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 linear 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 signal for voltages outside the normal range of the MAP sensor. If the PCM detects a MAP signal voltage that is intermittently high, DTC P1106 will be set.
Conditions for Setting the DTC
| • | No TP sensor DTCs present. |
| • | Engine has been running for a length of time that is determined by startup coolant temperature. The length of time ranges from 2 minutes at less than -30°C (-22°F) to 0.5 second at more than 30°C (86°F). |
| • | Throttle position is less than 2% when engine speed is less than 900 RPM. |
| OR |
| • | Throttle position is 0% when engine speed is greater than 900 RPM. |
| • | The MAP sensor indicates a signal voltage intermittently greater than 4.2 volts. |
| • | The above conditions are present for longer than 5 seconds. |
Action Taken When the DTC Sets
| • | The PCM will not illuminate the Malfunction Indicator Lamp (MIL). |
| • | The PCM will store conditions which were present when the DTC set as Fail Records data only. This information will not be stored as Freeze Frame data. |
Conditions for Clearing the MIL/DTC
| • | A history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | DTC can be cleared by using the scan tool Clear Information function or by disconnecting the PCM battery feed. |
Diagnostic Aids
Check for the following conditions:
- Poor connection at PCM - Inspect harness connectors for the following items:
- 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.
| - | Backed out terminals |
| - | Improper mating |
| - | Broken locks |
| - | Improperly formed or damaged terminals |
| - | Poor terminal to wire connections |
Review the Fail Records vehicle mileage since the diagnostic test last failed. This may help determine how often the condition that caused the DTC to be set occurs.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||||||||
2 | Select DTC info, Last Tst Fail and note any other DTCs set. Is DTC P0108 also set? | -- | Go to DTC P0108 Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage | |||||||
3 | Is DTC P1121 also set? | -- | ||||||||
4 | Check for a poor sensor ground circuit terminal connection at the MAP sensor. Was a problem found? | -- | ||||||||
5 | Check the MAP signal circuit between the MAP sensor connector and the PCM for an intermittent short to voltage. Was a problem found? | -- | ||||||||
6 | Check for an intermittent short to voltage on the 5 volt reference A circuit between the PCM and the following components:
Refer to Wiring Repairs . Was a problem found? | -- | ||||||||
7 | Check for a poor sensor ground circuit terminal connection at the PCM. Was a problem found? | -- | ||||||||
8 | Check for an intermittent open in the sensor ground circuit. Refer to Wiring Repairs . Was a problem found? | -- | Go to Diagnostic Aids | |||||||
9 | Replace the faulty harness connector terminal for sensor ground circuit. Refer to Wiring Repairs . Is action complete? | -- | -- | |||||||
10 | Locate and repair intermittent open/short circuit in wiring harness as necessary. Refer to Wiring Repairs . Is action complete? | -- | -- | |||||||
11 |
Does scan tool indicate DTC P1106 failed? | -- | System OK |
