DTC P0703 [AJ] (VIN: JMZ LW19J7*# 300001-, JM0 LW10J300 300001-301405, JM6 LW10J300 300001-, JM8 LW28J**# 300001-301513)

BME010200700201

DTC P0703

Brake switch input malfunction

DETECTION CONDITION

• The PCM monitors changes in input voltage from the brake switch. If PCM does not detect PCM terminal 92 voltage changes while alternately accelerating and decelerating 10 times, it determines that brake switch circuit has malfunction.
Diagnostic support note
• This is a continuous monitor (CCM).
• MIL illuminates if PCM detects the above malfunction condition in two consecutive drive cycles.
• PENDING CODE is available if PCM detects the above malfunction condition during first drive cycle.
• FREEZE FRAME DATA is available.
• DTC is stored in PCM memory.

POSSIBLE CAUSE

• Brake switch malfunction
• Open harness between brake switch terminal B and PCM connector terminal 92.
• PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
• Has FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record FREEZE FRAME DATA on repair order, then go to the next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
• Check for related Service Information availability.
• Is any related Service Information available?
Yes
Perform repair or diagnosis according to available Service Information.
• If vehicle is not repaired, go to the next step.
No
Go to the next step.
3
INSPECT BRAKE SWITCH SIGNAL CIRCUIT FOR SHORT TO POWER
• Measure voltage between brake switch connector terminal B and body ground.
• Is the voltage B+?
Yes
Repair or replace the wiring harness for short to power supply, then go to Step 9.
No
Go to Next step.
4
INSPECT BRAKE SWITCH CONNECTOR FOR POOR CONNECTION
• Turn the ignition switch off.
• Disconnect brake switch connector.
• Inspect for poor connection (such as damaged/pulled-out terminals, corrosion).
• Is there malfunction?
Yes
Repair or replace the terminal, then go to Step 9.
No
Go to the next step.
5
INSPECT BRAKE SWITCH POWER CIRCUIT FOR OPEN CIRCUIT
• Measure the voltage between brake switch connector terminal A and body ground.
• Is the voltage B+?
Yes
Go to the next step.
No
Repair or replace brake switch power circuit for open, then Go to Step 9.
6
INSPECT PCM CONNECTOR FOR POOR CONNECTION
• Turn the ignition switch to OFF.
• Disconnect PCM connector.
• Inspect for poor connection (such as damaged/pulled-out terminals, corrosion).
• Is there any malfunction?
Yes
Repair the terminal, then go to Step 9.
No
Go to the next step.
7
INSPECT BRAKE SWITCH SIGNAL CIRCUIT FOR OPEN CIRCUIT
• Disconnect the PCM connector.
• Connect brake switch connector.
• Turn the ignition switch to ON (engine OFF).
• Depress brake pedal and measure voltage between PCM terminal 92 and body ground.
• Is the voltage B+?
Yes
Go to the next step.
No
Repair or replace the wiring harness for open circuit, then go to Step 9.
8
INSPECT BRAKE SWITCH
• Perform brake switch inspection.
• Is brake switch normal?
Yes
Go to the next step.
No
Replace brake switch, then go to the next step.
9
VERIFY TROUBLESHOOTING OF DTC P0703 COMPLETED
• Make sure to reconnect all disconnected connectors.
• Clear the DTC from the PCM memory using the WDS or equivalent.
• Drive vehicle 30 km/h {18.6 mph} or above.
• Depress and release brake pedal above 10 times while driving vehicle.
• Is the PENDING CODE of same DTC present?
Yes
Replace the PCM, then go to the next step.
No
Go to the next step.
10
VERIFY AFTER REPAIR PROCEDURE
• Perform "After Repair Procedure".
• Is there any DTC present?
Yes
Go to the applicable DTC inspection.
No
Troubleshooting completed.