting this connector. The injectors will resume correct operation when the connector is reconnected.

1. Turn OFF the ignition.
2. Disconnect the multiple-way fuel injector connector.
3. With a scan tool, observe the Cyl. Injector Ckt. Status parameter for this injector while cranking the engine.

Does the scan tool indicate this parameter STUCK HIGH when the engine is cranking?

--

Go to Step 7

Go to Step 8

7 | Test for a short to voltage on the control circuit for this injector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 14
8 | Does the scan tool indicate this parameter STUCK LOW while cranking the engine? | -- | Go to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Between 10-35 Degrees C (50-95 Degrees F) or Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Outside 10-35 Degrees C (50-95 Degrees F) | --

9

1. Disconnect the multiple-way fuel injector connector.
2. Probe the control circuit of this injector on the PCM side of the multiple-way connector using a test lamp connected to B+ voltage.

Does the test lamp illuminate?

--

Go to Step 10

Go to Step 11

10 | Test for a short to ground on this injector control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the conditions? | -- | Go to Step 15 | Go to Step 14

11

1. Leave the test lamp connected.
2. Crank the engine.

Does the test lamp flash?

--

Go to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Between 10-35 Degrees C (50-95 Degrees F) or Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Outside 10-35 Degrees C (50-95 Degrees F)

Go to Step 12

12 | Test for an open on this injector control circuit between the multiple-way connector and the PCM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 13
13 | Inspect the injector control circuit for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 14
14 | Important: : The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the replacement? | -- | Go to Step 15 | --

15

1. Turn ON the ignition, leaving the engine OFF.
2. Use the scan tool in order to clear the DTCs.
3. Operate the vehicle within the Failure Records conditions.

Does the DTC reset?

--

Go to Step 2

System OK