Error Codes 21,28 And 63

[KevSeymour]

Hi All,

I've been having an intermittent engine cut out issue, yesterday i finally got round to reading the codes and got 3 from the engine/trans.

21 & 28 are "Main oxygen sensor signal", both banks. It's pretty clear what i have to do there - replace the main O2 sensors! (is it worth replacing the sub sensors too?)

Transmission code 63 is worrying me though because i don't understand what it means "Open or short circuit in no. 2 solenoid valve". How will this manifest as a problem? Is it serious?

Thanks in advance for the advice!

[Rupert Dubreaux]

Kev hi , if it was my car I would start here if you have not already replaced the ECU capacitors .

http://www.clublexus.com/forums/ls400/656360-all-my-crazy-lexus-issues-solved-ecu-leaking-capacitor.html

Steve 2006 was supplying the capacitor kits a few weeks back to forum members ,their was a thread about the issue on here as well .

I was getting 02 sensor codes and some other codes before I changed the capacitors in my 94 Mk2 , after they were changed no more codes and it ran almost like a new engine .

If you still get any codes after replacing the capacitors at least you will know they are genuine and can then investigate further .

If you do need 02 sensors on the early cars they have flanges that bolt on , the later screw in types don't fit so you have to get the right ones and they are expensive .

As for the shift solenoid if it has failed I would suspect you would notice some odd shifting going on , ECU capacitors can also have this effect . I had several fail on a Mk4 Astra a few years ago and it was very noticeable that something was wrong .

Hope you get it all sorted .

[KevSeymour]

Thanks Rupert, very interesting read - this is why i always seek out an owners forum when i buy a new car! (And by 'new', i mean 22 years old with 165k on the clock!)

[Malc]

Kev, you are talking to aficionados here ............ . we are all probably a bit potty .............. or very very canny in keeping our Ls400s ................... for ever.

Malc

[Rupert Dubreaux]

Speaking for myself probably more potty than canny . Kev 165k miles is nothing for an LS .

[KevSeymour]

Well, i finally got the capacitors changed on my ECU and have re-read the codes.

I now have a 41 to add to the 21, 28 and 63!

This car is not endearing itself to me!

[Rupert Dubreaux]

Kev hi ,sorry to hear you still have problems, is you engine still cutting out ? Did you find any visible problems when you replaced your ECU caps ? Strange you should now be getting a TPS code as well as the others , if you decide to replace the O2 sensors you might find these useful if yours are the flanged type .

http://www.ebay.co.uk/itm/371166774564?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

You will then be able to use the later screw in type much cheaper than the original flanged ones which might be hard to find also ,I used the Denso uni ones in mine they were about £50 each.

Good luck with your repairs ,when these engines are running right there great and well worth spending a little time and money on ,I try and spend as little of the latter as possible though .

[ambermarine]

Kev

Did you clear the original codes after you had done the remedial caps etc .This is done by removing and replacing the dome fuse in the engine bay fuse box.

[KevSeymour]

Kev hi ,sorry to hear you still have problems, is you engine still cutting out ? Did you find any visible problems when you replaced your ECU caps ? Strange you should now be getting a TPS code as well as the others , if you decide to replace the O2 sensors you might find these useful if yours are the flanged type .

http://www.ebay.co.uk/itm/371166774564?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

You will then be able to use the later screw in type much cheaper than the original flanged ones which might be hard to find also ,I used the Denso uni ones in mine they were about £50 each.

Good luck with your repairs ,when these engines are running right there great and well worth spending a little time and money on ,I try and spend as little of the latter as possible though .

Hi Rupert, The car hasn't cut out on me yet, but i haven't dared drive it to get stranded yet.

Are you sure about the flanged O2 sensors? The article on LexLS linked below doesn't mention it?

http://www.lexls.com/tutorials/EFI/mainoxygensensor.html

If you're sure then i'll get a pair of the flanges just in case.

[KevSeymour]

Kev

Did you clear the original codes after you had done the remedial caps etc .This is done by removing and replacing the dome fuse in the engine bay fuse box.

I haven't removed the fuse, but as the ECU was removed from the car to replace the caps i'm assuming i don't need to?

[ColinBarber]

Kev

Did you clear the original codes after you had done the remedial caps etc .This is done by removing and replacing the dome fuse in the engine bay fuse box.

I haven't removed the fuse, but as the ECU was removed from the car to replace the caps i'm assuming i don't need to?

correct, they would have been cleared when the power to the ECU was removed.

[ColinBarber]

given the different codes I would first check that your Battery is good and that earthing straps are clean and bolted down tightly.

[KevSeymour]

given the different codes I would first check that your battery is good and that earthing straps are clean and bolted down tightly.

A poor earth could cause these error codes?

[ColinBarber]

A poor earth can cause all sorts of poor running and incorrect error codes. The errors codes are, in theory, unrelated to each other with really only the electrical system and the ECU itself having something in common. Easier and cheaper to check the Battery and earthing before swapping out the ECU - normally I would say the fault is with the ECU, either capacitors or voltage regulation, however yours has been repaired.

[KevSeymour]

Does that just explain the error codes though, or could a faulty earth cause the car to intermittently cut out?

[Rupert Dubreaux]

Kev hi ,my 94 mk2 definitely has the flanges on the O2 sensors, another member on here Ian I think who has a Mk1 also had them on his . The ones in the Lexls how too do look like the normal type and he is fitting them to a Mk1, unless there is a difference for US models , I would have a look under your car to make sure before ordering any .

As Colin has pointed out a dodgy earth connection can cause all sorts of problems , the Lexus Battery terminals do suffer from hidden corrosion sometimes that can be a problem .

[KevSeymour]

Before spending any more £££ on this i've had a local mechanic look at it, he says i have a missfire which is probably the route cause of the problem - but couldn't tell me what was causing it (he only had the car for an hour so couldn't do too much with it).

He wants to start taking bits off and testing various things, but i'm not sure i want to start down that road, i never intended to keep the car long and wanted to spend s little as possible on it (hence buying a lexus not a jag!).

I can do plugs and leads myself, but that's another £80 in parts (Eurocarparts).

Thoughts?

[Malc]

Those 8 plugs and leads sound amazingly cheap at £80 .......... maybe the previous owner used cheap parts too and maybe contributed to the issues you now have !!

I would ask your mechanic guy for some sort of fixed price " testing " regime to try to get to the bottom of your problem....... and save that possible £80 to put towards his bill.

You might be lucky with him.

Malc