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 (high vacuum) to above 4 volts with the key ON, engine not running or at wide-open throttle (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), 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. |
| • | The idle speed is steady. |
| • | Throttle angle is above 0%, if engine speed is less than 1000 RPM. |
| • | Throttle angle is above 10%, if the engine speed greater than 1000 RPM. |
Conditions for Setting the DTC
| • | The MAP sensor signal voltage is less than 0.1 volt. |
| • | The above condition is present for more than 5 seconds. |
Action Taken When the DTC Sets
| • | The PCM will illuminate the malfunction indicator lamp (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 Failure Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn OFF the MIL 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. |
Diagnostic Aids
Check for the following conditions:
| • | Monitor the MAP sensor using the scan tool. 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 reference 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. |
| • | Poor connection at PCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. |
| • | Damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, observe the MAP 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 fault. |
If DTC P0107 cannot be duplicated, the information included in the Freeze Frame/Fail Records data can be useful in determining the conditions that were present when the DTC was last set. If it is determined that the DTC occurs intermittently, performing the DTC P1107 Diagnostic Chart may isolate the cause of the fault.
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table:
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
2 |
Important: If DTC P1635 is set, refer to DTC P1635 5 Volt Reference Circuit first.
Does the scan tool indicate MAP near the specified value? | 0V | ||
3 |
Does the scan tool indicate this DTC failed this ignition? | -- | Go to Diagnostic Aids | |
4 |
Does the scan tool indicate MAP near the specified value? | 4.9V | ||
5 |
Does the scan tool indicate MAP near the specified value? | 4.9V | ||
6 |
Did you find and correct the condition? | -- | ||
7 | Inspect the 5 volt reference A circuit for a faulty connection at the PCM. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs . Did you find and correct the condition? | -- | ||
8 |
Did you find and correct the condition? | -- | ||
9 | Test the MAP sensor signal circuit for a faulty connection at the PCM. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs . Did you find and correct the condition? | -- | ||
10 | Replace the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement Did you complete the replacement? | -- | -- | |
|
Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Did you complete the replacement? | -- | -- | ||
12 |
Does the DTC reset? | -- | System OK |
