My auto mechanic case: 2007 PASSAT no start problem

Yesterday, I repaired a 2007 VW PASSAT with 20,000 miles on it. The car owner, Mr. Lee, had the PASSAT towed to my auto repair shop as the vehicle could not start after waiting at the red light for about 3 minutes.

Lee told me on the phone that his PASSAT first started to shake violently when he was waiting for the red light. Then the car flamed out and could not be restarted anymore. However, when he got off and checked the engine, the engine was running at a normal speed.

“The car never had any problem before. I tried to use my VW scanner to pull trouble codes, but the car seemed alright. So I had to call a trailer to tow the car to your store,”said Mr. Lee.

After learning the whole story, I used a VAS 5054A VW diagnostic tool to troubleshoot, but just like Lee, I did not get any fault code. I carried a spark testing; there was fire with the spark plug. Then I removed the fuel feed pipe, I noticed there was no oil coming out. I believed the problem must be caused by oil-way failure.

The next was to prove if I was right. I checked the oil pump, and its fuse was in good condition, then I plugged off the fuel pump relay and found all of its pins were burned. I established a short circuit of the relay, and found the car could start smoothly without the relay. Finally I replaced the relay and the fault was cleared.