C0848
DTC C0847, C0848, C1240, or C1241
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 C0847 00
- Device Ignition 1 Circuit Low
DTC C0848 00
- Device Ignition 1 Circuit High
DTC C1240 00
- Electronic Brake Control Module Ignition On/Start Switch Circuit Low Voltage
DTC C1241 00
- Electronic Brake Control Module Ignition On/Start Switch Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
The body control module (BCM) controls the ignition relay through the control circuit by applying voltage to the circuit. The ignition circuit is energized when the vehicle power mode is Vehicle ON or Vehicle in Service Mode. The hybrid powertrain control module 2 sends the Vehicle ON or Vehicle in Service Mode power mode status in a serial data message to the electronic brake control module.
Conditions for Running the DTC
C0847 00, C1240 00
* Hybrid powertrain control module 2 is awake.
* System voltage between 9 and 16 V.
* Vehicle power mode is Vehicle ON or Vehicle in Service Mode.
* The DTC can only run when the output is activated.
C0848 00, C1241 00
* Hybrid powertrain control module 2 is awake.
* System voltage between 9 and 16 V.
* Vehicle power mode is Vehicle OFF.
Conditions for Setting the DTC
C0847 00, C1240 00
* Hybrid powertrain control module 2 is awake.
* Ignition output is active and a short to ground or open circuit is detected for greater than 5 seconds.
C0848 00, C1241 00
* Hybrid powertrain control module 2 is awake.
* Ignition output is not active and a short to battery is detected for greater than 5 seconds.
Action Taken When the DTC Sets
No action is taken.
Conditions for Clearing the DTC
* The current DTC will clear when the malfunction is no longer present during a DTC check.
* A history DTC clears when the module power mode cycle counter reaches the reset threshold of 40, without a repeat of the malfunction.
Diagnostic Aids
A short to voltage in the ignition circuit will keep the vehicle modules awake, which can drain the vehicle's battery.
Reference Information
Schematic Reference
Power Distribution Schematics Power Distribution Schematics
Connector End View Reference
Component Connector End Views Hybrid/EV Battery Pack X1
Description and Operation
Power Mode Description and Operation Power Mode
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. Verify DTC B144B is not set.
• If the DTC is set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
• If the DTC is not set
2. Refer to Circuit/System Testing.
Circuit/System Testing
1. Vehicle OFF, disconnect the harness connector at the K17 electronic brake control module.
2. Verify that a test lamp does not illuminate between the ignition circuit terminal 14 and ground.
• If the test lamp illuminates
Repair the short to voltage on the ignition circuit.
• If the test lamp does not illuminate
3. Vehicle in Service Mode
4. Verify a test lamp illuminates between the ignition circuit terminal 14 and ground.
• If the test lamp does not illuminate and the circuit fuse is OK
1. Vehicle OFF.
2. Test for less than 2 ohms in the ignition circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, verify the fuse is OK and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open
1. Vehicle OFF.
2. Test for infinite resistance between the ignition circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K17 electronic brake control module.
• If the test lamp illuminates
5. Refer to Power Mode Mismatch Power Mode Mismatch.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
See Control Module References Programming and Relearning for electronic brake control module replacement, programming and setup