Fiat Ducato Series 8 & 9spd autobox
Discussion
Hi guys - got an open thread in Commercials Chat which hasn't had any traction. Wonder if any of you guys can shed any light on experiences with the series 8 X290 Ducato on a heavy chassis (5.4t) with the 2.2l engine (180bhp) and ZF 9spd gearbox?
I bought my brand new Dethleffs XL Family back in March 2025. Back in May I took it back to the supplying dealer as I was concerned the engine & gearbox was labouring between 2,100-2,800rpm, particularly in 4th and 5th gear under load. The dealer testdrove it, scanned the OBD and said it drove like they all do and found no error messages. They did a 6926 upgrade bulletin remap which evidently addresses a known issue with a torque mismatch between torque converter and 2.2l engine and sent me on my way.
About 600miles and a month later, I get a Check Transmission warning light, followed by Transmission Fluid Overheating message and Fault Code P1DB7 (Torque Converter) read by Roadside Tech. It's now with a Fiat Professional Workshop (who I trust).
I know there are a number of threads on the internet of issues but want to check how widespread a problem it is. Supplying dealer reckons that it's all been blown out of proportion and a small amount of cases get disproportionate amount of attention. Could be the case but wanted to check views and experiences.
To say I'm deeply disappointed is an understatement. Particularly given I've stayed clear of Fiats all my motorhoming career and now, with no other choice of chassis, I have this experience early on in my ownership.
I bought my brand new Dethleffs XL Family back in March 2025. Back in May I took it back to the supplying dealer as I was concerned the engine & gearbox was labouring between 2,100-2,800rpm, particularly in 4th and 5th gear under load. The dealer testdrove it, scanned the OBD and said it drove like they all do and found no error messages. They did a 6926 upgrade bulletin remap which evidently addresses a known issue with a torque mismatch between torque converter and 2.2l engine and sent me on my way.
About 600miles and a month later, I get a Check Transmission warning light, followed by Transmission Fluid Overheating message and Fault Code P1DB7 (Torque Converter) read by Roadside Tech. It's now with a Fiat Professional Workshop (who I trust).
I know there are a number of threads on the internet of issues but want to check how widespread a problem it is. Supplying dealer reckons that it's all been blown out of proportion and a small amount of cases get disproportionate amount of attention. Could be the case but wanted to check views and experiences.
To say I'm deeply disappointed is an understatement. Particularly given I've stayed clear of Fiats all my motorhoming career and now, with no other choice of chassis, I have this experience early on in my ownership.
Spuffington said:
Hi guys - got an open thread in Commercials Chat which hasn't had any traction. Wonder if any of you guys can shed any light on experiences with the series 8 X290 Ducato on a heavy chassis (5.4t) with the 2.2l engine (180bhp) and ZF 9spd gearbox?
I bought my brand new Dethleffs XL Family back in March 2025. Back in May I took it back to the supplying dealer as I was concerned the engine & gearbox was labouring between 2,100-2,800rpm, particularly in 4th and 5th gear under load. The dealer testdrove it, scanned the OBD and said it drove like they all do and found no error messages. They did a 6926 upgrade bulletin remap which evidently addresses a known issue with a torque mismatch between torque converter and 2.2l engine and sent me on my way.
About 600miles and a month later, I get a Check Transmission warning light, followed by Transmission Fluid Overheating message and Fault Code P1DB7 (Torque Converter) read by Roadside Tech. It's now with a Fiat Professional Workshop (who I trust).
I know there are a number of threads on the internet of issues but want to check how widespread a problem it is. Supplying dealer reckons that it's all been blown out of proportion and a small amount of cases get disproportionate amount of attention. Could be the case but wanted to check views and experiences.
To say I'm deeply disappointed is an understatement. Particularly given I've stayed clear of Fiats all my motorhoming career and now, with no other choice of chassis, I have this experience early on in my ownership.
Haven't really seen anything like this, is it the 25MY base vehicle? We don't really see many 'vans over 3500/3850KG here. Should be the 8 speed which may be sourced from Toyota/Aisin I believe (correct me if im wrong!), which does drive quite differently.I bought my brand new Dethleffs XL Family back in March 2025. Back in May I took it back to the supplying dealer as I was concerned the engine & gearbox was labouring between 2,100-2,800rpm, particularly in 4th and 5th gear under load. The dealer testdrove it, scanned the OBD and said it drove like they all do and found no error messages. They did a 6926 upgrade bulletin remap which evidently addresses a known issue with a torque mismatch between torque converter and 2.2l engine and sent me on my way.
About 600miles and a month later, I get a Check Transmission warning light, followed by Transmission Fluid Overheating message and Fault Code P1DB7 (Torque Converter) read by Roadside Tech. It's now with a Fiat Professional Workshop (who I trust).
I know there are a number of threads on the internet of issues but want to check how widespread a problem it is. Supplying dealer reckons that it's all been blown out of proportion and a small amount of cases get disproportionate amount of attention. Could be the case but wanted to check views and experiences.
To say I'm deeply disappointed is an understatement. Particularly given I've stayed clear of Fiats all my motorhoming career and now, with no other choice of chassis, I have this experience early on in my ownership.
Hopefully your tame Fiat Professional agent will update you.
Thanks.
Mine is the very last of the series 8 with the 9spd XF. The van was coming in to stock as I was beginning to search and although I was considering holding off for the new Aisin 8spd box, I was told that the 9spd ZF was a known quantity had the 8spd was untested. I fell for it and the emotion of getting the van sooner. And here we are!
Mine is the very last of the series 8 with the 9spd XF. The van was coming in to stock as I was beginning to search and although I was considering holding off for the new Aisin 8spd box, I was told that the 9spd ZF was a known quantity had the 8spd was untested. I fell for it and the emotion of getting the van sooner. And here we are!
Thanks chaps.
From what I've read, it seems the early ZF 9spd boxes failing on the 2.3l engines were down to underfilled gearbox fluid from factory. However, this now seems to be replaced with a mismatching torque output from the 2.2l.
It seems that the last of the 2.3l with ZF 9spd are the most reliable once the transmission fluid issue was resolved. Which is ironic really, since we didn't buy a Burstner 747 on one of these because of issues with AdBlue!
A minefield!
From what I've read, it seems the early ZF 9spd boxes failing on the 2.3l engines were down to underfilled gearbox fluid from factory. However, this now seems to be replaced with a mismatching torque output from the 2.2l.
It seems that the last of the 2.3l with ZF 9spd are the most reliable once the transmission fluid issue was resolved. Which is ironic really, since we didn't buy a Burstner 747 on one of these because of issues with AdBlue!
A minefield!
So not yet had it fully in writing but high probability according to FIAT workshop that it will need a new gearbox. They’re just waiting for confirmation & signoff from Stellantis/FIAT.
Both annoyed beyond belief and happy that at least I’m not being fobbed off with “its just a sensor” or “they all do that sir”. But I’d be lying if my thoughts hadn’t turned to rejection since I’m not sure how I’m going to build trust with it again and the nagging feeling that a 3m old vehicle shouldn’t need a new gearbox.
Both annoyed beyond belief and happy that at least I’m not being fobbed off with “its just a sensor” or “they all do that sir”. But I’d be lying if my thoughts hadn’t turned to rejection since I’m not sure how I’m going to build trust with it again and the nagging feeling that a 3m old vehicle shouldn’t need a new gearbox.
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