Glow plug issue, but no DTCs?

[ian_uk1975]

E320 CDi V6. Glow plug light stays on after engine started, then eventually goes out. I know that this indicates 1, or more, glow plugs have failed or the glow plug control module is at fault.

Wanted to read the DTCs to see if that would narrow things down, but the scanner can't find any stored or pending codes, which is weird since there is clearly a glow plug issue! Reader is a USB ELM327 and I've tried Easy OBD and Scan Master. Live data is displayed fine.

Any ideas?

[S0 What]

Try a better scanner, to be frank all those are cr@p.

[DapperDanMan]

I tested my glow plugs for continuity as I couldn't get a code either.

Now access to the plugs is a little annoying it's been a while since I did it and I may well have just popped each connector in turn and tested it.

I replaced 1 and a few months later had a second one go so replaced the other 5 no problems since.

[ian_uk1975]

I was hoping to test the glow plugs by checking the end of the cable that plugs into the glow plug relay/controller (want to test that too). Trouble is, there are 12 pins on the controller output and only 6 glow plugs, which is rather confusing.