Over Excitable Traction Control

[Aussie]

Hi all,

Can anyone tell me if the traction control system in the NP pajero is normally really sensitive? Seems random, usually only occurs in the morning over 70km/h.

I will press the throttle about half way and the light starts flashing on the dash and will only accelerate very gradually.

If anyone has any ideas how to fix this problem. I disconnected the battery a few weeks ago and this is when it started happening (i think) only had the car for 1 week before that.

Cheers,
Ben

[john_char]

Never really heard of the problem. Hav you tried disconnecting that battery again?

The only thing I can think of is the senders at the wheels are loose. They are right at the hub on the CV joint. It's a little sensor that is adjacent to what looks like teeth on the CV joint. There is one for each hub.

I gather there's no light that stays on on the dash at start up?

John

[Aussie]

Hi John,

Thanks for the reply. Both lights come on when i turn the ignition to "on". But go out once all self tests are completed. When i lose power, the TC light flashes very rapidly (the one to the left of the TC off light).

Could a bad wheel alignment cause this? Suspension was done the same time the battery was disconnected. I fitted the springs and shocks myself and took it to a local Bridgestone dealer for an alignment.

I spose it's possible I knocked one of the sensors when fitting the rear coils I will check them on the weekend. I presume I will need to take the wheels off to inspect?

Thing that confuses me it that it is totally random and never happens if I stab the throttle off the line. Keeps full throttle all the way to 100km/hr. Only occurs when the wheels are already turning. Solid dry bitumen. Happened to me tonight at about 60km/hr when trying to maintain speed up a hill.

If the battery is disconnected, is there a time to wait after turning the key to "on" before starting the engine?

When i reconnected it last time, the "TC off" light stayed on for about 10-15 minutes of driving.

Everything else seems to work fine with the TC. Can't us manual turn off switch unless doing less then 40km/hr and automatically turns itself but on when speed hits 80km/hr.

Your input is greatly appreciated.

Thanks,
Ben.

[john_char]

As mine is a 03 Exceed, I don't have the TC control off button. So really can't comment too much on that, well, maybe check to see if that function works......

As suspension work was done, it could be possible that the TC sender at the hub could have been knocked off track or just be loose, by the sound of the intermitant nature of the problem, I would say the sender might be loose, or loose wiring. By having this problem the TC computer would be getting confusing inputs, like locking brakes then too much traction, whoa, lucky it's not a windows based car, or you would be crashing everywhere!!!!!!!!! No pun intended......

I think you will have to take the wheel off, if you know what your looking for, then it is possible doing it with the wheel on.

Maybe leave the battery disconnected for half an hour or so. I know there is a set procedure to carry out to "re-learn" the tranny, but I've never worried about it.

John

[psproule]

The traction control doesn't seem at all intrusive in our NP. I had to deliberately provoke it to get it to come on and I cant imagine how to make it do it at 70kph on road?

I believe John might be on the right track with the wheel sensors. The ABS wheel sensors are used for the traction control / ASC and after doing the suspension on our new NP over the weekend I can see how it would be easy to damage one of the cables if you are not careful in how you pull it apart.

In the NP the wheel that is loosing traction should flash on the 4WD display. If none are flashing then I would suggest that it might be the ASC kicking in.

The easiest way I can think of to check this is to ask Mitsu to plug their MUTT in and go for a short drive. They can look at all the wheel speeds straight off the sensors both at the wheels and the front and rear driveshafts. They should be able to quickly locate the problem.

The ASC also use an input from the steering wheel - not sure what else.

I don't think a battery disconnect will fix it.

[Aussie]

Hi Guys,

Thanks for the replies. When the small light flashes in the top left hand side of the instrument cluster, it flashes very rapidly. None of the green wheel lights flash when this is going on, just a huge reduction in power. It still accelerates, but only very slowly.

Does ATC rely on the ABS sensors as well? It will do it no whether im turning left, right or driving in a straight line, but I noticed tonight that it was more sensitive when travelling downhill??

Got me baffled. It's due for a service next week, so i spose I'll get MMA to look at it, although I normally do my own servicing.

Thanks for your input, it has been greatly appreciated.

Cheers,

Ben

[psproule]

You mean ASC - I think it does as well as looking at steering input. Not sure if it has Yaw sensors as well. I think getting MMA to look at it with a MUTT is the quickest way to go at this stage - unless you have pinouts for the ATC/ASC computer, a CRO and a bit of spare time.

Pat

[Aussie]

Hi guys,

Thanks for you comments. I think i have solved it. I downloaded the manual from a site the was posted in the mechanical section. THANKS PICKLE YOU'RE A CHAMPION .

In the M ASC and TC system pdf I found this.

Initializing the M-ASTC-ECU (Action to be taken
when the battery is removed)
When the battery is removed, the neutral point of the steering
wheel sensor will be erased, the Active skid control system
OFF indicator light will illuminates and DTC 83 (ST NO ADJ)
will be set. In this case, make the steering wheel sensor learn
the neutral point by following one of the procedures below.
Using scan tool MB991502
1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Turn the steering wheel 8?or more, and then return it to the
neutral (straight forward) position.
4. Execute item No.14 "ST SNSR: 0 " on the Actuator test.
5. Ensure that the Active skid control system OFF indicator
light is off.
6. Turn the ignition switch to the "LOCK" (OFF) position.
7. Disconnect scan tool MB991502.
Not using scan tool MB991502
CAUTION
1. If a different diameter or size of tires are equipped, the M-
ASTC-ECU may not learn the neutral position.
Turn the steering wheel 8?or more, and then return the
steering wheel to straight-ahead position.
2. Drive the vehicle straight forward at 35 km/h (25 mph) for
approximately one second.
3. Ensure that the Active skid control system OFF indicator
light is off.

I performed option 2 tonight and took the car for a run. I had to try really hard to get the ASC light to come on. Flat to the floor around a 90 degree corner and changing from 1st to 2nd at the apex. ASC kicked in then, as it should , but as soon as i corrected it, it powered on. as it should.

On the highway, I slowed to 70km/hr and floored it in automatic mode, and unlike what i had been getting, it dropped back into 3rd and took off and no ASC light.

So i hope this helps anyone that may come across this problem in the future.



Cheers,

Ben