P1703 Code: Complete DIY Repair Guide

The P1703 diagnostic trouble code (DTC) is a manufacturer-specific code related to the brake system and its communication with the vehicle’s powertrain control module (PCM). This code typically indicates an issue with the brake pedal position switch or its circuit during the key-on, engine-off (KOEO) self-test procedure.

Understanding the P1703 Code

The P1703 code is primarily associated with Ford vehicles, but it can also appear in other makes such as Hyundai and Suzuki. This code is set when the PCM detects an issue with the brake pedal position switch during the self-test procedure, which occurs when the key is turned to the “on” position without starting the engine.

Symptoms of P1703 Code

When the P1703 code is present, you may experience the following symptoms:

1. Illuminated Check Engine Light (CEL)
2. Difficulty starting the vehicle
3. Transmission shifting issues
4. Cruise control malfunction
5. Traction control system problems
6. Brake lights staying on or not working

It’s important to note that in some cases, there may be no noticeable symptoms other than the CEL illumination.

Technical Explanation

The brake pedal position switch is a crucial component in modern vehicles, as it provides input to various systems including the engine management, transmission control, and safety features like traction control and cruise control. During the KOEO self-test, the PCM expects to receive a specific signal from the brake switch. If this signal is outside the expected range or not received at all, the P1703 code is triggered.

Diagnosing the P1703 Code

To properly diagnose the P1703 code, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port and retrieve all stored codes and freeze frame data.
2. Clear the codes and perform a road test to see if the P1703 code returns.
3. If the code returns, inspect the brake pedal position switch and its wiring for any visible damage or corrosion.
4. Check the brake light fuse and replace it if blown.
5. Use a multimeter to test the continuity of the brake switch circuit.
6. Verify the proper adjustment of the brake pedal position switch.
7. If all physical components check out, consider updating the PCM software if applicable.

Warning: Always follow proper safety procedures when working on vehicle electrical systems. Disconnect the battery before performing any wiring repairs.

Solutions for P1703 Code

Depending on the root cause identified during diagnosis, here are some potential solutions:

1. Replacing the Brake Pedal Position Switch

If the switch is found to be faulty, replacement is necessary. This is often the most common fix for the P1703 code.

Step-by-step replacement:

1. Locate the brake pedal position switch near the brake pedal assembly.
2. Disconnect the electrical connector from the switch.
3. Remove the mounting hardware and extract the old switch.
4. Install the new switch, ensuring proper alignment with the brake pedal.
5. Reconnect the electrical connector and secure all mounting hardware.
6. Test the brake lights and clear the code to verify the fix.

Estimated cost: $50 to $150 for parts, plus labor if not done DIY.

2. Repairing Wiring Issues

If damaged or corroded wiring is found, repairs will be necessary.

Repair process:

1. Identify the damaged section of wiring.
2. Cut out the damaged portion and strip the wire ends.
3. Use appropriate gauge wire and connectors to splice in a new section.
4. Solder the connections and use heat shrink tubing for insulation.
5. Secure the repaired wiring with zip ties or electrical tape.

Estimated cost: $20 to $50 for materials if done DIY, significantly more if professional repair is required.

3. Adjusting the Brake Pedal Position Switch

Sometimes, the switch may simply be out of adjustment.

Adjustment procedure:

1. Locate the brake pedal position switch.
2. Loosen the mounting nuts or screws.
3. Adjust the switch position so it activates properly when the brake pedal is depressed.
4. Tighten the mounting hardware and test for proper operation.

Estimated cost: No parts cost, labor only if not done DIY.

4. Updating PCM Software

In some cases, a software update from the manufacturer may resolve the issue.

Update process:

1. Check with the dealership for any available PCM software updates.
2. If an update is available, have it installed by a qualified technician.
3. Clear the codes and perform a road test to verify the fix.

Estimated cost: $50 to $200 for the software update at a dealership.

Preventing Future P1703 Codes

To minimize the chances of encountering the P1703 code in the future:

1. Regularly inspect brake system components for wear and damage.
2. Keep electrical connections clean and protected from corrosion.
3. Avoid pressing the brake pedal excessively when starting the vehicle.
4. Ensure proper brake fluid levels are maintained.
5. Address any brake-related issues promptly to prevent cascading failures.

Remember: If you’re uncomfortable performing any of these repairs, it’s best to consult a professional mechanic. Improper repairs can lead to brake system failures and compromise vehicle safety.

Conclusion

The P1703 code, while not typically causing immediate drivability issues, should be addressed promptly to ensure proper function of your vehicle’s brake system and related safety features. By following this guide, you can diagnose and potentially repair the issue yourself, saving time and money. However, if you’re unsure about any step in the process, don’t hesitate to seek professional assistance. Your safety on the road is paramount.

Frequently Asked Questions About P1703 Code

• Can I drive my car with the P1703 code?
  While you may be able to drive, it’s not recommended as it could affect brake performance and safety systems. Have the issue diagnosed and repaired as soon as possible.
• How much does it cost to fix a P1703 code?
  Costs can range from $50 to $500 depending on the cause. Simple switch replacements are on the lower end, while more complex wiring or PCM issues can be more expensive.
• Will a P1703 code clear itself?
  The code may clear temporarily if the issue resolves, but it will likely return if the underlying problem isn’t fixed. Proper diagnosis and repair are necessary for permanent resolution.
• Can a bad battery cause a P1703 code?
  While uncommon, a weak battery can cause various electrical issues, including false trouble codes. Ensure your battery is in good condition as part of your diagnosis.
• Is the P1703 code serious?
  The P1703 code is moderately serious as it affects brake-related systems. While not an immediate emergency, it should be addressed promptly to maintain vehicle safety.
• Can I replace the brake pedal position switch myself?
  Yes, it’s possible for a DIY mechanic to replace the switch. However, ensure you have the proper tools and follow the vehicle’s service manual carefully.
• How often should the brake pedal position switch be checked?
  There’s no set interval, but it’s good practice to have it inspected during regular brake system maintenance, typically every 12,000 to 15,000 miles.
• Can weather conditions affect the P1703 code?
  Extreme temperatures and moisture can sometimes cause intermittent electrical issues, potentially triggering the P1703 code. However, persistent occurrences likely indicate a genuine problem needing repair.