1997 Lx450 Nightmare Solved!

[Andrewsreef]

Thi, Rookie and others who have helped me. My on going problem that I thought was tranny related and then engine turned out to be a defective design fault on the wireing harness. If any of you are having engine misfires or tranny shifting problems, examine the wiring harness comming off the firewall where it takes a 90 Degree turn under the drivers side of the motor. The wires over time rub against the EGR pipe and eventually rub all the insulation off. You get bare wires coming off the computer and arching on the metal tube for the EGR. Not good. Anyway, I wanted to share this info with you all so no one goes through the 2 month long nightmare I have been through.

I got lucky and found a guy on a land cruiser web site that had the same problem.

Thanks again.

Andrew

[Thi]

Congratulation Andrew. That was a weird problem. I need to take a look of the wiring harness on my car and maybe put some more insulation around it or something. Thanks for the information.

Thi

[Rookie]

Good for you Andrew. Hope you can start to enjoy your rig now. You've earned it!

Rookie.

[dougjohn]

Congrats Andrew!

Another thing to keep in mind is that if you start blowing EFI (electronic fuel inject) fuses for no apparent reason, it'll be tied to the same problem (frayed wire insulation). Happened to me....drove me crazy for a couple days. I'd be driving along and then, out of no where, no more power; had all electrical, but car would coast to a stop and wouldn't crank over.

I hate electrical stuff...

Congrats on finding the problem.

...

Doug

[SKperformance]

Call lexus and let them know about the defect.

They might be happy to know and help in some way.

[Andrewsreef]

Good point about calling the dealer. My mechanic did a nice job of fixing it and attached a cable to hold all the wires in the newly done harness away from the EGR pipe. He pointed out there is a place for a strap to prevent this from happening. Not sure if mine never got the strap (manufacture defect) or it somehow was removed or completely vanished. Check your trucks, if the wires are close or touching the EGR pipe, you will have problems down the road.

THe wires are now several inches away from the pipe. My guess is that all of you have a strap or this would be a much more common problem.

The truck sure does drive nice now. I am finally enjoying it. I still have the check engine light on for what I think is still the P0325 knock sensor I need to check out when I have some more $. I am going to invest in THI's recomended Car Chip here soon.

Thanks again and happy holidays.

Andrew

[Thi]

Andrew,

The P0325 knock sensor code could be a "left over" from the wire shortage problem that you had. You can try to reset the error and see if it gets trigger again. With the CarChip, you should be able to reset the engine check light. If you don't have the tool now, your cousin probably can reset it with his ODBII tool.

Thi

[dougjohn]

Another way to easily reset the codes and check engine light is to disconnect the battery cables for about a minute. This will clear any codes you have.

Cheers,

Doug

[Rookie]

Andrew,

Refresh my memory please. Is this the deal where you were getting a weird ca-chunk when reversing under load?

I haven't checked mine yet, but have been meaning to. Is the wiring harnest you're talking about pretty easy to identify? Any distinquishing feature's? .. other than bare wires I hope. :D

Thanks,

Rookie

[Andrewsreef]

Rookie, the Howell in reverse is another issue but I have heard other mention the noise in the snow lately so I hope it is not another problem.

The wire harness problem was causing my erratic tranny shifting and the engine misfire. THe main problems I had from day one.

Andrew

[JPI]

I'm glad that you have the problem fixed. I never run this problem but it's very nice to know.

www.jpimportz.org

[alaska_LX]

I'm glad that you have the problem fixed. I never run this problem but it's very nice to know.

www.jpimportz.org

Can someone please post a pic showing the wiring harness and wheew it frays? Thanks!

[dougjohn]

Look here:

frayed wires link

Might be one place to check.

[wooz34]

Andrew,

Refresh my memory please. Is this the deal where you were getting a weird ca-chunk when reversing under load?

I haven't checked mine yet, but have been meaning to. Is the wiring harnest you're talking about pretty easy to identify? Any distinquishing feature's? .. other than bare wires I hope. :D

Thanks,

Rookie

Rookie:

I think that I am experiencing what you described as: "weird ca-chunk when reversing under load", can you provide more information?

I was trying to back an empty ATV trailer and experienced a ca-chunk kind of a surging, no problem going forward. Tried it in low range (backing up a hill), had same result.

Thanks,

Jon

[Rookie]

Rookie:

I think that I am experiencing what you described as: "weird ca-chunk when reversing under load", can you provide more information?

I was trying to back an empty ATV trailer and experienced a ca-chunk kind of a surging, no problem going forward. Tried it in low range (backing up a hill), had same result.

Thanks,

Jon

I'm not sure I can add anything about the weird ca-chunk thing as I've not experienced that. I think I was just asking for clarification about what he was talking about.

I've always heard not to try to pull a heavy load in reverse, like pulling someone out of a ditch or something, because it's to much strain on the transmission, and it's not up to that kind of load in reverse. Wouldn't think backing a trailer up would cause a problem though.

Regards,

Rookie