• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
5-Volt Reference | P0107, P0405, P2122, P2138 | P0107 | P0108 | P0106 |
MAP Sensor Signal | P0107 | P0108 | P0108 | P0106 |
Low Reference | -- | P0106, P0108 | -- | P0106 |
Circuit | Short to Ground | Open | Short to Voltage |
---|---|---|---|
Operating Conditions: Engine operating in Closed Loop Parameter Normal Range: 32-48 kPa | |||
5-Volt Reference | 17 kPa | 15 kPa | 50 kPa |
MAP Sensor Signal | 15 kPa | 101 kPa | 101 kPa |
Low Reference | -- | 101 kPa | 101 kPa* |
* Internal ECM damage may occur if the circuit is shorted to B+. |
The manifold absolute pressure (MAP) sensor responds to pressure changes in the intake manifold. The pressure changes occur based on the engine load. The engine control module (ECM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit. The ECM provides a ground on the low reference circuit. The MAP sensor provides a signal to the ECM on the MAP sensor signal circuit which is relative to the pressure changes in the manifold. The ECM detects a low signal voltage at a low MAP, such as during an idle or a deceleration. The ECM detects a high signal voltage at a high MAP, such as the ignition is ON, with the engine OFF, or at a wide open throttle (WOT). The MAP sensor is also used to determine the barometric pressure (BARO). This occurs when the ignition switch is turned ON, with the engine OFF. The BARO reading may also be updated whenever the TP sensor is greater than 28 percent.
• | The ignition is ON. |
• | The DTCs run continuously once the above condition is met. |
The ECM detects that the MAP is less than 0.3 volt for greater than 1 second.
The ECM detects that the MAP is greater than 4.9 volts for greater than 1 second.
DTCs P0107 and P0108 are Type A DTCs.
DTCs P0107 and P0108 are Type A DTCs.
If a shared 5-volt reference circuit is shorted to ground or shorted to a voltage, other 5-volt reference circuits may be affected.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
J 23738-A Vacuum Pump
⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If the voltage is not with in the specified range, replace the MAP sensor. |
Vacuum Reading | Values |
---|---|
5 in Hg (17 kPa) | 3.12-3.20 Volts |
10 in Hg (34 kPa) | 2.38-2.50 Volts |
15 in Hg (51 kPa) | 1.65-1.75 Volts |
20 in Hg (68 kPa) | 0.94-1.02 Volts |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for ECM replacement, setup, and programming |