|
|
Post by charliefarlie on Feb 18, 2024 15:20:23 GMT
Try leaving both battery cables off. It really won't make any difference, assuming every cable has been removed from at least one of the battery terminals. Current flows in loops, there has to be a path back to the source of current, i.e. the source is the battery and the path has been broken. You can have local charge stored in "bulk" capacitors on the power supply lines within ECUs. If the power (battery supply) is removed, in simple terms, current will flow from the positive "plate" of those capacitors, through whatever circuitry is in the ECU back to the negative "plate" of the capacitor. i.e. current is still flowing in a loop back to the source and the source is the bulk capacitance in the ECU in this case. This current generally won't flow anywhere else, i.e. out of the ECU, because 99% of the time there will some reverse battery protection (often a diode) in the ECU preventing that. The bulk capacitance is there to do things like, for example, keep the ECU running should there be stuff like "micro-cuts" in the supply (milliseconds duration) or in the case of say airbags to still have sufficient local charge to fire the squibs if necessary. The above is why there is often advice to wait a few minutes after disconnecting the battery, for things to "discharge", but to be frank, most ECUs only have enough capacitance on the supply input to keep the ECU functioning through whatever supply cut/dropout/transient it has been specified to meet and those are very often much much less than 1 second duration. Believe me, I've seen enough of those VM specs in my time to know. I know you know Andy.... No question !! I was just considering the options that I would try. Thing with cars and electronics is they dont always play by the rules. |
|
|
|
Post by Hoovie on Feb 18, 2024 15:37:32 GMT
I know you know Andy.... No question !! I was just considering the options that I would try. Thing with cars and electronics is they dont always play by the rules. they definately don't! I am still confused from something just on Friday ... two battries in parallel ... one was dead (11.5V) and the other ok (12.4V). when charger on, the 11.5V one raisedto 14.5V and the 12.4V didn't change. So obviously NOT connected together, are they? But checked with a meter and there was zero resistance between the two batteries POS terms, and their NEG terminals. Don't understand that. |
|
|
|
Post by stewpot on Feb 28, 2024 17:19:51 GMT
Well I have to say I am stumped at this now, took it to an ex Toyota technician over the weekend, who has tested every wire and contact and has said if I start replacing components randomly it could end up costing me a fortune to cure a minor fault, he has used meters to test waveforms ?? when the car is moving and stationary but cannot detect the fault source, he finally thinks its the clocks, but I bought a replacement set that still showed the same issue, I have a short video of what he has done on what's app but do not know how to show it on here Sorry for being boring 😴 Stew  |
|
|
|
Post by firemac on Feb 28, 2024 19:11:18 GMT
Well I have to say I am stumped at this now, took it to an ex Toyota technician over the weekend, who has tested every wire and contact and has said if I start replacing components randomly it could end up costing me a fortune to cure a minor fault, he has used meters to test waveforms ?? when the car is moving and stationary but cannot detect the fault source, he finally thinks its the clocks, but I bought a replacement set that still showed the same issue, I have a short video of what he has done on what's app but do not know how to show it on here Sorry for being boring 😴 Stew You’ve probably already thought of this but perhaps the replacement clocks were also faulty? Would be a hell of a coincidence but, it’s been known……….🤔 |
|
|
|
Post by charliefarlie on Feb 28, 2024 19:15:07 GMT
Well I have to say I am stumped at this now, took it to an ex Toyota technician over the weekend, who has tested every wire and contact and has said if I start replacing components randomly it could end up costing me a fortune to cure a minor fault, he has used meters to test waveforms ?? when the car is moving and stationary but cannot detect the fault source, he finally thinks its the clocks, but I bought a replacement set that still showed the same issue, I have a short video of what he has done on what's app but do not know how to show it on here Sorry for being boring 😴 Stew It’s not boring Stu…. Electrics are not my strongpoint but I go on FBs RAV4 pages and I will ask on there. It’s a tough one but it’s by no means un fathomable….. |
|
|
|
Post by stewpot on Feb 28, 2024 20:25:55 GMT
Thanks Charlie these new electrics on cars are not for me I am afraid 😅
|
|
|
|
Post by charliefarlie on Feb 28, 2024 20:29:32 GMT
Have a look at this.  |
|
|
|
Post by charliefarlie on Feb 28, 2024 20:34:09 GMT
Another reply said
I had a similar thing on a verso, a constant code in the body control ecu and the keyless entry was very hit and miss, ended up being it had parking sensors fitted and somebody had cable tied the wiring too tight and it was pulling a pin out the plug of the keyless entry antenna, OSR rear the boot window. Spent weeks scratching my head just to cut a cable tie and push a pin in a plug 🤦♂️ found it eventually
|
|
|
|
Post by stewpot on Feb 29, 2024 1:20:36 GMT
That's brilliant Charlie, in fact that is pretty much what he found sounds to me that it may not be the clocks that are faulty but the wire or connector that is coming out of the cluster has a bad connection somewhere I will send the guy your post, many thanks 😀 Stew
|
|
|
|
Post by charliefarlie on Feb 29, 2024 9:27:28 GMT
That's brilliant Charlie, in fact that is pretty much what he found sounds to me that it may not be the clocks that are faulty but the wire or connector that is coming out of the cluster has a bad connection somewhere I will send the guy your post, many thanks 😀 Stew The guy that posted the above asked if you’d had any recent additions or changes to your electrics for instance sensors or a tow bar fitted. From that I’m supposing that errors could be the cause of your problem… I really am hopeless with wiring even the most basic wiring diagram I just can’t follow. You will I’m sure find a solution even if it takes a lot of messing about 👍👍👍 |
|
|
|
Post by stewpot on Apr 10, 2024 11:27:20 GMT
Well I have been on Rav4world USA, and some very helpful people although they do not have diesels still no answer to my minor fault🙃 however I think I have some perspective on it now, one guy cannot have his cell phone in his office but is able to start his Rav from his office with his watch which he does on cold days 🤐 Stew
|
|
