DTC P1129: Manifold Absolute Pressure (MAP) Sensor Signal Higher Than Expected: General Description
The manifold absolute pressure (MAP) sensor senses manifold absolute pressure (vacuum) and converts it into electrical signals. The MAP sensor outputs low signal voltage at high-vacuum (throttle valve closed) and high signal voltage at low-vacuum (throttle valve wide open).
The engine control module (ECM) compares a predetermined MAP value at a given throttle position and manifold absolute pressure to the output voltage value of the MAP sensor.
If the MAP sensor outputs high voltage during fuel cut-off operation for deceleration with the throttle valve fully closed, which should make the manifold absolute pressure lower, the ECM detects a malfunction and stores a DTC.
MONITOR EXECUTION, SEQUENCE, DURATION, DTC TYPE, OBD STATUS
| Execution | Once per driving cycle |
| Sequence | None |
| Duration | 2 seconds or more |
| DTC Type | Two drive cycles, MIL ON |
| OBD Status | PASSED/FAILED/NOT COMPLETED (STILL TESTING) |
ENABLE CONDITIONS CHART
| Condition | Minimum | Maximum |
|---|---|---|
| Engine coolant temperature | 156°F (69°C) | - |
| Engine speed | 1,300 rpm | 7,600 rpm |
| Vehicle speed | 15 mph (24 km/h) | - |
| Fuel feedback | During deceleration | |
| Throttle position | Fully closed | |
| No active DTCs | P0107, P0108, P0117, P0118, P0122, P0123, P0171, P0172, P0222, P0223, P0300, P0301, P0302, P0303, P0304, P0506, P0507, P1128, P2101, P2108, P2118, P2122, P2123, P2127, P2128, P2135, P2138, P2176, P2646, P2647, P2648, P2649, U0107 | |