Buick Regal: DTC C056E
Diagnostic Instructions
- Perform the Diagnostic System Check prior to using this diagnostic
procedure:Diagnostic System
Check - Vehicle
- Review the description of Strategy Based Diagnosis:Strategy Based
Diagnosis
- An overview of each diagnostic category can be found here:Diagnostic
Procedure Instructions
DTC Descriptor
DTC C056E 4B
Electronic Control Unit Software - Calibration Not Learned
Symptom Byte Information: Symptom Byte List
Circuit/System Description
For an overview of the component/system, refer to:Electronic Parking Brake
Description
Conditions for Running the DTC
Ignition = On
Conditions for Setting the DTC
- K17 Electronic Brake Control Module = Missing Calibration - Electric
Park Brake (J71)
Actions Taken When the DTC Sets
Electric Park Brake = DegradedorDisabled
Conditions for Clearing the DTC
K17 Electronic Brake Control Module = Calibrated - Electric Park Brake (J71)
Reference Information
Schematic Reference
Park Brake System Wiring Schematics
Connector End View Reference
COMPONENT CONNECTOR END VIEW INDEX
Master Electrical Component List
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References
Circuit/System Verification
DTC C056E 4B
1. Ignition - On / Vehicle - In Service Mode
2. Verify DTC C056E 4B is not set.
- Perform the necessary programming and setup procedure: K17 Electronic
Brake Control
Module - Step 4
- Verify the DTC does not set.
- If the DTC sets - Replace the component: K17 Electronic Brake
Control Module
- Go to next step: If the DTC is not set
- All OK.
- Go to next step: If the DTC is not set
3. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair:
Diagnostic Repair Verification
For control module replacement, programming, and setup refer to: Control
Module References
DTC C1138
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
- Diagnostic Procedure Instructions provides an overview of each
diagnostic category.
DTC Descriptors
DTC C1138 03
Supply Voltage Goes Below 7 V
DTC C1138 07
Supply Voltage Goes Above 16.5 V
DTC C1138 58
Signal Performance
Diagnostic Fault Information
Circuit/System Description
The Electronic Brake Control Module monitors its supply voltage to verify the
supply voltage is within
the normal operating range
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
DTC C1138 03
The EBCM detects its supply voltage of less than approximately 7 V.
DTC C1138 07
The EBCM detects a supply voltage of more than 16.5 V.
DTC C1138 58
The Park Brake Controller (PBC) loses communication with the EBCM during park
brake actuation.
Action Taken When the DTC Sets
- DTC is stored in memory.
- Park brake actuation unavailable.
Conditions for Clearing the DTC
The supply voltage returns to normal operating range.
Diagnostic Aids
- A high or low voltage DTC set or voltage value in multiple
modules/sensors indicates a concern in
the charging system.
- A possible cause of this DTC could be overcharging with a battery
charger or jump starting.
Reference Information
Schematic Reference
Park Brake System Wiring Schematics
Connector End View Reference
COMPONENT CONNECTOR END VIEW INDEX
Description and Operation
Electronic Parking Brake Description
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Verify that no other DTCs are set.
- If any other DTCs are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle.
- Go to next step: If no other DTCs are set
2. Vehicle OFF, measure and record the battery voltage at the battery
terminals.
3. Verify the battery voltage stabilizes between 12.4 V and 12.8 V within a few
minutes of turning
the vehicle OFF.
- If battery voltage is less than 12.4 V or more than 12.8 V
Refer to Battery Inspection/Test.
- Go to next step: If battery voltage is between 12.4 and 12.8 V
4. Engine running, headlights ON, measure and record the battery voltage at
the battery terminals.
5. Verify the voltage is at least 1 V greater than the voltage measured in step
1, but less than 15 V.
- If the voltage is not at least 1 V greater than the voltage measured
in step 2 or is
greater than 15 V.
Refer to Charging System Test.
- Go to next step: If the voltage is at least 1 V greater than the
voltage measured in step
2, but less than 15 V
6. Verify the K17 Electronic Brake Control Module scan tool ignition voltage
parameter is within 1
V of the battery voltage.
- If not within 1 V of the battery voltage
Refer to Circuit/System Testing.
- Go to next step: If within 1 V of the battery voltage
7. All OK.
Circuit/System Testing
NOTE:
- You must perform the Circuit/System Verification before
Circuit/System Testing.
- Some control module ground circuits may require up to 20 min after
the ignition is turned off before achieving a resistance reading of
less than 5 Ω. In most cases the readings will drop below 20 Ω
within 1 min indicating the control module is going to sleep.
DTC C1138 03 or DTC C1138 07
1. Ignition OFF and all vehicle systems OFF, disconnect the X1 harness
connector at the K17
Electronic Brake Control Module. It may take up to 2 min for all vehicle systems
to power down.
2. Test for less than 10 Ω between ground circuit terminal 46 and ground.
- Ignition OFF.
- Test for less than 2 Ω in the ground circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, repair the open/high resistance in the ground
connection.
- Go to next step: If less than 10 Ω
3. Verify a test lamp illuminates between B+ circuit terminal 1 and ground.
- If the test lamp does not illuminate and the circuit fuse is good
- Ignition OFF.
- Test for less than 2 Ω in the B+ circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, verify the fuse is not open and there is voltage
at the fuse.
- If the test lamp does not illuminate and the circuit fuse is open
- Ignition OFF.
- Test for infinite resistance between the B+ 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.
- Go to next step: If the test lamp illuminates
4. Replace the K17 Electronic Brake Control Module.
DTC C1138 58
1. Verify that no other DTCs are set.
- If any other DTCs are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle.
- Go to next step: If no other DTCs are set
2. Using the S91 Park Brake Control Switch, apply and release the park brake.
3. Verify that the DTC does not reset.
Replace the K17 Electronic Brake Control Module.
- Go to next step: If the DTC does not reset
4. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Control Module References for control module replacement, programming and setup.
READ NEXT:
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
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CAUTION: Refer to Fastener Caution.
NOTE: In the event that a bolt breaks upon removal of components, perform
an extraction of the broken bolt.
Tighten 14 N.m (10 lb ft)
Turbocharger Heat Shield
TURBOCHARGER REPLACEMENT
Removal Procedure
CAUTION: If a tur
Diagnostic Instructions
Perform the Diagnostic System Check prior to using this diagnostic
procedure: Refer to Diagnostic System
Check - Vehicle
Review the description of Strategy Based Diagnosis:Strategy Based
Diagnosis
An overview of each diagnostic category can be found here: Refer to