heartless Posted December 31, 2021 Share Posted December 31, 2021 (edited) Other half's car.. he messaged me last night to look up this "ER-HC" code, which i found to be a CAN high speed communication error... Car ran fine and he made it home fine... this morning he checked codes with scanner and got P0021 - Camshaft Sensor (says this one comes and goes) P0600 - Serial Communication Link P1718 - AT Can communication circuit P0700 - TCU Malfunction indicator lamp request Not thinking about it, codes were cleared with the scanner tool Next, we tried performing the "handshake" to get the car to go into DTC mode.. took several tries to get it, but finally did no additional ECU or TCU codes, but it did come up with some ABS/VCD codes, and those are.. C0105 - Abnormal rear ABS sensor - RR C0140 - CAN communication malfunction C0115 - abnormal ABS wheel speed sensor - any one of four (assuming the same sensor as above at this point) Conditions at time of noticing the ER-HC code... He was on his way home, made a couple of errand stops along the way.. at last stop, shut the car off, went in & got what he needed, came out, started car - noticed the brake light was on - fiddled with the parking brake handle to try to get it to turn off - DTRLs were on, so he figured, eh, whatever.. turned lights on, backed out of his parking spot.. said he thought he felt a little bit of a slip on ice feeling, but otherwise, not problem... Pulled out onto the road and glanced down at dash to see what lights were on (obviously something out of the ordinary), and that is when he noticed the error code.. Car ran fine, no issues, other than the light show in the dash.. Temps outside were pretty chilly, but not unusually so for Wisconsin this time of year.. maybe low 20s, hi teens How likely is it that we are looking at a major CAN problem here? could it be bad grounds? other wiring issues (rodents)? He is currently out for a test drive.. will update later Oh, and he said to say the David Bowie came up with a TVC-15 error Edited December 31, 2021 by heartless Quote Link to comment Share on other sites More sharing options...
heartless Posted December 31, 2021 Author Share Posted December 31, 2021 ok, so a 17 mile test run and everything seems to be fine... I dunno Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted December 31, 2021 Share Posted December 31, 2021 I have had failing batteries set 'spurious' codes on 3 occasions. maybe test batt and check all connections. on some cars, adding LED bulbs has caused CANBUS issues. sry, that's all I got. Quote Link to comment Share on other sites More sharing options...
heartless Posted January 1, 2022 Author Share Posted January 1, 2022 (edited) he did recently have to get a new alternator... might be worth checking battery out further. hmmm... was just informed he did put LEDs in the tail lights... could not find anything else at the time, lol Edited January 1, 2022 by heartless 1 Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted January 1, 2022 Share Posted January 1, 2022 Welcome to the hell that is planned obsolescence consumer products coupled with highly integrated CANBUS and non mil-spec wiring. These cars are EXTREMELY sensitive to grounding problems. I would suggest not just cleaning them but actually taking EVERY ground apart that you can find, clean or possibly even replace the ring terminals after cutting back into good copper, and then cleaning the landing pads and using NEW properly sized star washers to ensure paint, corrosion, etc are successfully pierced and good contact is made. Coat the whole mess in dielectric grease. GD 2 Quote Link to comment Share on other sites More sharing options...
idosubaru Posted January 2, 2022 Share Posted January 2, 2022 20 hours ago, heartless said: he did recently have to get a new alternator... might be worth checking battery out further. hmmm... was just informed he did put LEDs in the tail lights... could not find anything else at the time, lol Check alternator output voltage now. It would be no surprise for a new aftermarket alternator to be bad or over charging. Why was the alternator replaced? An overcharging alt will fry computers. Ive seen and repaired all of the above. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted January 2, 2022 Share Posted January 2, 2022 1 hour ago, GeneralDisorder said: These cars are EXTREMELY sensitive to grounding problems. I would suggest not just cleaning them but actually taking EVERY ground apart that you can find, clean or possibly even replace the ring terminals after cutting back into good copper, and then cleaning the landing pads I’m not questioning that - but why do a large number of Subarus I’ve seen drive fine with ground straps hanging off and dangling unconnected for years? My current 2006 abs 2008 are prime examples. I don’t even care to fix it because it’s so common. The common ones are the engine to frame rail so I guess the answer is those are less important. I know the one behind the power steering pump is crucial (some won’t start without it). Any others specifically worse than others? Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted January 2, 2022 Share Posted January 2, 2022 We have seen multiple occurrences of the ground straps from the frame rails to the bottom of the cylinder heads killing the ECU - either it doesn't run or runs REALLY bad and undriveable. We had about a 2010 or 2011 Outback that was towed in..... barely would idle and idle was horrendous. After HOURS of testing we made up new head to frame rail ground straps and it ran fine again. I told the customer it was a rusty mess and to get rid of the car - which they did not do. A year later almost to the day the car once again showed up with nearly the same problem. This time after more HOURS of testing we told the customer - can't find anything wrong going to have to throw an ECU at it. And after ECU replacement the engine ran fine again. Going through a similar problem right now with a 2008. Engine runs but heavy throttle produces a flashing CEL and misfire codes even though it doesn't appear to be misfiring. Another shop recently replaced the engine and never attached the main ground from the battery to the starter ear/bell housing. It also had a bad rear hatch harness where multiple wires were broken and shorted - put the car in reverse and it would blow illumination relay control fuses and the headlights would go out. The other shop couldn't figure out either of those issues after the customer had returned reportedly 15 times to have them diagnose it. In frustration the customer brough the car to us and we immediately identified the missing ground point and after a bit of investigation replaced his faulty rear hatch harness and now we are just left with the collateral damage of the previous shop's ignorance. GD 1 Quote Link to comment Share on other sites More sharing options...
idosubaru Posted January 2, 2022 Share Posted January 2, 2022 1 hour ago, GeneralDisorder said: We have seen multiple occurrences of the ground straps from the frame rails to the bottom of the cylinder heads killing CANBUS worse than others? I’m guessing there’s no test worth the time for grounds? Test for a voltage drop at grounds or a power supply point? From one engineer to another - for many to work fine missing a ground and others not, is unsatisfying! Grounds, and something additional, is at play. Rust? More than one compromised ground? My last 6 or more DDs are from rust free states. It’s so common I’m sure most shops have seen it. Quote Link to comment Share on other sites More sharing options...
heartless Posted January 2, 2022 Author Share Posted January 2, 2022 (edited) Thank you GD we have already discussed testing the charging system under load and also checking/cleaning grounds, especially underhood. we did have to make repairs to the liftgate harness not that long ago (2 summers ago, maybe)... what tipped us off to that was his license plate lights were not working, even with new bulbs...dug into it and found that all but a couple of the wires in that harness were broken. 13 hours ago, idosubaru said: Check alternator output voltage now. It would be no surprise for a new aftermarket alternator to be bad or over charging. was checked with just a basic multimeter yesterday... battery, cold, not running was 12.8v - and this was at about 12F ambient temps, started car and it tested at 14.4 - he did turn lights and heater on and said it maintained, but yeah.. should be checked properly under load... we are both very aware of the commonality of bad alt killing a battery and bad battery killing alts.. so.. Alt was replaced due to not charging - causing battery to be run down. but yeah.. not real impressed with the canbus stuff at all.. LOL so, is this something i am going to have to be worried about with the 04 Forester? I hate electrical problems time to start going backwards i think.. get rid of some of the excess electronics.. fewer electrical problems . Edited January 2, 2022 by heartless Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted January 2, 2022 Share Posted January 2, 2022 (edited) 12 hours ago, idosubaru said: CANBUS worse than others? I’m guessing there’s no test worth the time for grounds? Test for a voltage drop at grounds or a power supply point? From one engineer to another - for many to work fine missing a ground and others not, is unsatisfying! Grounds, and something additional, is at play. Rust? More than one compromised ground? My last 6 or more DDs are from rust free states. It’s so common I’m sure most shops have seen it. It's extremely frustrating. You can go down the path of fixing every poor connection and ground only to arrive at no solution and have to throw computers at it because of course there's no way to actually test anything when it comes to the CANBUS - you can look at waveforms on a scope and potentially see something that's being pulled high or low - but if the problem is intermittent - lotsa luck with that noise. And since the packet data is considered intellectual property and not published you would have to spend literally 100's (if not thousands) of hours sniffing the packets on a known good chassis to reverse engineer the CANBUS signaling and then build a data logger that could identify an intermittent bad packet and who sent it, etc. Who's going to pay for this? Currently I have no takers. And yes I have people at my disposal that can do it. The tools and expertise and the hours it would take FAR exceed the value of a 10+ year old Subaru. In consumer products there is not enough redundancy, not enough pre-release testing, insufficient on-board diagnostic equipment and software, and then on top of all that the manufacturer is actively trying to thwart your repair efforts by hiding how it works behind the curtain of "intellectual property". Basically they expect us to repair something that is essentially "PFM" (Pure F*cking Magic)..... what the really want is the car off the road so they can sell someone a new one. I'm entirely over it - why continue to fight this fight? It's one thing to fix something that's broken with proper documentation - it's another to have to HACK your car and play reverse engineer against a team of engineers that are paid to thwart your efforts...... yeah screw all that. GD Edited January 2, 2022 by GeneralDisorder 1 Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted January 2, 2022 Share Posted January 2, 2022 2 hours ago, heartless said: but yeah.. not real impressed with the canbus stuff at all.. LOL so, is this something i am going to have to be worried about with the 04 Forester? I hate electrical problems time to start going backwards i think.. get rid of some of the excess electronics.. fewer electrical problems. No CANBUS for 2004. They started with a half implementation of it on the 2005 Legacy chassis, but really full implementation of CANBUS wasn't till about 2006 - later for some models. GD 1 Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted January 2, 2022 Share Posted January 2, 2022 I have read that poor grounding can cause an increase in electrolytic corrosion - possibly leading to increased likelihood of head gasket or radiator core failure. You don't want to ever read any significant voltage between ground and the radiator coolant! should be under 0.3 or 0.4 volts. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted January 3, 2022 Share Posted January 3, 2022 10 hours ago, GeneralDisorder said: It's extremely frustrating. You can go down the path of fixing every poor connection and ground only to arrive at no solution and Oh right my question oversimplified comparing grounds, here we are diagnosing an unknown with CANBUS and controllers. Quote Link to comment Share on other sites More sharing options...
heartless Posted January 3, 2022 Author Share Posted January 3, 2022 19 hours ago, GeneralDisorder said: No CANBUS for 2004. Hallelujah!! LOL so, he is off to work this morning with it.. Seemed to be running fine when he left.. will remind him later to swing by Advance & get the charging system checked out under load - make sure the battery & Alt are OK Quote Link to comment Share on other sites More sharing options...
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