DTC P0106, P0107, or P0108

Engine Controls and Fuel - 3.0L LM2 Diesel | Diagnostic Information and Procedures | Document ID: 5507628 Diagnostic Instructions Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis An overview of each diagnostic category can be found here: Diagnostic Procedure Instructions DTC Descriptor DTC P0106 Manifold Absolute Pressure Sensor Performance DTC P0107 Manifold Absolute Pressure Sensor Circuit Low DTC P0108 Manifold Absolute Pressure Sensor Circuit High Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performanc
5 V Reference	P0651*	P0107	P0651*	P00C7
Signal	P0107	P0108	P0108	P00C7
Low Reference	—	P0108*	—	P00C7
* Additional DTCs may set

Typical Scan Tool Data Manifold Absolute Pressure Sensor

	Circuit	Short to Ground	Open	Short to Voltage
	Operating Conditions: Engine = Idling — At normal operating temperature. Accessories = Off Parameter Normal Range: Manifold Absolute Pressure Sensor = Barometric Pressure Sensor ± 5.0 kPa (± 0.7 PSI)
	5 V Reference	100.8 kPa (14.6 PSI)	0 kPa (0.0 PSI)	100.8 kPa (14.6 PSI)
	Signal	100.8 kPa (14.6 PSI)	435 kPa (63 PSI)	435 kPa (63 PSI)
	© 2023 Gener	al Motors. All right	s reserved.

Circuit/System Description

Circuit	Description
5 V Reference	Regulated voltage supplied by the control module.
Signal	The control module input circuit has an internal resistance connected to 5 V.
Low Reference	Grounded through the control module.

Component	Description
B65 Intake Manifold Pressure and Air Temperature Sensor	The assembly has several functions: Pressure The signal voltage increases when the pressure increases. Temperature The temperature sensor is a negative temperature coefficient thermistor, a resistor which changes based on temperature. Low temperature produces a high resistance: 1.2 kΩ @ 40°C (104°F) High temperature produces a low resistance: 109 Ω @ 120°C (248°F) The intake air temperature sensor 3 and the intake manifold pressure sensor are integrated in the same housing, which is located behind the throttle body. The sensor measures the temperature and pressure in the intake manifold between the throttle valve and the intake valves.
K20 Engine Control Module	The control module controls a series of actuators to ensure optimal engine performance. The control module does this by reading values from a variety of sensors, interprets the data and adjusts the engine actuators accordingly.

The sensor measures the pressure in the intake manifold. The signal is used to determine the engine load. When the engine is off or idling, the sensor pressure should be the same as the barometric pressure. Under wide-open throttle conditions the pressure will increase considerably. Conditions for Running the DTC P0106 DTC P0101, P0102, P0103, P0107, P0108, P0116, P0117, P0118, P0119, P0128, P0201, P0202, P0203, P0204, P020A, P020B, P020C, P020D, P0216, P02EE, P02EF, P02E8, P02E9, P02F0, P02F1, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0335, P0336, P062B, P062D, P111E, P122D, P1248, P1249, P124A, P124B, P126A, P16A0, P16A1, P16A2 P2147, P2148, P2150, P2151, P2227, P2228, P2229, P2230, P227C, P227D = Not set Ignition and Start Signal = Greater than 11 V Engine Speed = Less than 950 RPM Engine Coolant Temperature = Warmer than 70°C (158°F) Intake Air Flow Valve Position = Greater than 90% Frequency the DTC runs = Continuously After the running conditions are met P0107, P0108 Ignition and Start Switch Signal = On Engine ≠ Cranking Frequency the DTC runs = Continuously Conditions for Setting the DTC P0106 Manifold Absolute Pressure Sensor ≠ Barometric Pressure Sensor /Barometric Pressure Sensor 2 P0107 Signal circuit = Less than 0.2 V — For greater than 4 s P0108 Signal circuit = Greater than 4.5 V — For greater than 4 s Actions Taken When the DTC Sets DTCs listed in the DTC Descriptor category = Type A DTC Warning Message = Engine Power Is¦Reduced / Service Emission System / Service Exhaust Fluid System Reduced Engine Power = Active Conditions for Clearing the DTC DTCs listed in the DTC Descriptor category = Type A DTC Reference Information Schematic Reference Engine Controls Schematics Connector End View Reference Master Electrical Component List Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs DTC Type Reference Powertrain Diagnostic Trouble Code (DTC) Type Definitions Scan Tool Reference Control Module References Special Tools EN-23738-A Vacuum Pump Equivalent regional tools: Special Tools Circuit/System Verification

Note

If you were sent here from DTC P00C7 » Refer to: Circuit/System Testing.

1. Ignition » On / Vehicle » In Service Mode
2. Verify DTC P0641, P0651, P0697, P06A3, P06D2 is not set. ⇒ If any of the DTCs are set Refer to: DTC P0641, P0651, P0697, or P06A3 ⇓ If none of the DTCs are set
3. Verify the scan tool parameter: Manifold Absolute Pressure Sensor = The value should be within the range listed in the table: Altitude Versus Barometric Pressure ⇒ If not in the specified range Refer to: Circuit/System Testing ⇓ If in the specified range
4. Engine » Idling — At normal operating temperature.
5. Accessories » Off
6. Verify the scan tool parameter: Manifold Absolute Pressure Sensor = The value should be within the range listed in the table: Altitude Versus Barometric Pressure Manifold Absolute Pressure Sensor = The value should change with accelerator pedal input. ⇒ If not in the specified range or does not change Refer to: Circuit/System Testing ⇓ If in the specified range and changes
7. Verify the scan tool parameter: Manifold Absolute Pressure Sensor = The value should not spike or drop out. Perform the action while monitoring the parameter: Wiggle the harness and connector: B65 Intake Manifold Pressure and Air Temperature Sensor Wiggle the harness and connector: K20 Engine Control Module ⇒ If the value spikes or drops out Repair as necessary » Wiring / Terminal(s) / Electrical Connector(s) ⇓ If the value does not spike or drop out
8. 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 data. Verify that no DTCs are set. ⇒ If any DTC is set Refer to: Circuit/System Testing ⇓ If no DTC is set
9. All OK. Circuit/System Testing

Note

Circuit/System Verification must be performed before proceeding with Circuit/System Testing.

1. Ignition/Vehicle & All vehicle systems » Off
2. Verify the following conditions do not exist: B65 Intake Manifold Pressure and Air Temperature Sensor @ O-Ring / Leaking / Missing / Visible Damage B75 Mass Air Flow Sensor — Contamination of the measuring element / Water intrusion / Leaking / Visible Damage Q38 Throttle Body — Loose Clamps / Visible Damage Air Cleaner Element — Dirty / Restricted Dust Cover @ Barometric Pressure Sensor — Missing / Visible Damage / Water intrusion Intake Air Duct & Intake Manifold — Cracked / Loose Clamps / Restricted / Visible Damage Positive Crankcase Ventilation System — Leaking / Incorrect connection / Restricted — Water intrusion / Ice ⇒ If a condition exists Repair or replace as necessary ⇓ If no condition exists

Note

It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.

3. Disconnect the electrical connector: B65 Intake Manifold Pressure and Air Temperature Sensor
4. Test for less than 5 Ω between the test points: Low Reference circuit terminal 3 & Ground ⇒ If 5 Ω or greater 4.1. Disconnect the appropriate electrical connector: K20 Engine Control Module 4.2. Test for less than 2 Ω between the test points: Low Reference circuit terminal 3 @ Component harness & The other end of the circuit @ Control module harness ⇒ If 2 Ω or greater » Repair the open/high resistance in the circuit. ⇒ If less than 2 Ω » Replace the component: K20 Engine Control Module ⇓ If less than 5 Ω
5. Ignition » On / Vehicle » In Service Mode
6. Test for 4.8 to 5.2 V between the test points: 5 V Reference circuit terminal 2 & Low Reference circuit terminal 3 ⇒ If less than 4.8 V 6.1. Ignition/Vehicle » Off 6.2. Disconnect the appropriate electrical connector: K20 Engine Control Module 6.3. Test for infinite resistance between the test points: 5 V Reference circuit terminal 2 @ Component harness & Ground ⇒ If less than infinite resistance » Repair the short to ground on the circuit. ⇓ If infinite resistance 6.4. Test for less than 2 Ω between the test points: 5 V Reference circuit terminal 2 @ Component harness & The other end of the circuit @ Control module harness ⇒ If 2 Ω or greater » Repair the open/high resistance in the circuit. ⇒ If less than 2 Ω » Replace the component: K20 Engine Control Module ⇒ If greater than 5.2 V 6.1. Ignition/Vehicle » Off 6.2. Disconnect the appropriate electrical connector: K20 Engine Control Module 6.3. Ignition » On / Vehicle » In Service Mode 6.4. Test for less than 1 V between the test points: 5 V Reference circuit terminal 2 @ Component harness & Ground ⇒ If 1 V or greater » Repair the short to voltage on the circuit. ⇒ If less than 1 V » Replace the component: K20 Engine Control Module ⇓ If between 4.8 and 5.2 V
7. Verify the scan tool parameter: Manifold Absolute Pressure Sensor = Greater than 4.7 V ⇒ If 4.7 V or less 7.1. Ignition/Vehicle » Off 7.2. Disconnect the appropriate electrical connector: K20 Engine Control Module 7.3. Test for infinite resistance between the test points: Signal circuit terminal 4 @ Component harness & Ground ⇒ If less than infinite resistance » Repair the short to ground on the circuit. ⇒ If infinite resistance » Replace the component: K20 Engine Control Module ⇓ If greater than 4.7 V
8. Connect a 3 A fused jumper wire between the test points: Signal circuit terminal 4 & Low Reference circuit terminal 3
9. Verify the scan tool parameter: Manifold Absolute Pressure Sensor = Less than 0.2 V ⇒ If 0.2 V or greater 9.1. Ignition/Vehicle » Off & Remove » Jumper wire(s) 9.2. Disconnect the appropriate electrical connector: K20 Engine Control Module 9.3. Ignition » On / Vehicle » In Service Mode 9.4. Test for less than 1 V between the test points: Signal circuit terminal 4 @ Component harness & Ground ⇒ If 1 V or greater » Repair the short to voltage on the circuit. ⇓ If less than 1 V 9.5. Ignition/Vehicle » Off 9.6. Test for less than 2 Ω between the test points: Signal circuit terminal 4 @ Component harness & The other end of the circuit @ Control module harness ⇒ If 2 Ω or greater » Repair the open/high resistance in the circuit. ⇒ If less than 2 Ω » Replace the component: K20 Engine Control Module ⇓ If less than 0.2 V
10. Test or replace the component: B65 Intake Manifold Pressure and Air Temperature Sensor Component Testing Dynamic Test — Using Vehicle Harness

Note

Circuit/System Testing must be performed before proceeding with Component Testing.

1. Ignition/Vehicle » Off
2. Remove the component: B65 Intake Manifold Pressure and Air Temperature Sensor — Leave the electrical connector connected.
3. Install the special tool: EN-23738-A Vacuum Pump @ B65 Intake Manifold Pressure and Air Temperature Sensor
4. Use the tool to achieve a gauge reading between −13 and −21 kPa (−0.13 and −0.21 bar, −3.8 and −6.2 in Hg). Verify the scan tool parameter: Manifold Absolute Pressure Sensor = Decreases between 13 and 21 kPa (1.9 and 3.0 PSI) ⇒ If the parameter does not decrease between 13 and 21 kPa (1.9 and 3.0 PSI) Replace the component: B65 Intake Manifold Pressure and Air Temperature Sensor ⇓ If the parameter decreases between 13 and 21 kPa (1.9 and 3.0 PSI)
5. Use the tool to achieve a gauge reading between −30 and −38 kPa (−0.3 and −0.38 bar, −8.8 and −11.2 in Hg). Verify the scan tool parameter: Manifold Absolute Pressure Sensor = Decreases between 30 and 38 kPa (4.4 and 5.5 PSI) ⇒ If the parameter does not decrease between 30 and 38 kPa (4.4 and 5.5 PSI) Replace the component: B65 Intake Manifold Pressure and Air Temperature Sensor ⇓ If the parameter decreases between 30 and 38 kPa (4.4 and 5.5 PSI)
6. All OK. Dynamic Test — Using Jumper Wires
7. Ignition/Vehicle » Off
8. Remove the component: B65 Intake Manifold Pressure and Air Temperature Sensor
9. Connect a 3 A fused jumper wire between the test points: 5 V Reference terminal 2 & 5 V
10. Connect a jumper wire between the test points: Low Reference terminal 3 & Ground
11. Connect a DMM between the test points: Signal terminal 4 @ B65 Intake Manifold Pressure and Air Temperature Sensor & Ground
12. Install the special tool: EN-23738-A Vacuum Pump @ B65 Intake Manifold Pressure and Air Temperature Sensor
13. Use the tool to achieve a gauge reading between 0 and −15 kPa (0 and −0.15 bar, 0 and −4.4 in Hg). Verify the DMM displays between 0.2 and 4.9 V — The value should not spike or drop out. ⇒ If not between 0.2 and 4.9 V or the value spikes/drops out Replace the component: B65 Intake Manifold Pressure and Air Temperature Sensor ⇓ If between 0.2 and 4.9 V and the value does not spike/drop out
14. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Intake Air Pressure and Temperature Sensor Replacement — B65 Intake Manifold Pressure and Air Temperature Sensor For control module replacement, programming, and setup refer to: Control Module References Additional Procedures Barometric Pressure Sensor Reset — Perform only when the following component/system is replaced or serviced: B65 Intake Manifold Pressure and Air Temperature Sensor — Replaced K20 Engine Control Module — Replaced

Note

The DTC causing the Driver Information Center message/speed limitation to set must run and pass before the message/speed limitation will clear. This may require driving the vehicle.

1. Ignition » On / Vehicle » In Service Mode
2. Verify that all scan tool Event Data parameters under the following data list displays No: Exhaust Gas Recirculation System Malfunction Warning Event Data ⇒ If not the specified state Operate the vehicle within the Conditions for Running the DTC for the DTC identified by the Event Data parameter displaying Yes. ⇓ If the specified state
3. All OK.