Racelogic Traction Control Issues - Wierd ABS Sensor

[Guest shams]

Hi guys

Figured you guys would be the best to ask about this as i know quite a few of you are using the RLTC's

 

Any ideas for why i may be getting erratic wheel speed sensor read outs, its happening for all the wheels so doesnt look like its a faulty sensor.

I recently went to a stand alone ecu but the TC unit is taking the signals from the footwell where i believe it is directly from the wheel speed sensors itself.

 

1. The only 2 things i can think about is the TC wiring i have not shortened so is quite long and is coiled up at places.

2. The shielding that runs with the 4 wheel speed sensor cabling is not grounded anywhere

 

I am going to try these two things and see but is there anything else anyone can think of ?

Does the TC unit itself need to be screwed to the chassis for grounding or anything ?

 

http://img703.imageshack.us/img703/6898/prpt.jpg

 

http://img593.imageshack.us/img593/8625/llv6.jpg

[Guest suprageek]

There is a ground wire this may help

[Pig]

Be interested to find out your symptoms - Random occasions where the TC fails to kick in at all?

[Guest shams]

There is a ground wire this may help

Thanks for that i grounded the shielding for the wheel speed sensor wiring to the same as the ground of the unit which was to the chassis somewhere and it doesnt seem to have worked, infact i think it has made it worse as now the readings are hardly ever true, nearly always one sensor out by miles and the cut does up to 110 in places.

I noticed from the wheel speed sensor there are two wires. black and white (toyota supra) should i try connecting directly to them instead of through the cars factory loom ?

 

Be interested to find out your symptoms - Random occasions where the TC fails to kick in at all?

 

Prior to this issue with the factory computer i did have occations where it would not kick in at random times. I then started using it in the diagnostic mode all the time (unit plugged in) and then it seemed to learn from the first 3-4 times i spun the wheels and from then on would catch every time. Thing is i had to do this every time i started the car so got used to it.

Then i went to the stand alone ecu so all the wiring changes i guess as though i was using the factory loom some wiring was obsolete like the ignition out. I realised this just last week and then changed to use the tacho out which has fixed that.

[Ian C]

I had this once, with one of the wheel speed sensors erratically reporting anything up to 100mph more than the others. Turns out it was a bad RLTC unit. Swapped it for another one, and it worked perfectly. The fact the old unit rattled when we took it out was confirmation it was the unit

[Guest shams]

I had this once, with one of the wheel speed sensors erratically reporting anything up to 100mph more than the others. Turns out it was a bad RLTC unit. Swapped it for another one, and it worked perfectly. The fact the old unit rattled when we took it out was confirmation it was the unit

 

Just tried it with a brand new unit and still the same.

[Ian C]

According to the wiring diagram, only the front left hand wheel sensor has a black wire and a white wire going to it. The factory loom is pretty simple, see attached pic, so I wouldn't worry about that. If all four sensor are freaking out then you need to find a common source for the problem.

 

The front sensors go through a junction connector, one of the rears a different connector, and the other rear goes directly to the ABS ECU, so it's not going to be any of the intermediary wiring connections.

 

These wires should be shielded and the shielding is grounded off to FSS (Pin 10 A) and RSS (Pin 7 B) on the ABS ECU. All these ground points end up at IG, one of the grounds in the left-hand kick panel (passenger footwell). It's high up, not the easily visible one lower down when you take the trim off. I'd expect you to have more problems than this if that earth point was dodgy, but it's definitely worth a look, and it's the only common thing all the sensors use so far.

 

Does your ABS work? When I had my problems, the ABS system would intermittently throw a code and stop working as well.

 

Edit - attached pic of the earth point location as well. The pic is for left hand drive, so flip it in your head for RHD.

Edited November 20, 2013 by Ian C
added earth point piccy (see edit history)

[Guest shams]

Hi bud

 

thanks for your help.

The black and white wiring i am talkign about is the sensor itself before any colour coded wires start. I have only checked the rear but both sensors have black and white wires off the sensor. So looking at that diagram with colour codes should i be connecting to the + or - side ?

 

It may be because im a jap spec vvti but all the sensor wires come to the passenger footwell in a white connector which looks like IB6 (assuming we have to flip it) in your diagram.

 

No codes in ABS, have to check but i believe my abs works.

 

Thanks will try to have a look and see.

I noticed that the wires from the sensors themselves are not shielded.

One thing was with my vvti some of the wheel speed sensors were going through the ecu.

 

This is the footwell

 

VVTI TT WHITE FOOTWELL CONNECTOR:

 

Pin Wire Colour Function Destination(s)

1 Pink Unknown ECU C3

2 N/A No Connection N/A

3 N/A No Connection N/A

4 Black-White SIL (Diagnostic Connector) ECU C11

5 Yellow-Red FRO (ABS Computer) ECU H7

6 Blue-Orange FLO (ABS Computer) ECU H8

7 Red-Blue TC (Diagnostic Connector) ECU G5

8 White-Black ECU Ground ECU C22

9 Brown GND ECU D9, D21, D31, E17

10 Red Unknown ECU G14

11 Black Unknown ECU G4

12 Yellow MSW (Slip Control Off Switch) ECU H2

13 N/A No Connection N/A

14 N/A No Connection N/A

15 Green-Red RRO (ABS Computer) ECU G18

16 Purple-White RLO (ABS Computer) ECU G19

 

[Guest shams]

I forgot to add that i had this working previously or past 1-2 years and has only changed after i went to an aftermarket ecu.

[mellonman]

does the after market ecu have traction contol as it maybe conficting , or you have a loose conection in the foot well when this was fitted

[Guest shams]

does the after market ecu have traction contol as it maybe conficting , or you have a loose conection in the foot well when this was fitted

 

No traction control on the new ecu, even if it did the doesnt explain why the racelogic TC is picking up these readings and then kicking in.

Seems odd but yes could be a loose connection somewhere in the wiring that i cant see.

That was the next step to wire it directly to the sensors.

[mellonman]

if the new ecu has those sensors wired in then it might put a signal on the line or draw the voltage down enough to cause a issue , that is why i surgested the ecu as a possible cause

[Guest shams]

really ? not being silly but do some aftermarket ecu's that have traction control over ride the wheel speed sensors ?

Drawing down more current i can understand.

I wonder if i can measure the current across the sensor and see if it is up to "par"

[mellonman]

im not sure what you mean be traction control over ride for the sensors, but yes some standalone ecu's have traction control, launch contol, 2step, anti lag ect

when i signal on the sensor i simply mean interferance from the ecu

 

if they are conected and your standalone does not use them disconnect them so you know you have a clean sensor signal

[Guest shams]

hey guys

 

Anyone know whats the difference between a Front Speed Sensor and a FLO Abs Computer

 

eg

 

6 Blue-Orange FLO (ABS Computer) ECU H8

 

and

 

19 FL+ White Left Front Speed Sensor Pin 2

20 FL- Black Left Front Speed Sensor Pin 1

 

Im assuming i should have been connecting to the +ve pin2 terminals but i have been using the Abs computer outputs ? (FLO, FRO, RRO, RLO).

Rewired it tonight but didnt want to wake up the neighbours to test so will try in the morning.

[Guest shams]

Thought i would update this thread.

I was taking the wrong inputs for the wheel speed sensors.

Well I was taking the abs ecu output readings marked as FLO, RRO etc.

I think after taking out my factory ecu this has affected it somewhat.

So managed to find the vvti wiring diagram for abs/traction control unit and rewired everything.

SPOT on, now need to fine tune in a little as it was kicking in sometimes on full throttle with a hard cut.

Thanks guys for your help.