Fiat Grande Punto Dualogic issue - Skipping Gears

[shanakamm]

Hi All

I have a Fiat grande punto 2007 and recently experiencing this intermittent gearbox issue. I was driving the car for about 10-15 km without any issue and suddenly it stopped shifting to 1st 3rd and 5th gears. (Odd gears) only 2nd , 4th and Reverse are working. Can put to N and back to R. When putting to 1st from stationary position it will take 4,5 seconds and shows me 2nd on the screen. This is happening in both auto and manual mode. i can see the car is trying to change the gear from 4th to 5th but its stays on 4th. (Can see the RPM change on the gauge, fluctuating). after few kilometers it corrected automatically without doing anything and failed again after sometime.

Can hear the selespeed pump is working but i think its running longer than usual. (when opening the driver side door). In the recent past car automatically went to Neutral position while driving (Slow speeds 15-20kmph) and it happened 2, 3 times.  However there were no visual indication on the dashboard and the information display during these issues. also the selespeed pump and some other few parts have been replaced by the previous owner and did around 30k kms after that.

Highly appreciate your valuable comments. 

Thanks

Edited March 12, 2018 by shanakamm

[NeroX]

Sounds like your dualogic unit is faulty. Could be due to multiple issues. Best bet is to diagnose using a fiat ecu scanner. Main parts to check first is your hydraulic pump & accumulator condition. Connect a scanner let the pump run (open door or start engine). Ideally it should pressurize the system to somewhere around 48-50 bars. It should then hold the pressure steady maybe max dropping 2-3 bars/minute. Now try shifting gears. This should bring the pressure down faster, below to somewhere arnd 36-38 bars where the pump will kick in & pressurize back to 48-50 bars. If this is happening means your pump is okay. If it doesn't kick in or pressurize fast enough, replace the pump. Once pressurized, if its not holding & dropping very fast then you have an accumulator problem. Also if your pump is kicking in regularly that also refers to a faulty accumulator. If its either of the issues make sure you go for brand new parts or else you'll end up in the same situation given the age of most used parts by now. Especially the accumulator is an absolute no no to go with used parts.

The pressure leakage could also be due to leakage in your actuator mechanism also. So if a brand new accumulator didn't work next bet is to get a valve reapir kit & replace all the seals etc in the actuator with an experienced mechanic. Using any oil other than tutela selespeed oil is known to cause this issue as it leads to premature deterioration of your actuator seals. 

The above fixes should sort you out 99% of the time. Failing all the above only option is to replace the gearbox ecu which is located in the front passenger footwell under a plastic cover. It is rarely an issue with this but could be caused due to car electrical issues or water logging in your footwell. Also normally for faults in other parts even your fiat ecu scanner may log an "ECU faulty" error code first. Hence don't jump to that conclusion all of a sudden. Try the steps mentioned above & revert to ECU replacement as a last resort. Conversely if you get to this point you could swap ECU's with a working car to establish if its the real issue before buying one.

There is a very good detailed troubleshooting guide on a different forum (f*atforum) - Try searching as "Dualogic troubleshooting Guide". Refer to that also.

[shanakamm]

24 minutes ago, NeroX said:

Sounds like your dualogic unit is faulty. Could be due to multiple issues. Best bet is to diagnose using a fiat ecu scanner. Main parts to check first is your hydraulic pump & accumulator condition. Connect a scanner let the pump run (open door or start engine). Ideally it should pressurize the system to somewhere around 48-50 bars. It should then hold the pressure steady maybe max dropping 2-3 bars/minute. Now try shifting gears. This should bring the pressure down faster, below to somewhere arnd 36-38 bars where the pump will kick in & pressurize back to 48-50 bars. If this is happening means your pump is okay. If it doesn't kick in or pressurize fast enough, replace the pump. Once pressurized, if its not holding & dropping very fast then you have an accumulator problem. Also if your pump is kicking in regularly that also refers to a faulty accumulator. If its either of the issues make sure you go for brand new parts or else you'll end up in the same situation given the age of most used parts by now. Especially the accumulator is an absolute no no to go with used parts.

The pressure leakage could also be due to leakage in your actuator mechanism also. So if a brand new accumulator didn't work next bet is to get a valve reapir kit & replace all the seals etc in the actuator with an experienced mechanic. Using any oil other than tutela selespeed oil is known to cause this issue as it leads to premature deterioration of your actuator seals. 

The above fixes should sort you out 99% of the time. Failing all the above only option is to replace the gearbox ecu which is located in the front passenger footwell under a plastic cover. It is rarely an issue with this but could be caused due to car electrical issues or water logging in your footwell. Also normally for faults in other parts even your fiat ecu scanner may log an "ECU faulty" error code first. Hence don't jump to that conclusion all of a sudden. Try the steps mentioned above & revert to ECU replacement as a last resort. Conversely if you get to this point you could swap ECU's with a working car to establish if its the real issue before buying one.

There is a very good detailed troubleshooting guide on a different forum (f*atforum) - Try searching as "Dualogic troubleshooting Guide". Refer to that also.

Thank you NeroX

tomorrow i'm planing to visit my mechanic and do the scan.  I hope its not the pump cause my previous owner has replaced it and used tutela oil only.

if it is an accumulator issue do we have parts here in SL ? and how much  will it cost ?

I did read that article you mentioned and according to then this might be a solenoid issue too. apparently CFC328 Robot has two solenoid values for odd and even gears. "even gear pressure proportioning solenoid valve (2 - 4 - R) and odd gear proportioning solenoid valve (1 - 3 - 5)"

Thanks and Regards

 

[NeroX]

Great! you can find accumulators on ebay for around $200. Most of the stocks available locally are exhausted by now. Check with the usual sources if they have any.

Given your issue it does look more of a solenoid problem. Issue is the repair kits normally comes with seals for all the components. Check with your mechanic on what to do about the seals. Should be someone with experience disassembling/assembling these gearboxes.

[shanakamm]

Thanks NeroX

Supposed to scan the car today but my mechanic is out of Colombo. have to wait till weekend. Will update with the progress. 

 

[shanakamm]

Did the scan today and seems like one of the Solenoid valve in the selespeed unit is shot.  Checked the oil pressures in gears and they are all okay (pump and the accumulator working fine).  Cleared the error for now and drove another 100kms without any issue. if it comes again i definitely need to replace the part as per my mechanic. fingers crossed.

IF anyone know the correct part number for this solenoid please let me know. 

Thank you