|
C30 / S40 & V50 '04-'12 / C70 '06-'13 General Forum for the P1-platform C30 / S40 / V50 / C70 models |
Information |
|
S40 T5 won't start - Ignition switch?Views : 2629 Replies : 32Users Viewing This Thread : |
|
Thread Tools | Display Modes |
Aug 23rd, 2018, 19:04 | #11 |
Master Member
Last Online: Mar 14th, 2024 17:24
Join Date: Apr 2017
Location: South
|
The SCU is just a middle man receiver that passes the code along to the next module for starting as far as I'm aware.
__________________
2006 Volvo S40 T5 SE Sport
|
Aug 24th, 2018, 10:23 | #12 |
Premier Member
Last Online: Sep 14th, 2021 18:03
Join Date: Feb 2009
Location: Market Harborough
|
For the benefit of future readers (and me) what's an SCU ?
__________________
2005 S40 T5 SE - Manual. Bilstein B4's. (For Sale) 2010 Citroen C4 1.6 HDi (bizarre Gearbox model). 2010 Renault Twingo (refreshingly simple) 2018 Infiniti Q30 1.6T Business Executive (what's this button do?) |
The Following User Says Thank You to Welton For This Useful Post: |
Aug 24th, 2018, 10:29 | #13 |
Experienced Member
Last Online: Yesterday 22:26
Join Date: Jun 2007
Location: L/H side
|
the ignition switch ..
__________________
My comments are only based on my opinions and vast experience . |
Aug 24th, 2018, 10:35 | #14 | |
WowIcanwriteAnythingHere!
Last Online: Mar 26th, 2024 17:05
Join Date: May 2016
Location: Dublin/Meath
|
Quote:
Oddly though, I would have thought you wont be able to start the car if SCU is dead (its basically like trying to start it without the key, no?), but you managed to. Maybe it means that SCU is somehow working (like detecting the key, disabling immobiliser) but just doesnt send up POS3 starter command ? dunno, just thinking out loud...
__________________
2005 V50 T5AWD M66, Stage1 Hilton tune E-focus torque mount, E46 bi-xenon retrofit v2 , (also available in PDF form), DTSC fully-off mod, Brembo discs+ATE ceramic pads |
|
Aug 24th, 2018, 10:43 | #15 |
Premier Member
Last Online: Sep 14th, 2021 18:03
Join Date: Feb 2009
Location: Market Harborough
|
The ignition switch on mine sometimes doesn't 'engage' and I'll get a warning message about the key and 'try again' or something.
The dirty fix for me has always been a confident 'tap' on the back of the key!
__________________
2005 S40 T5 SE - Manual. Bilstein B4's. (For Sale) 2010 Citroen C4 1.6 HDi (bizarre Gearbox model). 2010 Renault Twingo (refreshingly simple) 2018 Infiniti Q30 1.6T Business Executive (what's this button do?) |
Aug 24th, 2018, 10:43 | #16 | |
Experienced Member
Last Online: Yesterday 22:26
Join Date: Jun 2007
Location: L/H side
|
Quote:
__________________
My comments are only based on my opinions and vast experience . |
|
Aug 24th, 2018, 10:48 | #17 |
Experienced Member
Last Online: Yesterday 22:26
Join Date: Jun 2007
Location: L/H side
|
The car is trying to tell you something , if you don't get it fixed you are going to be marooned in the most isolated place .. guaranteed !
__________________
My comments are only based on my opinions and vast experience . |
Aug 24th, 2018, 11:05 | #18 | ||
Master Member
Last Online: Mar 14th, 2024 17:24
Join Date: Apr 2017
Location: South
|
Quote:
1st - Key is inserted, fob/car codes checked amongst all modules, CEM talks to SCL and unlocks the wheel Ignition Pos I - Basic power to car, radio etc Ignition Pos II - Power to rest of car, lights, rest of console/modules etc Ignition Pos III - Sends signal to CEM to activate switched power line to relay/starter circuitry to fire engine. I kinda confirmed this in VIDA before dropping it off, VIDA shows you ignition positions, I and II were recognised, I got nothing on III..... I've asked Volvo to put my old SCU in the boot so I'll strip it apart when I get the car back and find out how it actually works. Quote:
You could do as I did above to get you going and short those pins out but be very confident you know what your shorting as you could potentially take out your CEM if you get it wrong.
__________________
2006 Volvo S40 T5 SE Sport
Last edited by FunkyMelon; Aug 24th, 2018 at 11:16. Reason: Typo. |
||
Aug 24th, 2018, 11:11 | #19 |
Premier Member
Last Online: Sep 14th, 2021 18:03
Join Date: Feb 2009
Location: Market Harborough
|
The key thing has only happened maybe 2 or 3 times in the last 9 years, I guess if it does it again that's when i'll be motivated to replace.
This is a good source of info in any case.
__________________
2005 S40 T5 SE - Manual. Bilstein B4's. (For Sale) 2010 Citroen C4 1.6 HDi (bizarre Gearbox model). 2010 Renault Twingo (refreshingly simple) 2018 Infiniti Q30 1.6T Business Executive (what's this button do?) |
Aug 24th, 2018, 11:29 | #20 | |
WowIcanwriteAnythingHere!
Last Online: Mar 26th, 2024 17:05
Join Date: May 2016
Location: Dublin/Meath
|
Quote:
SCU can go bad both ways: - mechanically, where for example contats degrade and no longer recognise key position - electronically, where components goes haywire and for example antennae no longer sends/receive signal or such signal is no longer passed from SCU to CEM. In the 1st scenario, like FunkyMelon, you can hardwire the car as everything works OK bar the actual "START" position In the 2nd scenario, you would not be able to even disengage SCL nor start the car as CEM would still be in "immobilised" mode. Dose that seem right?
__________________
2005 V50 T5AWD M66, Stage1 Hilton tune E-focus torque mount, E46 bi-xenon retrofit v2 , (also available in PDF form), DTSC fully-off mod, Brembo discs+ATE ceramic pads |
|
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
Thread Tools | |
Display Modes | |
|
|