Volvo xc70 mess in electronics

[mafia666]

It's a 2006 model with automatic transmission (AW50/51), diesel (eng. code: D5244T). Car was in accident - front was crushed.

So problems and symptoms:

1. hand brake on, ignition off - check engine lamp illuminates for a while.
I checked wiring from parking brake switch to DIM (dash) - no shortage. Maybe it's should be like this if there is problem with brakes? (Can't connect with dice to BCM - abs.)



2. No gear indicator lamp on dash. sometimes it appears, but then it disappears after minute. Same with odometer trip value...

I checked high speed can lines between ecm, tcm, cem modules - everything is fine. tried to disconnect plug from abs - no change.

Sometimes car starts, but the indications on dash are also sometimes working sometimes not...

If I connect Volvo dice on it - it always, every few min. drops connection with car. and no response from TCM.

Checked power supply and grounds to tcm - it's ok. Checked GSM - also all power, ground data line is ok....

Tomorrow i will continue my survey with this model. Any hint's would be appreciated.

[ominimicu]

maybe the ECu got damaged

[mafia666]

Ecu looks good. Not even bended or touched.... I am wondering about that hand brake and check engine lamp, which is lit when ignition is off and hand brake is pulled.

[mafia666]

Come to conclusion: CEM module. If I bring one from damp yard, how to adopt it on car? Swap eproms, mcu's? Maybe someone knows where is all info regarding car stored? I have vida dice china clone, but I know that I need special soft from dealer to program CEM. Is it possible to get it somehow and do it by myself?

[adam12112]

Dealer can program only new CEM if you have used you need clear it. Without dealer you can only swap chip(s) but i never did and i do not know details.

[mafia666]

Do you know, how to clean CEM? Does anybody knows about swapping chips? (which?)
These are my fault codes. Don't pay attention on airbag faults (after deployment) and immo fault (key is broken apart). I can start car, but dash doesn't show trip value, gear box possition, temperature and some lights are on (abs, check engine etc...)

[adam12112]

You have faults CAN, check CAN wiring.

[mafia666]

I checked high speed can bus between CEM, ECT, TCM, BCM. It was ok.

[adam12112]

If can is ok, try other CEM from damp yard, car do not start but CAN faults should disappear. I never met that circuits CAN be damaged in CEM. You can also try disconnect all high speed can control modules except CEM and ECM and make jumper CAN in TCM slot .

[mafia666]

it's a good idea. I was also thinking to do this today, just wasn't sure about jumpers do i need them or not. but in the country where i am it was snowing today and car is outside, so there was no chance to do this.

Just wondering about that check engine light when you pull the hand brake on (ignition is off and key is out of lock). No shortages in wiring between hand brake switch and dim, also dim has power supply, ground lines...What does that mean?

[adam12112]

country where i am it was snowing today and car is outside

not good conditions for such dignostic
Are you check all wire DIM (color, pin numbers, shortcut to ground and power)?

[mafia666]

Hi. So to update. found problem in CAN network mess: it's DEM, and corrosion in CEM. I will try to access DEM in next days...
I don't have idea about MIL lamp on dash together with handbrake on. Wiring is ok. Probably I will try to open dash. Maybe I will find something inside. Didn't have time to do this today... Actually, it's strange, because parking light on dash is working, but if you pull brake - it will light up check engine????