Schematic Reference: Engine Controls Schematics
Circuit Description
The Manifold Absolute Pressure (MAP) sensor is mounted to the top of the intake manifold. The MAP sensor measures pressure changes within the intake manifold which are an indication of engine load. The MAP sensor has a 5.0 volt reference, a ground and a signal circuit.
The MAP sensor contains a diaphragm which changes resistance based on pressure. When manifold pressure is low (high vacuum) sensor output voltage is low. When manifold pressure is high (low vacuum) sensor output voltage is high.
MAP sensor voltage (depending on altitude) can range from 1.0-1.5 volts at idle (high vacuum) to 4.0 - 4.9 volts at wide open throttle (low vacuum).
When the PCM senses a signal voltage lower than the normal operating range of the sensor, this DTC will set.
Conditions for Setting the DTC
| • | No TP sensor DTCs set. |
| • | TP Angle greater than 15%. |
| • | MAP is less than 0.24 volts. |
| • | All conditions met for 4.5 seconds. |
Action Taken When the DTC Sets
| • | The PCM will illuminate the Malfunction Indicator Lamp (MIL) on the second consecutive drive trip that the diagnostic runs and fails. |
| • | The PCM will record operating conditions at the time the diagnostic fails. The first time the diagnostic fails, this information will be stored in Failure Records. If the diagnostic reports a failure on the second consecutive drive trip, the operating conditions at the time of failure will be written to Freeze Frame and the Failure record will be updated. |
| • | The PCM will use TP sensor values to calculate MAP. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail. |
| • | A last test failed (Current DTC) will clear when the diagnostic runs and does not fail. |
| • | A History DTC will clear after forty consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | PCM battery voltage is interrupted. |
| • | Using a Scan tool. |
Diagnostic Aids:
| • | An intermittent may be caused by the following: |
| - | Mis-routed harness. |
| - | Rubbed through wire insulation. |
| - | Broken wire inside the insulation. |
| • | If other DTCs are set that share the same ground and/or 5.0 volt reference circuit, check for faulty connections and for faulty wiring. |
| • | The PCM 5 volt reference circuits are internally connected within the PCM. If all the MAP sensor circuits check to be OK, inspect related 5.0 volt reference circuits. |
| • | If it is determined that the DTC occurs intermittently, performing the DTC P1107 diagnostic table may isolate the cause of the fault. |
For intermittents, refer to Symptoms .
Test Description
Number(s) below refer to step numbers on the diagnostic table.
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Determines if the malfunction is present. For any test that requires back probing the PCM or component harness connectors, must use the Connector Test Adapter Kit J 35616-A. Using this kit will prevent any damage to the harness connector terminals.
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Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If the DTC cannot be duplicated, the information included in the Freeze Frame and/or Failure Records data can be useful in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also be used to determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that were noted. This will isolate when the DTC failed.
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If the scan tool displays 5.0 volts, indicates that the MAP sensor signal, 5.0 volt reference circuit and PCM are OK.
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If the scan tool displays 5.0 volts, indicates that the MAP sensor signal circuit and PCM are OK.
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Disconnecting the PCM will allow using the DVM (J 39200) to check continuity of the circuits. This will aid in locating an open or shorted circuit.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||||||||
Is MAP voltage below the specified value? | 0.24 V | |||||||||
Does the scan tool indicate that this diagnostic failed this ignition? | -- | Go to Diagnostic Aids | ||||||||
Is MAP voltage at the specified value? | 5.0V | |||||||||
Is MAP voltage at the specified value? | 5.0 V | |||||||||
Was the 5 volt reference circuit open or shorted to ground? | -- | |||||||||
7 | Check the 5 volt reference circuit for a poor connection at the PCM and replace the terminal if necessary. Refer to Repair Procedures in Electrical Diagnosis (8A Cell 5). Did the terminal require replacement? | -- | ||||||||
8 |
Was the MAP signal circuit open or shorted to ground? | -- | ||||||||
9 | Check the MAP sensor signal circuit for a poor connection at the PCM and replace the terminal if necessary. Refer to Repair Procedures in Electrical Diagnosis (8A Cell 5). Did the terminal require replacement? | -- | ||||||||
10 | Replace the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement . Is the action complete? | -- | -- | |||||||
11 |
Important:: Replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Is the action complete? | -- | -- | |||||||
12 |
Does the scan tool indicate that this test ran and passed? | -- | ||||||||
13 | Using the scan tool, select Capture Info, Review Info. Are any DTCs displayed that have not been diagnosed? | -- | Go to the applicable DTC table | System OK |
