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DTC Advanced Diagnostics: P0641
DTC P0641:Sensor Reference Voltage A Malfunction
General Description
The powertrain control module (PCM) provides power supply voltages for the sensors. The monitoring function checks this sensor supply voltages (outputs) and compares it with minimum and maximum thresholds. The PCM contains a linear voltage regulator (5V) to provide a reference voltage. The monitoring function checks the provided sensor supply voltages against the reference voltage. If the sensor power supply voltage is a specified value, the PCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
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Execution |
Continuous |
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Sequence |
None |
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Duration |
0.15 second or more |
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DTC Type |
One drive cycle, MIL on | |
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Enable Conditions
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Condition |
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Vehicle |
ON mode | |
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Malfunction Threshold
The sensor power supply voltage is less than 4.8 V, or greater than 5.2 V for at least 0.15 second.
Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
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Fuel rail pressure sensor VCC line short to power |
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Crankshaft position (CKP) sensor VCC line short to power |
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Camshaft position (CMP) sensor B VCC line short to power |
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Neutral position sensor VCC line short to power |
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Mass airflow (MAF) sensor/intake air temperature (IAT) sensor 1 VCC line short to power |
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Throttle body VCC line short to power |
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Acceleration pedal position (APP) sensor VCC line short to power |
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Camshaft position (CMP) sensor A VCC line short to power |
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Input shaft (mainshaft) speed sensor VCC line short to power |
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Output shaft (countershaft) speed sensor VCC line short to power |
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Turbocharger boost sensor VCC line short to power |
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Manifold absolute pressure (MAP) sensor/intake air temperature (IAT) sensor 2 VCC line short to power |
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Rocker arm oil pressure sensor VCC line short to power |
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Turbocharger VCC line short to power |
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A/C pressure sensor VCC line short to power |
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Fuel tank pressure (FTP) sensor VCC line short to power*1 |
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Fuel rail pressure sensor VCC line short to ground |
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CKP sensor VCC line short to ground |
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CMP sensor B VCC line short to ground |
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Neutral position sensor VCC line short to ground |
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MAF sensor/IAT sensor 1 VCC line short to ground |
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Throttle body VCC line short to ground |
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APP sensor VCC line short to ground |
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CMP sensor A VCC line short to ground |
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Input shaft (mainshaft) speed sensor VCC line short to ground |
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Output shaft (countershaft) speed sensor VCC line short to ground |
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Turbocharger boost sensor VCC line short to ground |
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MAP sensor/IAT sensor 2 VCC line short to ground |
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Rocker arm oil pressure sensor VCC line short to ground |
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Turbocharger VCC line short to ground |
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A/C pressure sensor VCC line short to ground |
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FTP sensor VCC line short to ground*1 |
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PCM internal circuit failure |
*1: KA/KC
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory.
Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command. | 