P0106
DTC P0106
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptor
DTC P0106
- Manifold Absolute Pressure (MAP) Sensor Performance
Diagnostic Fault Information
Typical Scan Tool Data
Circuit Description
The manifold absolute pressure (MAP) sensor measures the pressure inside the intake manifold. Pressure in the intake manifold is affected by engine speed, throttle opening, air temperature, and barometric pressure (BARO). A diaphragm within the MAP sensor is displaced by the pressure changes that occur from the varying load and operating conditions of the engine. The sensor translates this action into electrical resistance. The MAP sensor wiring includes 3 circuits. The engine control module (ECM) supplies a regulated 5 volts to the sensor on a 5V reference circuit. The ECM supplies a ground on a low reference circuit. The MAP sensor provides a signal voltage to the ECM, relative to the pressure changes, on the MAP sensor signal circuit. The ECM converts the signal voltage input to a pressure value.
Under normal operation the highest pressure that can exist in the intake manifold is equal to BARO. This occurs when the vehicle is operated at wide-open throttle (WOT) or when the ignition is ON while the engine is OFF. Under these conditions, the ECM uses the MAP sensor to determine the current BARO. The lowest manifold pressures occur when the vehicle is idling or decelerating. MAP can range from 10 kPa (1.5 psi), when pressures are low, to as much as 104 kPa (15.1 psi), when pressures are high, depending on the BARO. The ECM monitors the MAP sensor signal for pressure outside of the normal range.
Conditions for Running the DTC
* DTC P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0128, P0335, or P0336 is not set.
* The engine speed is 500-6800 rpm.
* The intake air temperature (IAT) sensor parameter is between -20 to +125°C (-4 to +257°F).
* The engine coolant temperature (ECT) sensor parameter is between -7 to +126°C (+20 to +259°F).
* This DTC runs continuously when the above conditions are met.
Conditions for Setting the DTC
The engine control module (ECM) detects that the MAP sensor pressure is not within range of the calculated pressure that is derived from the system of models for more than 0.5 s.
Action Taken When the DTC Sets
DTC P0106 is a Type B DTC.
Conditions for Clearing the MIL/DTC
DTC P0106 is a Type B DTC.
Diagnostic Aids
Note: Verify that the engine is in good mechanical condition before continuing with this diagnostic.
* A wide open throttle (WOT) acceleration from a stop should cause the MAP sensor parameter on the scan tool to increase rapidly to near the BARO parameter at the time of the 1-2 shift.
* The BARO that is used by the ECM to calculate the air flow models is initially based on the MAP sensor at ignition ON. When the engine is running, the ECM will continually update the BARO value near WOT using the MAP sensor and a calculation. A skewed MAP sensor will cause the BARO value to be inaccurate.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views A/C Compressor Clutch
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Special Tools
J-23738-A - Vacuum Pump
For equivalent regional tools, refer to Special Tools (Diagnostic Tools) Special Tools (Diagnostic Tools).
Circuit/System Verification
1. If DTC P0641 or P0651 are set, refer to DTC P0641, P0651, P0697, or P06A3 (ECM) Powertrain Management (ECM).
2. Verify that restrictions do not exist in the exhaust system. Refer to Restricted Exhaust Restricted Exhaust.
3. Verify that the engine is in good mechanical condition. Refer to Symptoms - Engine Mechanical Symptoms - Engine Mechanical for the 2.8L, 3.0L, 3.2L, or 3.6L engine.
4. Ignition OFF, and all vehicle systems OFF, it may take up to 2 minutes for all the systems to power down, determine the current vehicle testing altitude. Ignition ON, observe the scan tool BARO Sensor parameter. Compare the parameter to the Altitude Versus Barometric Pressure Altitude Versus Barometric Pressure table. The BARO sensor pressure parameter should be within the specified range indicated in the table.
5. A skewed B74 manifold absolute pressure sensor will also cause the first and second intake manifold models to disagree with the actual B74 manifold absolute pressure sensor measurements. Use the scan tool and compare the MAP Sensor parameter to a known good vehicle under various operating conditions. The readings should be within 3 kPa (0.4 psi) of the known good vehicle.
6. Ignition ON, observe the scan tool MAP sensor parameter. Start the engine. The MAP Sensor parameter should change.
• If the vehicle passes the Circuit System Verification Test, operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records list.
Circuit/System Testing
Note: All electrical components and accessories must be turned OFF and allowed to power down.
1. Verify the integrity of the air induction system by inspecting for the following conditions:
* Any damaged components
* Loose or improper installation
* Improperly routed vacuum hoses
* Any vacuum leaks
* Any type of restriction
* MAP sensor seal that is missing or damaged
2. Ignition OFF, and all vehicle systems OFF, it may take up to 2 minutes for all the systems to power down, disconnect the harness connector at the B74 manifold absolute pressure sensor.
3. Test for less than 2 ohms between the low reference circuit terminal 2 and ground.
• If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
4. Ignition ON, test for 4.8-5.2 V between the 5V reference circuit terminal 1 and ground.
• If less than the specified range, test the 5V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
• If greater than the specified range, test the 5V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
5. Verify the scan tool MAP Sensor parameter is less than 104 kPa (15.1 psi).
• If greater than the specified range, test the signal circuit terminal 3 for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
6. Install a 3A fused jumper wire between the signal circuit terminal 3 and the 5V reference circuit terminal 1. Verify the scan tool MAP Sensor parameter is greater than 103 kPa (14.9 psi).
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
7. If all circuits test normal, test or replace the B74 manifold absolute pressure sensor.
Component Testing
Note: You must perform the Circuit/System Testing in order to verify the integrity of the MAP sensor circuits before proceeding with the Component Testing.
Skewed Sensor Test
1. Using the following steps and referencing the table below will determine if the B74 manifold absolute pressure sensor is skewed.
2. Ignition ON, engine OFF, observe the MAP sensor scan tool parameter.
3. Use the observed MAP Sensor Scan Tool parameter that is closest to a value that is indicated in the first column.
4. Using the J-23738-A - pump to apply 5 in Hg of vacuum to the MAP sensor, the parameter in the first column should decrease by 17 kPa (2.5 psi). The acceptable range is indicated in the second column.
5. Using the J-23738-A - pump to apply 10 in Hg of vacuum to the MAP sensor, the parameter in the first column should decrease by 34 kPa (5.0 psi). The acceptable range is indicated in the third column.
Erratic Signal Test
1. Ignition OFF, remove the B74 manifold absolute pressure sensor.
2. Install a 3A fused jumper wire between the 5V reference circuit terminal 1 and the corresponding terminal of the B74 manifold absolute pressure sensor.
3. Install a jumper wire between the low reference terminal 2 of the B74 manifold absolute pressure sensor and ground.
4. Install a jumper wire at terminal 3 of the B74 manifold absolute pressure sensor.
5. Connect a DMM between the jumper wire from the terminal 3 of the B74 manifold absolute pressure sensor and ground.
6. Install the J-23738-A - pump to the B74 manifold absolute pressure sensor vacuum port.
7. Ignition ON, slowly apply vacuum to the sensor while observing the DC voltage on the DMM. The voltage should vary between 4.9-0.2 V without any spikes or dropouts.
• If the voltage is erratic, replace the B74 manifold absolute pressure sensor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Manifold Absolute Pressure Sensor Replacement Service and Repair
* Control Module References Control Module References for ECM replacement, setup, and programming