Diagnostics Doctor

Your electrical queries answered.

A friend’s 2006 Honda CR-V 2.2i CTDI will crank over but refuses to start. On the rare occasions when it does fire up, all the usual lights appear on the dash when the ignition is switched on, but the MIL never illuminates on the occasions it refuses to start. Apparently, this issue emerged intermittently, but now the engine will only start on rare occasions. The owner took the car to a Honda dealer who claimed that no fault codes were present and charged him £86, while claiming the battery was faulty and leaving him with a non-functioning radio (it’s a coded one).

Using my Sealey VS8802 reader, I found the following fault code logged: ‘P0602 – Control Module Programming’. It seems strange to me that the dealer-level equipment didn’t find this. I attempted to scan for live data while cranking, but nothing showed. I also attempted to erase the code, but all I got was a message about the ignition not being on, even though it was!

William Bamber

The code ‘P0602’ indicates an ECM programming error and would point to the ECM being at fault. However, before removing it and sending it off for testing/repair at either ecutesting.com or bba-reman.com, I would inspect the connecting pins on the ECM and the plug to confirm that no corrosion is present. I would also check the earth points to ensure that a bad earth is not the problem.

When the ECM fails it can cause connectivity problems for diagnostic equipment, which may explain why the dealer-level equipment couldn’t find anything and also why you could not retrieve any live data. Sadly, some dealers do not put quite so much effort into a vehicle which is more than 10 years old, possibly believing they may be able to sell a newer model to the owner. It’s a good job that not everyone thinks like that!