DTC P0107 or P0108

Engine Controls and Fuel - 5.3L L84 or 6.2L L87 | Diagnostic Information and Procedures | Document ID: 5805961 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 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	P0106, P0107, P0641	P0106, P0107	P0106, P0107, P0641	P0106
Signal	P0106, P0107	P0108	P0106, P0108	P0106, P1101
Low Reference	—	P0106, P0108	—	P0106

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: 26 to 52 kPa (3.8 to 7.5 PSI)
	5 V Reference	0 kPa (0.0 PSI)	0 kPa (0.0 PSI)	1 kPa (.15 PSI)
	Signal	0 kPa (0.0 PSI)	127 kPa (18.4 PSI)	127 kPa (18.4 PSI)
	Low Reference	—	127 kPa (18.4	—
	© 2023 Gener	al Motors. All right	s reserved.

Circuit	Short to Ground	Open	Short to Voltage

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
B74 Manifold Absolute Pressure Sensor	The sensor is a capacitive pressure transducer. Electronics in the sensor convert pressure into an analog voltage signal. The sensor measures the pressure in the intake manifold between the throttle valve and the intake valves. When the engine is idling or decelerating, the sensor pressure should be low. When the engine is off or under wide-open throttle conditions the pressure should be the same or close to the barometric pressure.
K20 Engine Control Module	The control module contains a microprocessor used to process input data to control outputs. 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.

Conditions for Running the DTC Ignition = On Frequency the DTC runs = Continuously Conditions for Setting the DTC P0107 Manifold Absolute Pressure Sensor = Less than 0.2 V — For greater than 4 s P0108 Manifold Absolute Pressure Sensor = Greater than 4.5 V — For greater than 4 s Actions Taken When the DTC Sets DTCs listed in the DTC Descriptor category = Type B DTC Conditions for Clearing the DTC DTCs listed in the DTC Descriptor category = Type B 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 P0068, P0101, P0106, P0121, P0236, P1101 » 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 = 26 to 52 kPa (3.8 to 7.5 PSI) ⇒ If not between 26 and 52 kPa (3.8 and 7.5 PSI) Refer to: Circuit/System Testing ⇓ If between 26 and 52 kPa (3.8 and 7.5 PSI)
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: B74 Manifold Absolute Pressure 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

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.

2. Disconnect the electrical connector: B74 Manifold Absolute Pressure Sensor
3. Test for less than 5 Ω between the test points: Low Reference circuit terminal 2 & Ground ⇒ If 5 Ω or greater 3.1. Disconnect the appropriate electrical connector: K20 Engine Control Module 3.2. Test for less than 2 Ω between the test points: Low 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 less than 5 Ω
4. Ignition » On / Vehicle » In Service Mode
5. Test for 4.8 to 5.2 V between the test points: 5 V Reference circuit terminal 1 & Low Reference circuit terminal 2 ⇒ If less than 4.8 V 5.1. Ignition/Vehicle » Off 5.2. Disconnect the appropriate electrical connector: @ K20 Engine Control Module 5.3. Test for infinite resistance between the test points: 5 V Reference circuit terminal 1 @ Component harness & Ground ⇒ If less than infinite resistance » Repair the short to ground on the circuit. ⇓ If infinite resistance 5.4. Test for less than 2 Ω between the test points: 5 V Reference circuit terminal 1 @ 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 5.1. Ignition/Vehicle » Off 5.2. Disconnect the appropriate electrical connector: K20 Engine Control Module 5.3. Ignition » On / Vehicle » In Service Mode 5.4. Test for less than 1 V between the test points: 5 V Reference circuit terminal 1 @ 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
6. Verify the scan tool parameter: Manifold Absolute Pressure Sensor = Greater than 4.7 V ⇒ If 4.7 V or less 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: Signal terminal 3 @ 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
7. Connect a 3 A fused jumper wire between the test points: Signal terminal 3 & Low Reference circuit terminal 2
8. Verify the scan tool parameter: Manifold Absolute Pressure Sensor = Less than 0.2 V ⇒ If 0.2 V or greater 8.1. Ignition/Vehicle » Off & Remove » Jumper wire(s) 8.2. Disconnect the appropriate electrical connector: K20 Engine Control Module 8.3. Ignition » On / Vehicle » In Service Mode 8.4. Test for less than 1 V between the test points: Signal terminal 3 @ Component harness & Ground ⇒ If 1 V or greater » Repair the short to voltage on the circuit. ⇓ If less than 1 V 8.5. Ignition/Vehicle » Off 8.6. Test for less than 2 Ω between the test points: Signal 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 0.2 V
9. Test or replace the component: B74 Manifold Absolute Pressure 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: B74 Manifold Absolute Pressure Sensor — Leave the electrical connector connected.
3. Install » Setup EN-23738-A Vacuum Pump @ B74 Manifold Absolute Pressure 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: B74 Manifold Absolute Pressure 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: B74 Manifold Absolute Pressure 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: B74 Manifold Absolute Pressure Sensor
9. Connect a 3 A fused jumper wire between the test points: 5 V Reference circuit terminal 1 & 5 V
10. Connect a jumper wire between the test points: Low Reference circuit terminal 2 & Ground
11. Connect a DMM between the test points: Signal terminal 3 @ B74 Manifold Absolute Pressure Sensor & Ground
12. Install » Setup EN-23738-A Vacuum Pump @ B74 Manifold Absolute Pressure Sensor
13. Ignition/Vehicle » On
14. 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: B74 Manifold Absolute Pressure Sensor ⇓ If between 0.2 and 4.9 V and the value does not spike/drop out
15. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Manifold Absolute Pressure Sensor Replacement — B74 Manifold Absolute Pressure Sensor For control module replacement, programming, and setup refer to: Control Module References