DTC P0703 [L3]

BME010200700202

DTC P0703

Brake switch input malfunction

DETECTION CONDITION

• The PCM monitors changes in input voltage from brake switch. If the PCM does not detect PCM terminal 1K voltage changes while alternately accelerating and decelerating 10 times, the PCM determines that the neutral 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 or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
• 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
• Poor connection of brake switch connector or PCM connector
• Short to power between brake switch terminal B and PCM connector terminal 1K
• Open harness between brake switch terminal B and PCM connector terminal 1K
• Open harness between battery positive terminal and brake switch terminal A
• 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
CLASSIFY HIGH INPUT OR LOW INPUT
• Connect WDS or equivalent to DLC-2.
• Access BOO PID.
• Verify BOO PID during brake pedal operation.
• Is BOO PID always OFF?
Yes
Go to Next step.
No
Go to Step 10.
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 any malfunction?
Yes
Repair or replace terminal, then go to Step 14.
No
Go to the next step.
5
CLASSIFY BRAKE SWITCH OR CIRCUIT
• Connect the WDS or equivalent to the DLC-2.
• Access BOO PID.
• Connect a jumper wire between brake switch terminal A and B.
• Is BOO PID on?
Yes
Go to the next step.
No
Go to Step 7.
6
INSPECT BRAKE SWITCH
• Perform brake switch inspection.
• Is the brake switch normal?
Yes
Go to Step 14.
No
Replace the brake switch, then go to Step 14.
7
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 circuit, then Go to Step 14.
8
INSPECT PCM CONNECTOR FOR POOR CONNECTION
• Turn the ignition switch off.
• Disconnect the PCM connector.
• Inspect for poor connection (such as damaged/pulled-out terminals, corrosion).
• Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 14.
No
Go to the next step.
9
INSPECT BRAKE SWITCH SIGNAL CIRCUIT FOR OPEN CIRCUIT
• Inspect for continuity between brake switch terminal B and PCM terminal 1K.
• Is there continuity?
Yes
Repair or replace the wiring harness for open circuit, then go to Step 14.
No
Go to Step 14.
10
INSPECT BRAKE SWITCH CONNECTOR FOR POOR CONNECTION
• Turn the ignition switch off.
• Disconnect the brake switch connector.
• Inspect for poor connection (damaged/pulled-out terminals, corrosion, etc.).
• Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 14.
No
Go to the next step.
11
CLASSIFY BRAKE SWITCH OR CIRCUIT
• Connect the WDS or equivalent to the DLC-2.
• Access BOO PID.
• Verify that BOO PID changes from ON to OFF when brake switch connector disconnected.
• Does BOO PID change from ON to OFF?
Yes
Go to the next step.
No
Go to Step 13.
12
INSPECT BRAKE SWITCH
• Perform brake switch inspection.
• Is the brake switch normal?
Yes
Go to Step 14.
No
Replace the brake switch, then go to Step 14.
13
INSPECT BRAKE SWITCH SIGNAL CIRCUIT FOR SHORT TO POWER
• Measure the 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 14.
No
Go to the next step.
14
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 more.
• Depress and release brake pedal more than 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.
15
VERIFY AFTER REPAIR PROCEDURE
• Perform "After Repair Procedure".
• Is there DTC present?
Yes
Go to the applicable DTC inspection.
No
Troubleshooting completed.