GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The manifold absolute pressure (MAP) sensor responds to changes in the intake manifold vacuum. The MAP sensor signal voltage to the powertrain control module (PCM) varies from less than 2 volts at idle to more than 4 volts with the key ON and the engine not running or at wide open throttle (WOT). The MAP sensor is used to update the barometric pressure reading (BARO), as an enabling factor for other diagnostics, and to determine any manifold pressure changes while the EGR flow test diagnostic is being run. Refer to DTC P0401 Exhaust Gas Recirculation (EGR) Flow Insufficient . 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 intermittently high, DTC P1106 will set.

Conditions for Running the DTC

    • No TP sensor DTCs are present.
    • System voltage more than 9.0 volts.
    • The ignition is ON.
    • The throttle angle is steady at less than 2 percent if the engine speed is less than 3000 RPM.
    • Throttle position above 30 percent if engine speed is above 3000 RPM.

Conditions for Setting the DTC

The MAP sensor intermittently indicates a voltage of more than 4.3 volts.

Action Taken When the DTC Sets

The PCM stores conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records.

Conditions for Clearing the MIL/DTC

    • The DTC becomes history when the conditions for setting the DTC are no longer present.
    • The history DTC clears after 40 malfunction free warm-up cycles.
    • The PCM receives a clear code command from the scan tool.

Diagnostic Aids

Inspect for the following conditions:

    • A poor connection at the PCM or the MAP sensor. Inspect the harness connectors for the following conditions:
       - Backed-out terminals
       - Improper mating
       - Broken locks
       - Improperly formed or damaged terminals
       - Poor terminal-to-wire connection
    • A 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 the connectors and the wiring harnesses related to the sensor. A change in the display indicates the location of the malfunction.

If the DTC cannot be duplicated and is determined to be intermittent, reviewing the Failure Records can be useful in determining when the DTC was last set. Also refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

DTC P1106 - MAP Sensor Circuit Intermittent High Voltage

Step

Action

Values

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

Is DTC P0108 also set?

--

Go to DTC P0108 Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage

Go to Step 3

3

Are DTCs P1111, P1115, or P1121 also set?

--

Go to Step 6

Go to Step 4

4

Inspect the ground circuit of the MAP sensor for a poor connection at the harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 5

5

Inspect the ground circuit of the PCM for a poor connection at the harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 8

6

Test the signal circuit of the MAP sensor for an intermittent short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 7

7

Test the 5 volt reference A circuit of the MAP for an intermittent short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 8

8

Test the ground circuit for an intermittent open.

Did you find and correct the condition?

--

Go to Step 9

Go to Diagnostic Aids

9

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK