I'm trying to fault find a 2006 RD9 2.2 Diesel CR-V.
Intermittent crank no start.
When working (i.e. crank and start) ignition is switched on a range of lights illuminate on the dash, including EML and Glow-plug light. After 2 seconds, glow plug and EML go out. Turn key to start, Engine cranks and starts.
When not working (i.e. crank no start) ignition is switched on a range of lights illuminate on the dash excluding EML and Glow-plug light. From this initial position, if I turn key to start, engine will crank but not start.
Turning ignition off and back on again repeatedly (1-25 times) will eventually see the correct EML and glow plug light briefly illuminate and the car will then start.
Code scan shows 1 DTC. P0602 "Control Module Programming Error" but Googling suggests this can be caused by wiring faults.
I've located the ECU (left side footwell). There's no obvious damage/moisture/corrosion.
Thinking the issue might be glow-plug related, I've swapped out the glow-plug relay, located adjacent to the battery. Removing the relay causes the fault condition. i.e. with the relay removed, I get no EML and no glow-plug light on the dash. The replacement relay (ebay Item ID: 196059010011) behaves just the same so unless I've been really unlucky and bought a used relay with the exact same fault as the original, I think the issue lies elsewhere.
I've pulled various relays in the underbonnet fuse box and also those under the dash but all test ok.
Any suggestions for testing/diagnosis gratefully received.
Thanks