P04CB

DTC P04C8, P04CA, or P04CB

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 P04C8 00
- Fuel Fill Door Open Request Switch Circuit

DTC P04CA 00
- Fuel Fill Door Open Request Switch Circuit Low Voltage

DTC P04CB 00
- Fuel Fill Door Open Request Switch Circuit High Voltage

Diagnostic Fault Information






Circuit/System Description

The hybrid powertrain control module 2 monitors the voltage values of the fuel fill door open request wake-up signal circuit and the fuel door request signal circuit. When the refuel request switch is pressed, the two switch contacts close. This provide B+ to the Wake-up Circuit input of the hybrid powertrain control module 2 and lowers the voltage on the fuel door request signal circuit input to the hybrid powertrain control module 2. The hybrid powertrain control module 2 detects the voltage on the signal circuits and commands the fuel system to vent and sends a serial data message to the driver information center to display the Wait to Refuel message. The hybrid powertrain control module 2 then energizes the fuel door lock/unlock actuator to unlock the fuel door.

Conditions for Running the DTC

The hybrid powertrain control module 2 is awake

Conditions for Setting the DTC

P04C8 00

The hybrid powertrain control module 2 the fuel fill door open request switch circuit voltage is mid-range between expected high and low voltage values.

P04CA 00

The hybrid powertrain control module 2 detects a short to ground in the refuel request signal circuit.

P04CB 00

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

Action Taken When the DTC Sets

The refuel request switch will still function normally.

Conditions for Clearing the DTC

DTC P04C8 00, P04CA 00 and P04CB 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, command the fuel filler door to UNLOCK by pressing the S117 refuel request switch, the M97 fuel door lock actuator should UNLOCK allowing the fuel filler door to open.

Circuit/System Testing

1. Vehicle OFF, disconnect the harness connector at the S117 refuel request switch.
2. Test for less than 70 ohm between the low reference circuit terminal 6 and ground.

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

3. Vehicle in Service Mode, test for 4.75-5.25 V between the signal circuit terminal 3 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 S117 refuel request switch.

Repair Instructions

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

* Fuel Tank Filler Door Lock Release Switch Replacement Fuel Tank Filler Door Lock Release Switch Replacement
* Control Module References Programming and Relearning for the hybrid powertrain control module 2 replacement, programming and setup