Diagnostic Instructions
| • | 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. |
DTC Descriptors
DTC P0641: 5-Volt Reference CircuitDTC P06A6: 5-Volt Reference Performance
Diagnostic Fault Information
Circuit | Short to Ground | Open or High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
5-Volt Reference | P0641 | P0641, P06A6 | P0641 | P06A6 |
Fuel Rail Pressure (FRP) Sensor Signal | P0192 | P0191, P0192 | P0193 | P0191 |
Fuel Line Pressure Sensor Low Reference | -- | P0641, P06A6 | -- | P06A6 |
Circuit/System Description
The fuel pressure sensor is located on the fuel line. The fuel pressure sensor monitors the fuel pressure in the fuel line. The fuel pump flow control module (FPCM) monitors the voltage signal from the fuel pressure sensor.
Conditions for Running the DTC
The ignition is on.
Conditions for Setting the DTC
The FPCM detects that the fuel pressure 5-volt reference is above or below a predetermined voltage threshold.
Action Taken When the DTC Sets
DTCs P0641 and P06A6 are Type A DTCs.
Conditions for Clearing the DTC
DTCs P0641 and P06A6 are Type A DTCs.
Diagnostic Aids
Using the Failure Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect harness connector of the fuel pressure sensor.
- Ignition OFF, test for less than 1.0 ohm between the low reference circuit terminal 2 and ground.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground.
- If all circuits test normal, replace the fuel pressure sensor.
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the FPCM. |
| ⇒ | 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 FPCM. |
| ⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the FPCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for FPCM replacement, setup, and programming
