1999 S80 cranks but doesn't start, Brake failure, Stop ASAP

[ColoNel]

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

[ColoNel]

Hey Folks,

i was trying to delete the faultcodes through VIDA, but the ABS Failure Status will return, no matter what i try. Now i noticed, that my brakes temperature Sensors read 114,6°C on the front as well as the rear brakes. Did some research, but couldn't find anything related to this.

Is it possible that this temperature reading is blocking the ABS fault codes from beeing deleted?

As stated before, i can't even start the Car in this actual state...

If somebody has a clue what is going on here, a short reply would be highly appreciated.

Thanks,
Colo

[jimmy57]

The temps are a fictional value calculated from ambient and increased for time brakes are on and reduced for time off brakes. No temp sensors are used. Ignore this, as it is a symptom of the network issue keeping ABS module from knowing ambient temp. There is likely a network wire issue. If you move the under hood fuse/relay box (clips and there is a bolt under the battery cable down in a hole at rear of box) and then hook battery cables back together, then unlatch the ABS module connector and probe between ground and the grren and then the white wires you will find twisted together. These are the network wires. The voltage should be 2.3 V DC and 2.8 V DC +/- 0.2 V dc. Unlatching and pulling up the cover disconnects the ABS module. The readings may be OK with it disconnected and then go wrong when it is connected. The same green and white wires can be found in the throttle module connector on that year model and can be checked there to see if it changes when ABS is plugged in or un plugged. The fault could be the ABS module itself. If the voltage on network wires (CAN wiring is also what the green and white wires can be called) is wrong all the time the fault is somewhere else. If the network signalling is blocked the Key chip is read and the CEM allows starter operation but the OK to run communication is not able to be received by the engine control module which shares the network with ABS, transmission, and ETM (throttle). Does the gear indicator in instrument cluster show a gear position or "---" ?

[dandiman]

Been having identical issue. Have replaced ABS module and still having issues. Common errors are: ABS--0093 and ABS--0095 (also getting ABS--00B4/00B5 errors as well. I'm getting the same error messages with both modules which leads me to believe it's something else. Otherwise, we've tried the same things and are having similar problems. Warm weather seems to allow my car to run longer between shut-downs.