1999 s80 cranks but doesn't start, brake failure, stop asap

[ColoNelJam]

Hi Guys,

i have a 1999 Volvo S80 2.9 with some problems. Long story short:

It began quite a while ago, maybe 3 years or so. While driving, the Gauges stopped working, "Brake failure, Stop ASAP" came up, but car drove normally. Turned it off, tried to turn it on again - no luck. It will crank, but will not start. So i pulled the Battery leads for 5min, put em back on and the car will start again. This happened several times over the last 2-3 years. But most of the time, a battery disconnect helped to get it working again.
One day, i came to my car, tried to start it up - and the message appeared again. But this time, the battery trick will not do it.
Even leaving the battery off for 48hrs didn't change anything. It will no longer start and always shoot out the "Brake failure, Stop ASAP" message.
I noticed that when i leave my car with the Battery connected, Battery will be empty after a few days. So there has to be a parasitic drain anywhere.

Repair / Troubleshoot History:

- Changed Battery to a new one (was about 3 years ago)
- Alternator was replaced by workshop.
- Cleaned all ground connections i could find. I know there's lots more, but can't find a wiring diagramm for my model so far.
- Cleaned immobilizer connections
- Tested the relais under the hood and the ones located at CEM - All seem ok.
- Checked CEM for corrosion or anything obvious - still nothing.
- Reworked the ABS Module (didn't find any cold solder joint, but gave it a try anyways since the S80 is known for problems with it.

Bought a VIDA, read all codes out and tried to delete them.
Most will be deletable, except for the ABS one. Strange thing is, that it sometimes puts out the ABS Module failure only, next time reading it with VIDA, more codes will apper. In Vida, i noticed that sometimes the Battery Voltage will drop to 11.3V and go back up to 12.3V just a second later. Sometimes it will even drop under 10V without anything obvious turned on in the car. Thats with the Key in Pos. 2.

Failure Codes:

First reading as follows:

- CEM-E000 Control module communication Faulty communication
- ECM-E003 Configuration fault - Faulty Configuration
- ECM-720A Immobilizer Communication - Signal missing
- ECM-902A Communication with trottle unit - Signal too low
- ABS-0095 Control module communication Control module communication

Cleared the codes....

Second reading:

- ABS-0095 Control module communication Control module communication


Again, tried to clear it, but it comes back up with the ECM code:

- ECM-E003 Configuration fault - Faulty Configuration
- ABS-0095 Control module communication Control module communication

Since i read from a dutch guy, having the exact same problems, solving it by resoldering the CAN Pins of the ECU, i gave it a try also. Still no luck.
He describes that he has had a resistance of 200 Ohm instead of 120 Ohm for the CAN-Bus Pins on the ECU (thats Pin B1 and Pin B13). Resoldering these solved all his problems.
Unfortunately not for me.
When i read my ECU's resistance between Pin "B1" and "B13", i get a reading of approx. 37K Ohm.
I can not find a Pinout diagram for my model ECU anywhere to confirm thats the right values. Its a "Bosch 0261204559 26SA5547" ECU.

Can someone confirm the Pins B1 and B13 should have a resistance of 120 Ohm between each other?

I am wondering what to check / do next? Should i send the ECU out for inspection/ repair?

Any ideas to get the car going again highly appreciated!

Best regards from Germany,
ColoNel

[oragex]

I didn't read the whole post, but one thing on the ABS module (BCM) a cold solder is not always visible to the eye, would rather have it inspected by a decent TV shop.

Just maybe some leads, I remember there was also talk about some brake related relay on the CEM going bad (the black boxes attached to it)

That may indicate a short somewhere. Lights and computers take exactly 10 minutes to switch off on the S60. That's when I would try to measure the battery and maybe look for a current drain (see at end of this video https://www.youtube.com/watch?v=VsrmpXpZGVs )

I also recommend getting one of these to have a real time measure of the alternator voltage https://www.youtube.com/watch?v=IVDHzTkjHlc

[ColoNelJam]

Hi Oragex,

thanks for your reply. As mentioned, i did a parasitic draw test today and noticed, that when i pull Fuse #28 from the interior left side fuse box (Roof Lights, Courtesy Lights) it drops from app. 35mA to about 28-30mA.
Also, i noticed that when Fuse#28 will be attached (Let the car rest for 10min again, so the computers can shut down) , the Multimeter will jump like wild between 30mA and 35mA. (Did the same in the beginning, when starting to pull the fuses one by one) Don't know if that may be an important hint?

Could 5-7mA drain my battery so much, that the car won't come alive after 4-6 days of resting?

Btw. ordered one of these car meter USB-type things you mentioned.

Regards!
ColoNel

[ColoNelJam]

Hm...Nobody an idea?

I noticed that my battery is not healthy anymore, will replace it soon. Apart from that, i unfortunately made no further progress. Tested the relais i could find, all good.

Any idea highly appreciated,

regards,
ColoNelJam