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For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 Savana 🢒 DTC 🢒 DTC P0237 Turbocharger Boost Sensor Circuit Low Voltage

Object Number: 195151 Size: MF
Engine Controls Components
Cell 22: Sensor Controls
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The powertrain control module (PCM) controls boost using the turbocharger wastegate solenoid. The solenoid is pulse width modulated (PWM). When the wastegate solenoid is not energized, the vacuum to the turbocharger wastegate solenoid is vented to atmosphere through the solenoid. As the pulse width is increased by the PCM, more vacuum is applied through the solenoid to the wastegate actuator. At idle a higher vacuum to the wastegate actuator helps keep the wastegate closed. At higher engine speeds the vacuum supplied by the solenoid is less, allowing the turbocharger boost pressure to overcome the wastegate actuator.

Conditions for Running the DTC

The ignition switch is in the ON position

Conditions for Setting the DTC
    • The boost pressure is less than 40 kPa.
    • The condition was met for 2 seconds.

Action Taken When the DTC Sets
    • The PCM illuminates the malfunction indicator lamp (MIL) on the second consecutive drive trip the diagnostic runs and fails.
    • The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the Failure Records store this information. If the diagnostic reports a failure on the second consecutive drive trip, the Freeze Frame records the operating conditions at the time of failure and updates the Failure Records.

Conditions for Clearing the MIL/DTC
    • The PCM will turn the MIL off after 3 consecutive trips without a fault condition.
    • A history DTC clears after 40 consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.
    • The scan tool Clear Info function was used.

Diagnostic Aids

An intermittent may be caused by the following:

    • Poor connections.
    • Rubbed through wire insulation.
    • Broken wire inside the insulation.

Check for opens or shorts to ground in the signal wire, or an open in the 5 volt reference circuit.

Test Description

The number(s) below refer to the step number(s) on the Diagnostic Table.

  1. This step will determine if DTC P0237 is the result of a hard failure or an intermittent condition.

    2.

  2. This Step simulates conditions for a DTC P0237. If the PCM recognizes the change, the PCM and the signal circuit are OK.

    3.

  3. In this step, components that share the 5 volt reference can cause the reference voltage to be shorted to ground. This can be checked by disconnecting each component one at a time, including the PCM while checking for continuity on that circuit to chassis ground.

Step

Action

Value(s)

Yes

No

1

Important: Before clearing any DTCs, use the scan tool Capture Info function to save the Freeze Frame and the Failure records for reference. The control module's data is deleted once the Clear Info function is used.

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Connect the scan tool.
  2. Allow the engine to idle.
  3. With J 39200 DMM connected to ground, probe the PCM harness connector boost signal circuit.

Does the J 39200 DMM display a boost pressure less than or equal to the specified value?

40 kPa (5.8 psi)

Go to Step 3

Go to Step 5

3

  1. Turn the ignition OFF.
  2. Disconnect the boost sensor electrical connector.
  3. Jumper the boost sensor 5 volt reference to the boost sensor signal circuit at the harness.
  4. Turn the ignition ON.

Does the scan tool display a Boost Pressure greater than or equal to the specified value?

202 kPa (29.30 psi)

Go to Step 6

Go to Step 4

4
  1. Turn the ignition OFF.
  2. Verify that the boost sensor is still disconnected.
  3. Remove the jumper wire.
  4. Jumper the boost sensor signal circuit at the harness with a J 35616-200 unpowered test lamp connected to B+.
  5. Turn the ignition ON.

Does the scan tool display a Boost Pressure greater than or equal to the specified value?

202 kPa (29.30 psi)

Go to Step 8

Go to Step 7

5

The DTC is intermittent. If no additional DTCs are stored, refer to Diagnostic Aids. If any additional DTCs are stored, refer to those table(s) first.

Are there any additional DTCs stored?

--

Go to the applicable DTC Table

Go to Diagnostic Aids

6
  1. Check for a poor connection at the boost sensor.
  2. If a problem is found, repair the problem as necessary. Refer to Wiring Repairs .

Did you perform a repair?

--

Go to Step 13

Go to Step 10

7
  1. Check for an open or a short to ground in the boost sensor signal circuit.
  2. If a problem is found, repair the problem as necessary. Refer to Wiring Repairs .

Did you perform a repair?

--

Go to Step 13

Go to Step 11

8
  1. Check for an open in the boost sensor 5 volt reference circuit.
  2. If a problem is found, repair the problem as necessary. Refer to Wiring Repairs .

Did you perform a repair?

--

Go to Step 13

Go to Step 9

9
  1. Check for a short to ground in the boost sensor 5 volt reference circuit.
  2. If a problem is found, repair the problem as necessary. Refer to Wiring Repairs .

Did you perform a repair?

--

Go to Step 13

Go to Step 12

10

Replace the boost sensor. Refer to Boost Sensor Replacement .

Is the action complete?

--

Go to Step 13

--

11
  1. Check the terminal connectors at the PCM for a poor connection.
  2. If a problem is found, repair the problem as necessary. Refer to Wiring Repairs .

Did you perform a repair?

--

Go to Step 13

Go to Step 12

12

Important: The new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Replace the PCM.

Is the action complete?

--

Go to Step 13

--

13
  1. Using the scan tool, clear the DTCs.
  2. Start engine.
  3. Allow the engine to idle until the normal operating temperature is reached.
  4. Select DTC and the Specific DTC function.
  5. Enter the DTC number that was set.
  6. Operate the vehicle within the Conditions for Setting this DTC until the scan tool indicates the diagnostic Ran.

Does the scan tool indicate the diagnostic Passed?

--

Go to Step 14

Go to Step 2

14

Does the scan tool display any additional undiagnosed DTCs?

--

Go to the applicable DTC Table

System OK