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Home >> Buick >> 2007 >> Lucerne CX >> Repair and Diagnosis >> External Pages >> Different car >> Section 70 (Engine Control System - 3.8L (DTC P1125 To DTC P2A01)) >> Diagnosis >> DTC P2432 (L26, Nu3) >> Test Description

Test Description

WARNING: This page is about a different car, the 2005 Buick LaCrosse and 2005 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.

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

  1. 6:  The measurement noted in this step will be used in subsequent steps if the measurement is not less than the specified value.
  2. 7:  This step calculates the resistance in the 5-volt reference circuit.
  3. 11:  A short between the AIR pressure signal and the AIR control solenoid valve voltage circuits can set this DTC. Prior to any repairs or part replacement, ensure that this condition does not exist.
DTC P2432 (L26, NU3)

Step Action Values Yes No
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Powertrain Control Module (PCM) 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. Start and idle the engine.
  2. Monitor the DTC information with the scan tool.
Is DTC P0641 also set?		 - Go to DTC P0641 Go to Step 3 
3 Observe the AIR pressure sensor parameter with a scan tool.
Is the voltage less than the specified value?		 0.1 V Go to Step 5  Go to Step 4 
4
  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start and idle 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 5  Go to Intermittent Conditions
5 Test for an intermittent and for a poor connection at the secondary air injection (AIR) control solenoid valve/pressure sensor assembly electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 - Go to Step 15  Go to Step 6 
6 
  1. Turn OFF the ignition.
  2. Disconnect the AIR control solenoid valve/pressure sensor assembly electrical connector.
  3. Turn on the ignition, with the engine OFF.
  4. Measure the voltage from the 5-volt reference circuit of the AIR pressure sensor to a good ground, with a DMM. Note the measurement as Supply voltage.
Is the voltage more than the specified value?		 4.8 V Go to Step 7  Go to Step 9 
7 
  1. Connect a test lamp and a DMM in series between the 5-volt reference circuit and the low reference circuit of the AIR pressure sensor at the harness connector.
  2. Measure the amperage with the DMM. Note the measurement as Amperage.
  3. Remove the DMM from the circuit.
  4. Connect the test lamp between the 5-volt reference circuit and the low reference circuit of the AIR pressure sensor, at the harness connector.
  5. Measure the voltage from the 5-volt reference circuit at the test lamp to a good ground, with the DMM. Note the measurement as Load voltage drop.
    6. IMPORTANT: Before any calculations are performed, ensure that all measurements are converted to like units. For example, volts/amps or millivolts/milliamps.
  6. Subtract the Load Voltage Drop from the Supply Voltage obtained in a previous step. Note the result as Supply Voltage Drop.
  7. Divide the Supply voltage drop by the Amperage.
Is the result more than the specified value?		 5 Ω Go to Step 10  Go to Step 8 
8
  1. Remove the test lamp from the previous step.
  2. Connect a 3-amp fused jumper wire between the 5-volt reference circuit of the AIR pressure sensor and the signal circuit of the AIR pressure sensor.
  3. Observe the AIR pressure sensor parameter with the scan tool.
Is the voltage more than the specified value?		 4.9 V Go to Step 13  Go to Step 11 
9 Test the 5-volt reference circuit between the powertrain control module (PCM) and AIR pressure sensor for an open or for a short to ground. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 15  Go to Step 12 
10 Test the 5-volt reference circuit between the PCM and the AIR pressure sensor for high resistance. Refer to Circuit Testing andWiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 15  Go to Step 12 
11  Test the AIR pressure sensor signal circuit between the PCM and the AIR pressure sensor for the following conditions:
  • A short to voltage
  • A short to ground
  • An open
  • High resistance

Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 15  Go to Step 12 
12 Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections andConnector Repairs .
Did you find and correct the condition?		 - Go to Step 15  Go to Step 14 
13 Replace the AIR control solenoid valve/pressure sensor assembly. Refer to Secondary Air Injection (AIR) Shut-Off Valve Replacement .
Did you complete the replacement?		 - Go to Step 15  -
14 Replace the PCM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 - Go to Step 15  -
15
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start and idle 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 16 
16 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
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