p1742 selespeed fault code please help - Alfa Romeo Forum
You are currently unregistered, register for more features.    
 
Thread Tools Search this Thread
(Post Link) post #1 of 25 Old 02-02-10 Thread Starter
Status: -
AO Member
 
Join Date: Feb 2010
Location: United Kingdom
Posts: 47

Member car:

156

Help p1742 selespeed fault code please help

Hi, i am now the proud owner of a lovely 156 selespeed. Only problem is after only doing 100 or so miles it went into safe mode on the selespeed gearbox so i only get 1/2 and reverse. After reading numurous threads on this site i went out and bought a cable and the alfadiag software. I hae read the code that is showing and it is p1742. I have searched high and low for the diagnosis of this code and cannot find it anywhere. There is another thread from a year ago but no solution. So i thought i would register and see if i could find a solution as when i have been able to drive this car what a joy it was.

I have tried various things on the alfadiag but to no avail. Any hints or tips would be greatly appreciated or if anyone has repaired this fault or knows how to i would be over the moon. Unless it means i need a new actuator

Many thanks in advance
matt bowland is offline  
Sponsored Links
Advertisement
 
Status: -
AO Member
 
Join Date: Sep 2009
Location: Germany
Posts: 135
findus is offline  
(Post Link) post #3 of 25 Old 02-02-10 Thread Starter
Status: -
AO Member
 
Join Date: Feb 2010
Location: United Kingdom
Posts: 47

Member car:

156

unfortunately this is the same problem but no resolution. All i need to know is which sensor it relates too??
matt bowland is offline  
Status: Hey Joe...
AO Gold Member
 
iainfm's Avatar
 
Join Date: May 2008
Location: United Kingdom
Posts: 6,268
Images: 5
From what I can gather, it's one of the selection range sensors on the actuator.

There are 3 iirc (black plastic things - I'll post a pic later). The electrical connections might need cleaning, or if that fails they can be found on ebay for 40 each (also try a fiat dealer though - they seem to be able to sell actuator parts, whereas AR will only sell the complete unit ).

You can try swapping them around to determine which is faulty, or measure their resistance with a multimeter. I forget what normal ohm-age is though... Under or around half-to one kOhm rings a bell...

If you're cleaning the electrics, do the 20-way block that connects the sele loom to the main loom as well.

Breaking X-Reg 156 1.6 TS. Most parts available.

S'cuse me, while I Kiss The Sky...
iainfm is offline  
Status: -
AO Member
 
Join Date: Sep 2009
Location: Germany
Posts: 135
The post and iainfm's answer basically tell the same: the sensors!

You may want to follow that road....

As iainfm told us, to get to the sensors ist simple...

Findus
findus is offline  
(Post Link) post #6 of 25 Old 03-02-10 Thread Starter
Status: -
AO Member
 
Join Date: Feb 2010
Location: United Kingdom
Posts: 47

Member car:

156

Thanks guys, i will be giving that a try on saturday as when i finish work it is dark. I hope it works so i can have some fun again. I have never drove anything that is so much fun!!! Will post results
matt bowland is offline  
Status: Alfa infected
AO Gold Member
 
purple145's Avatar
 
Join Date: Oct 2004
Location: United Kingdom
Posts: 6,827
purple145 is offline  
(Post Link) post #8 of 25 Old 03-02-10 Thread Starter
Status: -
AO Member
 
Join Date: Feb 2010
Location: United Kingdom
Posts: 47

Member car:

156

if i were to swap these sensors around would it through a different fault code?
matt bowland is offline  
Status: Hey Joe...
AO Gold Member
 
iainfm's Avatar
 
Join Date: May 2008
Location: United Kingdom
Posts: 6,268
Images: 5
Info on how to test the sensors (and lots more) here:

Alfa Romeo Selespeed - measuring sensors
iainfm is offline  
(Post Link) post #10 of 25 Old 04-02-10 Thread Starter
Status: -
AO Member
 
Join Date: Feb 2010
Location: United Kingdom
Posts: 47

Member car:

156

just to update, after many different tests it turns out that this fault code relates to the sensor on the rear of the accumalator, if you get a code of p1741/p1742/p1743 it is down the the three sensors. By uplugging each individual sensor it will throw different faults and then you can establish each sensor working or not working.
matt bowland is offline  
Status: Hey Joe...
AO Gold Member
 
iainfm's Avatar
 
Join Date: May 2008
Location: United Kingdom
Posts: 6,268
Images: 5
Quote:
Originally Posted by matt bowland View Post
just to update, after many different tests it turns out that this fault code relates to the sensor on the rear of the accumalator, if you get a code of p1741/p1742/p1743 it is down the the three sensors. By uplugging each individual sensor it will throw different faults and then you can establish each sensor working or not working.
Good stuff. You know which one to change then!

The rear one's the up/down sensor, which is kinda similar to moving a normal gearstick left and right.

Try a Fiat dealer. They *might* be able to get it for you, or there's the ebay link above
iainfm is offline  
Status: Hey Joe...
AO Gold Member
 
iainfm's Avatar
 
Join Date: May 2008
Location: United Kingdom
Posts: 6,268
Images: 5
From what I can make out, the p/n of the potentiometer is 71719387. That's for a Fiat Stilo, anyway.

ePer price is 31+VAT, so not much cheaper (if at all) than the eBay price.
iainfm is offline  
(Post Link) post #13 of 25 Old 05-02-10 Thread Starter
Status: -
AO Member
 
Join Date: Feb 2010
Location: United Kingdom
Posts: 47

Member car:

156

thanks for that, i have just put a thread on what i have found out. The said sensor is exactly the same as a throttle position sensor for a sxo vts/106 gti 16v. So a scrappy 10 each or new 30 each. It looks like they are common. It sounds like if your selespeed goes into ''safe mode'' it is a sensor fault and if it wont engage gears it is either stuck in gear/pump/actuator. If it is skipping gears then alfadiag and calibration from what i can see. I have read so many threads this week and to be honest with you i am no longer scared as anybody is fairly confident would be able to replace these parts with the help of alfadiag.

ALFADIAG is the way to go, before anything else people need to buy a cable and this software as it will save them money in the long run and help to maintain there selespeed by doing checks/service monthly. It only takes 30mins.

Thanks for the help everyone!!!
matt bowland is offline  
Status: Hey Joe...
AO Gold Member
 
iainfm's Avatar
 
Join Date: May 2008
Location: United Kingdom
Posts: 6,268
Images: 5
Quote:
Originally Posted by matt bowland View Post
thanks for that, i have just put a thread on what i have found out. The said sensor is exactly the same as a throttle position sensor for a sxo vts/106 gti 16v. So a scrappy 10 each or new 30 each.
Now THAT's useful info. And they'll fit nicely into pockets!

Quote:
Originally Posted by matt bowland View Post
ALFADIAG is the way to go, before anything else people need to buy a cable and this software as it will save them money in the long run and help to maintain there selespeed by doing checks/service monthly. It only takes 30mins.
Couldn't agree more!
iainfm is offline  
Status: -
AO Member
 
Join Date: Sep 2009
Location: Germany
Posts: 135
I've discussed this development briefly with our Selespeed guru, and his advice is caution. He says, there is a difference in reliability between Magnetti Marelli and third party sensors.

Btw: there are sensors in eper for the punto with the part number 71737620 (or 71752610 for Grande Punto) which are cheaper but it appears that all those sensors for dualogic/selespeed in eper are the same, despite the different numbers (and prices)

So given the delicacy of our beloved robotic transmission it seems (as i see it) advisable to stick to the original parts.

On the other hand, maybe it really works. If you try it, keep us posted.

Findus

Last edited by findus; 06-02-10 at 09:22. Reason: Part number for Grande Punto
findus is offline  
(Post Link) post #16 of 25 Old 06-02-10 Thread Starter
Status: -
AO Member
 
Join Date: Feb 2010
Location: United Kingdom
Posts: 47

Member car:

156

Hi findus!! You will find that the throttle position sensor for a saxo vts/106 gti are magnetti marelli and are identical to the selespeed sensor. I know this as i went to the scrappy this morning and took one of a 106gti and fitted it. Guess what works perfect fault gone calibration done! Smile on my face like the first time a slept with a bird!! Tell a lie its actually a bigger smile!!

So for anybody out there please bear this in mind as if you get one from scrappy it costs you hardly anything, then when this cures the problem buy one brand new and you know that you are not wasting your money!!
matt bowland is offline  
Status: Hey Joe...
AO Gold Member
 
iainfm's Avatar
 
Join Date: May 2008
Location: United Kingdom
Posts: 6,268
Images: 5
Quote:
Originally Posted by findus View Post
I've discussed this development briefly with our Selespeed guru, and his advice is caution. He says, there is a difference in reliability between Magnetti Marelli and third party sensors.
Yep. 3rd party ones are more reliable.
iainfm is offline  
Status: -
AO Member
 
Join Date: Sep 2009
Location: Germany
Posts: 135
Then its settled. And its good news.

Please keep us informed upon this subject (the reliability of said sensors)...

Keep up the good work

Findus
findus is offline  
Status: Alfa infected
AO Gold Member
 
purple145's Avatar
 
Join Date: Oct 2004
Location: United Kingdom
Posts: 6,827
cheap selespeed fix shock

and a dealer would charge 1500 for a new acctuator no doubt

who said Alfas had to be expensive to run

great work

BTW pity the poor woman who provides less pleasure than a 10 scrapyard sensor.......
purple145 is offline  
Status: Summers on the way
AO Member
 
Join Date: Nov 2008
Location: New Zealand
Posts: 35
ok, just to confirm the price difference, In New Zealand I used this part number to get a quote for the local Alfa dealership (who confiremd it was the same part for the selespeed), the quote i got was nz$556+12.5%Gst..that equates to around 220pounds...not cool
A Romeo is offline  
Status: -
AO Member
 
RSMK's Avatar
 
Join Date: Sep 2008
Location: Botswana
Posts: 143
very interesting thread. Suffered for a whole year from the same. Will revisit the area and I hope it works for me too.
RSMK is offline  
Status: -
Newbie
 
Join Date: Apr 2011
Location: Australia
Posts: 3

Member car:

156

p1742 fault flashing in 5th gear

potentiometer pf2c theres three of these on the actuator i replaced all 3 fixed problem. can be sourced cheaply on ebay , i brought lowe brand , it did the trick around 30 us dollars each search for pf2c used on many fiats etc cheers
capone156 is offline  
Bastek333
Status: - Update
Guest
 
Posts: n/a
Quote:
Originally Posted by capone156 View Post
potentiometer pf2c theres three of these on the actuator i replaced all 3 fixed problem. can be sourced cheaply on ebay , i brought lowe brand , it did the trick around 30 us dollars each search for pf2c used on many fiats etc cheers
I agree with You - Is MUCH better to buy new pf2c sensor than mess with second hand ones - the trouble with them (original ones to) is wear of the carbon track - it mean that it could be difficult to spot the problem even with measuring it by multimeter....
In my occasion i found my dead sensor by long time logging by FiatEcuScan only one parameters at time - then the reading is exact - i found that after about 30min drive sensor started mess around and give unstable log line.

I spend 30 quid for new sensor and problem GONE

But watch 2 things when You will try to change it - one is the torx screws are difficult to undo with not very good access to them, and dont try to move to far shaft when You take the sensor out - shaft have spring inside - i managed to snap it i think but fortunately pf2c sensor got spring working in the same direction that now sensor is doing all return work.
 
Status: -
Newbie
 
Join Date: Apr 2011
Location: Australia
Posts: 3

Member car:

156

hi i had 2 faults first 1 was my clutch speed sensor which is on the gearbox if look from under the car u will see 2 electrical connections the lower 1 is your reversing lights the upper is your clutch speed sensor that was faulty, replaced it and i was able to get 3rd and 4th gear also with alfa diag u will need to clear fault codes to reset the selespeed before u can try and drive the car again. also i replaced 3 potentiometers pf2c if u take your battery tray out u will see the top of your actuator u will see some solenoids plus 2 potentiometers plus there is another 1 at the back of the actuator on the firewall side. search ebay for pf2c and u will see what they look like . try cleaning the connections with contact cleaner before replacing if your dubious. access is very limited

Last edited by capone156; 18-07-11 at 08:31.
capone156 is offline  
Status: Gold Member
AO Gold Member
 
rarebear's Avatar
 
Join Date: Sep 2002
Location: The Netherlands
Posts: 6,994
hows the bird nowadays ???!
rarebear is offline  
Reply

Go Back   Alfa Romeo Forum > Supported Alfa Romeo Models > Technical & Vehicle Assistance > Alfa 147, 156 & GT

Tags
code , fault , p1742 , selespeed

Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome