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My '05 odometer was displaying "------", indicating a high/low speed CAN communication error. Took it to the dealer and they retrieved a bunch of codes from it and said the BIU was beginning to fail. They recommended replacing the BIU but said that may not be the only thing needed. A gauge cluster was mentioned as a possibility since the gauges work intermittently.

 

Is someone out there an expert on these that I can consult with?

I have the codes, and I'd like to know more about the BIU. Is it plug and play that I can get one from salvage? Does it require special programming to work in my car? Those kind of things. I don't want the dealer to just start throwing parts at it and costing mega bucks if not needed.

TIA

Edited by coblue
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The BIU (Body Integrated Unit) is integrated into the LAN system, which means it also communicates with the immobilizer system. Because of this, the BIU must be programed to your car via the Subaru Select Monitor (dealer tool). Once programed, it is forever married to that VIN/Immobilizer.

 

The sad fact is that the dealer would need to start with the BIU and see if everything else works like it should. The cluster may be bad (I really doubt it), but without the BIU working properly, there is no way to test it until the BIU is replaced.

I like to cook my pets and my family.

 

Use commas. Don't be a psycho.

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I have been fighting problems with my car too. I have gone through 2 ECU's and 2 BIU's and now 1 multi meter ( instrument cluster). Each time any of the above is replaced it must be paired with the immobilizer (BIU). So far I have spent 3K in repairs and my car still does not run. I feel your pain.

The BIU also requires new keys to be cut and programmed. I have paid for a total of 7 keys throughout this ordeal also.

If you woke up today, you have another chance to do it right.
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Thanks Danteneon. That explains it well.

This particular car has been a money pit already- I'd hate to go down the road wurkenman has been down.

Unfortunately, replacing the BIU first seems to be the only way to go.

 

Wurkenman- I recall seeing your post while searching. I'll go back and reread and maybe pm you.

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I agree - when in trouble of uncertain types always check the power (battery/alternator) and grounding first.

 

Secondary is the remaining parts of the wiring.

 

I have also noted that the backbone CAN in the Subies is exposed in the diagnostic port and if you attach a reader with bad termination you can get bad problems with the display and presentation.

 

Notice that the CAN bus needs to be terminated at both ends with a resistor. If the termination fails you can get random communication errors. The same goes if you have too many termination resistors involved for some reason.

 

The termination resistors are usually built into the "end" ECUs, so it's not just to look for a resistor.

 

In any case - changing ECUs shall be done when any other possible cause has been excluded. And if you did get the codes read - please make sure you get the list and post it here - and match to this list: http://bedug.com/pics/Subaru/obdcodes_Subaru.txt

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Alright! Seems like I have some good people trying to help me out.

Danteneon has me going down the B0101 trouble shooting path. Haven't finished yet but battery voltage is good at 12.4 volts, all fuses in the main box and cabin are good and seem tobe making good connection. I am also rechecking ground connections.

 

Here are the codes as ehsnils requested:

B0100 integrated unit system error

B0101 batt. P/supply malfunction cont

B0102 batt p/supply malfunction backup

B0103 ignition power failure

B0104 acc power failure

B0201 can-hs counter abnormal

B0221 can-has ECM no-receive data

B0321 can-ls meter no-receive data

B0401 m collation ng

B0500 keyless uart com. Malfunction

 

More details on the symptoms:

This happened 1 day after my last tune. The OBD port "may" have a bad wire- my AP will sometimes reboot while logging.

Odometer always displays flashing "------"

Center dash display shows "---" mpg, "---" avg mpg,"---" miles to empty; ET, outside temp, and clock are fine.

Gauges are set to sweep when key is turned. Sometimes they do, sometimes not.

Sometimes gauges are not lit.

Which gauges work is random, sometimes all work. Turning car off and back on will usually get all working at the same time, sometimes takes a couple tries.

Occasionally the tach reads high- like 2k at idle. Sometimes the needle moves more jerky than I remember.

 

I've removed the cluster to check connections, seem good and no rattle inside the cluster.

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I've gone through the diagnostic checklists for the above codes. Most of them lead to "perform the DTC clear mode" and then check for codes again. Is there anyway to clear the BIU codes without the SSM, like by disconnecting the battery for a long period?

 

From my service ticket, I can't tell if the tech performed the clear and reread, before recommending replacement of the BIU.

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Alright! Seems like I have some good people trying to help me out.

Danteneon has me going down the B0101 trouble shooting path. Haven't finished yet but battery voltage is good at 12.4 volts, all fuses in the main box and cabin are good and seem tobe making good connection. I am also rechecking ground connections.

 

Here are the codes as ehsnils requested:

B0100 integrated unit system error

B0101 batt. P/supply malfunction cont

B0102 batt p/supply malfunction backup

B0103 ignition power failure

B0104 acc power failure

B0201 can-hs counter abnormal

B0221 can-has ECM no-receive data

B0321 can-ls meter no-receive data

B0401 m collation ng

B0500 keyless uart com. Malfunction

 

More details on the symptoms:

This happened 1 day after my last tune. The OBD port "may" have a bad wire- my AP will sometimes reboot while logging.

Odometer always displays flashing "------"

Center dash display shows "---" mpg, "---" avg mpg,"---" miles to empty; ET, outside temp, and clock are fine.

Gauges are set to sweep when key is turned. Sometimes they do, sometimes not.

Sometimes gauges are not lit.

Which gauges work is random, sometimes all work. Turning car off and back on will usually get all working at the same time, sometimes takes a couple tries.

Occasionally the tach reads high- like 2k at idle. Sometimes the needle moves more jerky than I remember.

 

I've removed the cluster to check connections, seem good and no rattle inside the cluster.

 

I wish you well mt friend and I still feel your pain.

You and I seem to be in the same boat, except I get ZERO, ZIP, NADA codes. I even replaced my fuel pump control module and the key ring antenna. I knew it was a long shot, but still had to rule those out. I am currently "gutting" my car to gain access to the wiring harness in the dash and the body. Don't know where else to go at this point.

If you woke up today, you have another chance to do it right.
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My '05 odometer was displaying "------", indicating a high/low speed CAN communication error. Took it to the dealer and they retrieved a bunch of codes from it and said the BIU was beginning to fail. They recommended replacing the BIU but said that may not be the only thing needed. A gauge cluster was mentioned as a possibility since the gauges work intermittently.

 

Is someone out there an expert on these that I can consult with?

I have the codes, and I'd like to know more about the BIU. Is it plug and play that I can get one from salvage? Does it require special programming to work in my car? Those kind of things. I don't want the dealer to just start throwing parts at it and costing mega bucks if not needed.

TIA

 

My brother has a 09 OBXT and he was having exactly the same issues you are. They found the wiring harness under the intake manifold rubbed through and when they wiggled the harness, everything would work again, but it wouldn't stay that way.

 

Look under the intake manifold on the DS to see if yours has worn through and is shorting on the block. He was also getting the ErHC display as well as the ----- on his and it would do nothing at all sometimes and other times it would work fine. His gauges were all over the place and even his radio and climate control was goofy.

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Alright! Seems like I have some good people trying to help me out.

Danteneon has me going down the B0101 trouble shooting path. Haven't finished yet but battery voltage is good at 12.4 volts, all fuses in the main box and cabin are good and seem tobe making good connection. I am also rechecking ground connections.

 

Here are the codes as ehsnils requested:

B0100 integrated unit system error

B0101 batt. P/supply malfunction cont

B0102 batt p/supply malfunction backup

B0103 ignition power failure

B0104 acc power failure

B0201 can-hs counter abnormal

B0221 can-has ECM no-receive data

B0321 can-ls meter no-receive data

B0401 m collation ng

B0500 keyless uart com. Malfunction

 

More details on the symptoms:

This happened 1 day after my last tune. The OBD port "may" have a bad wire- my AP will sometimes reboot while logging.

Odometer always displays flashing "------"

Center dash display shows "---" mpg, "---" avg mpg,"---" miles to empty; ET, outside temp, and clock are fine.

Gauges are set to sweep when key is turned. Sometimes they do, sometimes not.

Sometimes gauges are not lit.

Which gauges work is random, sometimes all work. Turning car off and back on will usually get all working at the same time, sometimes takes a couple tries.

Occasionally the tach reads high- like 2k at idle. Sometimes the needle moves more jerky than I remember.

 

I've removed the cluster to check connections, seem good and no rattle inside the cluster.

 

Sorry for any late response.

 

Both the codes in bold above at the same time leads me to really want to investigate the ground circuits to the BIU and also at other locations in the vehicle - even the ground wire from the battery.

 

Even if the battery has a good voltage it may be out of punch so the voltage drops too low when cranking. Also check and possibly also replace the battery ground wire - even if it looks good. I have experienced that a bad crimping of the main wire from the battery messed up things, so just replacing them with "fat oversize stuff" will at least rule out that part.

 

As someone noted, a bad alternator can mess up things too. Try with disconnecting the alternator and put the car on a battery charger and see if that makes a difference.

 

Yet another item that can cause all kinds of headache is the ignition lock itself. When it gets old it may not work as well as it used to, so bypassing it with a switch on a pair of wires is one way to test if it's the culprit. (Pin 3 and 6 on the ignition lock, should be white and green wire)

 

Fuse number 12 in the footwell fuse box is the one feeding the BIU, make sure it's OK and that it's properly seated and that the wires aren't pushed out when you put the fuse back in.

 

The BIU has three ground connectors (C8, C9 and B22) and all three must be in place.

 

I would say that as long as an ECU can report about the health status and it has been around for a while in the car you should look for the problem elsewhere. Of course - even ECUs ages, but just replacing them at random is expensive and usually a waste of time. And if an ECU gets quirky when it's getting old it's either a bad soldering of a connector or a dried out capacitor that's the culprit.

 

The codes shall go away when removing battery and pressing brake pedal for 20 seconds with ignition on to drain every last volt from any built in capacitor.

 

The 2005 doesn't have CAN wired to the OBD connector, so it can't interfere there (later model do, but that's another issue and I was wrong in an earlier post :redface:). There are two CAN buses in the '05, one between BIU and Combination meter, and one between BIU and Steering Angle Sensor, ECM, TCM (for AT vehicles), VDC and ABS.

 

http://www.bedug.com/pics/Subaru/2005/CAN-01.png

 

http://www.bedug.com/pics/Subaru/2005/CAN-02.png

 

Start with the cheap stuff before you throw money at the expensive stuff. Most workshops today are just code readers and replaces stuff and hopes that the problem goes away. If not then they are about as lost as a rabbit in a wolf pack and they resort to replacing things at random.

 

In cases like this it's better to know about Kirchhoff's circuit laws than anything else.

 

And the fact that your AP reboots turns my head to the ground circuit. The diagnostics connector shares ground point with the BIU! So I think you REALLY shall check that wiring - and add your own ground wires to that circuit just for the heck of it to make sure that you don't have a gremlin there.

 

http://www.bedug.com/pics/Subaru/2005/GND-02.png

 

If you really can't solve the problem - find a good car with a blown engine and make an engine swap and part out the remains. That should be the last resort.

Edited by ehsnils
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Wow - thanks ehsnils, that should keep me busy for a while! This car just became my dd so I'll be tackling this in small pieces.

 

I'm also concerned about " code readers replacing parts" rather than finding the cause.

 

If I correct the cause of the codes, will the BIU clear the stored codes and return my display to normal?

Can an independent subie shop have a Subaru Select Monitor, or does SOA have tight control of them? Knowing if the codes are changing would be helpful.

 

I also think the ignition lock is a possibility- the car has 106k miles so many cycles on the lock. I forgot to mention that a couple times there is no response when turning the key if the car gets very hot in the sun.

 

I am keeping a log of what the gauge cluster does each time I start the car. It seems to be worse when the car has sat in the sun. I will probably run the diagnostic on it to see if the cluster is ok and see if the BIU is sending bad info.

 

Thanks again to all.

Edited by coblue
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Any news?

 

Nothing yet.

I've been keeping track of the gauge operation- basically if the needles sweep then all the gauges work. If the needles don't sweep then some gauges don't work; which gauges seems to be random. I thought it would happen less frequently as the outside temperature drops but don't have enough cold days to validate it. In the summer it can be hot enough after sitting in the sun that the starter won't turn over, and of course not gauges. But after a couple tries it starts.

Reading the trouble shooting decision tree for my dtc codes all seems to point to either a harness/ground problem, or bad BIU. Since this error just came up in the last few thousand miles, and everything that connects to the BIU seemed to be working before and since the error code (other than the gauges) I'm leaning toward replacing the BIU. I may spend some time chasing grounds this weekend, but electrical really isn't my thing.

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Ehsnils, You make two good points. I discounted the reboot when you said BIU wasn't directly involved with obd on an '05 ( if I understood correctly).

The reboot seems to be caused by something in the last 9" of wire or connector of the OBD. I can make it happen by moving the wire bundle.

Do you think it's related or not?

 

Time to get the multimeter out of the toolbox! :)

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Definitely related, the BIU and the OBD connector shares the same ground, but the data signal from the OBD is another business, so from a data traffic perspective the BIU and the OBD connector aren't closely related, but when you look at it from a power perspective they are.
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  • 2 weeks later...
  • 2 weeks later...

Spent a little time on it tonight.

I can cause the reboot of the AP by pushing the body wires sideways where they enter the OBD connector. I think it may be the number 4 or 7 pin, can't tell for sure because the probes on my multimeter are too large to fit into the OBD or BIU connectors reliably. need to figure something out that will be stable while I wiggle the wires.

If indeed the end of the wire is loose, I don't see how it would affect the BIU since the BIU doesn't ground through that wire of the OBD, does it?

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Nothing yet.

I've been keeping track of the gauge operation- basically if the needles sweep then all the gauges work. If the needles don't sweep then some gauges don't work; which gauges seems to be random. I thought it would happen less frequently as the outside temperature drops but don't have enough cold days to validate it. In the summer it can be hot enough after sitting in the sun that the starter won't turn over, and of course not gauges. But after a couple tries it starts.

Reading the trouble shooting decision tree for my dtc codes all seems to point to either a harness/ground problem, or bad BIU. Since this error just came up in the last few thousand miles, and everything that connects to the BIU seemed to be working before and since the error code (other than the gauges) I'm leaning toward replacing the BIU. I may spend some time chasing grounds this weekend, but electrical really isn't my thing.

 

WAIT...WAIT....WAIT....I haven't looked at this thread in a while and finally did tonight sitting in my hotel room in Las Vegas. OK...what you stated above that I highlighted and underlined.....When this happens, what does it make you think of? And then, when you couple it with the two codes below that came up when you scanned.....

 

B0101 batt. P/supply malfunction cont

B0102 batt p/supply malfunction backup

 

YOU have a cable issue from the battery, possibly the alternator, and probably the battery itself. Grounds need to be cleaned and/or completely replaced and most likely your battery cables too. The cables can corrode from the inside out if there is even the tiniest crack in the insulation and any low spots will hold water. That means the only reason your car won't turn over when it's hot is due to excessive resistance in the leads that power the starter and ground the engine block. You also said that when it's hot out, your gauge cluster seems to be more prone to not working correctly. You need to replace both of these cables and clean every contact point that they connect to. Then have the alternator checked because of the spike comment by Raj, because that can definitely make ECM/BCU do a bunch of funky things because they all run on milliamps and some of them run on millivolts within the modules.

 

Your gauges work sometimes, your car won't turn over when it's hot, as well as other electrical issues with the door locks, it has to be the source. Your battery is actually down by 25% at 12.4 volts. A fully charged battery is at 12.6 volts and if your battery goes down to 12.0 volts it is technically discharged and it can cause a ton of other issues.

 

With that being said, after the cables, I would suspect the alternator having a diode issue because of the battery not being fully charged. An alternator is NOT a battery charger, but a battery maintainer and it seems as though your alternator is not keeping it up to charge.

 

Very last thing is it could actually be the starter beginning to go bad, but I don't believe that's the issue. The solenoid on the starter can cause run circuit issues if it has excessive resistance inside, and no one ever thinks about this particular part of the circuit.

 

You said that you found in the OBDII harness bundle that you could wiggle them and have different results due to possible contact problems. I believe you're dealing with a source problem and without sufficient power, they will do a lot of funky things.

 

You MUST start at the source. The battery is the SOURCE of everything in a vehicle. Without a good battery to begin with, NOTHING will work. Then, you MUST have good connections- on BOTH SIDES. EVERY GROUND has to be a perfect connection and you can never have too many. If you wanted to have 25465196546564 grounds on your car, it would never hurt a thing, but if you don't have at least one good one, it causes everything to be haywire. Also remember that EVERY SINGLE CONNECTION on a vehicle must be perfect for every single thing on the car to work correctly and that many of the different circuits rely on each other to make them all work together. Once you have all of that done, then, you must go to the maintenance portion of the system that keeps the SOURCE in proper operational order-the alternator. Once you have all of these things in proper working order, then you begin to look further.

 

I would bet that once you do the cables, charge the battery up to full charge, have the alternator checked and re-install or replace it as necessary, making sure the belts are the correct tension, that you won't have the hot day start issue anymore and most likely, the rest of your issues will clear up. If not, then you begin to do deep diagnosis, and I would begin with the ignition switch as it's the next link in the chain from the battery to the rest of the operational systems in the vehicle.

 

Good luck my friend, but I believe you'll find your problems there. ;)

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  • 7 months later...
  • 3 weeks later...
Only bad news. One morning it wouldn't start, like the immobilizer kicked in (one of the codes above). Battery has been on a tender since and is at 12.7v. I cleaned and tested all the grounds in the engine bay and I have ground through the OBD II port (shared with the BIU). i've done all I can and will be taking it to the dealer. It's not me DD so it may be a few weeks while I save up for it. I'll post when I have news.
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My problem got solved. Ended up being the neutral position sensor on the back of the transmission. Can't hurt to check that. I just unplugged it and the car started. Been 2 weeks now. Cost me 4500 bucks to find a faulty 40 dollar switch.
If you woke up today, you have another chance to do it right.
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