Troubleshooting

Durandal · 08-26-2008, 07:03 PM

I just got a 1993 J-Spec supra tt and although I've been reading forums for quite awhile on possible problems before I even got it, some things I am unclear on.

When I turn the ignition on all my dash lights come on except for the cluster on the right with oil level, oil temp, and check engine and nothing in the little screen above those although that one kind of looks like nothing would display there anyway.

The reason I'm asking is I have been getting a warning light come on randomly when I'm driving and sometimes it goes off but mostly stays on. At first I thought it was a problem with the active front spoiler's auto feature which I found people with aftermarket stereos have problems with. I do have an aftermarket japanese stereo that was in the car when I bought it.

Some times when I start up the car, mostly a cold start, I can hear kind of a rattling coming from the back end and it idles low around 500rpm.

So I'm starting to get paranoid and want to do some troubleshooting. When I jumper E1 and TE1 in the diagnostic port 1 or 2 nothing happens to tell me if there are any problem codes.

Does any of this sound familiar or does anyone have any trouble shooting tips I can start with?

Thanks and sorry for the long post.

Durandal · 08-26-2008, 08:42 PM

OK the electrical connection to that cluster of telltale lights is bad and after taking it apart and taking out the LED's and putting them back in on whats left of the copper coating, I got them working.

Bad news is I do have 2 error codes

14 and 42

14 is Ignition signal, I don't know about this one and doesn't seem like a problem to me so I think I will clear it and see if it comes back.

42 is Speed Sensor, I'm pretty sure the speed sensor is on its way out just due to how its been acting and from what I hear is a common thing to go bad.

I just got to figure out a way to keep the check engine cluster from losing electrical connection.

pwpanas · 08-27-2008, 12:13 AM

Quote:

Originally Posted by Durandal

OK the electrical connection to that cluster of telltale lights is bad and after taking it apart and taking out the LED's and putting them back in on whats left of the copper coating, I got them working.

Quote:

Originally Posted by Durandal

Bad news is I do have 2 error codes

14 and 42

14 is Ignition signal, I don't know about this one and doesn't seem like a problem to me so I think I will clear it and see if it comes back.

42 is Speed Sensor, I'm pretty sure the speed sensor is on its way out just due to how its been acting and from what I hear is a common thing to go bad.

I just got to figure out a way to keep the check engine cluster from losing electrical connection.

Regarding the speed sensor signal, it's possible the problem is with the oem odometer cluster. Note these instructions are for the USDM-spec Mkiv-TT:

Remove the dash trim that houses the Odometer, on the odometer harness find the pink wire and cut it then splice the pink wire with the blue and red VSS input wire.

First try resolder the cold solder points on the board.

More info here:
http://www.mkiv.com/techarticles/trac_off_mil_odo/index.html

Durandal · 08-27-2008, 04:23 PM

Pulled the Check Engine light cluster out again to inspect the connections once more and I did find that some of the solder joints had broke off. After re-soldering them the telltale lights work fine.

When I started the supra up today it made some rattling and choking noises than preceded to rev from 500 RPM to 1500 RPM. I definitely need to look into the speed sensor fault more.

*Edit: I reset the ECU and then took it for spin to see if anything came back up. After driving it for about 10 mins and putting it through all the gears except 6, the engine light came on along with the warning light. I brought it back to the house to check the ECU code. I noticed it randomly revving up and down a bit while I let it run for about 2 mins before shutting it off.

Only Code 42 came back up after checking the ECU.

*Edit2: After doing a lot of reading on many different supra forums I have come to the conclusion the speed signal is getting lost in the buffer that happens in the ODO. I'm going to touch-up solder all my connections on the ODO cluster tomorrow and see if it gets resolved. If not I will just bypass the buffer by cutting the pink wire as Phil has mentioned.

Durandal · 08-29-2008, 12:50 AM

Cleaned up all my solder connections in my ODO and took it for a long test drive. I did not have any warning lights come on or code 42.

I was running low on gas so I filled up at what used to be a shell station where I got V-Power gasoline. After I had completely filled the tank I realized it wasn't shell anymore and the pumps were Ultramar. I had got the 91 Octane Supreme fuel. Will this be all right for my Supra? The reason I'm asking is 5 minutes later right in front of my house the car stalled.

Also on the way back I tried the cruise control. Pushed in the button the light came on and I clicked it down to set the speed and took my foot of the gas and it did not maintain speed. Is my cruise not working or am I missing something in the operation.

pwpanas · 08-30-2008, 05:26 AM

Quote:

Originally Posted by Durandal

...Also on the way back I tried the cruise control. Pushed in the button the light came on and I clicked it down to set the speed and took my foot of the gas and it did not maintain speed. Is my cruise not working or am I missing something in the operation.

Try holding it down for a few seconds (i.e. not just a click)...and be sure you're over 40mph.

Quote:

Originally Posted by Durandal

...*Edit2: After doing a lot of reading on many different supra forums I have come to the conclusion the speed signal is getting lost in the buffer that happens in the ODO. I'm going to touch-up solder all my connections on the ODO cluster tomorrow and see if it gets resolved. If not I will just bypass the buffer by cutting the pink wire as Phil has mentioned.

Um....my post above mentioned more than just cutting the pink wire, right? Either way, I'm glad that the ODO turned out to be the problem - hopefully my post (and not just the "many other supra forums" you read) helped you to isolate it.

mnewxv · 08-30-2008, 05:35 AM

91 octane shouldnt have any bad side effects. its spec.

Durandal · 08-30-2008, 02:38 PM

Quote:

Um....my post above mentioned more than just cutting the pink wire, right? Either way, I'm glad that the ODO turned out to be the problem - hopefully my post (and not just the "many other supra forums" you read) helped you to isolate it.

Yah I cut the pink wire coming out of the connector and spliced it to the red/blue one to bypass the ODO buffering thing. Your post was where I first read about bypassing the ODO buffer circuit and just tying the speed sensor directly to the cruise,PSteer,AS and electronic idling. I was looking on other supra forums to try and find a high volume of people with this exact problem and see if this was a test and tried fix.

On a side note when I did have my ODO cluster off I noticed on the very bottom right hand corner of the ODO display was a burn mark from within the sealed plastic display. Looking through the side of it I could see an electrical component but I don't know what it is.

*Edit: Took the car out for a test run this morning after the ODO wire fix. Cruise control works (just had to hold it down for about 5 seconds like you said). Active fron spoiler works automatically at 90km/h. Also I have not been able to reproduce the error 42 while going up hills or load driving

. Now I just need to clean her up and get some new rubber stops for the hatch. The ones in there now are the originals and are old and hard and bumps make the hatch rattle.

One question about the slip diff. (think its called TRAC in the USDM's). When I turn the ignition on for the telltale light test, I get two Lights related to slip diff.

Slip On
Slip Off

When I push the button to turn the slip off the lgiht comes on which is good. When I leave slip on I don't get a slip on light though. Does this light only come on when the slip diff kicks in?

mag · 10-09-2008, 07:27 AM

hi, first off thank you to those whove taken the time to post this fix online.

I too have the following lights on. JDM twin turbo AT

/!\ master warning - always on
O/D off - off at start up, on flashing after couple blocks of driving slow speeds
MIL engine check light - off after start up, on after reach prolonged highway crusing speeds or load.
Traction control OFF - always on, no flash
TRAC OFF - never on even at start up
(!) hand brake light - ON always

Just got the car, removed a speed meter/cut electronic device (left 2 wires connected to ECU but taped sealed open wire ends. Removed the turbo timer completely. Left the HKS fuel cut defenser. Cleaned up all taps that lead to open wires. It was a mess...

The indacator module that reads ABS, TRAC OFF etc ... has been tapped from circuit to circuit frankenstein style. ABS, Oil level still comes on at start then off which is all I need from this module so I left it alone. But I suspect that's why the trac off is always off. I don't like to use this function anyways so no problem there.

auto spoiler plug plugged in but no light. There was at one point, it flashed constantly as i have disconnected the auto spoiler. Dont use this so dont mind that it doesnt light up however i wonder if this hints to a problem area in the harness .

did the diagnostic check. code 42.

I did the pink blue/red wire splice procedure. AT fluids on mark at cold/hot. But the light still flashes. Car appears to be shifting fine ie no irratic searching. ODO appears to be counting. I have an aftermarket steering wheel that deletes the cruise control and SRS so no issues there.

I've read all the posts on the internet on this issue. Still left with this question...

If my tach and ODO and speedo are working normally. Then I guess the no.1 speed sensor is working. I'm terrible with the solder iron thus did the splice fix. Since this did not work, am I correct to assume the solder fix ( plus reverse splice fix) will not make a difference as well?

I assume the master /!\ light is on because of the code 42 or is it off because of my traction control always off? Im not sure how this was achieved. Also interesting of note. There is no speed limiter on my car. I can easily pass the 180km/hr mark but no electronic devices found. 7.5 TRAC fuse is plugged in. But Traction Control OFF stays on, control buttom lights up but no response when pressed.

Question: the pink wire feeds the odometer with the signal which is said to "buffer" or process this signal before it's sent back out via the blue/red wire out. So if this is spliced, then effectively a step in the process has been skipped. If this is true, than this means an incorrect or inaccurate signal is then sent out. Quite perplexed by this... this is the only reason i can think of that explains why my O/D is still flashing after the "fix" unless there's some other variable I haven't pinpointed yet.

Thanks in advance.

pwpanas · 10-30-2008, 07:39 PM

Quote:

Originally Posted by mag

hi, first off thank you to those whove taken the time to post this fix online.

I too have the following lights on. JDM twin turbo AT

/!\ master warning - always on
O/D off - off at start up, on flashing after couple blocks of driving slow speeds
MIL engine check light - off after start up, on after reach prolonged highway crusing speeds or load.
Traction control OFF - always on, no flash
TRAC OFF - never on even at start up
(!) hand brake light - ON always

Just got the car, removed a speed meter/cut electronic device (left 2 wires connected to ECU but taped sealed open wire ends. Removed the turbo timer completely. Left the HKS fuel cut defenser. Cleaned up all taps that lead to open wires. It was a mess...

The indacator module that reads ABS, TRAC OFF etc ... has been tapped from circuit to circuit frankenstein style. ABS, Oil level still comes on at start then off which is all I need from this module so I left it alone. But I suspect that's why the trac off is always off. I don't like to use this function anyways so no problem there.

auto spoiler plug plugged in but no light. There was at one point, it flashed constantly as i have disconnected the auto spoiler. Dont use this so dont mind that it doesnt light up however i wonder if this hints to a problem area in the harness .

did the diagnostic check. code 42.

I did the pink blue/red wire splice procedure. AT fluids on mark at cold/hot. But the light still flashes. Car appears to be shifting fine ie no irratic searching. ODO appears to be counting. I have an aftermarket steering wheel that deletes the cruise control and SRS so no issues there.

I've read all the posts on the internet on this issue. Still left with this question...

If my tach and ODO and speedo are working normally. Then I guess the no.1 speed sensor is working. I'm terrible with the solder iron thus did the splice fix. Since this did not work, am I correct to assume the solder fix ( plus reverse splice fix) will not make a difference as well?

I assume the master /!\ light is on because of the code 42 or is it off because of my traction control always off? Im not sure how this was achieved. Also interesting of note. There is no speed limiter on my car. I can easily pass the 180km/hr mark but no electronic devices found. 7.5 TRAC fuse is plugged in. But Traction Control OFF stays on, control buttom lights up but no response when pressed.

Question: the pink wire feeds the odometer with the signal which is said to "buffer" or process this signal before it's sent back out via the blue/red wire out. So if this is spliced, then effectively a step in the process has been skipped. If this is true, than this means an incorrect or inaccurate signal is then sent out. Quite perplexed by this... this is the only reason i can think of that explains why my O/D is still flashing after the "fix" unless there's some other variable I haven't pinpointed yet.

Thanks in advance.

As far as I know, the odo doesn't "buffer" the speed sensor signal - the odo simply acts as a pass-through.

08-26-2008, 07:03 PM	#1
Durandal Intake Join Date: Aug 2008 Location: Canada Posts: 42	Troubleshooting I just got a 1993 J-Spec supra tt and although I've been reading forums for quite awhile on possible problems before I even got it, some things I am unclear on. When I turn the ignition on all my dash lights come on except for the cluster on the right with oil level, oil temp, and check engine and nothing in the little screen above those although that one kind of looks like nothing would display there anyway. The reason I'm asking is I have been getting a warning light come on randomly when I'm driving and sometimes it goes off but mostly stays on. At first I thought it was a problem with the active front spoiler's auto feature which I found people with aftermarket stereos have problems with. I do have an aftermarket japanese stereo that was in the car when I bought it. Some times when I start up the car, mostly a cold start, I can hear kind of a rattling coming from the back end and it idles low around 500rpm. So I'm starting to get paranoid and want to do some troubleshooting. When I jumper E1 and TE1 in the diagnostic port 1 or 2 nothing happens to tell me if there are any problem codes. Does any of this sound familiar or does anyone have any trouble shooting tips I can start with? Thanks and sorry for the long post.

08-26-2008, 08:42 PM	#2
Durandal Intake Join Date: Aug 2008 Location: Canada Posts: 42	OK the electrical connection to that cluster of telltale lights is bad and after taking it apart and taking out the LED's and putting them back in on whats left of the copper coating, I got them working. Bad news is I do have 2 error codes 14 and 42 14 is Ignition signal, I don't know about this one and doesn't seem like a problem to me so I think I will clear it and see if it comes back. 42 is Speed Sensor, I'm pretty sure the speed sensor is on its way out just due to how its been acting and from what I hear is a common thing to go bad. I just got to figure out a way to keep the check engine cluster from losing electrical connection. Last edited by Durandal; 08-26-2008 at 08:51 PM.

08-27-2008, 04:23 PM	#4
Durandal Intake Join Date: Aug 2008 Location: Canada Posts: 42	Pulled the Check Engine light cluster out again to inspect the connections once more and I did find that some of the solder joints had broke off. After re-soldering them the telltale lights work fine. When I started the supra up today it made some rattling and choking noises than preceded to rev from 500 RPM to 1500 RPM. I definitely need to look into the speed sensor fault more. Edit: I reset the ECU and then took it for spin to see if anything came back up. After driving it for about 10 mins and putting it through all the gears except 6, the engine light came on along with the warning light. I brought it back to the house to check the ECU code. I noticed it randomly revving up and down a bit while I let it run for about 2 mins before shutting it off. Only Code 42 came back up after checking the ECU. Edit2: After doing a lot of reading on many different supra forums I have come to the conclusion the speed signal is getting lost in the buffer that happens in the ODO. I'm going to touch-up solder all my connections on the ODO cluster tomorrow and see if it gets resolved. If not I will just bypass the buffer by cutting the pink wire as Phil has mentioned. Last edited by Durandal; 08-28-2008 at 01:21 AM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Electrical Troubleshooting	go.stfu	MKIII Supra	0	10-21-2007 09:32 PM
Clutch Troubleshooting	ivire	MKIII Supra	9	11-09-2006 01:29 AM
fog light troubleshooting	SupraBoy	MKII Supra	6	10-31-2006 09:07 AM
troubleshooting	wishesforjdmswap	MKIII Supra	8	07-26-2006 07:09 AM
Electrical troubleshooting	claymore	Non-Generation Specific Questions	2	04-17-2005 01:15 PM

08-29-2008, 12:50 AM	#5
Durandal Intake Join Date: Aug 2008 Location: Canada Posts: 42	Cleaned up all my solder connections in my ODO and took it for a long test drive. I did not have any warning lights come on or code 42. I was running low on gas so I filled up at what used to be a shell station where I got V-Power gasoline. After I had completely filled the tank I realized it wasn't shell anymore and the pumps were Ultramar. I had got the 91 Octane Supreme fuel. Will this be all right for my Supra? The reason I'm asking is 5 minutes later right in front of my house the car stalled. Also on the way back I tried the cruise control. Pushed in the button the light came on and I clicked it down to set the speed and took my foot of the gas and it did not maintain speed. Is my cruise not working or am I missing something in the operation.

08-30-2008, 05:35 AM	#7
mnewxv 3" Exhaust Join Date: Aug 2008 Location: melrose, ma Posts: 108	91 octane shouldnt have any bad side effects. its spec.

10-09-2008, 07:27 AM	#9
mag Stock Join Date: Aug 2008 Location: HK Posts: 2	hi, first off thank you to those whove taken the time to post this fix online. I too have the following lights on. JDM twin turbo AT /!\ master warning - always on O/D off - off at start up, on flashing after couple blocks of driving slow speeds MIL engine check light - off after start up, on after reach prolonged highway crusing speeds or load. Traction control OFF - always on, no flash TRAC OFF - never on even at start up (!) hand brake light - ON always Just got the car, removed a speed meter/cut electronic device (left 2 wires connected to ECU but taped sealed open wire ends. Removed the turbo timer completely. Left the HKS fuel cut defenser. Cleaned up all taps that lead to open wires. It was a mess... The indacator module that reads ABS, TRAC OFF etc ... has been tapped from circuit to circuit frankenstein style. ABS, Oil level still comes on at start then off which is all I need from this module so I left it alone. But I suspect that's why the trac off is always off. I don't like to use this function anyways so no problem there. auto spoiler plug plugged in but no light. There was at one point, it flashed constantly as i have disconnected the auto spoiler. Dont use this so dont mind that it doesnt light up however i wonder if this hints to a problem area in the harness . did the diagnostic check. code 42. I did the pink blue/red wire splice procedure. AT fluids on mark at cold/hot. But the light still flashes. Car appears to be shifting fine ie no irratic searching. ODO appears to be counting. I have an aftermarket steering wheel that deletes the cruise control and SRS so no issues there. I've read all the posts on the internet on this issue. Still left with this question... If my tach and ODO and speedo are working normally. Then I guess the no.1 speed sensor is working. I'm terrible with the solder iron thus did the splice fix. Since this did not work, am I correct to assume the solder fix ( plus reverse splice fix) will not make a difference as well? I assume the master /!\ light is on because of the code 42 or is it off because of my traction control always off? Im not sure how this was achieved. Also interesting of note. There is no speed limiter on my car. I can easily pass the 180km/hr mark but no electronic devices found. 7.5 TRAC fuse is plugged in. But Traction Control OFF stays on, control buttom lights up but no response when pressed. Question: the pink wire feeds the odometer with the signal which is said to "buffer" or process this signal before it's sent back out via the blue/red wire out. So if this is spliced, then effectively a step in the process has been skipped. If this is true, than this means an incorrect or inaccurate signal is then sent out. Quite perplexed by this... this is the only reason i can think of that explains why my O/D is still flashing after the "fix" unless there's some other variable I haven't pinpointed yet. Thanks in advance.