• | 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 | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
5-Volt Reference | P0107, P0452, P0532, P0641 | P0106, P0107 | P0107 | P0106, P0108, P0453, P0533, P0641 | P0106, P1101 |
MAP Sensor Signal | P0107 | P0106, P0107 | P0107 | P0106, P0108, P0641 | P0106, P1101 |
Low Reference | -- | P0106, P0108 | P0106, P0108 | -- | P0106, P1101 |
Circuit | Short to Ground | Open or High Resistance | Short to Voltage |
---|---|---|---|
Operating Conditions: Engine Running. Normal MAP Parameter: 20-48 kPa | |||
5-Volt Reference | 10 kPa | 10 kPa | 104 kPa |
MAP Sensor Signal 2 | 10 kPa | 10 kPa | 104 kPa² |
Low Reference 2 | -- | 90-104¹,² kPa | -- |
¹Varies, depending on ECM software version ²Internal ECM or sensor damage may occur if the circuit is shorted to B+ |
The intake flow rationality diagnostic provides the within-range rationality check for the mass air flow (MAF), manifold absolute pressure (MAP), and the throttle position (TP) sensors. This is an explicit model-based diagnostic containing 4 separate models for the intake system.
• | 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 barometric pressure (BARO), TP, intake air temperature (IAT), and estimated MAP. The information from this model is displayed on the scan tool as the MAF Performance Test parameter. |
• | The first intake manifold model describes the intake manifold and is used to estimate 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. The information from this model is displayed on the scan tool as the MAP Performance Test 1 parameter. |
• | The second intake manifold model is identical to the first intake manifold model except that the MAF sensor measurement is used instead of the throttle model estimate for the throttle air input. The information from this model is displayed on the scan tool as the MAP Performance Test 2 parameter. |
• | The fourth model is created from the combination and additional calculations of the throttle model and the first intake manifold model. The information from this model is displayed on the scan tool as the TP Performance Test parameter. |
The estimates of MAF and MAP obtained from this system of models and calculations 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 following table illustrates the possible failure combinations and the resulting DTC or DTCs.
MAF Performance Test | MAP Performance Test 1 | MAP Performance Test 2 | TP Performance Test | DTCs Passed | DTCs Failed |
---|---|---|---|---|---|
-- | -- | OK | OK | P0101, P0106, P0121, P1101 | None |
OK | OK | Fault | OK | P0101, P0106, P0121, P1101 | None |
Fault | OK | Fault | OK | P0106, P0121, P1101 | P0101 |
OK | Fault | Fault | OK | P0101, P0121, P1101 | P0106 |
Fault | Fault | Fault | OK | P0121, P1101 | P0101, P0106 |
-- | -- | OK | Fault | P0101, P0106, P1101 | P0121 |
OK | OK | Fault | Fault | P0101, P0106, P0121, P1101 | None |
Fault | OK | Fault | Fault | P0101, P0106, P0121 | P1101 |
-- | Fault | Fault | Fault | P0101, P0106, P0121 | P1101 |
• | DTCs P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0128, P0335, P0336, P0401, P0405, P1404 are not set. |
• | The engine is running. |
• | The intake air temperature (IAT) is between -7 and +60°C (+19 and +140°F). |
• | The engine coolant temperature (ECT) is between 70-121°C (158-249°F). |
• | This DTC runs continuously when the above conditions are met. |
The engine control module (ECM) detects that the MAP sensor pressure is not within range of the calculated pressure that is derived from the system of models for greater than 0.5 second.
DTC P0106 is a Type B DTC.
DTC P0106 is a Type B DTC.
• | A wide open throttle (WOT) acceleration from a stop should cause the MAP sensor parameter on the scan tool to increase rapidly to near the BARO parameter at the time of the 1-2 shift. |
• | A skewed or stuck engine coolant temperature (ECT) or IAT will cause the calculated models to be inaccurate and may cause this DTC to run when it should not. Refer to Temperature Versus Resistance. |
• | The BARO that is used by the ECM to calculate the air flow models is initially based on the MAP sensor at ignition ON. When the engine is running, the ECM will continually update the BARO value near wide open throttle (WOT) using the MAP sensor and a calculation. A skewed MAP sensor will cause the BARO value to be inaccurate. Use a scan tool and compare the BARO parameter with the ignition ON to the Altitude vs. Barometric Pressure table. Refer to Altitude Versus Barometric Pressure. |
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
• | J 23738-A Mityvac |
• | J 35555 Metal Mityvac |
⇒ | If any of the DTCs are set, refer to DTC P0641 or P0651. |
• | Damaged components |
• | Loose or improper installation |
• | An air flow restriction |
• | A cracked or restricted MAP sensor vacuum hose |
• | An intake manifold leak |
⇒ | 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 an 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 terminal B 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. |
Important: You must perform the Circuit/System Testing before proceeding with Component Testing.
THEN
Ignition ON, Engine OFF, MAP Sensor Parameter | MAP Sensor Parameter With 5 Inches of Vacuum Applied | MAP Sensor Parameter With 10 Inches of Vacuum Applied |
---|---|---|
100 kPa | 79-87 kPa | 62-70 kPa |
95 kPa | 74-82 kPa | 57-65 kPa |
90 kPa | 69-77 kPa | 52-60 kPa |
80 kPa | 59-67 kPa | 42-50 kPa |
70 kPa | 49-57 kPa | 32-40 kPa |
60 kPa | 39-47 kPa | 22-30 kPa |
⇒ | If the voltage is erratic, replace the MAP sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for ECM replacement, setup, and programming |