DTC C0023:62/C0040:64/C0040:86 [DYNAMIC STABILITY CONTROL (DSC)]

id0402b2860100

DTC
C0023:62, C0040:64, C0040:86
Brake light/Brake switch
DETECTION CONDITION
•  C0023:62
―  Brake light ON signal is not input even though the brake light reqiest signal is input.
―  Brake light ON signal is input even though the brake light request signal is not input.
―  Brake light ON signal is not input when the brake fluid pressure sensor signal reaches the specified value.
―  Communication error with brake light is detected in CAN communication via RBCM.
•  C0040:64
―  Brake switch ON signal is input for 15 min or more when driving at a vehicle speed of 15 km/h {9.3 mph} or more.
•  C0040:86
―  Communication error with brake switch is detected in CAN communication via PCM.
FAIL-SAFE FUNCTION
•  C0023:62
―  Illuminates the master warning light.
―  Inhibits the Mazda Radar Cruise Control (MRCC), Smart Brake Support (SBS), and Smart City Brake Support (SCBS) controls.
•  C0040:64, C0040:86
―  Illuminates the ABS warning light, TCS/DSC indicator light, and master warning light*1.
―  Tire pressure monitoring system warning light illuminates after flashes*2.
―  Inhibits the ABS, brake assist, TCS, Hill Launch Assist (HLA), vehicle roll prevention function*2, DSC, Mazda Radar Cruise Control (MRCC)*2, Smart Brake Support (SBS)*2, Smart City Brake Support (SCBS)*2, Secondary Collision Reduction (SCR)*2, and TPMS*2 controls.
*1: Vehicles with Smart City Brake Support (SCBS), Mazda Radar Cruise Control (MRCC) and/or Smart Brake Support (SBS).
*2: If equipped.
POSSIBLE CAUSE
•  Open in wiring harness between the DSC HU/CM terminal AF and the ignition switch.
•  Brake switch malfunction
•  Poor connection at connectors (female terminal)
•  Rear Body Control Module (RBCM) malfunction
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
INSPECT POWER SUPPLY (SYSTEM) CIRCUIT
•  Switch the ignition ON (engine off).
•  Measure the voltage at the DSC HU/CM connector terminal AF (vehicle harness side) and body ground.
•  Is the voltage B+?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between ignition switch and DSC HU/CM terminal AF (vehicle harness side).
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a open circuit.
Go to Step 8.
2
VERIFY OPEN OR SHORT CIRCUIT IN BRAKE SWITCH SIGNAL
•  Switch the ignition ON (engine off).
•  Measure the voltage between the PCM connector terminal 2G (SKYACTIV-G 2.0/SKYACTIV-G 2.5)/2AA (SKYACTIV-D 2.2) (vehicle harness-side) and body ground when the brake pedal is depressed and released.
Voltage
Brake pedal depressed: B+
Brake pedal released: 1 V or less
•  Is the voltage normal?
Yes
Go to the Step 8.
No
If it is B+ under any condition, then go to the next step.
If it is 1 V or less under any condition, then go to Step 4.
3
INSPECT BRAKE SWITCH SIGNAL FOR SHORT TO POWER SUPPLY CIRCUIT
•  Disconnect the brake switch connector.
•  Measure voltage between the brake switch connector terminal D (vehicle harness-side) and body ground.
•  Is the voltage 1 V or less?
Yes
Go to Step 5.
No
Refer to the wiring diagram and verify whether or not there is a common connector between PCM connector terminal 2G (SKYACTIV-G 2.0/SKYACTIV-G 2.5)/2AA (SKYACTIV-D 2.2) (vehicle harness-side) and brake switch connector terminal D (vehicle harness side).
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to power supply.
Go to Step 8.
4
INSPECT BRAKE SWITCH SIGNAL FOR OPEN CIRCUIT
•  Disconnect the PCM connectors.
•  Disconnect the brake switch connector.
•  Inspect continuity between the PCM and brake switch as follows.
―  SKYACTIV-G 2.0/SKYACTIV-G 2.5
•  PCM connector terminal 2G (vehicle harness-side) and brake switch connector terminal D (vehicle harness-side)
―  SKYACTIV-D 2.2
•  PCM connector terminal 2AA (vehicle harness-side) and brake switch connector terminal D (vehicle harness-side)
•  Is there continuity?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between PCM connector terminal 2G (SKYACTIV-G 2.0/SKYACTIV-G 2.5)/2AA (SKYACTIV-D 2.2) (vehicle harness-side) and brake switch connector terminal D (vehicle harness side).
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to Step 8.
5
INSPECT BRAKE SWITCH
•  Inspect the brake switch.
•  Is the brake switch normal?
Yes
Go to the next step.
No
Replace the brake switch, then go to Step 8.
(See BRAKE PEDAL REMOVAL/INSTALLATION [L.H.D.].)
(See BRAKE PEDAL REMOVAL/INSTALLATION [R.H.D.].)
6
PERFORM REAR BODY CONTROL MODULE (RBCM) DTC INSPECTION
•  Reconnect all disconnected connectors.
•  Using the M-MDS, perform the DTC inspection for the rear body control module (RBCM).
•  Are any DTCs detected?
Yes
Go to applicable DTC inspection.
(See DTC TABLE [REAR BODY CONTROL MODULE (RBCM)].)
No
Go to the next step.
7
PERFORM PCM DTC INSPECTION
•  Using the M-MDS, perform the DTC inspection for the PCM.
•  Are any DTCs detected?
Yes
Go to applicable DTC inspection.
(See DTC TABLE [SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See DTC TABLE [SKYACTIV-D 2.2])
No
Go to the next step.
8
VERIFY THAT THE SAME DTC IS NOT PRESENT
•  Reconnect all disconnected connectors.
•  Clear the DTCs from the memory.
•  Start the engine and drive the vehicle at 20 km/h {12 mph} or more.
•  Are the same DTCs present?
Yes
Repeat the inspection from Step 1.
No
Go to the next step.
9
VERIFY THAT NO OTHER DTCS ARE PRESENT
•  Are any other DTCs output?
Yes
Go to the applicable DTC inspection.
(See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].)
No
DTC troubleshooting completed.