P04B8

DTC P04B8-P04BA or P04DC

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors
DTC P04B8 00
- Fuel Fill Door Position Sensor Circuit

DTC P04B9 00
- Fuel Fill Door Position Sensor Circuit Low Voltage

DTC P04BA 00
- Fuel Fill Door Position Sensor Circuit High Voltage

Diagnostic Fault Information






Circuit/System Description

The hybrid powertrain control module 2 provides a 5V signal through a pull-up resistor to the Fuel Door Position Sensor Circuit. The other end of the Fuel Door Position Sensor Circuit is connected to the Fuel Door Position Sensor in the Fuel Door Status Switch Assembly. The hybrid powertrain control module 2 monitors the voltage on the Fuel Door Position Sensor Circuit. In normal operation, when the Fuel Door moves to the open position, the switch in the Fuel Door Lock Position closes and lowers the voltage on the Fuel Door Lock Position Sensor Circuit.

Conditions for Running the DTC

Hybrid Powertrain Control Module 2 is awake.

Conditions for Setting the DTC

P04B8 00

The hybrid powertrain control module 2 detects the fuel door position signal circuit voltage is mid range between expected high and low voltage values.

P04B9 00

The hybrid powertrain control module 2 detects a short to ground in the fuel door open signal circuit.

P04BA 00

The hybrid powertrain control module 2 detects a short to voltage or an open or high resistance in the fuel door open signal circuit.

Action Taken When the DTC Sets

The driver information center will continuously display the Wait To Refuel message after the refuel request switch is pressed.

Conditions for Clearing the DTC

DTC P04B8 00, P04B9 00 and P04BA 00 are type B DTCs

Reference Information
Schematic Reference

Release Systems Schematics (Release) Release Systems Schematics (Release)Release Systems Schematics (Liftgate) Release Systems Schematics (Liftgate)
Connector End View Reference

Component Connector End Views Hybrid/EV Battery Pack X1
Description and Operation

Fuel Fill Door Description and Operation Fuel Fill Door
Electrical Information Reference

* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Programming and Relearning for scan tool information

Circuit/System Verification

Vehicle in Service Mode, transmission selector in Park, observe the scan tool Fuel Door Position parameter while opening and closing the fuel filler door, the value should change between Open and Closed.

Circuit/System Testing

1. Vehicle OFF, disconnect the harness connector at the B208 fuel door status switch assembly.
2. Test for less than 10 ohm between the ground circuit terminal 2 and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance.

3. Vehicle in Service Mode, test for 4.75-5.25 V between the signal circuit terminal 1 and ground.

• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K114B hybrid powertrain control module 2.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K114B hybrid powertrain control module 2.

4. If all circuits test normal, test or replace the B208 fuel door status switch assembly.

Component Testing

1. Vehicle OFF, disconnect the harness connector at the B208 fuel door status switch assembly.
2. Test for 180 ohm-190 ohm between the signal terminal 1 and the ground terminal 2 with the switch in the open position.

• If not within the specified range, replace the B208 fuel door status switch assembly.

3. Test for 2040 ohm-2065 ohm between the signal terminal 1 and the ground terminal 2 with the switch in the closed position.

• If not within the specified range, replace the B208 fuel door status switch assembly.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

Control Module References Programming and Relearning for the hybrid powertrain control module 2 replacement, programming and setup