98 LS400 getting "VSC" + "Check Engine" and throttle-cutoff
11-28-16, 01:30 AM
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98 LS400 getting "VSC" + "Check Engine" and throttle-cutoff
Hi,
just ran in trouble with my 98 LS400... Owning it >4 years from 165.000 km up to now 348.000 km
yes "Kilometers", I´m living in germany, so my lex had to eat up some distances on german autobahn the last years.
It´s my best car so far, I owned a GS300, Audi A4 V6 quattro, Mercedes Class E limo and some other stuff... no one beats a LS400!
Now, my problems with the lex started some weeks ago it locked in full throttle. It happened twice when accelerating on the autobahn, little frightening but I changed from "D" to "N" and switched off the engine.
When restarted, it drove like nothing happened....
Last week, i drove long distance across germany from south up in the east near Berlin, when the throttle was cut off while accelrating -oups... and "VSC" light came on and "Check Engine". The CruiseControl switched of, too.
Engine still running, but no throttle, just nothing... It was nearly midnight, I checked the throttle cable, was fine. Checked the wheel on the throttlebody, turned like always, I noticed it did not catch the throttlevalve until the last 2 or 3mm when turning the wheel.
OK, it is controlled electronically, only mechanical backup is in the last 2-3 mm on the wheel. So I drove home the last 250 km with WOT and it only revs up to 2200/2300 rpm and about ~ 65 mph.
Next day i cleaned the TB, all the small wholes and the 2 big ones, resetted the ecu, car ran fine for 10-15 minutes, then the game started again: No throttle, "VSC" and "Check Engine".
Ok , got a guy who checked my ECU, I got:
ENGINE ECU
P0135 Fault O² sensor Bank 1 sensor 1
P1128 ThrottleValvemotor locked
ABS/VSC ECU
C0371 Yawratesensor signal out faulty
C1208 steeringanglesensor signal out faulty
C1271 Low voltage front rpmsensor right
C1272 Low voltage front rpmsensor left
C1273 Low voltage rear rpmsensor right
C1274 Low voltage rear rpmsensor left
C1275 abnormal change of voltage rpmsensor front right
C1276 abnormal change of voltage rpmsensor front left
C1281 Maincylinderpressuresensor faulty
C1277 abnormal change of voltage rpmsensor rear right
C1278 abnormal change of voltage rpmsensor rear left
It may occure from:
Faulty ECU? Condensators....
Vaccuumsensor steeringpump getting oil in and weiring up the ecu?
EGR flexible piping cracked?
Powersteering runs fine, little oiling on the sealings left....
Its getting cold outside now, and I have no possibilty to wrench inside, so any help/advice is welcome!
Thanks Flo
edit:
Fuel-/air- and oilfilter are 8.xxx km old, as new, car is in really good overallcondition, I really care about my "bigblackwhale"
TB was pulled fully off and cleaned carefully, it was really sticky and dirty around the valveplate - so it looks like I had the problem for the sticking WOT...
just ran in trouble with my 98 LS400... Owning it >4 years from 165.000 km up to now 348.000 km
yes "Kilometers", I´m living in germany, so my lex had to eat up some distances on german autobahn the last years.
It´s my best car so far, I owned a GS300, Audi A4 V6 quattro, Mercedes Class E limo and some other stuff... no one beats a LS400!
Now, my problems with the lex started some weeks ago it locked in full throttle. It happened twice when accelerating on the autobahn, little frightening but I changed from "D" to "N" and switched off the engine.
When restarted, it drove like nothing happened....
Last week, i drove long distance across germany from south up in the east near Berlin, when the throttle was cut off while accelrating -oups... and "VSC" light came on and "Check Engine". The CruiseControl switched of, too.
Engine still running, but no throttle, just nothing... It was nearly midnight, I checked the throttle cable, was fine. Checked the wheel on the throttlebody, turned like always, I noticed it did not catch the throttlevalve until the last 2 or 3mm when turning the wheel.
OK, it is controlled electronically, only mechanical backup is in the last 2-3 mm on the wheel. So I drove home the last 250 km with WOT and it only revs up to 2200/2300 rpm and about ~ 65 mph.
Next day i cleaned the TB, all the small wholes and the 2 big ones, resetted the ecu, car ran fine for 10-15 minutes, then the game started again: No throttle, "VSC" and "Check Engine".
Ok , got a guy who checked my ECU, I got:
ENGINE ECU
P0135 Fault O² sensor Bank 1 sensor 1
P1128 ThrottleValvemotor locked
ABS/VSC ECU
C0371 Yawratesensor signal out faulty
C1208 steeringanglesensor signal out faulty
C1271 Low voltage front rpmsensor right
C1272 Low voltage front rpmsensor left
C1273 Low voltage rear rpmsensor right
C1274 Low voltage rear rpmsensor left
C1275 abnormal change of voltage rpmsensor front right
C1276 abnormal change of voltage rpmsensor front left
C1281 Maincylinderpressuresensor faulty
C1277 abnormal change of voltage rpmsensor rear right
C1278 abnormal change of voltage rpmsensor rear left
It may occure from:
Faulty ECU? Condensators....
Vaccuumsensor steeringpump getting oil in and weiring up the ecu?
EGR flexible piping cracked?
Powersteering runs fine, little oiling on the sealings left....
Its getting cold outside now, and I have no possibilty to wrench inside, so any help/advice is welcome!
Thanks Flo
edit:
Fuel-/air- and oilfilter are 8.xxx km old, as new, car is in really good overallcondition, I really care about my "bigblackwhale"
TB was pulled fully off and cleaned carefully, it was really sticky and dirty around the valveplate - so it looks like I had the problem for the sticking WOT...
Last edited by Aristsojzs; 11-28-16 at 01:42 AM.
11-28-16, 02:10 AM
#2
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Found this...
Gear ratio = Yaw rate?
when VSC and Check Engine on the tranny really shifts hard and "not comfotabel"
I own a transmission shop in Miami,Fl and have ran into this problem a few times.... First have a shop with an OBD II scanner that has the software to get into the TRANSMISSION side (not same as gen codes or driveability) check for gear ratio error code,If there clear code and drive again POOF! 99 out of 100 problem is gone! usually caused by playing with or bumping ECT power switch/OD cancel switch or moving selector during shift. ECM reads SLIP and sends pressure solenoid to Max to preserve unit.... Best advice do not ride around with hand on shifter and keep Li'l crumb snatchers in back seat away from pretty brite lites...Big Rob
when VSC and Check Engine on the tranny really shifts hard and "not comfotabel"
11-28-16, 02:58 AM
#3
The good news is it proves the carpet making the cars go full throttle is a fallacy, also it proves your car likes going fast down the autobahn. First things first, I'd be checking out that throttle motor real good, and the variable resistor for the pedal too as well as wiring to it. I'm not sure but I think the pedal has a cable that goes to the resistor on those cars? I'm not a 98 LS person so I don't know. Other codes, check fuses and electrical connectors.
11-28-16, 03:36 AM
#4
Moderator
Failed ECU capacitors often cause the harsh tranny shifts among 98-00 models first among other engine/tranny failures. I'd check the ripple as is introduced in the FAQ page.
Models between 98 and 00 consume less DC energy due to the new devices and those don't stress capacitors compared with earlier models but still those use QAS capacitors that cause the corrosion and the leaking problem as aged. It has been nearly 20 years and we have to be careful for the failure of QAS capacitors.
Models between 98 and 00 consume less DC energy due to the new devices and those don't stress capacitors compared with earlier models but still those use QAS capacitors that cause the corrosion and the leaking problem as aged. It has been nearly 20 years and we have to be careful for the failure of QAS capacitors.
11-29-16, 12:32 AM
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The good news is it proves the carpet making the cars go full throttle is a fallacy, also it proves your car likes going fast down the autobahn. First things first, I'd be checking out that throttle motor real good, and the variable resistor for the pedal too as well as wiring to it. I'm not sure but I think the pedal has a cable that goes to the resistor on those cars? I'm not a 98 LS person so I don't know. Other codes, check fuses and electrical connectors.
Yes cable goes in front to TB, but the throttlevalve only moves by electronic controlled motor
All sensors are fine, I´ll check the ecu caps like Yamae adviced...
Thanks guys!
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