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Home >> Buick >> 2004 >> Century Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls (DTC P0140 To P0496) >> Engine Controls Diagnosis >> DTC P0230 >> Test Description
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Test Description

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

  1. 4:  This step verifies that the PCM is providing voltage to the fuel pump relay.
  2. 5:  This step tests for an open in the ground circuit to the fuel pump relay.
  3. 6:  This step tests if voltage is constantly being applied to the control circuit of the fuel pump relay.
DTC P0230

Step Action Yes No
Schematic Reference:  Engine Controls Schematics 
Connector End View Reference:  Engine Controls Component Views  or  Powertrain Control Module (PCM) Connector End Views 
1 Did you perform the Diagnostic System Check-Engine Controls? Go to Step 2  Go to Diagnostic System Check - Engine Controls
2
IMPORTANT: Listen for the click when the fuel pump relay operates.
  1. Turn ON the ignition, with the engine OFF.
  2. With a scan tool, command the fuel pump relay ON and OFF.
Does the fuel pump relay turn ON and OFF with each command?
Go to Step 3  Go to Step 4 
3
  1. Observe the Freeze Frame/Failure Records data for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text or as close as possible to the Freeze Frame/Failure records data that you observed.
Does the DTC fail this ignition?
Go to Step 4  Go to Intermittent Conditions
  1. Turn OFF the ignition.
  2. Disconnect 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 connected to a good ground.
  5. With a scan tool, command the fuel pump relay ON and OFF.
Does the test lamp turn ON and OFF with each command?
Go to Step 5  Go to Step 6 
  1. Connect a test lamp between the control circuit of the fuel pump relay and the ground circuit of the relay.
  2. With a scan tool, command the fuel pump relay ON and OFF.
Does the test lamp turn ON and OFF with each command?
Go to Step 9  Go to Step 11 
Does the test lamp remain illuminated with each command? 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 in Wiring Systems.
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 in Wiring Systems.
Did you find and correct the condition?
Go to Step 14  Go to Step 10 
9 Inspect for poor connections at the fuel pump 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 14  Go to Step 12 
10 Inspect for poor connections at the harness connectors of 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 14  Go to Step 13 
11 Repair the ground circuit of the relay. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?
Go to Step 14  -
12 Replace the fuel pump relay.
Did you complete the replacement?
Go to Step 14  -
13 Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement .
Did you complete the replacement?
Go to Step 14  -
14
  1. Use the scan tool in order to clear the DTCs.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC run and pass?
Go to Step 15  Go to Step 2 
15 With a scan tool, observe the stored information, Capture Info.
Does the scan tool display any DTCs that you have not diagnosed?
Go to Diagnostic Trouble Code (DTC) List System OK