P0107
DTC P0107 Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage
Circuit Description
The PCM uses the manifold absolute pressure (MAP) sensor output voltage to control the fuel delivery and the ignition timing. The PCM supplies a 5 volt reference signal voltage and a ground circuit to the MAP sensor. As the manifold pressure changes, the output voltage of the sensor also changes. By monitoring the sensor output voltage, the PCM can detect the manifold pressure. A lower pressure (low voltage) output will range between 1.0 - 1.5 volts at idle. While a higher pressure (high voltage) output will range between 4.5 - 4.8 volts at wide open throttle (WOT). The PCM uses the MAP sensor to record the barometric pressure during engine start up and at wide open throttle. This allows the PCM to make adjustments for different altitudes.
Conditions for Running the DTC
- There are not any active TP DTCs.
- The engine speed is less than 1000 RPM.
Or
- The engine speed is more than 1000 RPM and the throttle position (TP) sensor reading is more than 15 percent.
Conditions for Setting the DTC
- The MAP is less than 0.08 V (11.8 kPa).
- The above conditions are met for at least 6.25 seconds.
Action Taken When the DTC Sets
- The control module illuminates the malfunction indicator lamp (MIL) if a failure is detected during 2 consecutive key cycles.
- The control module sets the DTC and records the operating conditions at the time the diagnostic failed. The failure information is stored in the scan tool's Freeze Frame and Failure Records.
Conditions for Clearing the MIL/DTC
- The control module turns OFF the MIL after 3 consecutive drive trips when the test has Run and Passed
- A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles. A warm up cycle occurs when the coolant temperature has risen 22° C (40° F) from the startup coolant temperature and the engine coolant reaches a temperature that is more than 70° C (158° F) during the same ignition cycle.
- Use the scan tool Clear Information function
Diagnostic Aids
IMPORTANT: After repairs, use the scan tool Fuel Trim Reset function in order to reset the long term fuel trim to 128 (0%).
- A restriction in the MAP sensor vacuum source may cause DTC P0107 to set. Examine the MAP sensor vacuum source for restrictions and inspect for casting flash on the intake manifold.
- With the ignition ON and the engine OFF, the manifold pressure is equal to the atmospheric pressure and the MAP sensor signal voltage is high. The PCM uses this voltage reading to determine the altitude of the vehicle. The comparison of this reading with a reading from a known good vehicle using the same sensor is a good way to verify the accuracy of a suspect sensor. Readings should be the same to within a range of 0.4 volt.
- Whenever a DTC P0107 is intermittent, refer to Symptoms or to MAP Sensor Output Diagnosis for further diagnosis.
Steps 1 - 4:
Steps 5 - 7:
Steps 8 - 11:
Steps 12 - 15:
Step 16:
Test Description
The numbers below refers to the step numbers on the Diagnostic Table.
1. The Powertrain OBD System Check prompts you to complete some of the basic checks and to store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data captured when the malfunction occurred. The scan tool stores this data for later reference.
2. This step determines if the DTC P0107 is the result of a hard malfunction or an intermittent condition.
3 Connecting a jumper wire into the connector terminals B to C (signal circuit to the 5.0 volt circuit) will determine if the MAP sensor is malfunctioning or if there is a problem with the PCM or the wiring.
6. The scan tool may not display 5.0 volts. The important thing is that the PCM recognizes the voltage as more than 4.0 volts, indicating that the PCM and the MAP sensor signal circuit are OK. A test lamp that illuminates indicates a short to ground in the signal circuit. 7
IMPORTANT: The Powertrain Control Module (PCM) uses a single internal 5.0 volt power supply to supply power to all the engine control components. If one component shorts its 5.0 volt reference circuit to ground or battery voltage, the other 5.0 volt reference circuits will also have a low or high voltage.
An open or short to ground in the 5.0 volt reference circuit could also set additional DTCs.
11. The MAP sensor vacuum source should be thoroughly checked for restrictions. A drill bit can be used to clean out any casting flash that may exist in the manifold vacuum port.
12. Program the replacement PCM and perform the crankshaft position system variation learn procedure. Refer to the latest Isuzu Technical Communications System (ITCS) information for PCM programming.