GM Service Manual Online
For 1990-2009 cars only

Object Number: 548508  Size: MF
Engine Controls Components
Engine Controls Schematics
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The PCM provides ignition positive voltage to control the fuel pump relay. The PCM has the ability to detect an electrical malfunction on the relay control circuit. When the ignition switch is first turned ON, the PCM energizes the fuel pump relay which applies power to the fuel pump. The fuel pump relay will remain ON as long as the engine is running or cranking and the PCM is receiving reference pulses. If no reference pulses are present, the PCM de-energizes the fuel pump relay within 2 seconds after the ignition is turned ON or the engine is stopped. With the engine stopped, the fuel pump can be turned ON by using the scan tool output controls function. If an electrical malfunction is detected, the PCM will set DTC P0230.

Conditions for Running the DTC

    • The ignition is ON.
    • System voltage is between 9 and 18 volts.

Conditions for Setting the DTC

    • The PCM detects an electrical malfunction on the fuel pump relay control circuit.
    • The condition is present for more than 30 seconds.

Action Taken When the DTC Sets

The PCM stores conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records.

Conditions for Clearing the MIL/DTC

    • The DTC becomes history when the conditions for setting the DTC are no longer present.
    • The history DTC clears after 40 malfunction free warm-up cycles.
    • The PCM receives a clear code command from the scan tool.

Diagnostic Aids

Inspect for the following:

Many situations may lead to an intermittent condition. Perform each inspection or test as directed.

Important: :  Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

    • Loose terminal connection
       -  Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
       -  Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
    • Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.
    •  Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.

If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.

Test Description

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

  1. Listen for an audible click when the relay operates. Command both the ON and OFF states. Repeat the commands as necessary.

  2. Verifies that the PCM is providing voltage to the relay.

  3. Tests for an open in the ground circuit to the relay.

  4. Tests if voltage is constantly being applied to the relay.

  5. The PCM utilizes Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is replaced, the new PCM must be programmed.

P0230 -- Fuel Pump Relay Control Ckt. (HSD)

Step

Action

Values

Yes

No

1

Did you perform the On-Board (OBD) Diagnostic System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

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

Does the relay turn ON and OFF with each command?

--

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the control circuit of the relay with a test lamp connected to a good ground.
  5. With a scan tool, command the relay ON and OFF.

Does the test lamp turn ON and OFF with each command?

--

Go to Step 4

Go to Step 5

4

  1. Connect a test lamp between the control circuit of the relay and the ground circuit of the relay.
  2. With a scan tool, command the relay ON and OFF.

Does the test lamp turn ON and OFF with each command?

--

Go to Step 8

Go to Step 10

5

Does the test lamp remain illuminated with each command?

--

Go to Step 7

Go to Step 6

6

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

Did you find and correct the condition?

--

Go to Step 13

Go to Step 9

7

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

Did you find and correct the condition?

--

Go to Step 13

Go to Step 9

8

Inspect for poor connections at the relay. 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 13

Go to Step 11

9

Inspect for poor connections 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 13

Go to Step 12

10

Repair the ground circuit of the relay. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 13

--

11

Replace the relay.

Did you complete the replacement?

--

Go to Step 13

--

12

Important: Perform the set up procedure for the PCM.

Replace the PCM.

Refer to Powertrain Control Module Replacement/Programming

Did you complete the replacement?

--

Go to Step 13

--

13

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Fail Record conditions.

Does the DTC reset?

--

Go to Step 2

System OK