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Q: glow plug symbol flashing without OBDII code

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My problems started with my engine light on and glow plug symbol flashing. The OBDII code was P0380 The 50 amp fuse was out so I replaced it. The flashing glow plug symbol remained, engine symbol was gone. The glow plugs had under 1 ohm resistance so I figured they must be good. I purchased new relay and heat temperature sensor. I don't know about the relay but the heat temperature sensor wasn't working. I changed these two but the glow plug flashing symbol is remaining. I forgot to say that the glow plug harness is working fine and it also looks like the previous owner replaced it. Thank you

My car has 148000 miles.
My car has a manual transmission.

Oddly enough, a flashing glow plug light does not necessarily mean you have a problem in the pre-glow system. It can also mean there is a fault in other aspects of engine management. Much of the information that the car can give you can be detected by any OBD-II scanner. OBD-II codes are a universal code system that all cars sold in the US have to conform to. But the manufacturers can add any number of their own specific lines of code that are not accessible to the OBD-II scanners. In a case like this, your car needs to be scanned by a VW specific scan tool, or one of the knock off’s like the Baum or the Ross Tech VAG COM scanners. I recommend having an expert technician diagnose the warning lights for you in person so that you can move forward with the proper repairs instead of replacing unnecessary parts.

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