Gasoline Without LY6
DTC C0880, C0890, C1115, C1116, C1117, or C1118 (Gasoline Without LY6)
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 C0880 00
- Device Voltage Reference Output 2 Circuit
DTC C0890 00
- Device Voltage Reference Output 3 Circuit
DTC C1115 08
- Manual Trailer Brake Apply Request Switch Signal Invalid
DTC C1115 5A
- Manual Trailer Brake Apply Request Switch Signal Plausibility Failure
DTC C1116 00
- Manual Trailer Brake Apply Request Signal 1
DTC C1117 00
- Manual Trailer Brake Apply Request Signal 2
DTC C1118 00
- Trailer Brake Control Sensitivity Switch Circuit
DTC C1118 08
- Trailer Brake Control Sensitivity Switch Circuit Signal Invalid
Diagnostic Fault Information
Circuit/System Description
The fuel pump/trailer brake control module system has a control panel with the trailer gain and manual apply switches. The switches are located on the instrument panel to the left of the steering column. The control panel and switches allows you to adjust the amount of output, referred to as trailer gain, available to the electric trailer brakes and allows you to manually apply the trailer brakes. The Trailer Brake Control Panel, and switches are used along with the Trailer Brake Display Page on the Driver Information Center to adjust and display power output to the trailer brakes.
Conditions for Running the DTC
* Battery voltage is 9.5-17 V.
* The module is powered up and completes initialization.
Conditions for Setting the DTC
C0880 00 or C0890 00
The fuel pump/trailer brake control module detects the 5 V reference circuit voltage is less than 4.8 V or greater than 5.2 V.
C1115 08 or C1115 5A
* The fuel pump/trailer brake control module detects the manual apply switch is applied before the ignition is cycled OFF, and continuously applied for 30 seconds after ignition is cycled to ON.
* The fuel pump/trailer brake control module detects the manual apply switch is applied continuously for 5 minutes.
* The fault is detected if the manual apply switch input and redundant apply switch input exceeds a threshold for an extended amount of time.
C1116 00
* The fuel pump/trailer brake control module detects a short to ground, open or a short to voltage on the manual apply signal circuit.
* The fuel pump/trailer brake control module detects a open on the low reference circuit.
C1117 00
* The fuel pump/trailer brake control module detects a short to ground, open or a short to voltage on the redundant manual apply signal circuit.
* The fuel pump/trailer brake control module detects a short to voltage on the manual apply signal circuit.
* The fuel pump/trailer brake control module detects a open on the low reference circuit.
C1118 00
* The fuel pump/trailer brake control module detects a short to ground, open or a short to voltage on the user gain signal circuit.
* The fuel pump/trailer brake control module detects a open on the low reference circuit.
C1118 08
* The fuel pump/trailer brake control module detects the user gain switch is applied before the ignition is cycled OFF, and continuously applied for 30 seconds after ignition is cycled to ON.
* The fuel pump/trailer brake control module detects the user gain switch is applied continuously for 5 minutes.
Action Taken When the DTC Sets
* The trailer brake control will be disabled for the remainder of the ignition cycle.
* The driver information center (DIC) will display Service Trailer Brake System.
Condition for Clearing the DTC
* The condition for the DTC is no longer present.
* The fuel pump/trailer brake control module clears the history DTC when a current DTC is not detected in 40 consecutive drive cycles.
Reference Information
Schematic Reference
Trailer Brake Control Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Trailer Brake Controls Description and Operation (Trailer Brake Controls)
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 (Control Module References)for scan tool information
Circuit/System Verification
Ignition ON, observe the scan tool trailer brake controls user gain parameter. The reading should be between 0-100 percent, and change with operating the gain switch up or gain switch down.
Circuit/System Testing
Note: These diagnostics are based on having no trailer connected.
1. Ignition ON, verify that DTC P2534 is not set.
• If the DTC is set, refer to DTC P2534 (Wiring Systems and Power Management).
2. Ignition OFF, disconnect the harness connector at the trailer brake controller switch.
3. Test for less than 5 ohm between the low reference circuit terminal 8 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the fuel pump/trailer brake control module.
4. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground.
• If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the fuel pump/trailer brake control module.
• If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the fuel pump/trailer brake control module.
5. Verify the scan tool Manual Apply Switch parameter is less than 5 percent.
• If greater than the specified range, test the signal circuit terminal 4 for a short to voltage. If the circuit tests normal, replace the fuel pump/trailer brake control module.
6. Install a 3 A fused jumper wire between the signal circuit terminal 4 and the 5 V reference circuit terminal 3. Verify the scan tool Manual Apply Switch parameter is greater than 90 percent.
• 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 fuel pump/trailer brake control module.
7. Verify the scan tool Redundant Manual Apply Switch parameter is greater than 90 percent.
• If less than the specified range, test the signal circuit terminal 5 for a short to voltage. If the circuit tests normal, replace the fuel pump/trailer brake control module.
8. Install a 3 A fused jumper wire between the signal circuit terminal 5 and the 5 V reference circuit terminal 3. Verify the scan tool Redundant Manual Apply Switch parameter is less than 2 percent.
• If greater 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 fuel pump/trailer brake control module.
9. Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 6 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 fuel pump/trailer brake control module.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the fuel pump/trailer brake control module.
10. If all circuits test normal, test or replace the trailer brake controller switch panel.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Trailer Brake Control Switch Replacement (Trailer Brake Control Switch Replacement)
* Control Module References (Control Module References)for fuel pump/trailer brake control module replacement, setup, and programming