Diagnostic Instructions

DTC Descriptors

DTC P0105 03: Manifold Absolute Pressure (MAP) Sensor Circuit Voltage Below Threshold

DTC P0105 07: Manifold Absolute Pressure (MAP) Sensor Circuit Voltage Above Threshold

DTC P0105 5A: Manifold Absolute Pressure (MAP) Sensor Circuit Plausibility Failure

Circuit/System Description

The turbocharger pressure sensor measures the pressure inside the intake manifold. Pressure in the intake manifold is affected by turbocharger output, engine speed, accelerator pedal input, air temperature, and barometric pressure (BARO). A diaphragm within the turbocharger pressure sensor is displaced by the pressure changes that occur from the varying load and operating conditions of the engine. The engine control module (ECM) supplies a regulated 5 volts to the sensor on the 5-volt reference circuit. The ECM supplies a ground on the low reference circuit. The turbocharger pressure sensor provides a signal voltage to the ECM, relative to the pressure changes, on signal circuit. The ECM converts the signal voltage input to a pressure value. Under normal operation, the lowest pressure that can exist in the intake manifold is equal to the BARO. This occurs when the engine is operating at idle or when the ignition is ON and the engine is OFF. The ECM uses the turbocharger pressure sensor to aid in diagnosis of the turbocharger performance. The highest manifold pressures occur when the turbocharger output is high. Manifold pressure can range from 58 kPa (8 psi) when pressure is low, to greater than 240 kPa (34 psi) when pressure is high, depending on the BARO. The turbocharger pressure sensor has a range of 33-255 kPa (4-36 psi).

Conditions for Running the DTC

Conditions for Setting the DTC

P0105 03, P0105 07

The ECM detects the MAP sensor signal circuit is open, shorted to ground, or shorted to a voltage for greater than 1 second.

P0105 5A

The ECM detects the difference between the MAP sensor signal and the BARO sensor signal is greater than 20 kPa for greater than 2 seconds.

Action Taken When the DTC Sets

DTC P0105 is a Type B DTC.

Conditions for Clearing the DTC

DTC P0105 is a Type B DTC.

Diagnostic Aids

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 23738-A Mity Vac

Circuit/System Verification

1. Ignition On, observe the DTC information with a scan tool. Verify that DTCs P0641, P0651, or P0697 is not set.

⇒	If any DTCs are set, refer to DTC P0641, P0651, or P0697 for further diagnosis.

2. Determine the current vehicle testing altitude. Ignition ON, observe the scan tool BARO Sensor parameter. Compare the parameter to the Altitude Versus Barometric Pressure.
3. Ignition ON, observe the scan tool MAP sensor parameter. The MAP sensor parameter should match the BARO sensor parameter.
4. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Verify the integrity of the entire air induction system by inspecting for the following conditions:

•	Damaged components

•	Loose or improper installation

•	Any vacuum leak

•	Verify there are no restrictions in the turbocharger pressure sensor port or vacuum source.

⇒	If a condition is found, repair as necessary.

2. Ignition OFF, and the MAIN fuse removed, disconnect the harness connector at the turbocharger boost pressure sensor.
3. Test for less than 5 Ω between the low reference circuit terminal 4 and ground.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.

4. Install the MAIN fuse. Ignition ON, test for 4.8-5.2 V between the 5-volt reference circuit terminal 2 and ground.

⇒	If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

⇒	If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

5. Verify the scan tool MAP sensor parameter is less than 24 kPa.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

6. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the 5-volt reference circuit terminal 2. Verify the MAP sensor parameter is between 40-45 kPa.

⇒	If less than the specified range, test the signal circuit for an open or a short to ground. If the circuit tests normal, replace the K20 ECM.

⇒	If greater than the specified range, test the signal circuit for a high resistance. If the circuit tests normal, replace the K20 ECM.

7. If all circuits test normal, test or replace the turbocharger boost pressure sensor.

Component Testing

1. Ignition OFF, perform one of the following applicable procedures.

•	Disconnect the vacuum supply hose from the turbocharger boost pressure sensor

•	Remove the turbocharger boost pressure sensor from the intake manifold

2. Ignition ON, observe and record the scan tool MAP sensor pressure data parameter. This is the first MAP sensor reading.
3. Engine running, with the J 23738-A Mity Vac apply 5 in Hg (17 kPa) of vacuum to the turbocharger boost pressure sensor. Observe and record the scan tool MAP sensor pressure data parameter. This is the second MAP sensor reading.
4. Subtract the second MAP sensor reading from the first MAP sensor reading. Verify that the vacuum decrease is within 1 in Hg (4 kPa) of the applied vacuum.

⇒	If not within the specified range, replace the MAP sensor.

5. With the J 23738-A Mity Vac apply 10 in Hg (34 kPa) of vacuum to the MAP sensor. Observe and record the scan tool MAP sensor pressure data parameter. This is the third MAP sensor reading.
6. Subtract the third MAP sensor reading from the first MAP sensor reading. Verify that the vacuum decrease is within 1 in Hg (4 kPa) of the applied vacuum.

⇒	If not within the specified range, replace the turbocharger boost pressure sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.