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Home >> Pontiac >> 2007 >> Vibe Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System & Fuel System - DTC P0134 To DTC P0451 >> DTC P0325 >> Test Description

Test Description

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

  1. 1:  The Diagnostic System Check - Vehicle prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool, if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
  2. 2:  This step checks whether the DTC P0325 is the result of a hard failure or an intermittent condition. Operating the vehicle in Check mode enhances the diagnostic capabilities of the PCM.
  3. 4:  This step checks the resistance of the KS.
  4. 5:  This step checks the knock sensors ability to output the correct frequency signal for a given engine speed.
DTC P0325

Step Action Values Yes No
Schematic Reference:  Engine Controls Schematics 
1  Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle
2 
  1. Turn OFF the ignition.
  2. Disconnect the knock sensor (KS) electrical connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the voltage across the KS connector, harness side, with a DMM.
Is the voltage near the specified value?		 5 V Go to Step 4  Go to Step 3 
3 Measure the voltage from the KS Signal High circuit to a good ground with the DMM.
Is the voltage near the specified value?		 5 V Go to Step 7  Go to Step 6 
4 
  1. Turn OFF the ignition.
  2. Connect the KS electrical connector.
  3. Disconnect the powertrain control module (PCM) electrical connector C2.
  4. Measure the resistance between the KS Signal High circuit and the KS Signal Low circuit with the DMM.
Is the resistance near the specified value?		 200k ohms at 20°C (68°F) Go to Step 5  Go to Step 8 
5 
  1. Turn OFF the ignition.
  2. Reconnect the C2 PCM connector.
  3. Backprobe between the KS Signal High circuit and the KS Signal Low circuit with the DMM.
  4. Select AC voltage and set to indicate Hz.
  5. Start the engine.
  6. Observe that the Hz frequency at idle is within the first specified value.
  7. Operate the engine at 4,000 RPM while observing that the Hz frequency increased to more than the second specified value.
Was the Hz frequency observed during both tests within the specified values?		 0.5-2 kHz
21-29 kHz		 Go to Diagnostic Aids Go to Step 8 
6
  1. Inspect for an open or a short in the KS Signal High circuit.
  2. Repair as necessary. Refer to Wiring Repairs .
Did you find and repair a condition?		 - Go to Step 12  Go to Step 10 
7
  1. Inspect for an open in the KS Signal Low circuit.
  2. Repair as necessary. Refer to Wiring Repairs .
Did you find and repair a condition?		 - Go to Step 12  Go to Step 10 
8
  1. Inspect for a poor connection at the KS. Refer to Testing for Intermittent Conditions and Poor Connections .
  2. Repair as necessary. Refer to Wiring Repairs .
Did you find and repair a condition?		 - Go to Step 12  Go to Step 9 
9 Replace the knock sensor. Refer to Knock Sensor Replacement .
Did you complete the replacement?		 - Go to Step 12  -
10
  1. Inspect for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections .
  2. Repair as necessary. Refer to Wiring Repairs .
Did you find and repair a condition?		 - Go to Step 12  Go to Step 11 
11 Replace the PCM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 - Go to Step 12  -
12
  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 13  Go to Step 2 
13 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 - Vehicle System OK
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