Boblex

On my 1999 RX, ABS light is solid on all the time when engine is on. No problems with car itself. I need help with troubleshooting this problem.

maxSteel

See this post:
https://www.clublexus.com/forums/rx-...ml#post6890808

While the trouble code list looks good I don't know if the procedure is.

The diagnostic manual says "To access the diagnostic codes"
Open DLC1
Disconnect the short pin (bottom right)
Junper Tc and E1
Turn the ignition switch on and count the ABS light pulses.

When there has been a malfunction the pattern will be 4 seconds pause, then first digit begins. Number of times lamp blinks before a 1.5 second pause is the first digit. Then second digit.
If there is more than one code the lowest code number will be first, then a 2.5 second pause, then next code number.

To clear the abs codes:
open DLC1
remove short pin
jumper Tc and E1
turn key on
hit brake pedal 8+ times in 3 seconds

Don't forget to put the short pin back when you are done.

jkp356

I tried to jumper the tc and e1 on the round diagnostic module under the dash and when I turn the ignition on, the cruise and airbag lights flash but the abs light stays solid. Tapping the brake pedal multiple times does nothing. Any help appreciated.

maxSteel

It's not under the dash, it's under the hood.

salimshah

under the hood it is DLC1 rectangular box. TC-E1
If you use DLC2, the round one near the shin area of the driver TC-E

Look for flashing ABS OR flashing TRACK OFF when you turn the ignition to on/run

Count flashing two digit sequence flash-flash pause flash long pause repeat [21]
If there are more than one code then the long pause will be followed by the next error flashes.

To clear disconnect the battery or pump the brake 8 times or more within 5 sec with the above jumper in place.

Remember to remove the jumper before starting the RX

I have few more code description than the list in the thread mentioned my MaxSteel.

I get code 43 when it gets hot. In winter, there is no problem. Also I have the Traction control option in '99 model. That requires a unique pump, which is not readily available. 4454048020 (most likely)



Salim

salimshah

Late update:

My ABS codes were due to bad alternator. Battery died and overladed the alternator leading to demise of a couple of diodes. Once I replaced the diodes the dc voltage n=became stable. With the few diodes gone there were gaps in the charging cycle, which sent spikes down the +12v line and into the ABS computer module.

I wasted many hours chasing a ghost.

Salim

Roop10

Battery & abs lights came on and car died about 30mins later. Replaced alternator, battery light went off. Went to head home, same thing, lights came on. I smelt something different than any fluid I've smelt or plastic melting, made it home, saw smoke, popped the hood and one of the battery caps had blown off and blew battery acid everywhere. On the battery terminal leads, I had to clean what I could and what I couldn't, I replaced with the same gauge wire. I checked the battery, even though it says it's good n it could be having a cell go bad. Checked alt. it's good. Only issue is if I give it more throttle at idle, my battery tester goes over 16v-17.48v & it says "high voltage, turn engine off". I've got some sort of electrical issue going on and it's got me thinking it wasn't from the battery acid but from the battery itself or ecu throwing too much to & from the alternator? I've had a parasitic draw but thought it was just from the blend door actuator going off randomly when the car isn't running. But now I'm starting to think it's something else causing battery to drain but it's not done it in the last couple of days. I'm all ears if someone has a starting point

maxSteel

When you rev it the voltage is spiking. The regulator is built in to the alternator.

salimshah

I hope nothing else fried. See if you can hold the shop responsible for selling you a bad alternator which has caused the obvious and I hope nothing else.

Salim

Roop10

I know that it is built in. I bought it and installed it, I do my own mechanic work and have done everything to my RX myself and this one is about to make me pull out the power probe 4 and figure this issue out. I just put a new battery in it today and the battery light & abs lights are still on so I'm going to hook up my scanner and try to reset the battery light. Some vehicles don't have all 28 special reset functions in the particular scanner I bought a few months back. I figured I'd post about the issue incase someone had seen something similar in here because I hadn't used CL in awhile, several years actually because I hadn't needed to use it. I still have the factory alternator. I gave them one off a parts truck I have as a core just incase mine was still good. BTW it has 216k on it, I bought it at 116k.

salimshah

I followed up in another thread, but my ABS problem went away after I replaced the diode pack in the alternator. I had couple of diodes that were open, causing dead phases and ripple on the output. The troubleshooting guide for ABS clearly states to verify the voltage is good.

If you still have the original alternator, servicing it is fairly easy. I replaced the brushes, diodes and the voltage controller. Bearings were good and slip rings needed fine emry paper touch. I was expecting heavy soldering, but every thing is screwed down in place.

Salim

Roop10

I'll take my original alternator apart and see what I find. Did you buy the factory brush kit, etc online or at a local alternator repair shop? Also I should have mentioned the ABS light only comes on when the engine is driven or revved to 2500rpms.

salimshah

I suspect you you still are getting over-voltage as you rev up. It should be around 14.2 on the high side.
I ordered the parts through Bell Lexus (Arizona?), an on line retailer.

I do my own repairs and can not afford testing parts from unknown manufacturer and retailer. I save on the labor and spend extra on parts. I alway check with local Lexus dealer to establish a base point on cost [no shipping cost]. Lot of folks may disagree with my approach, but I have never had any issue due to fit or non-working part.

Salim