By on July 27, 2011


Chuck writes:

My son enjoys being able to spread out when driving and also appreciates the convenience of hauling several of his buds around. He drives a 2001 Cadillac DHS. He has just moved to Massachusetts and registered the car there. It failed inspection with OBD codes P1860 and P0741.  He has 60 days to resolve the problem. A little internet searching informs that these codes are related to the torque converter clutch circuit and the solenoid valve.

The codes may indicate anything from a bad electrical connection to a failed plastic solenoid (I hate plastic) to a worn TC clutch. Other than the not so likely electrical connection fix, labor is at least 12 hours, even for the solenoid. I don’t see this as an emissions or safety issue, but then I’m not the state of Massachusetts.

I see his options as: a) rebuild the transmission for from 1/3rd to 2/3rds (dealer platinum level rip-off) the value of the car , OR b) get an economic hardship waiver for a year and figure out what to do – an alternative is selling the car in a state that isn’t as awful as MA c) clear the codes and drive veeery slowly to the inspection station (mixed forum opinions on whether this could work). On the ethics of selling a car with a possibly dodgy transmission – he’ll disclose it and furthermore the transmission could stop working tomorrow or could last much longer, according to the Caddy forums.

I’ve taken that gamble in the past and won more often than I’ve lost. In this instance, many comments in the forums suggest the impact is likely just a 1 MPG penalty from not having lockup – BFD. You get that penalty from moderately underinflated tires.

Any other suggestions, beyond drive the thing into Back Bay? Moving is not an option, certainly not in 60 days.

Sajeev answers:

First off, you can’t clear the codes and pass inspection: the shop will notice the lack of data and ask you to come back after driving the car a coupla days.  That’s the beauty of OBD-II electrics, you bow down before them, as you are at their mercy! Well, sometimes…

But that’s not the point. The economic hardship paperwork is your son’s best choice until he can find someone to dig into the transaxle for a reasonable price.  If this was a 2001 Lincoln Continental with it’s less-well-known transaxle, I’d just give up and find a different car.  That’s because your average transmission shop, for one reason or another, usually knows how to rebuild a GM transmission blindfolded. And other oddball trannies are, well, out of luck. You experience may vary, maybe I’ve just been that unlucky.

For sure, have someone examine the plastic connector(s), because that’s cheap and easy.  Many transmission shops do free diagnosis, and a free quote to do the work afterwards.  But no matter what, I always recommend a full rebuild if you’re going in there. Its just a waste of labor if you do not replace all the wear items when they dig in there.

My advice?  Sell that ‘Lac to someone in the American South who could use a decent foundation for a Swanga. Just kidding.  But only a little bit.

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35 Comments on “Piston Slap: A DHS, A Darn Hard Situation...”

  • avatar

    I agree that a transmission problem is unrelated to emissions and out of scope for the inspection, just be glad they don’t pull driving data out from somewhere and hit you with speed tickets.

    I don’t know that trans well enough to conjure a solution but Selling the car would be hard since it isn’t current on registration. Fools are aplenty that would buy it anyway but it’s still tough to move a 10 year old car like this quickly.

    take it to three shops for estimates and see how good a flogging they give you. Here is a proposed solution that runs a few hundred

    Of course there is always the option of trading it in at a buy here pay here lot on the shady side of town.

  • avatar

    The DHS has a Northstar right? Just wondering if it’s really worth fixing the transmission only to have to then worry about when the engine is going to kill itself.

  • avatar

    I had a 97 Firebird with a 4L60E, the 4T65E has a similar design flaw – the Pulse-width modulated solenoid wears out the valve body, allowing ATF to bypass the lockup clutch valve. I paid about $400 for a transmission shop here in Mass. to fix it in 2004. The valve body was not replaced; the shop used a service kit designed to fix this problem by re-boring the valve body and installing a new type of solenoid that won’t wear out the valve body.

    The reason why Mass. inspection will fail this car is because any ODBII trouble code causes a failure. In this case, a non-functioning lockup torque converter clutch means your engine’s burning more fuel than necessary (and also heating up your tranny significantly, burning up your fluid in the process). Fortunately, when I cleared the codes, the code would not be thrown unless I went on a very long trip. A good transmission shop will sit in the car with you with an Auto X-Ray or other scanner and monitor the clutch operation after clearing codes. In my situation the clutch would actually work for a while before the ATF completely warmed up, and then when it thinned it just blew by the valve and it stopped locking up. That was with a marginal case, if the valve body is badly worn it may not even lock up at all.

    While the DHS has a transverse mounted transaxle, the act of fixing the valve body should not really be any worse than it is on a 4L60E, which requires a similar amount of disassembly.

  • avatar

    Speaking from my time as a GM parts guy, the 4T80 is a very strong transmission, kinda the TH400 of its day. You probably don’t need a transmission rebuild, and I never sold torque converters for these vehicles. However the TCC and shift solenoids were a problem on these vehicles. I believe they are located behind the side cover in the valve body. The trans shouldn’t have to come out to replace them. I think you can support the engine from above, remove to cradle bolts, and remove the side cover. A dealership trans guy should do this for 4-6 hours plus the $50 for the solenoid.

  • avatar

    You may be able to just clear the codes and pass the test. The key is that the TCC won’t come into play at lower speeds. So if you can get it to run all the true emissions monitors while driving in D and keeping your speed under about 40MPH you should be able to pass.

    Purchase a scanner that shows whether the monitors have run. Verify which ones the vehicle is equipped with and clear the codes. Then proceed to drive slowly and in D until the scanner shows the appropriate monitors have been run.

    Also if it is an intermittent problem you may be able to drive it “normally” and get lucky.

    Of course you should have the wiring checked as well as the resistance of the solenoid (through the trans side connector). There is a reason the aftermarket offers replacement pigtails for many GM transmission connectors, and you can bet it’s not because the have a low failure rate.

  • avatar

    I’ve never been able to figure out why automatic transmission cars don’t have their own “CHECK TRANSMISSION” light. (I guess some cars, including Fords, flash the “O/D Off” light, but most don’t.)

    Can anyone explain this to me? Why doesn’t the transmission have its own diagnostic code system, separate from the engine/emissions codes?

    Edit: “kefkafloyd” explains that certain parts failing in a transmission technically affect emissions. Still, why don’t most automatic transmission cars have a transmission warning light?

    • 0 avatar

      I can see customers freaking out from information overload. Most people could care less if the transmission needs help, they just need a light to warn them of something. It doesn’t matter what “that something” may be, it just needs to be a light to tell them to fix it.

      Combined with the fact that many vehicles have one computer over all mechanical systems, a check tranny light isn’t necessary.

      • 0 avatar

        I seem to recall reading an article a decade or more ago where one of the detroit car companies were arguing for a more informative CEL because they didn’t want the dealers bothered with warranty work every time somebody forgot to tighten down their gas cap. The government on the other hand wanted the more generic CEL because they thought it would put the fear of god into people and have them run back to the dealer. The thought was that if the warning said “pollution control” or something more specific, people would ignore it.

      • 0 avatar

        In the original OBD-II code spec (SAE J1979) pretty much all of the codes were directly related to the engine and emissions systems. As time went on, and more and more computer-controlled systems went into cars, manufacturers started adding in more codes that were all manufacturer-specific for any errors in these systems. Sometimes these errors are safety or emissions related and sometimes they aren’t.

        The manufacturer has no real incentive to separate out stuff like transmission error codes from the rest of the CEL codes so that state emissions tests are more meaningful. If you are covered under their powertrain warranty, they’ve got to pay for the repairs anyway, whether it causes an inspection failure or not. If you aren’t under warranty, or if you bought the car used, they have no reason to care about you.

      • 0 avatar

        I know some vehicles will throw a “check gas cap” warning versus lighting up the CEL – I’ve had one car that would do that. Loose/failed gas cap is the number one cause of a CEL I had read somewhere.

  • avatar

    I can’t see this being something serious – you’d notice it immediately, but you didn’t say how the car drives. Did you check that? If it does drive normally, then I’d definitely check all the wiring and those awful, cheap, plastic plugs and fittings plus the wiring. You just may get fortunate and save you and/or your son a ton of money.

    BTW, I know how your son feels – I had a big car when I was young and hauled the guys around a lot, as I was the only one with a car (in the service). Plus, there’s a young guy in my neighborhood who owns one of the late-80’s Caddy DeVilles complete with Continental Kit and just cruises easy – the car is in outstanding shape, too!

    If this turns out to be a minor issue, he can cruise easy for years!

  • avatar

    How mechanically inclined is your son, and does he have the tools to fix the issue himself (or with help from you or his friends)? There’s a Youtube video (search for “TCC Solenoid Cadillac” and the author is BigBlok502) showing that the TCC solenoid in a DHS can be accessed and swapped without pulling the transmission from the car. I have the same code and plan to fix this in the next 2 weeks.

    If he does proceed, get the factory service manual or an AllData suscription. Chilton and Haynes are useless or worse.

  • avatar
    Robert Schwartz

    “First off, you can’t clear the codes and pass inspection: the shop will notice the lack of data and ask you to come back after driving the car a coupla days.”

    Maybe things have changed in the People’s Republic of Massachusetts, but I bet they haven’t. I am certain that there any number of shops that could make the codes disappear from the inspection report and not notice that they had been cleared for a small cash consideration.

    • 0 avatar
      Wagon Of Fury

      Having been down this road once upon a time with a poorly tuned supercharged Honda, how do you make this proposition to the tech ? The one guy just about threw me out of his shop, the second said he wouldn’t be willing to lose his license over it (speaking in a tone as though we were being recorded) and the third wanted more ($500) than it would cost to fix the actual problem.

    • 0 avatar

      I’ve never had a problem clearing codes prior to an inspection in Massachusetts – even at some strict shops. If they say anything, just tell them you fixed the problem and cleared the codes. I’ve had failures, fixed the problem, then gone in within minutes of finishing the repair and clearing the codes. Never had a problem.

    • 0 avatar

      It depends on the code, and the vehicle too. 3 years running, our 96 chevy van has been popping a catalytic converter code. 3 years running, I’ve cleared it with a scangauge II, driven straight to the emissions, gotten checked, and drove off. The light usually pops again, within half an hour or so.

      My advice would be to clear the codes. start the car and let it warm up to operating temp. Shut it down. Let it cool, start again, drive to testing station. From what I’ve heard the car’s (on a chevy) computer needs 1 or two full temp cycles to gather enough data, its not mileage related.

      My friend with the JDM civic knew the emissions test guy before he got the civic, and knew that he would fudge the tests before hand.

      Approaching them blindly will probably make them think you are some kind of undercover emissions checker.

  • avatar

    If he went to a dealership or repair shop for the “safety” inspection he might have better luck going to someplace that doesn’t do car repairs. When I lived there 12 years ago, my Chevy was failed by a dealership for play in the tilt steering. A colleague at work mentioned that he went to a truck repair shop that did state inspections as a sideline. The shop owner did the inspection and was amused that it was failed at the dealership–passed with no problem.

    Of course I haven’t set foot in the state for the past 12 years, so if safety inspections are done by the state instead of by licensees then maybe you’re out of luck.

    I’ve always viewed “safety” inspections as a scam for repair shops to make money. The same car was failed in UT because the guy (at a car repair place) thought the driver’s seat was too loose (which was right after I had rebuilt it with a new frame–it was fine). I took it down the street to an “inspections only” place and it passed without a hitch. Since then I always find a place that does inspections only (I live in TX now) so I don’t get failed by some place that just wants to make unnecessary “repairs” (got newer cars too).

  • avatar

    Computer codes include such global warming sins as power steering pump switches and transmission gear selector sensor failures.

    But the overlords decided anything short of a All Clear means it pollutes, without taking any considerations into what the codes say

    • 0 avatar

      They can’t take into consideration what the codes say. Every code not listed in SAE J1979 is manufacturer-specific and subject to change at any time and can vary between models and years based on the whims of that manufacturer. Some of those manufacturer-specific codes are related to safety and/or emissions (for example, ABS error codes are there). The codes are generally not publicly available and subscriptions for decoding nonstandard PIDs can cost an enormous amount of money and often must be bought from each manufacturer separately.

      The manufacturers didn’t want to actually compromise on a unified standard for more codes to update J1979, instead preferring to sell the extra PID data to dealerships and mechanics for ridiculously high amounts of money. So you, the used car buyer, got screwed. (Guess how much the manufacturers care?)

      • 0 avatar

        No in most states if it is not a primary or secondary emissions code it doesn’t cause a failure.

        Many of the mfg specific codes are easily available and included with moderate priced DIY code readers.

    • 0 avatar

      …Computer codes include such global warming sins as power steering pump switches and transmission gear selector sensor failures…

      I guess it was only a matter of time for some stupidity to rear its head and that time has arrived.

  • avatar

    “He has just moved to Massachusetts and registered the car there.”

    The problem is with the second half the the above sentence. One may dwell in Masachusetts while simultanenously calling another state home. Legal residency generally requires but physical presence plus intention to stay, and until one establishes legal residency in a new state by meeting the above critieria, they remain a resident of the former state.

    • 0 avatar

      Insurance companies are generally a little leery about people who report the car’s primary garaging address as a different address than where the car is registered.

      Oh, you didn’t inform the insurance company that you moved, and that the car is now primarily parked at this new address? Good luck getting a payout if the thing gets stolen.

      Also, he might want some of the other benefits of being registered as a legal resident of the state where he actually resides, such as voting in a local election, or registering for a city parking pass, or whatever.

      • 0 avatar

        I suppose if it were financially worthwhile to insure a ten year old Caddy with transmission problems against auto theft, or your parking permit and voting card were worth all the mechanic’s bills/buying a new car, I could see your point.

        I know plenty of younger people who move around enough that they never establish an intent to stay, subjective standard that it is, and thus remain legit legal residents of the state they were born in.

      • 0 avatar

        That’s fair. A buddy of mine wanted to keep his registration in his former state (mostly to avoid the hassle of dealing with the DMV) but Baltimore would not give him a permit to park on the street overnight (well, aside from a sixty-day “just moved” permit) unless he changed his address. Overnight parking at a private lot, every night, was kind of expensive.

        Personally, I think the guy should use a code reader to clear the codes and then find a mechanic who doesn’t really give a shit. Does Massachusetts state law really require them to actually verify that the car has been driven for x length of time since the last code reset (which, with some models, can happen just from a dead battery)? Or do they just see if the light is off? Find one of those chain places where half the staff is bored high school dropouts. The kind of place you’d never trust with an actual repair is sometimes the perfect place for a state-mandated inspection.

      • 0 avatar

        Generally, insurance companies do not care where a car is registered at all. States generally do not care where a car is insured, as long as its insured. Kids go to college, people work out of town, etc. Register it wherever you want/can, then tell the insurance where its garaged.

  • avatar

    Sajeev: Not sure what you mean about the Lincoln Continental transmission. The Continental used the AX4N/4F50N, an update to Ford’s AXOD, that was shared with the Taurus, Sable, Windstar, etc. They are common and cheap, available used for $400 – $500.

  • avatar

    Chuck here. Thanks for all the input. It turns out that because the car never passed an inspection in MA, the one year economic hardship waiver doesn’t apply. Took a while to find that out – the MA bureaucracy is so very helpful. The car is currently in my driveway – unfortunately sans plates and registration. That does make it quite a bit harder to drag it off to transmission shops for a diagnosis. I can only hope that a shortcut fix can be done or its just the electrical connections.

    FWIW, I think that it could be made to pass. Certainly true here in RI, where my brother-in-law remembers one time receiving his inspection sticker through the mail, back in the mid 70s. Things have tightened up somewhat since then…..

  • avatar

    There isn’t really any way around this. When the inspection machine is connected to the vehicle, it will will pull the vin from the PCM. This eliminates using a different car for the test. Not sure if the drive it slow idea is going to work either as the comprehensive component monitor is likely going to need some highway operation to complete. Additionally the registry is fairly strict as far as inspection shops are concerned. They’ll send in ringers to see if you’re performing inspections correctly, watch shops from across the street, etc. That inspection machine is like big brother, if you’re doing inspections in minimal time it will be flagged as a reason to check you out. Other issues like having a significantly lower failure rate than expected will raise eyebrows as well. Sorry for your issue, but it’s really not worth the shop’s or the inspection tech’s license to pass you outside the law.

  • avatar

    Mitt Romney is from Massachusetts.

  • avatar

    This thread makes me realize how glad I am to live in a state and county that doesn’t put us through that crap.

  • avatar

    As a (nearly) lifelong resident of the People’s Republic, I welcome your son to Massachusetts. He’s already learned about the many civil liberties and freedoms we enjoy. (But does he know cars are routinely rejected here for minor rust issues? True fact.) Two unsavory suggestions:

    1. He can drive around on a Rejection sticker for ages. I know guys who’ve thrashed about with those stickers for over a year. It’s Russian Roulette, of course, but the odds are with him.

    2. I never trade a car in at a dealership – UNLESS it’s got a significant problem that the dealer’s quickie inspection is sure to miss. Ahem.

  • avatar

    We bought a new Madza 3 in 2010 for our oldest daughter. This year, I took it to a local shop to get the required state inspection (NC) and it failed – at first, due to the window tint. This was tint the dealer applied, not us. I was about to go back to the dealer so they could either pass the car or redo the tint, when the shop owner “reinspected” it and whadyaknow, it passed! Wow, guy said the old dude doing the inspections was really paranoid, should lay off the reefer…

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