P1703 is a manufacturer-specific OBD-II diagnostic trouble code. Its exact definition depends on the vehicle application, most commonly indicating that the brake switch failed its self-test on Ford and Mazda vehicles.
The exact application must be verified before diagnosis. The code indicates the control module did not detect the expected brake pedal state change during testing, but physical inspection is required to identify the root cause.
Quick Navigation
Key Takeaways
- P1703 is a manufacturer-specific code, meaning its exact definition varies by automaker and vehicle application.
- On Ford and Mazda applications, it indicates the Brake On/Off (BOO) switch did not cycle correctly during the onboard self-test.
- Possible causes include a misadjusted brake switch, damaged wiring, or a failing switch mechanism.
- Diagnosis requires verifying the exact factory definition and testing the brake switch circuit and pedal adjustment.
P1703 Code Description and Implications
P1703 is a manufacturer-specific powertrain code. Because the second digit is “1”, the definition is controlled by the automaker rather than the SAE standardized list.
Some Ford and Mazda applications: P1703 indicates that the Brake On/Off (BOO) switch is out of its self-test range. During a self-test, the control module requires the brake pedal to be applied and released.
If the switch state does not change as expected, this fault code is set. Because this is a manufacturer-specific code, the exact definition and diagnostic steps vary by automaker.
Common Causes of the P1703 Code
Possible causes depend entirely on the specific vehicle application.
For Ford and Mazda applications, an improperly adjusted brake light switch is a frequent culprit, preventing the switch from triggering when the pedal is pressed.
Damaged wiring, corroded connectors, or a failed brake switch mechanism can also prevent the correct signal from reaching the powertrain control module.
In some cases, a blown brake light fuse or burned-out bulbs can affect the circuit feedback on certain older systems.
Symptoms Associated With P1703
The primary symptom is an illuminated check engine light, often accompanied by a failure to pass an onboard emissions self-test.
Drivers may notice that the cruise control will not engage or set, as the system requires a valid brake switch signal to operate safely.
In some applications, the shift interlock may prevent the vehicle from being shifted out of park, or the brake lights may remain on or fail to illuminate.
Diagnosing the P1703 Trouble Code
Diagnosis must begin by confirming the exact factory definition for the specific make, model, and year.
Technicians inspect the brake light switch adjustment and verify that the brake lights illuminate and extinguish correctly when the pedal is pressed and released.
The switch circuit is tested for proper voltage and ground, and live data is monitored to ensure the control module accurately registers the brake pedal state changes.
Repairing the P1703 Issue
Repairs follow the confirmed diagnosis for the specific application.
If the brake switch is misadjusted, repositioning and securing the switch to the correct pedal clearance resolves the issue.
If the wiring is damaged or the switch mechanism has failed internally, replacing the confirmed failed component restores proper circuit operation.
Cost Considerations for P1703 Repairs
Repair costs vary depending on the underlying fault and the vehicle application.
Adjusting a brake switch or replacing a blown fuse involves minimal parts and labor costs.
If the repair requires replacing the brake switch assembly or repairing a damaged wiring harness, labor and parts costs increase slightly.
Cost depends on diagnostic time, component accessibility, required parts, programming requirements, and labor.
Prevention Strategies for Future Occurrences
Ensuring the brake pedal assembly and switch are not disturbed during unrelated under-dash repairs helps prevent misadjustment.
Keeping the brake light bulbs in good working order ensures the circuit operates within its designed parameters on applications where bulb feedback is monitored.
Troubleshooting Tips and Best Practices
Never assume a manufacturer-specific code has a universal meaning. Always verify the exact factory service information for your specific vehicle.
Do not replace the powertrain control module without first verifying the brake switch adjustment, wiring, and pedal mechanics.
If P1703 is accompanied by cruise control or shift interlock issues, suspect a shared brake switch circuit fault rather than multiple simultaneous module failures.
More OBD-II Codes
| P1692 | P1693 | P1694 | P1695 |
| P1700 | P1702 | P1704 | P1705 |
| P1706 | P1707 | P1708 | P1709 |
| P0504 | P0571 | P0572 | P0703 |
| P1711 | P1712 | P1713 | P1714 |
| P1715 | P1716 | P1717 | P1718 |
Frequently Asked Questions
Is P1703 a generic OBD-II code?
No. P1703 is a manufacturer-specific code, meaning its exact definition and diagnostic procedure depend entirely on the vehicle’s make, model, and application.
Can I drive my vehicle with a P1703 code?
It depends on the application. While the engine may run normally, safety features like cruise control or the shift interlock may be disabled until repaired.
Will a P1703 code disable cruise control?
Yes. On applications where P1703 indicates a brake switch self-test failure, the control module often disables the cruise control to prevent unsafe operation.
Does P1703 always mean the brake switch is broken?
No. The code often points to a misadjusted switch, damaged wiring, or a blown fuse rather than a mechanically failed brake switch component.
How do I clear a manufacturer-specific P1703 code?
Clearing the code requires fixing the underlying circuit or adjustment fault and successfully completing the self-test. Simply erasing the code will not repair the root cause.
What Should You Do About the P1703 Code?
Confirm the exact factory definition for your specific vehicle, then follow the applicable manufacturer diagnostic procedure for the relevant system and components.
Because P1703 is manufacturer-specific, testing the exact brake switch circuits, pedal adjustments, or wiring identified by the factory service information is required to find the root cause.
Once the fault is confirmed, perform the necessary repairs and verify the fix by clearing the codes and completing a test drive.
