P1107

DTC P1107 Manifold Absolute Pressure (MAP) Sensor Circuit - Intermittent Low Input:

Manifold Absolute Pressure (MAP) Output Check:

CIRCUIT DESCRIPTION
The Manifold Absolute Pressure (MAP) sensor responds to changes in intake manifold pressure (vacuum). A 5 volt reference is applied to the sensor on CKT 474. A variable resistor moves in relation to manifold pressure and a voltage signal is sent back to the Vehicle Control Module-A (VCM-A) on CKT 432. This voltage signal will vary from 1 - 1.5 volts at closed throttle to 4 - 4.6 volts at wide open throttle (low vacuum). The VCM-A utilizes the MAP signal and throttle position to determine the correct amount of fuel delivered to the engine. DTC P1107 is a Type "D" DTC.

DTC P1107 WILL SET WHEN
^ No Throttle Position (TP) sensor faults are set.
^ Engine running.
^ MAP voltage is less than 0.31V.
^ TP is at least 0% when engine speed is no more than 850 RPM or TP is at least 15% when engine speed is at least 850 RPM.

ACTION TAKEN (VCM-A WILL DEFAULT TO)
The VCM-A will store DTC P1107 to history if an intermittent problem is detected.

DTC P1107 WILL CLEAR WHEN
The VCM-A will turn the MIL "OFF" after three consecutive trips without a fault condition present. A history DTC will be cleared if no fault conditions have been detected for forty warm-up cycles [coolant temperature has risen 22°C (40°F) from start-up coolant temperature and engine coolant temperature exceeds 71°C (160°F) that same ignition cycle] or the Tech 1 clearing feature has been used.

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This step determines if DTC P1107 is the result of a hard failure or an intermittent condition.
2. Jumpering harness terminals "B" to "C" (5 volts to signal circuit) will determine if the sensor is at fault, or if there is a problem with the VCM-A or wiring.
3. The Tech 1 scan tool may not display 5 volts. The important thing is that the VCM-A recognized the voltage as more than 4 volts, indicating that the VCM-A and CKT 432 are OK.
4. This will determine if 5.0 volts are present at the sensor.

DIAGNOSTIC AIDS
An intermittent open in CKT 432 or CKT 474 will result in a DTC P1107.

With the ignition "ON" and the engine "OFF," the manifold pressure is equal to atmospheric pressure with the signal voltage high. This information is used by the VCM-A as an indication of vehicle altitude.

Comparison of this reading with a known good vehicle using the same sensor is a good way to check accuracy of a "suspect" sensor. Readings should be the same ±0.4 volt. Also, MAP Output Check can be used to test the MAP sensor. MAP Sensor Output Diagnosis

Refer to Intermittents. - Intermittent Malfunctions

Disconnect sensor from bracket and twist sensor by hand (only) to check for intermittent connections. Output changes greater than 0.1 volt indicates a bad connector or connection. If OK, replace sensor.


NOTE: Make sure electrical connector remains securely fastened.