GM Service Manual Online
For 1990-2009 cars only

Object Number: 404075  Size: SF
Engine Controls Components
OBD II Symbol Description Notice
Cell 21: Engine Data Sensors-A/C Refrig Press, TP, MAP, ECT, IAT
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

VIN K

The Manifold Absolute Pressure (MAP) sensor responds to changes in intake manifold pressure (vacuum). The PCM supplies a 5 volt reference and ground for the MAP sensor. The MAP sensor provides a signal to the PCM relative to pressure changes in the manifold. The MAP sensor signal voltage to the PCM varies from below 2 volts at idle (low manifold absolute pressure - high vacuum) to above 4 volts with the key ON, engine not running or at wide-open throttle (high manifold absolute pressure - low vacuum). 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 low, DTC P1107 will be set.

VIN 1

The Manifold Absolute Pressure (MAP) sensor responds to changes in intake manifold pressure. The PCM supplies a 5 volt reference and a ground for the MAP sensor. The MAP sensor provides a signal to the PCM relative to pressure changes in the manifold. With the key ON, engine not running, the MAP sensor signal voltage to the PCM varies between 1.5 to 2.5 volts. With the engine running, the MAP sensor voltage to the PCM varies from below 2 volts at idle (low manifold absolute pressure - high vacuum) to above 4 volts at wide-open throttle (high manifold absolute pressure - low vacuum). The PCM monitors the MAP signals for voltage outside the normal range of the MAP sensor. If the PCM detects a MAP signal voltage that is intermittently low, DTC P01107 will be set.

Conditions for Running the DTC

    • No TP sensor DTCs are present.
    • The ignition is ON.
    • Throttle angle is steady above 0% if engine speed is less than 1000 rpm.
    • Throttle angle is steady above 10% if engine speed is greater than 1000 rpm.

Conditions for Setting the DTC

The MAP sensor intermittently indicates a manifold absolute pressure below 0.1 volt.

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 Info function or by disconnecting the PCM battery feed.

Diagnostic Aids

Check for the following conditions:

    • Poor connection at PCM or MAP sensor.
         Inspect PCM 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 malfunction.

Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.

DTC P1107 - MAP Sensor Circuit Intermittent Low Voltage

Step

Action

Value(s)

Yes

No

1

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

Select DTC info, Last Test Fail and note any other DTCs set.

Is DTC P0107 also set?

--

Go to DTC P0107 Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage

Go to Step 3

3

Is DTC P1122 also set?

--

Go to Step 6

Go to Step 4

4

Check for a poor 5 volt reference A circuit or MAP signal circuit terminal connection at the MAP sensor.

Was a problem found?

--

Go to Step 9

Go to Step 5

5

Check the MAP signal circuit between the MAP sensor connector and the PCM for an intermittent open or short to ground.

Was a problem found?

--

Go to Step 10

Go to Step 8

6

Check for an intermittent short to ground on the 5 volt reference A circuit between the PCM and the following components:

    • The MAP sensor
    • The EGR valve
    • The TP sensor

Refer to Wiring Repairs .

Was a problem found?

--

Go to Step 10

Go to Step 7

7

Check for a poor 5 volt reference A terminal connection at the PCM.

Was a problem found?

--

Go to Step 9

Go to Step 8

8

Check for an intermittent open in the 5 volt reference A circuit.

Was a problem found?

--

Go to Step 10

Go to Diagnostic Aids

9

Replace the malfunctioning harness connector terminals for the 5 volt reference A circuit and/or the MAP signal circuit as necessary. Refer to Wiring Repairs .

Is action complete?

--

Go to Step 11

--

10

Repair intermittent open/short circuit in wiring harness as necessary. Refer to Wiring Repairs .

Is action complete?

--

Go to Step 11

--

11

  1. Review and record scan tool Fail Records data.
  2. Clear DTCs.
  3. Operate vehicle within Fail Records conditions as noted.
  4. Using a scan tool, monitor Specific DTC info for DTC P1107.

Does scan tool indicate DTC P1107 failed?

--

Go to Step 2

System OK