By Ezra Lane Your Nissan's P0703 error code indicates a fault in the Torque Converter or Brake Switch B Circuit, specifically with the Brake Pedal Position (BPP) switch. This issue can disrupt communication between the brake system and the Engine Control Module (ECM), potentially affecting your car's transmission and safety features. You might notice symptoms like non-functional brake lights, difficulty shifting gears, or unexpected vehicle behaviors. Addressing this requires checking the BPP switch, wiring, and connectors for damage or misalignment. Since this problem can compromise driving safety, it's crucial to tackle these repairs promptly. Proper troubleshooting could reveal deeper insights into the necessary solutions.
P0703 Nissan Code Meaning
The P0703 Nissan code indicates a problem with the Stop Lamp Switch Circuit, specifically the Brake Pedal Position (BPP) switch's input to the ECM.
Inspect the BPP switch and circuit for wear or damage.
Professional help may be needed if issues persist.
Error Code P0703 Symptoms
Understanding what the P0703 Nissan code means helps identify the issues you might see in your car. This code often points to troubles in the brake switch circuit.
Here's what you might notice:
- "Service Engine Soon" Light Comes On: This dashboard light may turn on, indicating a problem in the brake system or transmission due to a faulty Brake Pedal Position (BPP) switch.
- Brake Lights Not Working: Your brake lights mightn't function because the BPP switch isn't telling the Engine Control Module (ECM) that the brakes are applied.
- Hard to Shift Gears: Shifting gears may be difficult. This happens because the ECM isn't getting the right signals from the BPP switch, which messes with the transmission control.
- Weird Car Behavior: The car might speed up unexpectedly or stall. This strange behavior comes from the ECM getting wrong or no signals from the BPP, which is key for engine and transmission tasks.
These problems can make driving unsafe and affect how your car works.
Causes of Nissan P0703 Fault Code
When your Nissan shows the P0703 code, it means there's a problem with the brake pedal switch. This switch tells the car's computer when you're using the brakes, affecting how the transmission works.
Here's what might cause this issue:
- Broken Brake Pedal Switch: The switch might be worn out or not working anymore.
- Wrong Alignment: If the switch isn't set up right, it won't send the correct signals about the pedal.
- Wiring Problems: If there are breaks, shorts, or loose connections in the switch's wires, the signal can get messed up.
- Brake Lights Not Working: If the brake lights fail, it might be because of a problem with the switch or its connections.
Check these areas to find what's causing the code and fix it.
Tools Needed to Diagnose
When you want to find out what's causing the P0703 code in your Nissan, you'll need some tools to figure it out. These tools help you see what's wrong and understand the car's electrical system. Here's what you'll need:
- Digital Multimeter: This checks if the Brake Pedal Position Switch is working and if the wires are okay. It shows if the electrical parts are getting power and doing their job.
- Scan Tool with Diagnostic Features: This tool reads and clears error codes, confirming the P0703 code. It also lets you see real-time data from the sensors.
- Nissan Wiring Diagrams: These help you follow the wires and find where the problem is in the system.
- Basic Mechanical Toolset: Includes items like screwdrivers, pliers, and a socket set. These are needed to reach and replace the Brake Pedal Position Switch if it's broken.
Always wear safety gloves and glasses to protect yourself when using these tools.
How to Fix P0703 Nissan Error Code – Step by Step
Step 1:
Check if the brake lights illuminate when you press the brake pedal. This initial step will help you determine whether the Brake Pedal Position (BPP) switch is functioning correctly. If the brake lights don't turn on, there's likely an issue with the BPP switch.
Step 2:
Visually inspect the BPP switch for any signs of damage or misalignment. Ensure that the switch is properly adjusted. If the switch appears faulty, replace it to rectify the issue.
Step 3:
Examine the wiring harness and connectors linked to the BPP switch. Look for signs of wear, corrosion, or loose connections that could disrupt signal transmission and cause the error code.
Step 4:
Use a multimeter to test the continuity and resistance in the BPP switch circuit. This step is crucial to identify any open or shorted wires that may be triggering the error code.
Step 5:
If the circuit tests show normal results but the error persists, the issue might be within the Engine Control Module (ECM). Diagnose the ECM for faults to ensure it properly receives input from the BPP switch.
Common Diagnosis Mistakes
When dealing with the P0703 error code in a Nissan, don't forget to check if the brake lights turn on when you press the pedal. Always verify this to rule out any issues.
Here are some common mistakes to avoid:
- Assuming the Brake Pedal Switch is Fine: Check the brake lights when you press the pedal. Don't just assume the switch is working.
- Ignoring Wiring Problems: Look at the wiring harness for any signs of wear or damage. Overlooking this could lead to thinking there's a problem with the car's computer, which mightn't be true.
- Overlooking Switch Adjustment: Ensure the brake pedal switch is set up correctly. If it's not, it might send wrong signals and cause unnecessary part replacements.
- Mixing Up Similar Codes: Be sure to tell P0703 apart from other similar error codes. Confusing them can waste time and lead you the wrong way in fixing the problem.
P0703 Nissan Repair Cost
Repairing a P0703 error in a Nissan can cost different amounts depending on the problem and where you live. Labor costs usually range from $75 to $150 per hour.
Fixing a simple issue like the Brake Pedal Position (BPP) switch takes about an hour. The switch itself costs between $30 and $100.
If your car has a bigger problem, like a bad Engine Control Module (ECM), it will be more expensive. Replacing an ECM, including parts and labor, can cost over $1,000.
Check if there are any safety recalls for your vehicle. These might cover the P0703 repair costs and save you money.
Choose a good mechanic for a proper diagnosis and repair. This helps avoid paying for things you don't need.
Related Error Codes on Nissan
When dealing with a P0703 error in your Nissan, it's useful to also know about other error codes that might come up. These codes often relate to transmission or brake system problems and can affect how your car runs.
Here are some related codes you might see:
| Code | What It Means |
|---|---|
| P0700 | Trouble with the transmission control system |
| P0720 | Problem with the output speed sensor circuit |
| P0703 | Issue with the torque converter or brake switch |
If your car is shifting strangely or the torque converter isn't working right, check the brake lights and the Brake Pedal Position switch. Fixing these issues together can help your car run better for longer.
Can I drive safely with P0703 Nissan?
It's not safe to drive your Nissan with a P0703 code.
This means there's a problem with your brake system that can make it hard for other drivers to see when you're stopping.
Get it fixed by a mechanic to stay safe.
People Also Ask
What Is the Role of the Torque Converter in a Nissan?
In a Nissan, the torque converter helps move power from the engine to the wheels, letting the car speed up and slow down smoothly. It also keeps the engine running when the car is not moving, so it doesn't stall.
How Does a Brake Switch Function in Vehicle Systems?
When you press the brake pedal in a car, the brake switch turns on. This makes the brake lights light up so others see you're stopping. It also helps with things like adjusting the transmission to keep the car running smoothly.
What Impacts Can a P0703 Code Have on Fuel Efficiency?
A P0703 code can make your car use more gas. This happens because the transmission doesn't work right, making the engine work extra hard. When the engine struggles, it burns more fuel, which means you have to fill up the tank more often.
Are There Any Preventive Measures to Avoid P0703 in Nissans?
Check your brake pedal switch and its wires often to make sure they're okay. Look at your brake lights to see if they work. Also, keep an eye out for any recalls about the brake system and fix them if needed.
How Often Should the Brake Switch Be Inspected in a Nissan?
Check your Nissan's brake switch every 30,000 miles or as your owner's manual suggests. Also, look at it once a year to make sure it isn't worn out, rusty, or broken. This helps to keep your brakes working safely.