3-bar problem again....

[cccscotland]

Hi guys & gals,

After a couple of months of happy smart ownership my 2002 pulse has thrown the 3-bar problem. It beeps and shows the 3 bars when trying to start (without turning over), it will eventually start after lots of gearstick waggling. When it starts, if you try and drive it straightaway with it seemingly in gear it will rev to about 4,000 before the clutch suddenly kicks in and it moves off in a bit of a jolt. If you drive through that it then drives just fine with all gears selecting as normal. Stop and start again within 5 mins and all is fine. Leave it for more than 10 and you need to start all over again.

Using info on this forum and Evilution I've done the following:
Checked the battery
Disconnected the battery for 20 mins. After this, the car had no 3-bar error, turned over but would not start. It did this twice and then on the thrid time the 3-bar error re appeared but the engine would not turn over.
At no point is there any banging or clunking, and rocking the car makes no difference.
I've taken off the clutch actuator, relubed and reset it and it *seems* ok.
I can't see any chafing on the wires and the connectors seem OK.

I can get the car started as I mentioned before. It requires a good 5-10 minutes of gear wobbling and attempted starts and eventually the selector picks neutral and the car will then start. It then usually selects R or 1 fine but the clutch won't disengage until the revs get to about 4,000 and then it lurches forward. If once it has started I kill it then restart it usually the clutch bite is restored to normal. It also seems temp related - the warmer it is the less problems there are getting started, and when it runs, it runs perfectly!

I suspect it is electrical rather than mechanical - is my first port of call a new gearbox position sensor or is there anything else you'd suggest before doing that?
Thanks in advance for any help,
cheers
Matt

[MrPoo]

Gear position sensor sounds possible. Check the wires as per this guide...

http://www.fq101.co.uk/how-to-guides...he-3-bars.html

[tolsen]

I doubt this problem is caused by faulty gear position sensor. A fault there won't affect clutch operation which as per your description is main physical problem.
I suspect either stiff clutch actuator or faulty wiring to clutch actuator. I have a spare second hand clutch actuator in good condition which you could borrow. Faulty wiring is best checked by sending/ injecting current through the harness between clutch actuator plug and ECU connectors. Resistance readings may not be conclusive. A 21 watt bulb with test leads, a 12V starter battery and connector pinout diagram is all you need.

[JMM]

Or it could be you've adjusted the actuator wrong?

[tolsen]

Or it could be you've adjusted the actuator wrong?

Not possible. Positioned too far out leads to clutch engaging early, not at 4000 RPM.

[TAIM]

gear pos sensor is ~£50 iirc !, so you'd better be sure of your (mis)diagnosis

I'd go with poor connections/dodgy cables as per Tolsens suggestion

[tolsen]

gear pos sensor is ~£50 iirc !, so you'd better be sure of your (mis)diagnosis

50 pounds? I sold one of them gear position sensors last week for 25 pounds. Turned out it was brand new and the old one is still in my Smart.

It is good preventative maintenance to remove the gear position sensor perhaps every 3 - 4 years, clean the seal area and apply some silicon grease to prevent water ingress. It is water ingress that knackers the sensor as there is a potentiometer inside.

[little black un]

when we had 3 lines it was lack of oil..........................i know some people will slam me for this cos it always happens on here
but worth checking

[tolsen]

when we had 3 lines it was lack of oil..........................i know some people will slam me for this cos it always happens on here
but worth checking

That is a good point often overlooked!

[cccscotland]

Do you use ATF in the gearbox? Or gearbox oil?