2003 Nissan Pathfinder Won’t Start: OBD2 Codes 502 and 1122

If your 2003 Nissan Pathfinder won’t start and you’re seeing OBD2 codes 502 (Power Steering Oil Pressure Sensor Circuit Malfunction) and 1122 (Throttle Position Sensor Circuit Intermittent Malfunction), you’re in the right place. This article will break down these codes, explain why they’re appearing, and guide you through diagnosing and fixing the problems so you can get back on the road.

Understanding OBD2 Code 502 in Your Nissan Pathfinder

Code 502 indicates an issue with the power steering oil pressure sensor. While this might seem unrelated to starting, it can indirectly cause starting problems, especially in Pathfinders. The power steering system on some models is linked to the engine control module (ECM). A faulty sensor can send incorrect signals to the ECM, affecting fuel delivery and ignition timing, potentially leading to a no-start condition. This isn’t always the case, but it’s worth investigating. You’ll need to check the power steering fluid level, wiring, and the sensor itself.

2003 Nissan Pathfinder Power Steering Sensor Location

Decoding OBD2 Code 1122 in Your Pathfinder

Code 1122 points to an intermittent problem with the throttle position sensor (TPS). The TPS tells the ECM how open or closed the throttle is, allowing it to regulate fuel delivery. An intermittent malfunction means the signal is inconsistent, which can cause the engine to stall, hesitate, or refuse to start altogether. Checking the TPS wiring and connector is a good first step. A faulty TPS itself will likely need replacement.

Can These Two Codes Be Related?

While seemingly unrelated, codes 502 and 1122 can sometimes appear together due to shared wiring harnesses or grounding issues. If one circuit has a problem, it can impact others nearby. This is something to consider when troubleshooting.

2003 Nissan Pathfinder TPS Wiring Diagram

Diagnosing and Fixing the Problem: A Step-by-Step Guide

1. Check the Power Steering Fluid: Ensure the fluid is at the correct level. Low fluid can trigger code 502. Top it off if needed.

2. Inspect Power Steering Sensor Wiring: Look for any damage, corrosion, or loose connections to the power steering oil pressure sensor. Repair or replace as necessary.

3. Test the Power Steering Sensor: Use a multimeter to test the sensor’s voltage and resistance. Consult your Pathfinder’s service manual for the correct specifications.

4. Inspect TPS Wiring and Connector: Look for damaged or loose wires and connectors related to the TPS. Clean any corroded connections and secure loose ones.

5. Test the Throttle Position Sensor: Using a multimeter, test the TPS voltage as you move the throttle. Again, consult your service manual for specific values.

6. Check for Shared Grounding Issues: Ensure both the power steering oil pressure sensor and TPS have proper grounds. A poor ground can cause erratic readings.

Why Won’t My 2003 Nissan Pathfinder Start with Codes 502 and 1122?

The combination of these codes suggests a potential issue with the electrical system affecting both the power steering and throttle control. Addressing these individually and checking for common ground issues is crucial for resolving the no-start condition.

“When diagnosing these codes, remember to check for any other related trouble codes. This can provide a more comprehensive picture of the problem,” advises John Miller, ASE Certified Master Technician.

2003 Nissan Pathfinder OBD2 Scanner Showing Codes 502 and 1122

Conclusion: Getting Your Pathfinder Back on Track

Addressing OBD2 codes 502 and 1122 in your 2003 Nissan Pathfinder is crucial for resolving the no-start condition. By following the steps outlined in this article, you’ll be well on your way to identifying the root cause and getting your SUV running smoothly again.

FAQ

1. Can I drive my Pathfinder with these codes? While sometimes possible, it’s not recommended. These codes indicate potential problems that can worsen and cause further damage.

2. Are these expensive repairs? The cost varies depending on the specific issue. Sensor replacements are generally affordable, but wiring issues can be more complex.

3. Do I need special tools? A basic OBD2 scanner and a multimeter are helpful for diagnosing these codes.

4. What if I’ve tried everything and it still won’t start? Consult a qualified mechanic for further diagnosis.

5. Could a bad battery cause these codes? While unlikely, a severely discharged battery can sometimes trigger sensor-related codes. Make sure your battery is good.

6. Are there any preventative measures for these codes? Regular maintenance and inspections can help prevent issues with sensors and wiring.

7. Where can I find more information? Check our other articles on OBD2 codes and Nissan Pathfinder troubleshooting.

Related Issues

You might also find helpful information about issues with the crankshaft position sensor, camshaft position sensor, or fuel pump relay.

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