DTC P0504:00 [MZ-CD 1.6]


id0102g8155600

DTC P0504:00

Brake switch signal correlation

DETECTION CONDITION
•  The PCM monitors changes in the input signal for the brake switch signal (from instrument cluster). If the PCM detects a condition that either the brake switch signal is on or off for 200 s, the PCM determines that the brake switch signal have a compatibility malfunction.
POSSIBLE CAUSE
•  Communication error between instrument cluster and PCM
•  Brake switch malfunction
•  Open or short circuit in wiring harness between brake switch and ground through brake light
•  Open or short circuit in wiring harness between brake switch terminal D and PCM terminal 1U
•  Open or short circuit in wiring harness between brake switch terminal C and instrument cluster terminal 2N
•  Open circuit in wiring harness between brake switch terminal B and body ground
•  Instrument cluster malfunction
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
•  Has the FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2
VERIFY RELATED REPAIR INFORMATION AVAILABILITY
•  Verify related service repair information availability.
•  Is any related repair information available?
Yes
Perform repair or diagnosis according to the available repair information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3
VERIFY STORED CAN COMMUNICATION DTC IN PCM AND INSTRUMENT CLUSTER
•  Retrieve the PCM and instrument cluster DTC using the M-MDS.
•  Is the CAN communication DTC present?
Yes
Go to the applicable DTC inspection.
No
Go to the next step.
4
INSPECT BRAKE SWITCH CONNECTORS CONDITION
•  Switch the ignition to off.
•  Disconnect the brake switch connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 10.
No
Go to the next step.
5
VERIFY STOP LIGHT OPERATION
•  Verify the stop light operation.
•  Is the stop light turn on and off according to brake pedal conditions?
Yes
Go to Step 8.
No
Stop light is always on
•  Repair or replace for a possible short to power supply between brake switch terminal D and PCM terminal 1U, then go to Step 10.
Stop light is always off, go to the next step.
6
VERIFY STOP FUSE CONDITION
•  Verify the STOP fuse condition.
•  Is the STOP fuse normal?
Yes
Go to the next step.
No
If the fuse is blown:
•  Repair for short to ground in following wiring harness:
―  Between STOP fuse and brake switch
―  Between brake switch terminal D and PCM terminal 1U
•  If the fuse is deterioration:
―  Replace the fuse.
Then go to Step 10.
7
VERIFY WHETHER MALFUNCTION IS BRAKE SWITCH OR OPEN CIRCUIT
•  Inspect the brake switch.
•  Is there any malfunction?
Yes
Replace the brake switch, then go to Step 10.
No
Repair for a possible open circuit between brake switch terminal A and STOP fuse, then go to Step 10.
8
INSPECT BRAKE SWITCH SIGNAL CIRCUIT FOR OPEN
•  Measure the voltage between PCM terminal 1U (wiring harness-side) and body ground.
•  Is the voltage normal?
Yes
Go to the next step.
No
Repair for a possible open circuit between brake switch terminal D and PCM terminal 1U, then go to Step 10.
9
VERIFY WHETHER MALFUNCTION IS INSTRUMENT CLUSTER OR BRAKE SWITCH HARNESSES
•  Measure the voltage between instrument cluster terminal 2N (wiring harness-side) and body ground.
•  Is the voltage normal?
Yes
Replace the instrument cluster, then go to the next step.
(Instrument cluster can not transmit brake switch signal to PCM)
No
Repair for a possible open or short circuit between following, then go to the next step.
•  Brake switch terminal C and instrument cluster terminal 2N
•  Brake switch terminal B and body ground
10
VERIFY THAT DTC P0504:00 TROUBLESHOOTING IS COMPLETED
•  Switch the ignition to ON.
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Run the vehicle under the FREEZE FRAME DATA stored condition.
•  Is the same DTC present?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the PCM.
Go to the next step.
No
Go to the next step.
11
VERIFY AFTER REPAIR PROCEDURE
•  Perform the after repair procedure.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
No
DTC troubleshooting completed.