Trac Issues (no Cel) On 1990 Ls400

[new2mud]

I live at high altitude and am getting the OBDI TRAC errors 19 (accumulator pressure leakage) and 51 (engine computer error). I am not getting any CEL light in conjunction, so that rules out O2 sensors, etc.

I have heard that if the TRAC motor has to run for 10 consecutive brake presses then it will trip code 19. However, mine will trip after a period of time on the road even without pressing the brake.

Here's the catch: When I drove down to sea level this past weekend the TRAC light did NOT light up at ALL during the duration I was at lower altitude. When I drove back up to altitude, sure enough, it tripped again.

Any thoughts as to how the altitude is causing this problem?

[pishta]

I live at high altitude and am getting the OBDI TRAC errors 19 (accumulator pressure leakage) and 51 (engine computer error). I am not getting any CEL light in conjunction, so that rules out O2 sensors, etc.

I have heard that if the TRAC motor has to run for 10 consecutive brake presses then it will trip code 19. However, mine will trip after a period of time on the road even without pressing the brake.

Here's the catch: When I drove down to sea level this past weekend the TRAC light did NOT light up at ALL during the duration I was at lower altitude. When I drove back up to altitude, sure enough, it tripped again.

Any thoughts as to how the altitude is causing this problem?

You live at lower ambient air pressure at altitude, I wonder if the sensor is so sensetive that it detects the lower ambient air pressure as a leak? I would get a call into a Denver Lexus dealership and try and talk to a master tech there, see if he has ever heard of that problem.

[new2mud]

You live at lower ambient air pressure at altitude, I wonder if the sensor is so sensetive that it detects the lower ambient air pressure as a leak? I would get a call into a Denver Lexus dealership and try and talk to a master tech there, see if he has ever heard of that problem.

It worked fine for 1 winter, 1 summer, and now as winter cold sets in is when it is getting triggered. (Of course it's buggering up when I'll need it most!)

[new2mud]

Anyone else with experience?

I'll do a complete brake fluid flush (+ trac flush) today and see if that helps.

[Bali26]

I had the same problem as you.

Remove ect fuse for an hour to reset computer. Then jump Tc and E1 points on ODB diagnose under the parking brake lever. Press brake more than 8 times in 3 sec to reset trac. Just keep tapping fast and it will reset.

That solved it for me.

[new2mud]

I had the same problem as you.

Remove ect fuse for an hour to reset computer. Then jump Tc and E1 points on ODB diagnose under the parking brake lever. Press brake more than 8 times in 3 sec to reset trac. Just keep tapping fast and it will reset.

That solved it for me.

I had already done the ecu reset and ODB jump/clearing the codes. It came right back on the first drive (after a few minutes).

I did a complete fluid flush including TRAC actuator and accumulator this past weekend--haven't been able to drive it long enough for it to come back on--will hope that solved it, as it has for some others.

[aarman4]

I am just wondering(as I had this problem), is there a chance your CEL is burnt out?

[Bali26]

But you didn't do the brake tap reset + Ect (at the same time)?