I have an Opel Frontera 1999 2.2 Diesel. It refused to turn over a couple of years ago and it's taken me this long to get to doing anything about it. I was advised that it was something wrong with the key/immobiliser so the garage replaced it with a secondhand system consisting of ECU, Immobiliser, Ignition, Key, Key card reader ( i think it was called) and RCL controller ( not sure if that one was used or not in the end).

The garage (who I trust and I also think they are very competent) said that they tried everything but couldn't get the jeep to turn over. The main problem was they couldn't do any troubleshooting because they couldn't get the diagnostics unit to connect with either ECU - ie the old one or the new one. The suspicion was that there was some issue with the wiring loom. Does this sound plausible? It does to me I suppose especially because the problem was originally intermittent and it ultimately took a few months to break completely. If it does then I think I will elect to scrap the car because it just seems like it might not be the end of the line with the repairs, but I just wanted to ask here in case there might be something else obvious that we were missing.

  • If they used the OpCom software and selected the right model, then I don't know. Is the battery charged? I know it's a stupid question, but the car's been standing for a while. No battery, no comms. But I doubt that. Commented May 5, 2014 at 13:23
  • No they are a competent garage ... battery was charged I'm sure. Commented May 5, 2014 at 13:32

1 Answer 1


The inability to communicate with the ECU could be explained by the lack of power from the battery. This could be due to:

  • a flat battery (ruled out)
  • a break in the wiring
  • high voltage drop across the positive wire (assuming the ECU is negative-grounded)
  • thanks but jeep has been scrapped since - garage spent a lot of time trying to trace the fault but it was going to cost more than it was worth - possibly an issue in the wiring loom - we had already replaced a few bits of gear such as the ECU and the RCL controler and a few others that I can't remember Commented Dec 14, 2015 at 15:17

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