96 ls400 - abs light on, will not go into gear, improper alt charging


auctionjunkie
07-22-2015, 10:47 PM
Vehicle: 1996 Lexus LS400 200k miles (bought from car auction)

The vehicle ran fine on road trips until the following occurred on a recent 100 mile trip.

Symptoms:

1. Will not come out of park without shifter release override button pressed down
2. Yellow ABS light to left of dash is on
3. Cruise Control inoperable
4. Unresponsive when additional power is needed on freeway
5. At end of 100 mile trip, instrument cluster went blank, vehicle lost all power


Troubleshooting performed:

1. 12.5 volts at battery with vehicle off, 12.2 volts with vehicle on (I recharged the battery and it turns over and idles fine, holds a charge if left alone for a couple of days)
2. Took alternator off and took it to auto parts store, the alternator has no issues (fairly new looking rebuilt denso).. the battery also checked out fine, Lexus battery, 84 month warranty
3. No check engine code, OBD2 port works, I disconnected the MAF and the CEL came on with the correct code reading.
4. Removed ECU and visually inspected for leaky capacitors, the board was in perfect shape.
5. All brake lights work when I step on the brake pedal
6. Checked left trunk hinge for faulty wiring, everything looks like it's in tiptop condition
7. Checked all fuses under dash and hood, everything is good. Did not check relays.
8. Cleaned all terminals and links at battery.

I'd like to know if this is one problem causing the shift, cruise, and charging issues or if they are two separate issues. I hear clicking in the ignition switch when I step on the brake pedal and move the shifter, but i don't hear the solenoid beneath the shifter click.

Can this be the ignition switch? What would cause all those problems to occur simultaneously? How shall I proceed? Thanks

Brian R.
07-23-2015, 07:50 AM
Check the quality of the wire and connections between the battery and the fusebox. Sometimes it becomes bad and causes unpredictable symptoms.

Check the voltage of the alternator from terminal "B" (main connection) to ground at fast idle with terminal "B" wire disconnected. Should be 13.2 - 14.8 V. If high, voltage regulator is bad. If low, ground terminal "F" on voltage regulator. Check voltage from terminal "B" to ground. If low, alternator is bad, if high, voltage regulator is bad.

Add your comment to this topic!