P0105

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) supplies a 5-Volt reference circuit and a low reference circuit to both 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, and the MAP sensor sends a voltage signal back to the PCM relative to the intake manifold pressure. The PCM can detect if the TP sensor or the MAP sensor are out of range by comparing the two values against the high and low limits and engine speed defined within the engine calibration. If the TP or the MAP are not within the expected limits of the engine calibration, DTC P0105 is set.

CONDITIONS FOR RUNNING THE DTC
DTCs P0107, P0108, P0117, P0118, P0122, P0123, P0125, P0128, P0130, P0131, P0132, P0171, P0172, P0201-P0204, P0300, P0301, P0304, P0336, P0440, P0442, P0446, P0452, P0453, P0502, P0506, P0507, or P1441 are not set.
^ The engine run time is more than 40 seconds.
^ The engine speed is between 900-6,375 RPM for a manual transmission.
^ The engine speed is between 600-6,375 RPM for an automatic transmission.
^ 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 above conditions are present for 1.5 seconds.

CONDITIONS FOR SETTING THE DTC
The MAP sensor or the TP sensor is out of an expected range defined by the engine calibration for 14 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
^ The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
^ A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
^ Use a scan tool in order to clear the MIL and the DTC.

DIAGNOSTIC AIDS
^ If a DTC P0105 cannot be duplicated, the information included in the Freeze Frame/Failure Records data can be useful. Use the scan tool DTC information data in order to determine the status of the DTC.
^ DTC P0105 may set due to any condition that may cause an unreasonably high or low map value including the following engine conditions:
- Incorrect cam timing
- Restricted exhaust
- Worn piston rings
- Low fuel pressure
^ A TP sensor that is stuck may attempt to auto zero every time the engine runs. An indication if this happens is the TP percentage will be 0 percent and TP voltage will be high.
^ The MAP sensor needs a dedicated vacuum source. Check the MAP sensor and the MAP sensor vacuum source for a vacuum leak.

TEST DESCRIPTION

Steps 1-11:

Steps 12-24:

Steps 25-36:

The numbers below refer to the step numbers on the diagnostic table.
3. The TP sensor may be able to auto zero itself after several engine starts if it is stuck, but may not be able to reach its range near 100 percent. The TP angle should increase steadily. If the voltage value spikes high or low, consider the test failed.
4. The TP sensor has an auto zeroing feature. If the voltage reading is between 0.2-0.9 volts, the PCM will assume the TP sensor is at a closed throttle position of 0 percent. If the reading is out of the auto zeroing range at closed throttle, look for a binding or damaged linkage.
6. While starting the engine, the MAP sensor should detect any changes in manifold pressure. This test is to determine if the sensor is stuck at a value.
7. A normal MAP sensor will react as quickly to the throttle changes as they can be made. A MAP sensor should not appear to be "lazy" or catch up with the throttle movements.
28. Spread terminals or faulty electrical connections can produce normal results when the circuits are probed but cause incorrect readings when the circuits are connected. Be sure to check all terminals for this condition.