Volkswagen Repair: check engine light, jetta tdi, volkswagen dealer

Question
autozone diagnostic said change heat exchanger glow plug on 2002 jetta tdi.  I changed all the engine glow plugs and heat ex. glow plug and light is still on. any suggestion.

Answer
Hi Ed;
The glow plugs all have to be the same.  Some are made by Bosch, some are made by Beru.  Make sure the ones you have are all the same.  Also, the strip that feeds power to the glow plugs may be corroded, especially at the connectors to the glow plugs themselves.  The Volkswagen dealer has a repair kit for this "strip."  It's the big round wire on top of the glow plugs.  It probably needs to be replaced too.  Once you check your glow plugs for brand, and make sure they are all the same, and once you change the strip, your problems should be gone.  That cures about 99% of them.  Good luck, Ed.