Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
5-Volt Reference | P0641, P0452, P0107, P0335, P0532, P0522, P0106 | P0106, P0107 | P0107 | P0641, P0533, P0532, P0106 | P0106, P0107 |
MAP Sensor Signal | P0107, P0106 | P0106, P0107 | P0107 | P0641, P0108, P0106, P0523 | P0106, P0107, P1101 |
Low Reference | -- | P0106, P0107 | P0106, P1101 | -- | P0106, P0108 |
Circuit | Normal Range | Short to Ground | Open | Short to Voltage |
---|---|---|---|---|
5-Volt Reference | -- | 10 kPa | 10 kPa | 104 kPa |
MAP Sensor Signal | 12-103 kPa | 10 kPa | 10 kPa | 104 kPa |
Low Reference | -- | 36 kPa | 93 kPa | -- |
The manifold absolute pressure (MAP) sensor measures the pressure inside the intake manifold. Pressure in the intake manifold is affected by engine speed, throttle opening, air temperature, and barometric pressure (BARO). A diaphragm within the MAP sensor is displaced by the pressure changes that occur from the varying load and operating conditions of the engine. The sensor translates this action into electrical resistance. The MAP sensor wiring includes three circuits. The control module supplies a regulated 5 volts to the sensor on a 5-volt reference circuit. The control module supplies a ground on a low reference circuit. The MAP sensor provides a signal voltage to the control module, relative to the pressure changes on the MAP sensor signal circuit. The control module converts the signal voltage input to a pressure value.
Under normal operation, the highest pressure that can exist in the intake manifold is equal to the BARO. This occurs when the vehicle is operated at wide open throttle (WOT), or when the ignition is ON while the engine is OFF. Under these conditions, the control module uses the MAP sensor to determine the current BARO. The lowest manifold pressures occur when the vehicle is idling or decelerating. The MAP can range from 10 kPa when pressures are low to as much as 104 kPa when pressures are high, depending on the BARO.
The control module should detect a low signal voltage at a low MAP, such as during an idle or a deceleration. The control module should detect a high signal voltage at a high MAP, such as the ignition is ON, with the engine OFF, or at a WOT.
Within the control module, the intake flow rationality diagnostic has the ability to determine an inaccurate input from the three systems it monitors. Calibrated within the diagnostic are estimates for the MAP, the mass air flow (MAF), and the throttle position (TP) for all engine operating conditions.
The diagnostic uses the following system of models and calculations that are then compared to the actual measured values from the MAF, MAP, and the TP sensors and to each other to determine the appropriate DTC to fail.
• | The throttle model describes the flow through the throttle body and is used to estimate the MAF through the throttle body as a function of BARO, TP, intake air temperature (IAT), and estimated MAP. |
• | The intake manifold model describes the intake manifold and is used to estimate the MAP as a function of the MAF into the manifold from the throttle body, and the MAF out of the manifold caused by engine pumping. The flow into the manifold from the throttle uses the MAF estimate calculated from the above throttle model. |
• | DTCs P0016, P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0128, P0335, or P0336 are not set. |
• | The engine is running. |
• | The engine coolant is between 70-125°C (158-257°F). |
• | The intake air temperature is between -7 and +125°C (+19.4 and +257°F). |
• | DTCs P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0641, P0651 or P2135 are not set. |
• | The engine is running greater than or equal to 400 RPM. |
• | The throttle position is greater than or equal to 0 percent when the engine speed is less than or equal to 1,000 RPM. |
OR |
• | The throttle position is greater than or equal to 12.5 percent when the engine speed is greater than 1,000 RPM. |
• | The engine has been running for a length of time that is determined by the start-up coolant temperature. The length of time ranges from 5.5 minutes at less than -30°C (-22°F) to 10 seconds at more than 30°C (86°F). |
• | DTCs P0120, P0121, P0122, P0123, P0220, P0222, P0223, or P2135 are not set. |
• | The engine is running. |
• | The throttle position is less than or equal to one percent when the engine speed is less than or equal to 1,200 RPM. |
OR |
• | The throttle position is less than or equal to 20 percent when the engine speed is greater than 1,200 RPM. |
• | The control module detects the MAP sensor is not within the predicted range for more than 2 seconds. |
• | This diagnostic runs continuously. |
• | The control module detects that the MAP sensor voltage is less than 0.05 volt for more than 5 seconds. |
• | This diagnostic runs continuously. |
• | The control module detects that the MAP sensor voltage is more than 4.9 volts for more than 5 seconds. |
• | This diagnostic runs continuously. |
• | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
• | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
• | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
• | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
• | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
• | Clear the MIL and the DTC with a scan tool. |
J 23738-A Mityvac
Always perform the Diagnostic System Check - Vehicle .
• | Disconnected, damaged, or incorrectly routed vacuum hoses |
• | MAP sensor disconnected from the vacuum source |
• | Restrictions in the MAP sensor vacuum source |
• | Intake manifold vacuum leaks |
• | For properly functioning oxygen sensor--Refer to Scan Tool Data List . |
⇒ | If more than 5.2 volts, then test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the control module. |
⇒ | If less than 4.8 volts, then test the 5-volt reference circuit for high resistance, an open, or an intermittent and poor connection at the control module. If the circuit tests normal, replace the control module. |
⇒ | If the MAP sensor is more than 12 kPa, then test the MAP sensor signal circuit for a short to voltage. If the circuit tests normal, replace the control module. |
⇒ | If the MAP sensor is less than 103 kPa, test the MAP sensor signal circuit for a short to ground, an open, or high resistance. If the circuit tests normal, replace the control module. |
⇒ | If the resistance is more than 5 ohms, test the circuit for an open, or high resistance. If the circuit tests normal, replace the control module. |
⇒ | If decrease in pressure is not consistent, then test for intermittent and poor connections at the MAP sensor. |
⇒ | If connections test normal, replace the MAP sensor. |
⇒ | If more than 34 kPa, test for an intermittent and a poor connection at the MAP sensor. |
⇒ | If connections test OK, replace the MAP sensor. |