GM Service Manual Online
For 1990-2009 cars only

Circuit Description

When the ignition switch is turned ON, the control module enables the fuel pump relay, which supplies current to the fuel pump. The fuel pump remains enabled as long as the engine is cranking or running and the control module receives ignition reference pulses. If there are no ignition reference pulses, the control module shuts the fuel pump OFF approximately 2 seconds after the ignition was switched to the ON position or if the engine stops. The control module monitors the voltage on the fuel pump relay control circuit. If the control module detects an incorrect voltage on the fuel pump relay control circuit, a fuel pump relay control DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0230 Fuel Pump Relay Control Circuit

Conditions for Running the DTC

    • The ignition is ON.
    • The system voltage is between 9-18 volts.

Conditions for Setting the DTC

    • The engine control module (ECM) detects that the commanded state of the driver and the actual state of the control circuit do not match.
    • The above conditions are present for a minimum of 2.5 seconds.

Action Taken When the DTC Sets

    • The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

Test Description

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

  1. This step verifies that the ECM is providing voltage to the fuel pump relay.

  2. This step tests for an open in the ground circuit to the fuel pump relay.

  3. This step tests if the voltage is constantly being applied to the control circuit of the fuel pump relay.

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Turn ON the ignition, with the engine OFF.
  2. Command the fuel pump relay ON and OFF with a scan tool.

Does the fuel pump relay turn ON and OFF when commanded with a scan tool?

Go to Step 3

Go to Step 4

3

  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. 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.

Did the DTC fail this ignition?

Go to Step 4

Go to Testing for Intermittent Conditions and Poor Connections

4

  1. Turn OFF the ignition.
  2. Remove the fuel pump relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the control circuit of the fuel pump relay with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors .
  5. Command the fuel pump relay ON and OFF with a scan tool.

Does the test lamp turn ON and OFF when commanded with a scan tool?

Go to Step 5

Go to Step 6

5

  1. Connect a test lamp between the control circuit of the fuel pump relay and the ground circuit of the fuel pump relay.
  2. Command the fuel pump relay ON and OFF with a scan tool.

Does the test lamp turn ON and OFF when commanded with a scan tool?

Go to Step 9

Go to Step 11

6

Does the test lamp remain illuminated?

Go to Step 8

Go to Step 7

7

Test the control circuit of the fuel pump relay for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 10

8

Test the control circuit of the fuel pump relay for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 10

9

Test for an intermittent and for a poor connection at the fuel pump relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 12

10

Test for an intermittent and for a poor connection at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 13

11

Test the ground circuit of the fuel pump relay for an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 14

--

12

Replace the fuel pump relay.

Did you complete the replacement?

Go to Step 14

--

13

Replace the ECM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 14

--

14

  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. 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.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 15

15

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List - Vehicle

System OK