Case Study: VW Jetta MIL on with no drivability issues

July 28, 2022
The customer brought his Jetta into the shop because the malfunction indicator light (MIL) was on. There were no obvious drivability issues.

Vehicle: 2016 Volkswagen Jetta Sedan (163), L4-1.4L Turbo (CZTA), Automatic Transmission/Transaxle

Mileage: 122,368

Problem: The customer brought his Jetta into the shop because the malfunction indicator light (MIL) was on. There were no obvious drivability issues.

Case Details: The technician connected a scan tool and pulled the following seven diagnostic trouble codes (DTCs):

  • P2279 - Intake Air System Leak
  • P1250 - Fuel Level Too Low
  • P0300 - Random misfire detected
  • P0301 - Cylinder 1 misfire
  • P0302 – Cylinder 2 misfire
  • P0303 - Cylinder 3 misfire
  • P0304 - Cylinder 4 misfire

With this many DTCs, the technician thought it would be best to call ALLDATA Tech-Assist for some diagnostic advice. The Tech-Assist consultant suggested reviewing a technical service bulletin (TSB) # 01 15 28 in ALLDATA. In it, VW says that if DTCs P0301 - P0308 (Cyl.1 Misfire Detected - Cyl.8 Misfire Detected) are accompanied by P1250 (fuel level too low), it’s likely the faults occurred due to low fuel level and not a component malfunction.

Confirmed Repair: The technician spoke to the customer who confirmed the fuel tank was run low several times. The DTCs were cleared by the technician who then filled the fuel tank and went for a test drive. The DTCs did not return, and the MIL stayed off. He released the vehicle to the customer who reported a month later there were no further issues. Problem solved!

Reprinted with permission from ALLDATA.

About the Author

Richard Diegle | Senior Automotive Editor for ALLDATA

Rich Diegle has been in the automotive industry since 1978. After graduating from a local community college, he began working at a Nissan dealership as a used car technician. Since then, he’s worked as a Nissan and ASE master automotive technician, shop owner, marketing copywriter, automotive editor, public relations manager, instructor, ALLDATA Tech-Assist team manager, and a senior automotive editor. 

Sponsored Recommendations

AIRCAT Solutions - Small Ratchets With Enormous Power

Experience the power of AIRCAT's diverse ratchet selection. Each designed with a unique transmission gear for faster torque buildup and unbeatable performance. Their compact sizes...

Unmatched Power and Comfort: AIRCAT Grinders for Every Workspace

AIRCAT grinders deliver powerful performance with high RPM and efficient, quiet operation. Designed for comfort and control, they feature ergonomic handles, extended reach, and...

What Are the Advantages of Air Tools Over Cordless Tools?

Discover the advantages of air tools over cordless tools.

AIRCAT Tool Reviews: The Nitrocat 1056-XL Compact

Hear what senior autotechs have to say about the AIRCAT Nitrocat 1056-XL compact impact wrench. They’ll provide their reviews on tools they own and have been using every day on...

Voice Your Opinion!

To join the conversation, and become an exclusive member of Vehicle Service Pros, create an account today!