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Home >> Chevrolet >> 2004 >> Optra Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - 1.4L DOHC - DTC P0336 To DTC P1385 >> DTC P1231 >> Test Description
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Test Description

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

  1. 2:  Listen for a click when the fuel pump relay operates. When the fuel pump relay is commanded On with the scan tool, the ECM pulses the fuel pump relay ON and OFF several times. Repeat the command as necessary.
  1. 4:  This step tests if voltage is constantly being applied to the control circuit of the fuel pump relay.
Step Action Yes No
Schematic Reference:  Engine Controls Schematics 
Connect End View Reference:  Engine Controls 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 
  1. Turn ON the ignition, with the engine OFF.
  2. Command the fuel pump ON with a scan tool.
Does the fuel pump relay turn ON and OFF?		 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.
Did the DTC fail this ignition?		 Go to Step 4  Go to Diagnostic Aids
4 
  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. Command the fuel pump ON with a scan tool.
Does the test lamp pulse ON and OFF?		 Go to Step 6  Go to Step 5 
5 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 10  Go to Step 7 
6 Test for shorted terminals and 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 10  Go to Step 8 
7 Test for shorted terminals and poor connections at the engine control module (ECM). 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 10  Go to Step 9 
8 Replace the fuel pump relay.
Did you complete the replacement?		 Go to Step 10  -
9 Replace the ECM. Refer to Engine Control Module Replacement .
Did you complete the replacement?		 Go to Step 10  -
10
  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.
Did the DTC fail this ignition?		 Go to Step 2  Go to Step 11 
11 Are there any DTCs that have not been diagnosed? Go to Diagnostic Trouble Code (DTC) List System OK
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