Circuit Description
The manifold absolute pressure (MAP) sensor responds to changes in intake manifold pressure (vacuum). The MAP sensor signal voltage to the PCM varies from below 2 volts at idle, or high vacuum, to above 4 volts with the key ON, engine not running or at wide open throttle (WOT), or low vacuum.
The MAP sensor is used to determine manifold pressure changes while the EGR flow test diagnostic is being run. Refer to DTC P0401 Exhaust Gas Recirculation (EGR) Flow Insufficient , to determine engine vacuum level for some other diagnostics and to determine barometric pressure (BARO). The PCM monitors the MAP signals for voltages outside the normal range of the MAP sensor. If the PCM detects a MAP signal voltage that is excessively low, DTC P0107 will be set.
Conditions for Running the DTC
| • | No TP sensor DTCs present. |
| • | The engine is running. |
| • | System Voltage is more than 9 volts. |
| • | Idle speed is steady. |
| • | Throttle angle above 0 percent, if engine speed is less than 1000 RPM. |
| • | Throttle angle above 10 percent, if engine speed is more than 1000 RPM. |
Conditions for Setting the DTC
| • | The MAP sensor signal voltage is less than 0.1 volt. |
| • | Above conditions are present for more than 5 seconds. |
Action Taken When the DTC Sets
| • | The PCM will illuminate the MIL during the second consecutive trip in which the diagnostic test has been run and failed. |
| • | The PCM will store conditions which were present when the DTC set as Freeze Frame and Fail Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn the MIL OFF during the third consecutive trip in which the diagnostic has been run and passed. |
| • | The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed. |
Diagnostic Aids
| • | Monitor the MAP sensor using the scan tool and verify the following conditions: |
| - | If the MAP sensor does not respond to throttle changes, check the 3X circuits from the ignition control module to the PCM. |
| - | If the 3X signal is lost the PCM will only update the MAP sensor reading once per key cycle, when the engine is first started. |
| - | Depending on where the MAP sensor voltage, high voltage or low voltage, is when the engine is started, the high or low voltage MAP sensor DTCs will set. |
| • | Inspect for the following conditions: |
| - | Poor connection at PCM |
| - | Backed out terminals |
| - | Improper mating |
| - | Broken locks |
| - | Improperly formed or damaged terminals |
| - | Poor terminal to wire connection--Use a corresponding mating terminal to check for proper terminal tension. |
| - | Damaged harness--If the harness appears to be OK, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the display will indicate the location of the malfunction. Refer to Wiring Repairs . |
| • | If DTC P0107 cannot be duplicated, the information included in the Fail Records data can be useful in determining the conditions present when the DTC was last set. If the DTC occurs intermittently, performing the DTC P1107 diagnostic table may isolate the cause of the fault. |
Test Description
The number below refers to the step number on the diagnostic table:
-
This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On Board Diagnostic (OBD) System Check? | -- | ||
2 |
Important: If DTC P1635 5 Volt Reference Circuit is set, perform that diagnostic first.
Does the voltage measure less than the specified value? | 0.1 volt | ||
3 |
Does the DTC reset? | -- | Go to Diagnostic Aids | |
4 |
Does the voltage measure near the specified value? | 4.95 V | ||
5 |
Does the voltage measure near the specified value? | 4.95 V | ||
6 |
Did you find and correct the condition? | -- | ||
7 | Inspect the 5 volt reference A circuit of the MAP sensor for a poor connection at the PCM . If a problem is found, repair as necessary. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
8 |
Did you find and correct the condition? | -- | ||
9 | Inspect the signal circuit and the 5 volt reference circuit of the MAP sensor for a poor connection at the MAP sensor . If a problem is found, repair as necessary. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition? | -- | ||
10 | Inspect the signal circuit and the 5 volt reference circuit of the MAP sensor for a poor connection at the PCM. If a problem is found, repair as necessary. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find and correct the condition? | -- | ||
11 | Replace the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement . Did you complete the replacement? | -- | -- | |
12 |
Important:: Perform the set up procedure for the PCM. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the replacement? | -- | -- | |
13 |
Does the DTC reset? | -- | System OK |
