how to clear P0171 code in Tesla Model S Plaid/Refresh (2021-present)

Tesla Model S Plaid/Refresh (2021-present)

Error Codes

2-4 hours

Time

medium

Difficulty

medium

Severity

Error Code: P0171

4 min read

624 words

Problem Statement

Learn how to diagnose and fix P0171 lean fuel mixture issue in Tesla Model S Plaid. Step-by-step guide with diagnostic procedures and repair instructions.

Error Code

P0171

Affected Component

Engine

Estimated Time

2-4 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

•Disconnect the battery before working on electrical systems.
•Allow the engine to cool before inspecting or working on the intake system.

Symptoms

•Check engine light illuminated
•Decreased engine performance
•Poor fuel economy
•Engine hesitation during acceleration
•Increased emissions

Diagnostic Steps

1
Scan the vehicle's OBD-II system using a compatible diagnostic tool to confirm the presence of the P0171 code.
2
Visually inspect the air intake system for any leaks, cracks, or loose connections.
3
Check the mass air flow (MAF) sensor for contamination or malfunction by cleaning or testing its function.
4
Inspect the fuel delivery system, including fuel pressure and fuel filter condition.
5
Examine the vacuum hoses and intake manifold for any leaks that could cause a lean condition.
6
Monitor the fuel trims using the OBD-II scanner to assess how the engine control module is attempting to compensate for the lean condition.

Solution

💡 Expert Tip

For complex repairs like this, consider taking photos at each step. This helps if you need to reverse a step or consult with a mechanic. Also, keep all removed parts organized - you may need to reference them during reassembly.

Verification

After completing the repair, verify that the issue has been resolved:

✓Test the affected component to ensure it functions correctly
✓Check for any error codes or warning lights
✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

•Follow the manufacturer's recommended maintenance schedule
•Address warning signs early before they develop into major issues
•Use quality parts and fluids recommended for your vehicle
•Keep detailed records of all repairs and maintenance

Tools & Equipment Required

•OBD-II scanner
•Torque wrench
•Screwdrivers (flathead and Phillips)
•Pliers
•Cleaning supplies (MAF cleaner)

Parts Required

•MAF sensor (if replacement is needed)
•Fuel filter (if replacement is needed)
•Vacuum hoses (if replacement is needed)

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Diagnostic Steps

1
Scan the vehicle's OBD-II system using a compatible diagnostic tool to confirm the presence of the P0171 code.
2
Visually inspect the air intake system for any leaks, cracks, or loose connections.
3
Check the mass air flow (MAF) sensor for contamination or malfunction by cleaning or testing its function.
4
Inspect the fuel delivery system, including fuel pressure and fuel filter condition.
5
Examine the vacuum hoses and intake manifold for any leaks that could cause a lean condition.
6
Monitor the fuel trims using the OBD-II scanner to assess how the engine control module is attempting to compensate for the lean condition.

Solution

1. Preparation

Gather tools and parts needed for the repair.
Ensure the vehicle is parked on a level surface and the parking brake is engaged.

Tools Required:

OBD-II scanner
Torque wrench
Screwdrivers (flathead and Phillips)
Pliers
Cleaning supplies (MAF cleaner)

2. Inspect and Repair Air Intake System

Inspect Air Intake Hoses
- Check all hoses for cracks or disconnections.
- Tighten any loose clamps or replace damaged hoses if necessary.
Check MAF Sensor
- Disconnect the wiring harness from the MAF sensor.
- Remove the MAF sensor using the appropriate screwdriver.
- Clean the sensor with MAF cleaner and allow it to dry completely.
- Reinstall the MAF sensor and reconnect the wiring harness.

3. Examine Fuel Delivery System

Check Fuel Pressure
- Connect a fuel pressure gauge to the fuel rail.
- Turn the ignition key to the "ON" position to prime the fuel system.
- Compare the reading to manufacturer specifications; replace the fuel pump if pressure is low.
Inspect Fuel Filter
- Locate and remove the fuel filter (if applicable).
- Replace it with a new filter if it is clogged or has not been changed per maintenance schedule.

4. Vacuum Leak Inspection

Visual Inspection
- Inspect all vacuum lines for damage or disconnections.
- Replace any broken or cracked vacuum hoses.
Use Smoke Test (if necessary)
- Introduce smoke into the intake system to visually identify any leaks.

5. Clear DTC

Use the OBD-II scanner to clear the P0171 code from the ECM after making repairs.
Ensure all systems are functioning correctly before completing the repair process.