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, DTC P0105 is set.
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. |
The MAP sensor or the TP sensor is out of an expected range defined by the engine calibration for 14 seconds.
• | 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. |
• | 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. |
• | If 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. |
The numbers below refer to the step numbers on the diagnostic table.
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.
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 the sensors range near 100 percent. The TP angle should increase steadily. If the voltage value spikes high or low, consider the test failed.
The TP sensor has an auto zeroing feature. If the voltage reading is between 0.2-0.9 volt, 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.
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.
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.
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.
Step | Action | Values | Yes | No | ||||
---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||||||
Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | ||||||
2 |
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 | ||||
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 | |||||
Check the throttle body for the following conditions:
Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 17 | |||||
5 |
Is the diference between the MAP values less than the specified value? | 3 kPa | Go to Step 6 | Go to Step 9 | ||||
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 | |||||
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 |
Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 9 | ||||
9 |
Does the scan tool indicate that the voltage is near the specified value? | 0 V | Go to Step 10 | Go to Step 12 | ||||
10 |
Does the test lamp illuminate? | -- | Go to Step 11 | Go to Step 14 | ||||
11 |
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 |
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 |
Does the scan tool indicate that the voltage is near the specified value? | 0 V | Go to Step 18 | Go to Step 21 | ||||
18 |
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 |
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 |
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:
Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 30 | ||||
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 |
Does the scan tool indicate that this diagnostic ran and passed? | -- | 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? | -- | System OK |