HoniaraKid

"Knows" what I am doing with reference a CANbus is a little strong. 🙂 I wish I had a tenth the skills of Super Mario Diagnostics or Diagnose Dan.

Spectacular piece of coincidence. The misfire was down to coil plug being adrift on coil 3. I am saying three - left bank 3 in facing the windscreen. Car was serviced about two months ago. So no ECU worries. 🙂 Interestingly now the radio is working the error for the AVC/LAN bus has gone. So without research I can only guess it has something to do with the Mark Levinson system bus. It has a Pionner headunit installed that I fitted about 2 years ago, but that uses a Lexus data converter so the Levinson system works as it should including the steering wheel buttons. Had a A/C DTC, that was logged as Historic but didnt show last scan. Also had two DTC for the oleft and right Solar sensors. Hardly surprising with the car in agarage 8 months of the year. Just taken it for the final test drive before handover and the Solar Sensor DTC has gone and taken the AC fault with it, so happy days. Will let owner use it for a week then plug in again and see if anything has occured. More info on the fault finding later. Thank you to everyone.

The car is now running. It does however have a misfire and one AVC/LAN bus is down. All systems are up, except the radio. I will do a more comprehensive report soon. Apart from the new battery and the 140A fuse, there were nine other fuses and arc damage to one the ECU plugs. One pin to be precises must have been hit with a fair bit of current. When I took the ECU out I could smell it. I am going to scope the coil triggers to see if the misfire is a FET issue or loom/coil coincidence. I do not believe the monster reverse surge would have gone through the ECU to a coil without killing the ECU forst. On inspection it looks fine inside. Anyway I have been documenting my finds so I will publish soon.

Thank you to @Malc1 I am still laughing. I have managed to remove it. A very poor design. When you look at it, it appears to come out from the top, but it does for those that know come up and bit then the base slides out after being unscrewed. It was clips of stupidity that are so annoying. Anyway the 140A is replaced but the car is still dead as expected. Got Disco 5 to service tomorrow then I will go back and check all the relevant fuses. I have the list from the link above so thank you for that. The fuses block under the glovebox smells a bit so it will need to come out to see if its been damaged. I still cant read the VIN so comms are still done. I know there is an OBD fuse which I will be check. I have an 220w dummy load in series with the battery just to make sure that car doesnt try to take more than 18A without me noticing, during testing. I have the rad fan disconnected as that is running continously currently. I had noticed the power window fuse (41) is open circuit, so I replaced that and the windows came backs online and keyfob is dead so I have a 1616 coming for that. The locks are still offline from the key barrel but do work from the lock inside on the door. Seems odd, but I see there is another fuse associated with that circuit. More when I look tomorrow. Thank you for the video @Neil E it is similar but the four main clips were holding on for life. It doesnt help that the loom has no slack. Anyway thanks everyone. Just download for $20 the entire wiring schematic for the 2010 SC430. Here is the power section if anyone wants it.

Gentlemen, the risk or using brute force and or C4 grows by the minute. How in the name of flying chimps does the top part of the narrow fuse box come off? I have undone the 10mm on the main feed. I have trying feelker guages, screwdrivers etc in each of the four clips and prising upwards. Nothing budges. I have looked on YT but not found anything remotely useful. Can anyone assist please. Sanity on hold for now. Cheers

Thank you very much. Current draw was high when the battery was first renewed and the 140A fused bridged as the radiator or condensor fan was running flatout. I am going to look again at the car soon when Lexus deliver the new 140A fuse. I shall be back.

Thank you for that headsup @Jon Dee That will be added to my list. Cheers

Greetings All, Friend trying to assist a friend. 2009 SC430 30k. The car is only used between April and September. Hold your stomachs in this is hilarious. Owners tried to jump start the car THREE times with reverse polarity!!!!!!!!!!. Neighbour said he could see arc light from over the road. I get there and find the battery has no voltage at all. Literally 0.2v. Positive terminal has MOVED about 3mm in casing. New battery fitted with 50w in series as choke. Only door lights, door open light on dash and headlights work. No comms on OBD. 50w bulb removed, no change. 140A main ALT fuse destroyed. When bridged and current monitored with amp clamp, rad fan spins up immediately to full power. Other various underbonnet items come online. Dash lights come on, dial backlighting etc. Crank no start. Power windows, locks remote unlock etc offline. No other fuses I can see are blown. No comms on OBD. Only had 15mins on this visit. Anyone been here before? Suspicious of Gateway Module onwards now unless I am missing other fuses. Reverse polarity is no joke so reckon ECU's died before 140A blew up. Laughter on a postcard please. Thanks