PRE-RELEASE
DTC P0641
| DTC P0641 |
| Diagnostic Instructions |
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Perform the
Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
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Review
Strategy Based Diagnosis
for an overview of the diagnostic approach.
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Diagnostic Procedure Instructions
provides an overview of each diagnostic category.
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| DTC Descriptor |
DTC P0641 00
5V Reference 1 Circuit Malfunction
| Circuit/System Description |
The engine control module (ECM) has three 5 V reference circuits. The ECM provides the 5 V reference to various sensors. Each reference circuit provides a 5 V reference for greater than one sensor. A short to ground or voltage on one of the 5 V reference circuits affects all the components connected to that 5 V reference circuit. The ECM monitors the 5 V reference circuit's voltage.
| Conditions for Running the DTC |
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The ignition is ON.
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The DTCs run continuously when the above condition is met.
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| Conditions for Setting the DTC |
The control module detects a voltage above 5.5 V or below 4.5 V on any of the 5-volt reference circuits for greater than 0.5 s.
| Action Taken When the DTC Sets |
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DTC P0641 is a Type B DTC.
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The ECM commands the throttle actuator control (TAC) system to operate in a Reduced Engine Power mode.
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| Conditions for Clearing the DTC |
DTC P0641 is a Type B DTC.
| Diagnostic Aids |
If a shared 5 V reference circuit is shorted to ground or shorted to a voltage, other 5 V reference circuits may be affected.
P0641
The 5-volt reference 1 circuit provides 5 V to the accelerator pedal position (APP) sensor 2, A/C refrigerant pressure sensor, throttle position sensor, exhaust gas recirculation (EGR) valve, turbocharger vane position sensor, clutch pedal position (CPP) sensor and diesel particulate filter pressure sensor.| Reference Information |
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
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Circuit Testing
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Connector Repairs
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Testing for Intermittent Conditions and Poor Connections
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Wiring Repairs
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DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
| Circuit/System Verification |
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Ignition ON, check the diagnostic trouble code (DTC) information with a scan tool. The DTC P0641 should not be set.
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Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
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| Circuit/System Testing |
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Ignition OFF, disconnect the harness connector at all appropriate sensors for the applicable DTC. Refer to Diagnostic Aids. |
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Ignition ON, test for 4.6-5.4 V between the 5 V reference circuit and ground.
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If the voltage is less than the specified range, test the 5 V reference circuit for a short to ground. If all circuits test normal, replace the K20 Engine Control Module.
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If greater than the specified range, test the 5 V reference circuit for each component associated with the 5 V reference circuit for a short to voltage. If all circuits test normal, replace the K20 Engine Control Module.
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Observe the scan tool that DTC P0641 is not set while connecting each component associated with the 5 V reference circuit one at a time. |
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If the DTC set when a component is connected, test the signal circuit for a short to voltage. If all circuits test normal, replace the component.
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| Repair Instructions |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
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Accelerator Pedal Position Sensor Replacement
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Throttle Body Assembly Replacement
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Exhaust Gas Recirculation Valve Replacement
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Clutch Pedal Cruise Control Release Switch Replacement
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Exhaust Pressure Sensor Replacement
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Control Module References
for ECM replacement, setup, and programming
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