P06D7 - Sensor Reference Voltage 6 Circuit Low

Theory of Operation

This sensor supply circuit provides a 5-Volt supply to the Fuel Rail Pressure (FRP) Sensor. The Powertrain Control Module (PCM) illuminates the MIL lamp immediately after the diagnostic runs and fails. The ETC lamp will also flash. During this time the customer will be in a limp home mode. The PCM will turn off the MIL lamp after the diagnostic runs and passes in four consecutive drive cycles.

When Monitored:

With the ignition on, PCM powered.

Set Condition:

Low voltage detected at the 5-Volt Supply circuit.

Possible Causes

FUEL RAIL PRESSURE (FRP) SENSOR
5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
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).

Diagnostic Test

1. ACTIVE DTC

1. Turn the ignition on.
2. Using the scan tool, record all Freeze frame data.
3. Using the scan tool, erase DTCs.
4. Turn the ignition off for 75 seconds.
5. Turn the ignition on.
6. Using the scan tool, read DTCs.

Did the DTC reset?

Yes
• Go To 2

No
• Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

2. CHECK THE FRP SENSOR

1. Turn the ignition off.
2. Disconnect the FRP sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (K350) 5-Volt Supply circuit at the FRP sensor harness connector.
Is the voltage reading between 4.9 and 5.1 Volts?

Yes
• Replace the Fuel Rail Pressure Sensor in accordance with the service information.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

No
• Go To 3

3. CHECK THE (K350) 5-VOLT SUPPLY CIRCUIT FOR A SHORT TO GROUND
1. Disconnect the PCM C1 harness connector.
2. Measure the resistance between ground and the (K350) 5-Volt Supply circuit at the PCM C1 harness connector.
Is the resistance below 10k Ohms?

Yes
• Repair the (K350) 5-Volt Supply circuit for a short to ground.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (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 POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).