P0107 - Manifold Absolute Pressure Sensor Circuit
Theory of Operation
The Charge Air Cooler Temperature Sensor (CAC) and the Boost Pressure Sensor are combined in one sensor. This combination sensor is called the Temperature/Pressure MAP Sensor. It is located on the EGR Airflow Throttle Control Valve on the Regular Cab. For the Cab and Chassis, it is located on the Intake Manifold. The Cab and Chassis version also receives the Intake Manifold Temperature signal. The Regular Cab still has a separate Intake Manifold Temperature Sensor. The Boost Pressure Sensor is used to measure pressure in the intake manifold. The Powertrain Control Module (PCM) provides a 5-Volt supply and sensor ground for the Boost Pressure Sensor. The Boost Pressure Sensor provides a signal back to the PCM on the Boost Pressure Sensor Signal circuit. The PCM will detect a low signal voltage at operating conditions such as
during an idle or a deceleration. The PCM will detect a high signal voltage during high engine load operating conditions. At key on, the readings for the Boost Pressure Sensor, Exhaust Gas Pressure Sensor, and Barometric Pressure Sensor are compared. This fault code occurs if the boost pressure reading is different from the others. During normal engine operation, the PCM estimates the Boost Pressure Sensor value using
other fuel system related inputs. The PCM compares the actual Boost Pressure Sensor reading to this estimated value. If the two values are out of range for a calibrated period of time, an error is recorded.
When Monitored and Set Conditions
When Monitored: This diagnostic runs continuously when the following conditions are met:
• With the ignition on.
• Battery voltage greater than 10.4 Volts.
Set Conditions:
• The Powertrain Control Module (PCM) has detected the Boost Pressure Sensor Signal circuit is below a
calibrated threshold.
Default Actions:
• The MIL is illuminated.
Possible Causes
5-VOLT SUPPLY CIRCUIT OPEN/HIGH RESISTANCE
BOOST PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO THE BOOST PRESSURE SENSOR
RETURN CIRCUIT
BOOST PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
BOOST PRESSURE SENSOR SIGNAL CIRCUIT OPEN/HIGH RESISTANCE
TEMPERATURE/PRESSURE MAP SENSOR
POWERTRAIN CONTROL MODULE (PCM)
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTCBased Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
Diagnostic Test
1. ACTIVE DTC
NOTE: If there are any 5-Volt supply DTCs present, repair those DTCs before proceeding.
1. Turn the ignition on.
2. With the scan tool, record all Freeze frame data.
3. With the scan tool, erase DTCs.
4. Turn the ignition off for 75 seconds.
5. Turn the ignition on.
6. With the scan tool, read DTCs.
Did the DTC reset?
Yes
• Go To 2
No
• Perform to the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
2. CHECK THE (F857) 5-VOLT SUPPLY CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Ignition on.
2. Disconnect the Temperature/Pressure MAP (T/P MAP) Sensor harness connector.
3. With a voltmeter, measure the voltage of the (F857) 5-Volt Supply circuit at the T/P MAP Sensor harness connector.
Is the voltage reading between 4.9 and 5.1 volts?
Yes
• Go To 3
No
• Repair the (F857) 5-Volt Supply circuit for an open or high resistance.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
3. CHECK THE BOOST PRESSURE SENSOR
1. While monitoring the scan tool, connect a jumper between the (F857) 5-Volt Supply circuit and the (K37) Boost Pressure Sensor Signal circuit at the T/P MAP Sensor harness connector.
Did the P0108 DTC set?
Yes
• Replace the Temperature/Pressure MAP Sensor in accordance with the Service Information.(Refer to 14
- Fuel System/Fuel Injection/SENSOR, TMAP-Intake Manifold/Removal)
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based
Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
• Go To 4
4. CHECK FOR THE (K37) BOOST PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO THE (K916) BOOST PRESSURE SENSOR RETURN CIRCUIT
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Measure the resistance between the (K37) Boost Pressure Sensor Signal circuit and (K916) Sensor Ground circuit at the T/P MAP Sensor harness connector.
Is the resistance below 10k Ohms?
Yes
• Repair the short between the (K37) Boost Pressure Sensor Signal circuit and (K916) Sensor Ground circuit.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
• Go To 5
5. CHECK THE (K37) BOOST PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Measure the resistance between ground and the (K37) Boost Pressure Sensor Signal circuit.
Is the resistance below 10k Ohms?
Yes
• Repair the (K37) Boost Pressure Sensor Signal circuit for a short to ground.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
• Go To 6
6. CHECK THE (K37) BOOST PRESSURE SENSOR SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K37) Boost Pressure Sensor Signal circuit between the T/P MAP Sensor and the PCM C1 harness connectors.
Is the resistance below 5.0 Ohms?
Yes
• Go To 7.
No
• Repair the (K37) Boost Pressure Sensor Signal circuit for an open or high resistance.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
7. POWERTRAIN CONTROL MODULE
1. Disconnect all PCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
• Proper connector installation.
• Damaged connector locks.
• Corrosion.
• Other signs of water intrusion.
• Weather seal damage (if equipped).
• Bent terminals.
• Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
• Terminals that have been pushed back into the connector cavity.
• Perform a terminal drag test on each connector terminal to verify proper terminal tension. Repair any conditions that are found.
5. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Using the recorded Freeze Frame and Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
10. With the scan tool, read PCM DTCs.
Did the DTC return?
Yes
• Replace the Powertrain Control Module (PCM) in accordance with the Service Information. (Refer to 08 - Electrical/8E - Electronic Control Modules/MODULE, Powertrain Control/Removal) .
• Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
• Test complete.
• Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain
Control (PCM) - Standard Procedure).