DTC P0703:00 [MZR 1.6]

id0102h3706500

DTC P0703:00

Brake switch input circuit problem
DETECTION CONDITION
•  The PCM monitors the input signal from the brake switch. If the input signal does not change while following decelerating 8 times, the PCM determines that there is a brake switch input circuit problem.
MONITORING CONDITIONS
―  Vehicle speed becomes from above 30 km/h {19 mph} to 0 km/h {0 mph}
―  Deceleration rate exceeds 3.8 km/h {2.4 mph} per 0.1 s
Diagnostic support note
•  This is a continuous monitor (CCM).
•  The check engine light illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
•  PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
•  FREEZE FRAME DATA (Mode 2)/Snapshot data is available.
•  DTC is stored in the PCM memory.
POSSIBLE CAUSE
Caution
•  Inspect the brake switch with it installed to the brake pedal, otherwise the brake switch may not operate normally. If the brake switch is removed from the brake pedal, replace the brake switch with a new one.
•  Brake switch connector or terminals malfunction
•  Open circuit or short to ground in brake switch No.1 power supply circuit
―  Short to ground in wiring harness between battery positive terminal and brake switch terminal A
―  MAIN 200 A fuse and/or STOP 10 A fuse malfunction
―  Open circuit in wiring harness between battery positive terminal and brake switch terminal A
•  PCM connector or terminals malfunction
•  Short to ground in wiring harness between brake switch terminal D and PCM terminal 1U
•  Short to power supply in wiring harness between brake switch terminal D and PCM terminal 1U
•  Open circuit in wiring harness between brake switch terminal D and PCM terminal 1U
•  Brake switch No.1 malfunction
•  PCM malfunction

Diagnostic Procedure

STEP

INSPECTION

ACTION
1
VERIFY FREEZE FRAME DATA (MODE 2)/SNAPSHOT DATA HAS BEEN RECORDED
•  Has the FREEZE FRAME DATA (Mode 2)/snapshot data been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA (Mode 2)/snapshot data on repair order, then go to the next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to the available Service Information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3
INSPECT BRAKE SWITCH CONNECTOR CONDITION
•  Switch the ignition 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 or terminals, then go to Step 10.
No
Go to the next step.
4
INSPECT BRAKE SWITCH NO.1 POWER SUPPLY CIRCUIT FOR OPEN CIRCUIT OR SHORT TO GROUND
•  Brake switch connector is disconnected.
•  Measure the voltage at the brake switch terminal A (wiring harness-side).
•  Is the voltage B+?
Yes
Go to the next step.
No
Inspect the MAIN 200 A fuse and STOP 10 A fuse.
•  If the fuse is blown:
―  Refer to the wiring diagram and verify whether or not there is a common connector between battery positive terminal and brake switch terminal A.
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 ground.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
•  Replace the fuse.
•  If the fuse is damaged:
―  Replace the fuse.
•  If all fuses are normal:
―  Refer to the wiring diagram and verify whether or not there is a common connector between battery positive terminal and brake switch terminal A.
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 10.
5
INSPECT PCM CONNECTOR CONDITION
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector or terminals, then go to Step 10.
No
Go to the next step.
6
INSPECT BRAKE SWITCH NO.1 SIGNAL CIRCUIT FOR SHORT TO GROUND
•  Verify that the brake switch and PCM connectors are disconnected.
•  Inspect for continuity between brake switch terminal D (wiring harness-side) and body ground.
•  Is there continuity?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between brake switch terminal D and PCM terminal 1U.
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 ground.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
Go to Step 10.
No
Go to the next step.
7
INSPECT BRAKE SWITCH NO.1 SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY
•  Verify that the brake switch and PCM connectors are disconnected.
•  Switch the ignition ON (engine off).
Note
•  Another DTC may be stored by the PCM detecting an open circuit.
•  Measure the voltage at the brake switch terminal D (wiring harness-side).
•  Is the voltage 0 V?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between brake switch terminal D and PCM terminal 1U.
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 10.
8
INSPECT BRAKE SWITCH NO.1 SIGNAL CIRCUIT FOR OPEN CIRCUIT
•  Verify that the brake switch and PCM connectors are disconnected.
•  Switch the ignition off.
•  Inspect for continuity between brake switch terminal D (wiring harness-side) and PCM terminal 1U (wiring 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 brake switch terminal D and PCM terminal 1U.
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 10.
9
INSPECT BRAKE SWITCH NO.1
•  Inspect the brake switch No.1.
•  Is there any malfunction?
Yes
Replace the brake switch, then go to the next step.
(See BRAKE PEDAL REMOVAL/INSTALLATION [L.H.D.].)
(See BRAKE PEDAL REMOVAL/INSTALLATION [R.H.D.].)
No
Go to the next step.
10
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Always reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
Caution
•  While performing this step, always operate the vehicle in a safe and lawful manner.
•  When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later.
•  Drive the vehicle.
•  Repeat deceleration 8 times under both of the following conditions:
―  Vehicle speed: from above 30 km/h {19 mph} to 30 km/h {19 mph} or less
―  Deceleration rate should exceed 3.8 km/h {2.4 mph} per 0.1 s
•  Perform the Pending Trouble Code Access Procedure.
•  Is the PENDING CODE for this 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.
(See DTC TABLE [MZR 1.6].)
No
DTC troubleshooting completed.