2003 Pathfinder Won’t Start OBD2 Code 1122: Troubleshooting and Reset Guide

Experiencing a no-start issue with your 2003 Nissan Pathfinder accompanied by OBD2 code 1122 can be frustrating. This code often points to problems within the electronic throttle control system. Before assuming major component failures, resetting your vehicle’s systems can sometimes resolve the issue. This guide provides step-by-step instructions on how to perform several reset procedures that may help get your 2003 Pathfinder started and clear that OBD2 code 1122.

Understanding OBD2 Code 1122 and Potential Reset Solutions

OBD2 code P1122 (manufacturer-specific code for Nissan, generally displayed as 1122 by generic OBD2 scanners) typically indicates a fault in the Throttle Position Sensor (TPS) or the Accelerator Pedal Position (APP) sensor circuit. These sensors are crucial for communicating your throttle input to the engine control unit (ECU). A malfunction can prevent the engine from starting or cause it to run poorly.

Sometimes, these codes and the associated no-start condition can arise from temporary glitches or sensor misalignments. Performing system resets can recalibrate these sensors and the ECU, potentially resolving the issue without needing immediate parts replacement. Here are several reset procedures you can try on your 2003 Nissan Pathfinder.

Easy ECU Reset Method

This simplified ECU reset method is a quick way to attempt clearing any temporary electronic glitches.

1. Turn the Ignition “ON”: Without starting the engine, turn the ignition key to the “ON” position and count to 3 seconds.
2. Pedal Depress/Release (5 Times): Fully depress and then fully release the accelerator pedal rapidly five times. Ensure you do this quickly and completely each time.
3. Wait and Depress (10 Seconds): Count to 10 seconds, and then fully depress the accelerator pedal and hold it down.
4. Wait and Release (12 Seconds): Count to 12 seconds. You should observe the Service Engine Soon (SES) light blinking. Once it is blinking, release the accelerator pedal.
5. Wait and Depress (10 Seconds): Count to 10 seconds, then fully depress the accelerator pedal again and hold.
6. Wait and Release (10 Seconds): Count to 10 seconds, and then release the accelerator pedal.
7. Turn Off and Start: Turn the ignition off completely, and then attempt to start your 2003 Pathfinder.

Accelerator Pedal Released Position Learning

This procedure teaches the ECU the closed position of the accelerator pedal, which is vital for correct sensor readings.

1. Release Pedal: Ensure the accelerator pedal is fully released and not being touched.
2. Ignition ON (2 Seconds): Turn the ignition switch to the “ON” position and wait for at least 2 seconds.
3. Ignition OFF (10 Seconds): Turn the ignition switch to the “OFF” position and wait for at least 10 seconds.
4. Ignition ON (2 Seconds): Turn the ignition switch back to the “ON” position and wait for at least 2 seconds.
5. Ignition OFF (10 Seconds): Turn the ignition switch to the “OFF” position again and wait for at least 10 seconds.

Throttle Valve Closed Position Learning

This reset calibrates the throttle valve’s fully closed position, which is crucial for idle control and overall engine performance.

1. Release Pedal: Make sure the accelerator pedal is fully released.
2. Ignition ON: Turn the ignition switch to the “ON” position.
3. Ignition OFF (10 Seconds): Turn the ignition switch to the “OFF” position and wait for at least 10 seconds. Listen carefully; you should be able to hear the throttle valve move during these 10 seconds, confirming the system is active.

Idle Air Volume Learning (Throttle Position Learning)

This is the most comprehensive reset and should be performed after the previous two. It teaches the ECU the correct idle air volume and throttle position for smooth idling.

1. Perform Previous Procedures: First, complete both the “Accelerator Pedal Released Position Learning” and “Throttle Valve Closed Position Learning” procedures outlined above.
2. Warm Up Engine: Start the engine and allow it to reach its normal operating temperature.
3. Ignition OFF (10 Seconds): Turn the ignition switch to the “OFF” position and wait for at least 10 seconds.
4. Release Pedal, Ignition ON (3 Seconds): Confirm the accelerator pedal is fully released, then turn the ignition switch to the “ON” position and wait for 3 seconds.
5. Repeat Pedal Procedure (5 Times within 5 Seconds): Quickly repeat the following sequence five times within 5 seconds:
   a. Depress Pedal (HARD): Fully depress the accelerator pedal forcefully.
   b. Release Pedal: Fully release the accelerator pedal.
6. Wait, Depress and Hold (20 Seconds): Wait for 7 seconds, then fully depress the accelerator pedal and hold it down for approximately 20 seconds. Watch for the Check Engine Light (CEL) to start blinking and then turn solid ON.
7. Release Pedal (within 3 Seconds): Within 3 seconds after the CEL turns solid ON, fully release the accelerator pedal.
8. Start Engine and Idle: Start the engine and allow it to idle without touching the accelerator pedal.
9. Wait (20 Seconds): Let the engine idle for 20 seconds.
10. Rev Engine: Rev up the engine two or three times. Check to ensure the idle speed and ignition timing are within the manufacturer’s specifications.

Conclusion: Resolving 2003 Pathfinder No-Start and OBD2 Code 1122

By carefully following these reset procedures, you may be able to resolve the no-start condition and clear the OBD2 code 1122 on your 2003 Nissan Pathfinder. These resets are designed to recalibrate the electronic throttle control system and can often address issues stemming from sensor misalignments or minor electronic glitches.

If your Pathfinder still won’t start or the OBD2 code 1122 returns after performing these resets, it may indicate a more serious underlying issue, such as a faulty Throttle Position Sensor, Accelerator Pedal Position sensor, or wiring problems. In such cases, professional diagnostic service from a qualified mechanic is recommended to accurately pinpoint and fix the problem.