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 engine control module (ECM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit. The ECM, also, provides a ground on the low reference circuit. The MAP sensor provides a signal to the ECM on the MAP sensor signal circuit which is relative to the pressure changes in the manifold. The ECM should detect a low signal voltage at a low MAP, such as during an idle or a deceleration. The ECM 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 ECM monitors the MAP sensor signal for voltage outside of the normal range.
The ECM calculates a predicted value for the MAP sensor based on throttle position (TP) and engine speed. The ECM then compares the predicted value to the actual MAP sensor signal. If the ECM detects that the MAP sensor signal is not within the predicted range, DTC P0106 sets.
Conditions for Running the DTC
| • | DTC P0068, P0107, P0108, P0117, P0118, P0120, P0122, P0123, P0125, P0128, P0130, P0131, P0132, P0133, P0134, P0135, P0171, P0172, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0300, P0301, P0302, P0303, P0304, P0336, P0340, P0341, P0442, P0446, P0452, P0453, P0455, P0496, P0502, P0506, P0507, P1133, P1134, P1516, P1680, P1681, P1682, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, or P2176 are not set. |
| • | The engine run time is more than 60 seconds. |
| • | The change in engine speed is less than 50 RPM. |
| • | The engine speed is between 600-6,200 RPM. |
| • | The change in throttle angle is less than 2 percent. |
| • | The torque converter clutch (TCC) is stable to within 1.3 percent. |
Conditions for Setting the DTC
The ECM detects that the MAP sensor voltage is outside of the predicted range for more than 12 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 number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Engine Control Module 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 29 | Go to Step 3 | ||||||||
3 |
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 4 | Go to Step 5 | ||||||||
Is the difference between the values less than the specified value? | 3 kPa | Go to Step 6 | Go to Step 11 | |||||||||
5 |
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 6 | Go to Step 11 | ||||||||
6 |
Does the MAP sensor pressure change? | -- | Go to Step 7 | Go to Step 11 | ||||||||
7 |
Is the decrease in MAP sensor pressure consistent? | -- | Go to Step 8 | Go to Step 11 | ||||||||
8 | Apply vacuum with the J 23738-A until 20 in Hg is reached. Is the MAP sensor pressure less than the specified value? | 34 kPa | Go to Step 9 | Go to Step 11 | ||||||||
9 | Disconnect the J 23738-A from the MAP sensor. Does the MAP sensor pressure return to the value observed in step 4 or 5? | -- | Go to Step 10 | Go to Step 27 | ||||||||
10 | Inspect for the following conditions:
| -- | Go to Step 29 | Go to Intermittent Conditions | ||||||||
11 | 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 29 | Go to Step 12 | ||||||||
12 |
Is the voltage less than the specified value? | 0.1 V | Go to Step 13 | Go to Step 19 | ||||||||
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. Note the measurement as Supply voltage. Is the voltage more than the specified value? | 5.2 V | Go to Step 20 | Go to Step 14 | |||||||||
14 | Is the voltage more than the specified value? | 4.8 V | Go to Step 15 | Go to Step 21 | ||||||||
15 |
Is the amperage equal to the specified value? | 0 mA | Go to Step 24 | Go to Step 16 | ||||||||
Important: Before any calculations are performed, ensure that all measurements are converted into like units, for example volts/amps or millivolts/milliamps. Is the result more than the specified value? | 5 ohms | Go to Step 22 | Go to Step 17 | |||||||||
Important: Before any calculations are performed, ensure that all measurements are converted into like units, for example volts/amps or millivolts/milliamps. Is the result more than the specified value? | 5 ohms | Go to Step 25 | Go to Step 18 | |||||||||
18 |
Is the voltage more than the specified value? | 4.9 V | Go to Step 27 | Go to Step 23 | ||||||||
19 | Test the MAP sensor signal circuit between the ECM 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 29 | Go to Step 26 | ||||||||
20 | Test all branches of the 5-volt reference circuit that is 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 29 | Go to Step 26 | ||||||||
21 | Test the 5-volt reference circuit between the ECM and the MAP sensor for an open or for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 29 | Go to Step 26 | ||||||||
22 | Test the 5-volt reference circuit between the ECM and 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 29 | Go to Step 26 | ||||||||
23 | Test the MAP sensor signal circuit between the ECM and the MAP sensor for the following:
Did you find and correct the condition? | -- | Go to Step 29 | Go to Step 26 | ||||||||
24 | Test the low reference circuit between the ECM and the MAP sensor for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 29 | Go to Step 26 | ||||||||
25 | Test the low reference circuit between the ECM and 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 29 | Go to Step 26 | ||||||||
26 | Test for shorted terminals and for poor connections at the ECM. 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 29 | Go to Step 28 | ||||||||
27 | Replace the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement . Did you complete the replacement? | -- | Go to Step 29 | -- | ||||||||
28 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 29 | -- | ||||||||
29 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 30 | ||||||||
30 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |||||||||
