GM Service Manual Online
For 1990-2009 cars only

Object Number: 12976  Size: SF
Engine Controls Components
IAT/ ECT/ TP/ MAP and BBV Sensors
OBD II Symbol Description Notice
ESD Notice
ESD Notice

Circuit Description

The Manifold Absolute Pressure (MAP) sensor is a sensor that changes resistance based upon manifold vacuum. The PCM provides a 5 volt reference and ground. The MAP sensor signal varies between ground and 5 volts as manifold vacuum varies. As MAP decreases, voltage decreases (low engine load, high vacuum). As MAP increases, voltage increases (high engine load, low vacuum). The PCM uses the MAP sensor values as an indicator of engine load. DTC P1106 sets when the PCM detects a MAP sensor signal that is too high.

Conditions for Setting the DTC

Test Conditions

    •  DTCs P0107, P0108, P0122 and P0123 not set.
    •  Engine running.
    •  Throttle angle 20.5 degrees or less.

Failure Condition

The MAP sensor reading has been 5.06 volts or greater too long.

Action Taken When the DTC Sets

    •  The Malfunction Indicator Lamp (MIL) will not illuminate.
    •  No message will be displayed.

Conditions for Clearing the DTC

    •  A History DTC will clear after forty consecutive warm-up cycles with no failures of any non-emission related diagnostic test.
    •  A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
    • Use a scan tool to clear DTCs.
    • Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Clearing Diagnostic Trouble Codes in PCM Description and Operation.

Diagnostic Aids

DTC P1106 may set due to random engine backfires or mechanical problems. Check for possible mechanical causes of high manifold pressure. If no mechanical causes are found, perform Powertrain Ground Check table.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

  1. If DTC P0108 is also set, diagnose it first because it may help to diagnose an intermittent MAP sensor.

Step

Action

Value(s)

Yes

No

1

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

--

Go to Step 2

Go to A Powertrain On Board Diagnostic (OBD) System Check

2

Turn the key ON.

Is DTC P0106 or P0108 also set?

--

Go to DTCs that are set

Go to Step 3

3

  1. Turn the key to OFF.
  2. Disconnect the fuel rail connector.
  3. Examine terminals M, R and S of both halves of the connector.
  4. Repair terminal contact if needed.

Was terminal contact repaired?

--

Go to Powertrain Control Module Diagnosis for Verify Repair

Go to Step 4

4

  1. Record the fluid life indexes, turn the key to OFF and wait 30 seconds.
  2. Disconnect PCM connector C1.
  3. Examine terminals 46, 64 and 69 of C1.
  4. Repair terminal contact if needed.

Was terminal contact repaired?

--

Go to Powertrain Control Module Diagnosis for Verify Repair

Go to Step 5

5

  1. Disconnect MAP sensor connector.
  2. Examine all MAP sensor terminals.
  3. Repair terminal contact if needed.

Was terminal contact repaired?

--

Go to Powertrain Control Module Diagnosis for Verify Repair

Go to Step 6

6

  1. Check the MAP sensor 5 volt reference circuit and the MAP sensor signal circuit for an intermittent short to voltage.
  2. Check the MAP sensor ground circuit for an intermittent open.

Are any circuit failures found and repaired?

--

Go to Powertrain Control Module Diagnosis for Verify Repair

Fault not present. Go to DTC P0106 Manifold Absolute Pressure (MAP) System Performance