Hello all, I bought a 2007 diesel sprinter and have recently encountered a glow plug module problem. Is there a way to test. I was told #3 plug was bad and also the relay. But could not be provided with a DTC. OK, got back to home town and dealer said no codes except for boost pressure sensor fault. Now the glow plug symbol comes on after its been started or just driving down the road. I recently replaced the starter /battery/alternator cables as instructed by sprinter tech. That solved the battery/ alternator light but not the glow plug issue, he said it solved the problem on the others ( ok , worth a try, cable was in bad shape). Unfortunately the code came back today, but this intermittent DTC doesn't warrant replacement. I am worried about serious GP failure, requiring head removal. So curious if any suggestions might lead dealer & I to a solution. Thanks

 

Welcome to DF
I work next to a guy that works on sprinters. He told me, anytime you replace glow plug also the glow plug module. And all glow plugs.

 

THANK YOU! For the info, I have never heard that before. 58/GP and 728/ module. Gets pretty expensive. Is there a reason to replace all of them ? What I /we can't figure out is the intermitent code issue. Thus I was hoping repairing the cable would resolve the issue but it hasn't. Dash GP light still comes on while driving but its not storing a hard code. Just had it check Thursday a, again. Is there a preferred scan tool for reading/ resetting codes? It seems theres way more info on the net that in any or most dealers combined. Again thanks for your time.

 

On some of the sprinters we use a DRB3 with an interfaze cable and sprinter card and the newer sprinters we use a Witech pod.

 

Im not trying to telling you to do something different than what is already suggested, but I would replace the $30.00 glow plug first(the failed one) and then if it melts right away again, I would replace the module and the corresponding plug. Im sure the modules are in the $300.00 and up range. Just a suggestion.....We replace a LOT of glow plugs w/out the modules,but sometimes the module is the primary failed part that progressively damages the plug....

 

Thanks Dallas, and you were correct. I found a new dealer and plenty of competent techs at the new place. They did exactly what you recommended. They went into a computer scan/test/ whatever mode and checked the module further or more thoroughly than the last 2 places. 1 gp is all it took and its been good so far no other GP troubles.