P0103-MASS AIR FLOW SENSOR CIRCUIT HIGH
P0103-MASS AIR FLOW SENSOR CIRCUIT HIGH
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For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The Intake Air Temperature (IAT) Sensor is combined with the Mass Air Flow Sensor. It is located on the Air Cleaner Box and is used to monitor the temperature of the air entering the intake system. The Intake Air Temperature Sensor operates as a typical two wire sensor. It receives a 5-Volt signal on the (K362) Intake Air Temperature Sensor Signal circuit and uses the (K916) Sensor Ground circuit. When this fault code is active the EGR system will be disabled.
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When Monitored:
No reference Voltage DTCs present. With the engine running and engine speed below 5100 RPMs.
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Set Condition:
The (K157) Mass Air Flow Sensor Signal is above 4.9 Volts for 1.5 seconds.
Possible Causes |
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| (K157) MASS AIR FLOW SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE |
| (K957) MASS AIR FLOW SENSOR GROUND CIRCUIT SHORTED TO VOLTAGE |
| (K957) MASS AIR FLOW SENSOR GROUND CIRCUIT OPEN/HIGH RESISTANCE |
| MASS AIR FLOW SENSOR |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
| NOTE: | If any Sensor Reference DTCs are present, perform the applicable diagnostic procedure before continuing with this test. |
| 1. | Ignition on, engine not running. |
| 2. | With the scan tool, clear DTCs in the PCM. |
| 3. | Start the engine and allow it to reach normal operating temperature. |
| 4. | With the scan tool, select View DTCs. |
Is the status Active for this DTC?
Yes
- Go To 2
No
- Perform the INTERMITTENT DTC diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
2. CHECK THE (K157) MASS AIR FLOW SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
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| 1. | Turn the ignition off. |
| 2. | Disconnect the Mass Air Flow Sensor harness connector. |
| 3. | Turn the ignition on. |
| 4. | Measure the voltage of the (K157) Mass Air Flow Sensor Signal circuit in the Mass Air Flow Sensor harness connector. |
Is there any voltage present?
Yes
- Repair the (K157) Mass Air Flow Sensor Signal circuit for a short to voltage.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
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Go To 3
3. CHECK THE (K957) MASS AIR FLOW SENSOR GROUND CIRCUIT FOR A SHORT TO VOLTAGE
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| 1. | Measure the voltage of the (K957) Mass Air Flow Sensor Ground circuit in the Mass Air Flow Sensor harness connector. |
Is there any voltage present?
Yes
- Repair the (K957) Mass Air Flow Sensor Ground circuit for a short to voltage.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
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Go To 4
4. CHECK THE (K957) MASS AIR FLOW SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
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| 1. | Turn the ignition off. |
| 2. | Disconnect the PCM C1 harness connector. |
| 3. | Measure the resistance of the (K957) Mass Air Flow Sensor Ground circuit between the Mass Air Flow Sensor connector and the PCM C1 harness connector. |
Is the resistance below 5.0 Ohms?
Yes
- Go To 5
No
- Repair the (K957) Mass Air Flow Sensor Ground circuit for an open or high resistance.
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Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM)
- Standard Procedure).
| 1. | Reconnect the PCM C1 harness connector. |
| 2. | Replace the Mass Air Flow Sensor in accordance with the service information. |
| 3. | Turn the ignition on. |
| 4. | With the scan tool, clear DTCs. |
| 5. | Start the engine and allow it to reach normal operating temperature. |
| 6. | With the scan tool, select View DTCs. |
Is the status Active for this DTC?
Yes
- Go To 6
No
- Test Complete.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
| 1. | Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Mass Air Flow Sensor and the Powertrain Control Module (PCM). |
| 2. | Look for any chafed, pierced, pinched, or partially broken wires. |
| 3. | Look for broken, bent, pushed out or corroded terminals. |
| 4. | Perform any Technical Service Bulletins that may apply. |
Were any problems found?
Yes
- Repair as necessary.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
- Replace the Powertrain Control Module in accordance with the service information.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).