Just picked up a 2005 S40 2.4i last night (145K miles) for my girlfriend. The timing belt was replaced 25K ago, car is in overall great shape, drives nice. Was throwing a P0172 code last night to my scanner but the CEL was not lit (others we looked at were doing the same thing so I figured it was just some programming issue since there was no CEL).

Only had 1 key so my girlfriend stopped at Volvo to get another made. Well, they were unable to program a new key because the communication system is not functioning properly. (see attached photos of their diagnostic system and list, I can't upload these from work but I will tonight).

Diagram on the diagnostic computer shows
CCM, ICM, DIM, SRS, IAM, DDM, PDM in red,
CEM, EPS, ECM, TCM, BCM, SWM in green
KVM MMM AFM TMC AUD AEM TRM PAM GPS SUB PHM PSM DEM MPM CPM in blue

List shows multiple active BCM DTCs, and non active DTCs for CEM, ECM, EPS, SWM, and TCM

Carfax shows no accidents or flooding (southern california car for it's entire life)

I've read a bit about the CEM connector issues and corrosion so I am going to start there tonight. The odd thing is the car functions fine. Does "DTC not active" mean that it is a historic fault?

Based on the diagram it looks like CCM/ICM are all out of whack. I saw a thread earlier where someone bypassed the communication with their ICM and everything came back up so they replaced it and they were fine.

What is the best book to get as far as detailed wiring diagrams and diagnostics?


I will post the screenshots tonight, can't upload from work.

I remember my 89 740 with 315k miles on it fondly, hopefully this S40 doesn't put a bad taste in my mouth.

Thanks for all your help in advance.

Andy

 

This one is a whole new animal from the 740. For the best info get the VIDA software. You will need 32 bit Windows XP Pro or 7 Pro or 7 Ultimate (Not sure about 8 Pro) to run it. You don't need the newest version, just so you have 2005 covered. 64 bit Windows versions will not work either.

For diagnostics consider the DiCE scanner tool. It talks with the VIDA software. You can look at all the various computer modules and even reset each one. I once found an error code stored in the Climate Control Module which did not light the CEL.

Here is both in one place:
2013 Promotion volvo scanner vida dice !Support Firmware Update and Selftest! with High quality Chip Import From US-in Code Readers & Scan Tools from Automobiles & Motorcycles on Aliexpress.com

 

You can see attached the printouts from the dealer and also the view from the diagnostic software.

I'm looking at getting a Vida/Dice diagnostic tool. I'm going to give cleaning up the connectors and applying a dielectric grease to them a try.

I find it interesting that EVERYTHING in the car works (even cruise control). This makes me think it is a communication issue and nothing important has failed, or worst case something unimportant is overloading the low speed network. Based on the car diagnostic you can see most everything in Red is in the low speed non-vital network.

The only "symptom" that I can see is that the clock on the infodisplay shows "--:--"

Does anyone have experience with de-energizing the control systems? I saw direction to remove the negative (-) from the battery and hold it to the positive (+) for a half hour, this seems interesting to me. Is it safe to do this?

 

The CEM-DF16 is what needs to be fixed. There's a short somewhere. Hopefully it's a chafed wire because a module that does it is harder to prove sometimes.

 

I haven't gotten a hold of the EWM and VIDA/DICE yet. Do you know if there is a certain color that is used for intermodule communication? Once I can determine the wires to check I'll just start doing continuity/ohm checks from unit to unit.

I'm still hoping its an issue with the connector or loose pin somewhere.

Thank you for the response, that's soothed my worries about it being a horrendous computer failure.

Is there a good source for wiring diagrams besides the EWM?

 

I pulled the CEM out tonight, looked like some of the wires on the small bottom connectors were hit by someones feet but not enough to knock them free. There was no corrosion and all pins and connector sockets were in place and looked fine. I blew out the little bits of dust, put some dielectric grease on the pins and reassembled.

It didn't fix anything (well, the dash still shows "--:--") so I'm guessing that nothing was fixed.

I need to wait until my VIDA/DICE and EWD shows up. I'll start tracing wires for grounds.

My plan is to jumper over modules in the network 1 at a time until I can restore network function. I will be checking for grounds/open circuits on com wires between all of the modules while I'm checking them.

Has anyone jumpered these modules before?

 

Well I feel stupid, I turned the **** on the dash and updated the time. I was hoping the CEM communicated the time to the DIM but nope.

Anyway, still waiting on VIDA/DICE, but I got a hold of wiring diagrams from matthew's volvo site. Once VIDA/DICE is up and running I will unplug modules one at a time to see if it restores the rest of the communications.

I'm expecting that when I unplug the offending module it will turn red and the rest of the communications loop will turn green.

 

check connection of Low speed CAN bus from OBD socket to CEM socket.
I think they cannot reprogram remote because the whole low speed bus is not responding to DiCE.
Also you can check the resistance between 2 can bus wires (twisted low speed) without battery it should be about 60 Om

 

Good catch, I'll give that a shot.
Is 60 ohms with one plug unplugged and other still attached or with everything installed?

When the Dice shows equipment at blue I'm guessing that means not installed.
Green = communication OK
Red = communication failure?

 

60 ohms is for everything installed.
As for Dice If you talking about Network Tab that is right.

 

Resistance across the low speed network OBD pins measured 80 ohms.

I hooked up the DICE tool and cleared all DTCs. The communication/network showed that everything was green and communicating properly. I was able to read information from the different modules that the dealer said were not communicating which meant to me that function was restored.

1. While communicating with the car the ABS light on the DIM would flash, is this normal? (on for 1 sec, off for 1 sec) once DICE was unplugged and car stopped/started the ABS light would stop flashing and extinguish.

The dealer tried to code a new key and said again that they had no communication with the low speed network.

2. Is there some way that the tool would be able to communicate with the network correctly until it tries to program a new key?

I am thinking that the pins in the car's OBD connector are getting old and worn, they may not be making contact with the Dealer's DICE tool since it is probably also worn. I will remove the pins and tighten them slightly to see if that has an effect.

Any help would be greatly appreciated!

Andy

 

The CEM module is 2 modules for the car and diagnostics. One on Hi speed and another on low one.
So the low one is the issue.
I think there should be parameters that shows the current number of remotes programmed. Can you see them?

Flashing ABS light while reading codes is normal.

 

The issue could also be the dealers DiCE tool.

 

I very much doubt it is the DLC pins or the dealer's DiCE. They work on plenty of cars, it wouldn't take long before they figures out they had a bad DiCE.

 

So, interesting turn of events. Took the car to a different dealer (dealer 2) to see what would happen and an hour later they give us a new key and send us on our way! No mention of any issues with the computers.

I kind of feel like the other dealer (dealer 1) was trying to scam us. I would be surprised if their DICE tool had issues and they didn't notice it.

Anyway, thanks for all the information, hopefully the issue doesn't reappear!

Oh, the only work I did was pull all the connectors off the CEM and apply some dielectric grease to the pins then reassemble, that was before I had a DICE so maybe that fixed it, but it went back to the original dealer (Dealer 1) after that and they still said there were issues. No changes between dealer 1 and dealer 2.