P0105
DTC P0105 Manifold Absolute Pressure (MAP) Sensor Performance/Range
Circuit Description
The PCM supplies a 5.0 volt reference signal and a ground to the throttle position (TP) sensor and the manifold absolute pressure (MAP) sensor. The TP sensor sends a voltage signal back to the PCM relative to the throttle plate opening. The MAP sensor sends a voltage signal back to the PCM relative to the intake manifold pressure. The PCM uses these signals to determine whether the TP sensor and the MAP sensor are functioning correctly. If the TP sensor or the MAP sensor signal voltages are not within the limits specified for the engine calibration, a DTC P0105 is set. During the DTC P0105 test, the PCM compares the actual MAP value to the high and low limits specified for the engine's speed and load. If the actual MAP value is higher or lower than specified, a malfunction is indicated.
Conditions for Running the DTC
- There are not any active MAP DTCs.
- There are not any active engine coolant temperature (ECT) DTCs.
- There are not any active TP DTCs.
- There are not any active oxygen sensor DTCs.
- There are not any active fuel trim DTCs.
- There are not any active injector control DTCs.
- There are not any active Misfire DTCs.
- There are not any active knock sensor (KS) DTCs.
- No active camshaft position sensor (CMP) DTCs.
- There are not any active EVAP DTCs.
- There are not any active vehicle speed sensor (VSS) DTCs.
- There are not any active idle air control (IAC) DTCs.
- The engine has been running for more than 40 seconds.
- The engine speed is between 900 - 6375 RPM.
- The torque converter clutch (TCC) is stable to within 2.5 percent.
- The engine speed is stable to within 50 RPM.
- The idle air control (IAC) valve is stable to within 5 counts.
- The TP sensor is stable to within 2 percent
- The above conditions are present for 1.5 seconds.
Conditions for Setting the DTC
The MAP sensor reading is outside of the range specified by the engine calibration for 14 out of 16 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
- With the ignition turned ON and the engine stopped, the manifold pressure is equal to atmospheric pressure and the signal voltage will be high. The PCM uses this voltage reading to determine the vehicle's altitude. Comparison of this reading with a known good vehicle with the same sensor is a good way to check the accuracy of a suspect sensor. Readings should be the same to within 0.4 volt.
- The MAP sensor vacuum source should be thoroughly checked for restrictions at the intake manifold.
- A TP sensor that is stuck will attempt an auto zero every time the engine runs.
- If a DTC P0105 cannot be duplicated, the information included in the Freeze Frame and Failure Records data can be useful. Use the scan tool DTC information data in order to determine the status of the DTC.
1. A DTC P0105 may set as a result of any condition that causes an unreasonably high or low map value. The following conditions may result in a DTC P0105:
- Incorrect cam timing
- A restricted exhaust
- Worn piston rings
- Low fuel pressure
2. A TP sensor that is stuck may attempt to auto zero every time the engine runs. A TP percentage reading of 0 percent accompanied by a high TP voltage reading is an indication that the sensor may be stuck..
3. Testing the 5.0 volt reference circuits with a digital multimeter (DMM) may not detect small amounts of resistance within the malfunctioning circuit. Connecting a jumper wire from the 5.0 volt reference circuit to the signal circuit is a more effective method of detecting small amounts of resistance.
4. Certain conditions will result in a normal reading when the connectors are probed, but cause incorrect reading when the connectors are connected. Check the TP and MAP sensor electrical connectors for any of the following conditions:
- Spread terminals
- Poor electrical terminal connections
5. The MAP sensor needs a dedicated vacuum source. Check the MAP sensor and the MAP sensor vacuum source for the following conditions:
- A vacuum leak
- A split vacuum hose
- A shared vacuum source
Step 1:
Steps 2 - 4:
Steps 5 - 7:
Steps 8 - 13:
Steps 14 - 17:
Test Description
The numbers below refer to the step numbers on the Diagnostic Table.
2. A DTC P0507 may also set under Last Test Failed if a vacuum leak is present. Refer to DTC P0507 Idle Speed High.
5. A normal MAP sensor will react quickly to throttle changes. A MAP sensor should not appear to be lazy or to catch up with the throttle movements.
8. 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 vacuum port.
15. Replacement PCM's must be programmed and the Crankshaft Position System Variation Learn Procedure must be performed. Refer to the latest Techline information for programming procedures.