Sweet Righteous Vindication - Thank You Paul!

I'm not sure which area would have been best suited to post this. I settled on Case Study Videos thinking that might be closest.

Yesterday was one of those really unpleasant days at work until the end where I had my moment of glory. Something that I owe entirely to ScannerDanner. After yesterday I totally wish I could have bought you a beer and shaken your hand...

Don't get me wrong, I like where I work and I like the guys but we're a medium sized shop pretending to be a small shop. We have no designated counter staff. Just the boss. Then when he's not there or when he's too busy I'm doing front and back. My boss is a great guy and all but he's not very organized and doesn't handle stress well. He tries to do too much and when it gets busy he can't keep up. Then it becomes less than fun... Yesterday my boss was very much a mood of, "Here's a job. Get it in, done and out. I don't care about anything else with the vehicle. Go! Go! Go! We have a lot of jobs waiting!" :huh:

Yesterday my boss gave me a 2003 Dodge Grand Caravan 3.8L FWD. Tells me the speedo is inaccurate and it's shifting funny. I even told him then that alternators can do that... But he told me it's probably the speed sensor and to take it for a drive then put it in the air and check out the speed sensor. I check for codes and it has lots of tranny codes. Fault immediately after shift, gear ratio error in 1st, and a couple others. Idling in Park the speedo was at 0 but in any gear it was reading about 20mph when stationary. In Park the trans input speed sensor was reading same as engine RPM but the output sensor was reading 1100 RPM! I thought it odd that the input sensor was working fine. I put the vehicle in the air and unplugged the output sensor harness. It then read 0. So that rules out wires rubbing and feeding false signal into the sensor wires.

At this point my boss came up to me with the new sensor and told me to put it in. After I replaced it he sees me waiting for the scanner to reconnect to the vehicle. He then asks me why I'm waiting and just put it in Drive and see if the speedo is out of whack. I run it and sure enough the speedo is still at 25mph and the output sensor is still reading 1100 rpm when my foot is on the brake and the engine rpm is only 800. Just as soon as I tell him it made no difference he told me to get the vehicle off the hoist so he can take it for a drive and figure out what's wrong with it. At this point he's mad at me like I'm only going to waste time on it with my "fancy gadgets"... Like I should just go do some tires and just leave it to him. After he comes back he tells me (word for word), "The vehicle's good. The tranny just had to re-remember itself. The speedo just doesn't work" It felt like he punched me in the brain.... :pinch: I can handle him not caring much about my opinion but when he gets angry with me that a vehicle has a problem like it's my fault... THAT'S the part that's so difficult to deal with!

The oil pan was leaking a lot on this vehicle. Customer said that if the sensor fixed the issue then go ahead on oil pan. So my boss calls her and tells her everything's fixed and we're going to do the oil pan. He gets the old timer to do the oil pan. When that guy finished the job I told him to take it easy on the test drive. The tranny still has an incorrect output speed signal. When that guy brings the vehicle back he tells me it's shifting bad. Of course it's shifting bad... It has faulty output speed data! The old timer is very old school. He wants to visually inspect everything. Tells me he wants to pull out the sensor and inspect inside. Why??? If the output shaft of the transmission were actually moving at 1100 RPM while you're stationary then the differential would have shot spider gears across the shop! So while they're both pouring over the vehicle talking about "inspecting this", "smacking that" or "replacing this" I walked over, unplugged the alternator, got in, drove it, came back and told them the tranny's fine and it needs an alternator. They're both stunned. All of a sudden my opinion matters again and my boss half apologizes.

On a less ranting note... I'm not sure why the input speed sensor was unaffected... The sensors are virtually the same. They're both 2 wire variable reluctance sensors that share the same sensor ground... Either way it was a case of excess A/C voltage from bad alternator diodes. It was only after I disconnected the harness to the alternator did I realize how much noise that thing was making!

Anyways, thanks again for helping me justify and prove the merits of LEARNING and THINKING. Somedays you face so much opposition to that that you think you're back in the days of Salem and are being yelled at for being a heretic...

YES! In the UK we have saying for situations like that "You scored a few Brownie (Girl Guide) points on that one".
Pauls video on the same type of problem is one of my favourites.

I wonder if the problem would have shown up with checking the the output voltage at the alternator with a DVOM set to AC Voltage.

From one "heretic" to another - nice to get your point across with the nay-sayers.
I have the same issues as you at work, I'm at the sunset of my time on the shop floor, looking for an exit strategy due to physical constraints and battle daily with a boss and other techs who have no idea how systems on a car function.
Would have been nice to get a shot of the A/C ripple across the alternator, printed it and stuck it to your box lid - then next time just simply point at the picture and walk away.
I have a plastic pot full of blown fuses and shorted sensors that other techs have checked off as "good" sat on my work station as a visual reminder for the non-believers.
Cheers
Steve...

Andy.MacFadyen wrote: YES! In the UK we have saying for situations like that "You scored a few Brownie (Girl Guide) points on that one".

This isn't even brownie points. This is fighting to raise your status from "dirty peasant" to at least "lowly commoner"... :huh:

Andy.MacFadyen wrote: I wonder if the problem would have shown up with checking the the output voltage at the alternator with a DVOM set to AC Voltage.

I've wondered about that for a while too. The vehicle's still at the shop undisturbed and I have to go swap my winter tires on so I think I'll try that. Plus I should probably grab some captures and save them for my collection.

Doc wrote: Would have been nice to get a shot of the A/C ripple across the alternator, printed it and stuck it to your box lid - then next time just simply point at the picture and walk away.

Sadly, I don't think it would be that easy. None of them believe in that witchcraft. It's hard enough to get them to look at scan data. Like with this car after I swapped the speed sensor. The conversation went like:

Boss> Well?
Me> No change. Still an output signal when wheels stationary.
Boss-Annoyed> Get it down so I can take it out and I'll figure out what's wrong with it.
Me> This is data coming directly from the TCM...
Boss-Angry> Get it down.
Me> Okay...

We're a transmission shop. Boss-Man has 25+ years experience rebuilding them. So the last thing he's going to want to do is take advice from a dirty peasant. I'm TOTALLY okay with that too. I respect his experience and I've learned a lot from him. I just wish these people would put down the hammer for one second and just THINK. If a transmission is seeing a signal saying the output shaft is spinning at 1100 RPM when the car isn't moving then of course it's not going to shift right. No amount of road testing will help that. And a road test is totally unnecessary! It's a physical impossibility for the output shaft to be spinning while the wheels are stationary and not have something in between be disintegrated. There's no need to "figure out what's wrong with it". That IS what's wrong with it. The question of "WHAT" has been answered. The question we're on now is "WHY". As in, "Why is that false signal there?". :pinch: *bangs head against table* :pinch:

I even showed them a nice waveform of an old GM car. It would stall when warm. Had the Multec1 injectors that were shorted out. I had a capture where the current shot straight up to like 8 amps before it had any bend to it. Hard to get more of a short than that and I still got a, "Well, I dunno... I still want to put a crank sensor in it. We used to do lots of crank sensors in these." When I got the old ones out and the new ones arrived I even Ohm'd them all. Then I told them that the new ones were all at spec and within 0.1 ohms of each other whereas the old ones were all over the place. I think the worst old one was only a third of spec for resistance. That was cold too. The response I got was, "Well, we'll cross our fingers..."

Btw, I kinda like the sound of that... Instead of "Junior Member" under my avatar it's too bad I couldn't get it to say "Dirty Peasant"

Nice work man! I understand your workplace struggle for sure! Keep doing what you do, they'll trust you more and more as you prove the value of your methods.
My shop is a combo Garage/Junkyard/Used car lot. There's not a whole lot of diagnosing going on with the junkyard to lean on as a never ending parts crutch.
I recently posted this in the "Request for help" thread.

Noah wrote:

Week 1: Part 18 (2014) Alternator Diode Testing
-Effects of A/C voltage on the ECM
-Effects of low voltage on the ECM
-Current output testing
-A/C ripple test (alternator diode test)
-A/C coupling
-Acceptable A/C voltage levels
I've fixed 3 Chrysler's thanks to this lesson! The last one was a Pacifica where the mechanics at the junkyard I work at replaced the transmission with a used unit. Of course it had the same no shift symptom when they got done. I just happened to be walking through the garage and heard the alternator howling, and asked the mechanic, "where do you think that noise is coming from?".... although I knew damn well where it was coming from.
"I don't know, somewhere in the front of the engine. You gave me the wrong transmission, it won't shift and it's setting a Incorrect Gear Ratio Code! You have another transmission in the back?"
I explained to him the code has to do with slippage and nothing to do with having the wrong transmission. Then I proceeded to lead him in the area of the alternator again.
"I'm not worried about that noise, it still won't shift, I've got to pull this transmission back out."
Then I blew his mind by saying " I bet the speedometer isn't working correctly right? Why do you think that is? Disconnect the alternator and take it for a ride before I pull you another transmission for no reason at all, and you tie up this lift for another 2 days...FOR NO REASON AT ALL."

Now that I think about it, I casually diagnose a lot of his work just passing through the garage on my way to and from smashing windows and stripping junks....

It's probably petty of me to say this, but I LOVE that feeling :evil: My current boss does this, to an extent. Sometimes it feels like he has the car diagnosed for me, before I've even gotten in the car

To be honest, I've left jobs over stuff like this. Some owners are just dyed in the wool parts changers, and don't know how to let their techs do what they're paid to do.

Btw, I kinda like the sound of that... Instead of "Junior Member" under my avatar it's too bad I couldn't get it to say "Dirty Peasant"

:lol: I'm not sure if custom ranks are possible, but that'd be awesome to do. You can actually change the Personal Text in your Profile to whatever you want, and it'll show up above your post count.

Tyler wrote:

Sometimes it feels like he has the car diagnosed for me, before I've even gotten in the car

To be honest, I've left jobs over stuff like this. Some owners are just dyed in the wool parts changers, and don't know how to let their techs do what they're paid to do.

Guys it just sounds sooo familiar! :lol: Guess we all know these situations and how it feels. Sometimes it just makes my blood boil. I HATE this way of working and being surrounded by parts changers.

.
We're a transmission shop. Boss-Man has 25+ years experience rebuilding them

I'm sure it was a shot to his ego.
I'm surprised that he gave it the OK after the first test drive when it very clearly wasn't fixed.

Noah wrote: I'm sure it was a shot to his ego.
I'm surprised that he gave it the OK after the first test drive when it very clearly wasn't fixed.

It wasn't a shot to his ego because he's convinced it was fine when he took it and then it messed up again. The problem with my boss when it comes to road testing is he doesn't road test under enough different conditions. He puts his foot into it on road tests. Something like this is going to have more of an impact at low speeds when the output sensor isn't generating much of its own signal. Then the noise from the bad alternator will be the primary contributor to the signal. The tranny would try shifting into second at like 5mph when driving in the parking lot. He would have felt that and attributed that to the tranny relearning shift points. Then when he's driving it hard the signal from the output sensor will overcome the alternator noise and it'll feel, more or less, normal. If this were happening to the input speed sensor then you'd really feel it in the higher gears. But being with the output speed sensor you're really only going to feel it when slowly taking off from a stop. Even coming to a stop would feel relatively normal.

So it felt bad in the beginning of the test drive then smoothed right out, ergo... TRANNY FIXED! :dry:

I went back to this vehicle and used a multi meter across the alternator terminals on AC setting. It bounced around a bit but was right around 0.35VAC. Unfortunately I didn't take an after reading because this vehicle went crazy.

The key was left in the ACC position over the weekend which killed the batter. Was stone dead. Dash lights wouldn't even come on. We got one of those new NAPA battery chargers that pulse the charge. I don't know if I like these chargers. It's good for topping up a charge or boosting but I don't think I like it for charging of weak batteries. It has an auto maintaining selection that's 2-6A and then every other selection is labelled as a boost. I think one's a 60A, ones like 200A and then it's got a 6v setting. So I put it on the 60A setting. As soon as I turned the charger on all the modules in the car started flipping out trying to do their junk. Boss-Man was away so was stuck up front most of the day. Took me forever to get a chance to change this alternator. In the meantime the charger was on this van. For two hours I had it on the 60A boost setting then for about 3 hours I had it on the 2-6A auto maintaining setting.

The customer initially said they were in no rush for it but then started calling after noon asking about it. The last time he called I at least had had enough time to change the alternator and was just putting the belt on. So I made the mistake of telling him to come down. Will only be 10 mins. :ohmy: This is for sure the fix. I absolutely KNOW those are words you never want to say but he had been calling so many times and it's a simple job. When he comes 15 minutes later I still haven't had a chance to put the belt on yet because I'm the service advisor for everyone else in the shop. The guy starts lingering. Watching me... I HATE that! Things always go wrong when they're there and you tell them it's just about done. I was nice to him and didn't say anything because it had taken me six hours to find the time to finish this simple alternator change.

I finish and the battery's still low. Only 11.5V. So I put the charger on the 11.5V scale. My Verus is waiting on some memory so I have to grab the shop's Verdict. This thing is a piece of junk. It was on for a long time too. Not sure if that played into it. Well I hook it up and make sure there are no codes before starting it. Shouldn't be because the battery was dead but anyways. Nothing in the engine. That communicated fine. I then check the tranny module and it won't communicate. As soon as I select the tranny module the Verdict screen says "Testing PCI Bus. Please wait". It normally only says that for 3-5 seconds. After about 30 seconds the headlights come on the vehicle. Then 10 seconds later every gear in the PRNDL display lights up then the scanner says no comm. The customer is watching everything. I slowly start freaking out inside thinking something cooked the tranny module. I go make sure nobody unplugged anything over the weekend. Everything's connected. I still haven't started the vehicle and the charger is still on. I try this a couple times and still the same thing. Disconnect the charger and still the same. I try starting it and it'll start then die 2 seconds later. it has no comm with the TCM. When I start it the PRNDL display lights up and it dies. The EATX relay is wigging out. Clicking on and off like it has Tourettes. Also the relay is really warm. Noticeably warmer than the rest.

The customer goes for a walk at this point. THANK YOU! GET THE F@#$ OUT OF HERE! :ohmy:

So, I put a new battery in it and hook up my small, hand held Autel scanner. Everything seems to be working. I can check for codes in the TCM. I then go to data and check select output, input and engine RPMs. I start the vehicle and everything's good. Customer comes back and I tell him of the situation. His battery might be messed. It has a 2014 sticker on it though so should be fine. I tell him that the vehicle has "reset itself" with the new battery and now I'm going to try it with his old one and see if it'll work now. I have no idea what happened but you can't admit that. I'm just happy that the TCM is fine! I put his battery in and everything is fine!

I don't know what happened but I didn't care at the time! I just wanted it gone. I didn't hook that charger or the Verdict back up to it. But ya, things were looking pretty scary for a moment there!

I had a similar experience that occurred in my daughter's 2007 Equinox below is an excerpt from it:

rn8849 wrote: Tyler,

Also, I panicked when upon trying to restart after reconnecting the battery it did nothing, and I mean nothing except I think there was one red light on the dash for like a seat belt or something. No gauge check, no check engine light, no battery light, nothing. And to make matters worse, it would not release the key. I was furiously searching the InterWebs trying to figure out what to do and I read horror story after horror story about people having to have their cars towed to the dealer for a several hundred dollar reflash or a new BCM just because they unhooked their battery. After trying over and over, finally I literally bowed my head in prayer, turned the headlights on, then off, and it started. I have no idea if the Good Lord fixed it for me, if turning the headlights on/off did some good, or, as I seem to have read along the way, enough time had passed for some kind of relearn to take place. But, since that incident I have been really gunshy about working on this thing. What can you tell me about that deal? Is there are right way to do that without it crapping out on me like that?

Gary

I haven't had the courage to disconnect the batter and try that again but at some point I will. As I reread the above I see that I failed to mention as I retried starting it, every so often with each key cycle a new dash light would come on, or the radio lit up, or the HVAC lit up, it was like it was slowly 'waking up'.

Maybe that is somewhat of a common thing?
Gary

Agree with you totally dude. I had a Lincoln in the shop which ran fine and the battery never discharged, but the speedo read 16 mph sitting there idling. I put a scope on the alternater and found close to 4 volts of AC ripple. We replaced the alternator and problem solved. Happy boss, Happy customer..