Circuit Description
The manifold absolute pressure (MAP) sensor is mounted in front of the intake manifold. The MAP sensor measures pressure changes within the intake manifold, which is an indication of engine load. The MAP sensor has a 5.0 volt reference, a ground and a signal circuit. The MAP sensor contains diaphragm which changes resistance based on pressure. When manifold pressure is low (high vacuum) sensor output voltage is low. When manifold pressure is high (low vacuum) sensor output voltage is high. MAP sensor voltage (depending on altitude) can range from 1.0-1.5 volts at idle (high vacuum) to 4.0-4.9 volts at wide open throttle (low vacuum). When the powertrain control module ( PCM) senses a signal voltage lower than the normal operating range of the sensor.
Conditions for Running the DTC
| • | No TP sensor DTCs are set. |
| • | The engine is running. |
| • | TP sensor is more than 0 percent when engine is less than 800 RPM. |
| • | TP sensor is more than 12.5 percent when engine is more than 800 RPM. |
Conditions for Setting the DTC
| • | The Ignition voltage is between 10 and 11 volts. |
| • | The MAP voltage is less than 0.05 volts for more than 1 second. |
Action Taken When the DTC Sets
| • | The PCM turns on the malfunction indicator lamp (MIL) on the second consecutive drive trip that the diagnostic runs and fails. |
| • | The PCM will record operating conditions at the time the diagnostic fails. The first time the diagnostic fails, this information will be stored in Failure Records. If the diagnostic reports a failure on the second consecutive drive trip, the operating conditions at the time of failure will be written to Freeze Frame and the Failure record will be updated. |
| • | The PCM will use TP sensor values to calculate MAP. |
Conditions for Clearing the MIL/DTC
| Important: If the last failure was during a non-typical driving condition, the MIL may remain ON longer than 3 drive trips. Review Freeze Frame and Failure Records for the last failure conditions. |
| • | The PCM turns the MIL OFF after 3 consecutive drive trips when the test has Run and Passed and not Failed. |
| • | A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant temperature exceeds 70°C (160°F) during the same ignition cycle). |
| • | Use the scan tool Clear Information function. |
| • | A last test failed (Current DTC) will clear when the diagnostic runs and does not fail. |
| Use the scan tool Clear Information function. |
| • | Disconnect the PCM battery feed for 30 seconds. |
Diagnostic Aids
| • | An intermittent open in the MAP sensor signal circuit or the 5 volt reference circuit will result in a DTC P1107. |
| • | With the ignition ON and the engine OFF, the manifold pressure is equal to atmospheric pressure with the signal voltage high. The PCM uses this information as an indication of the vehicle's altitude. Comparison of this reading with a known good vehicle using the same sensor is a good way to check accuracy of a suspect sensor. Readings should be the same ±0.4 volts. |
| • | An intermittent open in the MAP sensor signal circuit or the 5 volt reference circuit will result in a DTC P1107. |
| • | For any test that requires probing the PCM or component harness connectors, use the Connector Test Adapter Kit J 35616 . Using this kit will prevent any damage to the harness connector terminals. |
| • | The PCM 5 volt reference circuits are internally connected within the PCM. If all the MAP sensor circuits check to be OK, inspect all PCM 5 volt reference component/circuits for a malfunction. |
| Important: The electrical connector must remain securely fastened. |
| • | Inspect the electrical connections. |
| Important: After removing the MAP sensor from the intake manifold, replace the MAP sensor to intake manifold seal. |
| • | Remove the MAP sensor. Twist the sensor by hand (only) in order to check for intermittent connections. Output changes more than 0.1 volt indicates a bad connector or connection. If OK, replace sensor. Refer to Manifold Absolute Pressure Sensor Replacement . |
| • | For further diagnostic aids, refer to Symptoms . |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step determines if the malfunction is present.
-
Using the Freeze Frame and Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and Failure Records data can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can also help determine how many ignition cycles the diagnostic reported a pass and a fail. Operate the vehicle within the same Freeze Frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed. This will isolate when the DTC failed.
-
If the scan tool displays 5.0 volts, the MAP sensor signal, 5 volt reference circuit, and the PCM are OK.
-
If the scan tool displays 5.0 volts, the MAP sensor signal circuit and the PCM are OK.
-
Disconnecting the PCM allows using the DMM in order to check the continuity of the circuits. This aids in locating an open or a shorted circuit.
Step | Action | Values | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||||||||
Monitor the MAP sensor voltage on Engine 1 Data List on the scan tool. Is the MAP sensor voltage below the specified value? | 0.10 V | |||||||||
Does the scan tool indicate that this diagnostic failed this ignition? | -- | Go to Diagnostic Aids | ||||||||
Is the MAP sensor voltage near the specified value? | 5.0 V | |||||||||
Is the MAP sensor voltage near the specified value? | 5.0 V | |||||||||
Did you find the 5 volt reference circuit open or shorted to a ground? | -- | |||||||||
7 |
Did the terminal require replacement? | -- | ||||||||
8 |
Did you find the MAP sensor signal circuit open or shorted to a ground? | -- | ||||||||
9 | Inspect the MAP sensor signal circuit for a poor connection at the PCM and replace the terminal if necessary. Refer to Wiring Repairs in Wiring Systems. Did the terminal require replacement? | -- | ||||||||
10 | Replace the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement . Did you complete the replacement? | -- | -- | |||||||
11 | Replace the PCM. Refer to Powertrain Control Module Replacement . Is the action complete? | -- | -- | |||||||
12 |
Does the scan tool indicate that this test ran and passed? | -- | ||||||||
13 | Select the Capture Info option and the Review Info option using the scan tool. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to the applicable DTC table | System OK |
