For 1990-2009 cars

### Circuit Description

The powertrain control module (PCM) supplies a 5-volt reference 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, a diagnostic trouble code (DTC) P0105 is set.

### Conditions for Running the DTC

DTCs P0107, P0108, P0117, P0118, P0122, P0123, P0125, P0128, P0130, P0131, P0132, P0171, P0172, P0201, P0202, P0203, P0204, P0300, P0301, P0302, P0303, 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.

• | Clear the MIL and the DTC with a scan tool.

### 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.

• | A 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. If this happens, 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

The numbers below refer to the step numbers on the diagnostic table.

1. The Diagnostic System Check-Engine Controls prompts the technician to complete some basic checks and stores the Freeze Frame/Failure Records data on the scan tool if applicable. This creates an electronic copy of the data that was taken when the malfunction occurred. The information is then stored in the scan tool for later reference.

2. The TP sensor may be able to auto zero itself after several engine starts if the sensor 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.

3. 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.

4. 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.

5. 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.

6. 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.

#### DTC P0105 -- TP/MAP Sensor Performance

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
Schematic Reference: Engine Controls Schematics
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls
2 |

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Observe the TP sensor voltage on the scan tool.

Does the scan tool display a TP voltage less than the specified value when the throttle is fully closed?

0.90 V

Go to Step 3

Go to Step 4

3 |

1. Select the TP angle parameter on the scan tool.
2. Monitor the scan tool while slowly depressing the accelerator pedal to the floor, then slowly release the pedal. Repeat the procedure several times.

Does the TP angle value increase steadily when the accelerator pedal is depressed to more than the first specified value and decrease steadily, returning to less than the second specified value when the pedal is released?

98%

1%

Go to Step 5

Go to Step 17

4 | Check the throttle body for the following conditions:

• | Binding linkage

• | Damaged linkage

Did you find and correct the condition?

--

Go to Step 34

Go to Step 17

5 | Compare the barometric pressure (BARO) reading with a known good vehicle. The BARO value should be within the specified value of the other vehicle. Is the BARO reading normal for your altitude? | 3 kPa | Go to Step 6 | Go to Step 9
6 | Start the engine while watching the MAP sensor value with the scan tool. Does the MAP sensor value change while starting the engine? | -- | Go to Step 7 | Go to Step 8
7 | With the engine running, snap the throttle while watching the MAP sensor display on the scan tool. Does the MAP sensor value change rapidly when the throttle position changes? | -- | Go to Diagnostic Aids | Go to Step 8
8 |

1. Turn OFF the ignition.
2. Remove the MAP sensor from the vacuum source.
3. Inspect the port for the following conditions:

• | Vacuum restrictions

• | Vacuum leaks

Did you find and correct the condition?

--

Go to Step 34

Go to Step 9

9 |

1. Turn OFF the ignition.
2. Disconnect the MAP sensor electrical connector.
3. Turn ON the ignition.
4. Observe the MAP sensor voltage on the scan tool.

Does the scan tool indicate that the voltage is near the specified value?

0 V

Go to Step 10

Go to Step 12

10 |

1. Connect a test lamp to a good ground.
2. Probe the 5-volt reference circuit of the MAP sensor with the test lamp.

Does the test lamp illuminate?

--

Go to Step 11

Go to Step 14

11 |

1. Connect a 3 amp fused jumper to the MAP sensor 5-volt reference circuit.
2. Connect the other end of the 3 amp fused jumper to the MAP sensor signal circuit.

Does the scan tool indicate that the voltage is near the specified value?

5 V

Go to Step 13

Go to Step 15

12 | Test the MAP sensor signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 30
13 |

1. Connect a test lamp to B+.
2. Probe the MAP sensor low reference circuit with the test lamp.

Does the test lamp illuminate?

--

Go to Step 28

Go to Step 16

14 | Test the 5-volt reference circuit of the MAP sensor for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 30
15 | Test the signal circuit of the MAP sensor for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 30
16 | Test the MAP sensor low reference circuit for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 30
17 |

1. Turn OFF the ignition.
2. Disconnect the TP sensor electrical connector.
3. Turn ON the ignition.
4. Observe the TP sensor voltage on the scan tool.

Does the scan tool indicate that the voltage is near the specified value?

0 V

Go to Step 18

Go to Step 21

18 |

1. Connect a test lamp to a good ground.
2. Probe the 5-volt circuit of the TP sensor with the test lamp.

Does the test lamp illuminate?

--

Go to Step 19

Go to Step 23

19 | Measure the voltage from the TP sensor 5 volt reference circuit to a good ground. Does the voltage measure more than the specified value? | 5.2 V | Go to Step 24 | Go to Step 20
20 |

1. Connect a 3 amp fused jumper to the TP sensor 5-volt reference circuit.
2. Connect the other end of the 3 amp fused jumper to the TP sensor signal circuit.

Does the scan tool indicate that the voltage is near the specified value?

5 V

Go to Step 22

Go to Step 25

21 | Test the TP sensor signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 30
22 |

1. Connect a test lamp to B+.
2. Probe the TP sensor low reference circuit at the TP sensor electrical connector with the test lamp.

Does the test lamp illuminate?

--

Go to Step 29

Go to Step 26

23 | Test the 5-volt reference circuit of the TP sensor for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 30
24 | Test the 5 volt reference circuit of the TP sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 27
25 | Test the TP sensor signal circuit for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 30
26 | Test the TP sensor low reference circuit for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 30
27 | Test the 5 volt reference circuit of the following sensors for a short to voltage:

• | A/C high side pressure sensor

• | Fuel tank pressure sensor

Did you find and correct the condition?

--

Go to Step 34

Go to Step 30

28 | Inspect for poor connections at the MAP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 31
29 | Inspect for poor connections at the TP sensor electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 32
30 | Inspect for poor connections at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 33
31 | Replace the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement . Did you complete the replacement? | -- | Go to Step 34 | --
32 | Replace the TP sensor. Refer to Throttle Position Sensor Replacement . Did you complete the replacement? | -- | Go to Step 34 | --
33 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 35 | --
34 | Use the scan tool in order to perform the Fuel Trim Reset procedure. Did you complete the procedure? | -- | Go to Step 35 | --
35 |

1. Use the scan tool in order to clear the DTCs.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate the vehicle within the Conditions for Running this DTC as specified in the supporting text.

Does the DTC run and pass?

--

Go to Step 36

Go to Step 2

36 | With a scan tool, observe the stored information, Capture Info. Are any DTCs displayed that have not been diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List | System OK