P04C8
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 Systems Schematics
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
1. Vehicle in Service Mode.
2. Verify the operation of the fuel filler door when commanding the fuel door lock actuator to UNLATCH by pressing the refuel request switch.
• If the fuel door lock actuator does not UNLATCH
Refer to Circuit/System Testing
• If the fuel door lock actuator does UNLATCH
3. All OK.
Circuit/System Testing
1. Vehicle OFF, disconnect the harness connector at the S117 refuel request switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 70 ohms between the low reference circuit terminal 6 and ground.
• If 70 ohms or greater
1. Disconnect the harness connector at the K114B hybrid powertrain control module 2
2. Test for less than 2 ohms in the low reference circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K114B hybrid powertrain control module 2.
• If less than 70 ohms
3. Vehicle in Service Mode, test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground.
• If less than 4.8 V
1. Vehicle OFF, disconnect the harness connector at the K114B hybrid powertrain control module 2.
2. Test for infinite resistance between the 5 V reference circuit and ground
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the 5 V reference circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K114B hybrid powertrain control module 2.
• If greater than 5.2 V
1. Vehicle OFF, disconnect the harness connector at the K114B hybrid powertrain control module 2, Vehicle in Service Mode.
2. Test for less than 1 V between the 5 V reference circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K114B hybrid powertrain control module 2.
• If between 4.8-5.2 V
4. 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