TPMS Scanner Troubleshooting: Common Issues and How to Fix Them Leave a comment

P0172 Code Fix? Here’s the Exact Fix (Step-by-Step)

Symptoms:

• Rough idle and decreased fuel efficiency
• Black exhaust smoke or strong fuel smell
• Check Engine Light (CEL) illumination with P0172 code

Tools Needed:

• DiagtPro X400 Scanner
• Multimeter
• Vacuum pump and gauge
• Smoke machine (for smoke test)

Step 1: Test Fuel Trim Values

• Hook up DiagtPro to check fuel trim values. A fuel trim value above 10% indicates a rich condition.
• Use the multimeter to check the voltage of the O2 sensor. A voltage above 0.45V indicates a rich condition.

Step 2: Inspect Vacuum Leaks

• Listen for hissing near the intake manifold, throttle body, and vacuum hoses.
• Use a smoke machine to perform a smoke test. Introduce smoke into the intake system and look for signs of smoke escaping.

Step 3: Avoid This Mistake

• Don’t assume the O2 sensor is bad—test wiring and connections first. Corrosion or damage to the wiring harness can cause false readings.
• Don’t ignore the Mass Airflow (MAF) sensor. A dirty or faulty MAF sensor can cause the engine to run rich.

Final Fix:
Replace the MAF sensor, then clear codes with DiagtPro. Make sure to check and repair any vacuum leaks and inspect the wiring harness for corrosion or damage. Reset the fuel trim values and monitor the engine’s performance. If the problem persists, consult a professional mechanic for further diagnosis and repair.