C0241
DTC C0241
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provides an overview of each diagnostic category.
DTC Descriptors
DTC C0241 00
- Powertrain Control Module (PCM) Indicated Request Torque Malfunction
Diagnostic Fault Information
Circuit Description
The EBCM and the powertrain control module PCM or engine control module ECM simultaneously control the traction control. The EBCM sends a Requested Torque message via pulse width modulated (PWM) signal to the PCM or ECM to deliver. Normal values are between 10 and 90 percent duty cycle. The signal should be at least 90 percent when traction control is not active and at lower values during traction control activations. The PCM or ECM supplies the pull up voltage that the EBCM switches to ground to create the signal.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The PCM/ECM diagnoses the requested torque PWM signal circuit and sends a class 2 serial data message to the EBCM indicating a fault is present. A fault exists in the circuit if the PCM/ECM detects one of the following conditions:
* The requested torque PWM signal is less than 5 percent duty cycle or greater than 95 percent duty cycle.
* The requested torque PWM signal is not present for 10 seconds.
Action Taken When the DTC Sets
If equipped, the following actions occur:
* The EBCM disables the ABS/TCS/VSES/DRP for the duration of the ignition cycle.
* A malfunction DTC will set.
* The ABS indicator turns ON.
* The Stability Off indicator turns ON.
* The Antilock Brake System (ABS) remains functional.
Conditions for Clearing the DTC
* The condition for the DTC is no longer present.
* The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
Diagnostic Aids
* Check both the EBCM, PCM, and ECM grounds, ensuring that each ground is clean and torqued to the proper specification.
* Disconnecting the EBCM connector and turning ON ignition could cause other modules to set loss of communication DTCs (Uxxxx). Once the EBCM is reconnected, the EBCM may set DTC C0241.
* This vehicle is equipped with a PCM or ECM which is electrically erasable programmable read only memory (EEPROM). When replacing the PCM or ECM, the replacement PCM or ECM must be programmed.
Reference Information
Schematic Reference
Antilock Brake System Schematics ([1][2]Antilock Brakes / Traction Control Systems)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
ABS Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning)for Scan Tool Information
Circuit/System Verification
Engine ON, verify the scan tool Torque Request signal parameter in the PCM or ECM data list.
The specified value should be less than 100 percent.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the EBCM connector C1 terminal 13 or 14.
2. Test for less than 1.0 ohm of resistance between the ground circuit connector C1 terminal 16 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between the B+ circuit of the EBCM supply voltage terminal connector C1 terminal 13 or 14 and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse (ABS MTR 40-amp) or (ABS SOL 25-amp) or (ABS 10-amp) in the fuse block underhood BEC is open, test all components connected to the B+ circuit and replace as necessary.
4. Engine ON, measure the DC Hz for 121-134 Hz between the PCM or ECM requested torque signal circuit connector C3 terminal 40(L26 - 3.8L) or 17(LS4 - 5.3L) and a good ground.
• If the value is below the specified range, test the PCM or ECM requested torque signal circuit for an open/high resistance. If the circuit tests normal replace the PCM or ECM.
• If the value is above the specified range, test the PCM or ECM requested torque signal circuit for an short to voltage. If the circuit tests normal replace the PCM/ECM.
5. Connect a DMM between the requested torque signal circuit connector C3 terminal 40(L26 - 3.8L) or 17(LS4 - 5.3L) of the PCM or ECM and a good ground.
6. Test the requested torque signal circuit for 4-6 volts.
• If the voltage is below the specified range, test the requested torque circuit for a short to ground, or open/high resistance. If the circuit tests normal, replace the EBCM.
• If the voltage is above the specified range, test the requested torque circuit for a short to voltage. If the circuit tests normal, replace EBCM.
7. If all circuits test normal, replace the EBCM.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning) for EBCM, PCM, or ECM replacement, setup, or programming