Circuit Description
The manifold absolute pressure (MAP) sensor responds to pressure changes in the intake manifold. The pressure changes occur based on the engine load. The MAP sensor has the following circuits:
| • | A 5-volt reference circuit |
| • | A low reference circuit |
| • | A MAP sensor signal circuit |
The powertrain control module (PCM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit. The PCM, also, provides a ground on the low reference circuit. The MAP sensor provides a signal to the PCM on the MAP sensor signal circuit which is relative to the pressure changes in the manifold. The PCM should detect a low signal voltage at a low MAP, such as during an idle or a deceleration. The PCM should detect a high signal voltage at a high MAP, such as the ignition is ON, with the engine OFF, or at a wide-open throttle (WOT). The MAP sensor is also used in order to determine the barometric pressure (BARO). This occurs when the ignition switch is turned ON, with the engine OFF. The BARO reading may also be updated whenever the engine is operated at WOT. The PCM monitors the MAP sensor signal for voltage outside of the normal range.
The PCM calculates a predicted value for the MAP sensor based on throttle position (TP) and engine speed. The PCM then compares the predicted value to the actual MAP sensor signal. If the PCM detects that the MAP sensor signal is not within the predicted range, DTC P0106 sets.
Conditions for Running the DTC
| • | DTCs P0121, P0122, P0123 are not set. |
| • | The engine is running. |
| • | The engine speed is between 1,000-4,000 RPM. |
| • | Any change in the idle air control (IAC) position is less than 15 counts. |
| • | The change in engine speed is less than 125 RPM. |
| • | Traction control is not active. |
| • | The change in exhaust gas recirculation (EGR) position is less than 10 percent. |
| • | The A/C compressor clutch is steady. |
| • | The engine overtemp protection is not active. |
| • | The change in the throttle position is less than 4 percent. |
| • | The torque converter clutch (TCC) state does not change. |
| • | The power steering is stable. |
| • | The brake switch state does not change. |
| • | The above conditions are met for 3 seconds. |
Conditions for Setting the DTC
The PCM detects that the MAP sensor voltage is not within the predicted range for 2 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. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests the MAP sensors ability to correctly indicate BARO.
-
This step tests the MAP sensors ability to respond to an increase in engine vacuum.
-
This step tests for a proper MAP sensor pressure with an applied vacuum.
Step | Action | Values | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views | ||||||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||||||
2 | Inspect for the following conditions:
Did you find and correct the condition? | -- | Go to Step 26 | Go to Step 3 | ||||||||
3 |
Does the TP sensor parameter increase steadily when the pedal is depressed to more than the first specified value, and then decrease steadily when the pedal is released, returning to less than the second specified value? | 98% 1% | Go to Step 4 | Go to DTC P0121 | ||||||||
4 |
Important: The vehicle used for the comparison is not limited to the same type of vehicle as is being serviced. A vehicle known to provide an accurate reading is acceptable. Do you have access to another vehicle in which the MAP sensor pressure can be observed with a scan tool? | -- | Go to Step 5 | Go to Step 6 | ||||||||
Is the difference between the values less than the specified value? | 3 kPa | Go to Step 7 | Go to Step 12 | |||||||||
6 |
Important: The Altitude vs Barometric Pressure table indicates a pressure range for a given altitude under normal weather conditions. Weather conditions consisting of very low or very high pressure and/or very low or very high temperature may cause a reading to be slightly out of range.
Does the MAP sensor indicate the correct barometric pressure? | -- | Go to Step 7 | Go to Step 12 | ||||||||
Does the MAP sensor pressure change? | -- | Go to Step 8 | Go to Step 12 | |||||||||
8 |
Is the decrease in MAP sensor pressure consistent? | -- | Go to Step 9 | Go to Step 12 | ||||||||
Is the MAP sensor pressure less than the specified value? | 34 kPa | Go to Step 10 | Go to Step 12 | |||||||||
10 |
Does the MAP sensor pressure return to the original reading observed in Step 5 or 6? | -- | Go to Step 11 | Go to Step 24 | ||||||||
11 | Inspect for the following engine conditions:
Did you find and correct the condition? | -- | Go to Step 26 | Go to Intermittent Conditions | ||||||||
12 |
Is the voltage less than the specified value? | 0.5 V | Go to Step 13 | Go to Step 17 | ||||||||
13 | Measure the voltage from the 5-volt reference circuit of the MAP sensor to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems. Is the voltage more than the specified value? | 5.2 V | Go to Step 18 | Go to Step 14 | ||||||||
14 | Probe the 5-volt reference circuit of the MAP sensor with a test lamp that is connected to a good ground. Refer to Circuit Testing and Probing Electrical Connectors in Wiring Systems. Is the test lamp OFF? | -- | Go to Step 19 | Go to Step 15 | ||||||||
15 |
Is the voltage more than the specified value? | 4.8 V | Go to Step 16 | Go to Step 20 | ||||||||
16 |
Is the voltage more than the specified value? | 0.2 V | Go to Step 21 | Go to Step 22 | ||||||||
17 |
Important: Disconnecting the PCM may eliminate the short during testing. Important: The MAP sensor may have been damaged if the circuit was shorted to a voltage source. Test the MAP sensor signal circuit between the powertrain control module (PCM) and the MAP 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 26 | Go to Step 25 | ||||||||
18 |
Important: Disconnecting the PCM may eliminate the short during testing. Important: The MAP sensor may have been damaged if the circuit was shorted to a voltage source. Test all of the branches of the 5-volt reference circuit that are shared with the MAP 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 26 | Go to Step 25 | ||||||||
19 | Test the 5-volt reference circuit between the PCM and the MAP sensor for an open or for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 26 | Go to Step 23 | ||||||||
20 | Test the MAP sensor signal circuit between the PCM and the MAP sensor for the following conditions:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 26 | Go to Step 23 | ||||||||
21 | Test the low reference circuit between the PCM and the MAP sensor for high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 26 | Go to Step 23 | ||||||||
22 | Test for an intermittent and for a poor connection 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 26 | Go to Step 24 | ||||||||
23 | Test for an intermittent and for a poor connection 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 26 | Go to Step 25 | ||||||||
24 | Replace the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement . Did you complete the replacement? | -- | Go to Step 26 | -- | ||||||||
25 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 26 | -- | ||||||||
26 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 27 | ||||||||
27 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |||||||||
