by dbeckwith » Today, 12:19
[quote="dbeckwith"]Just purchased a 95 Volvo 850 with 264,000 miles on it. What concerns me is that when I come to a stop sign or lite sometimes it acts like it goes into neutral. I have to increase rpms before it will engage and move. Anybody have any ideas?

Just finished PNP clean and reinstall. Recently changed fluid. Still the same issue. Anyone have thoughts about seafoam trans tune? I usually don't buy into these magic potion remedies but I have used this is the past with great success on my 88 Grand Am, but this is not a GM tranny and I am fearful of doing anything that would make it worse.


Still brainstorming about this issue. Being attentive I noted that while driving in third my shift points were as follows:
1st to 2nd 12 mph
2nd to 3rd 26 mph
3rd to ? 33 mph (I am assuming this is the lock up engaging)

I recognize that specs are given with consideration to 60% throttle. I seldom accelerate more aggressively than 3000 rpm so I am not sure how a person would measure what percent of throttle this would represent. It seems to me (at least the lock up) is occurring way too slow, although drive ability doesn't seem to be compromised.

I am assuming the TCM is responsible for shift speeds. Could the TCM be off this much without trigger some kind of fault(code)?



Application MPH
Economy Mode
1st-2nd ............................................. 24
2nd-3rd ............................................. 48
3rd-4th ............................................. 75
4th-3rd ............................................. 60
3rd-2nd ............................................. 36
2nd-1st ............................................. 15
Sport Mode
1st-2nd ............................................. 35
2nd-3rd ............................................. 68
3rd-4th ............................................ 101
4th-3rd ............................................. 86
3rd-2nd ............................................. 57
2nd-1st ............................................. 24
(1) - With shift lever in "D" position and throttle valve
open 60 percent.


Application MPH
Economy Mode
Lock-Up ON
2nd Gear .......................................... 25
3rd Gear .......................................... 49
4th Gear .......................................... 73
Lock-Up OFF
2nd Gear .......................................... 23
3rd Gear .......................................... 44
4th Gear .......................................... 68


Would love to hear from someone that is pundit when it comes to these transmissions. Thank you

 

First question for you... when you change the fluid, what method did you use?

Second... what did the fluid look like when it was drained?

Third... does the transmission slip when shifting from 1st to 2nd, 2nd to 3rd, 3rd to 4th?

The good thing is, you still have gears that are shifting. There are sensors that help the transmission computer decide when to shift.

 

The transmission does not slip. When going from park to reverse it is within specs(1.2 seconds) and when going from park to 1st it is within specs(approx 1 second). Trans was pumped thru oil cooling line but I must say it was in need of it. I don't know maintenance history of this car but I would guess that it hadn't been changed before. I am thinking there must be a sensor or something that tells the TCM when to shift.

 

Sounds like you did a through fluid change. My guess is that there is a sensor going bad or something. When my transmission was not going into 1st at a stop light I replaced the fluid 3 times (simple drain and refill) it started working properly after 2 weeks. Maybe you need a little more time for the fluid change to really make a difference.

Under a mild load, it doesn't seem that those shift points are that bad. I usually try to keep my rpm's under 2,500 and it shifts pretty quick. Maybe it's the lock-up feature that is not working good. I believe the lock-up keeps it from downshifting to soon for no reason.

 

Any thoughts about oil temp sensor. When trans is cold it shifts perfectly under all conditions.

 

Have you tried pulling all of the codes from the diagnostic module? The trans port is the A1 port. I'm in the middle of trying to figure out what to do next now that I have the codes. Check out this link for a listing of the trans codes:
Dtc Information - Volvospeed Forums
Also, look at this link, too
1993-1995 Diagnostic Connectors (Check Engine)
The Haynes manual has a good explanation on how to pull the codes for the ignition and fuel sections; the trans codes are pulled in the same way.
Last thing - this is a very good Volvo 850 Transmission Diagnostic manual:
http://www.volvoclub.org.uk/tech/ser...sDiagnosis.pdf
Print it out and it has detailed diagnostic and repair procedures for each code. Most of them the DIYer can handle. Good luck.

 

What kind of issues have you been having? My issue does not trigger any codes. I am in the process of installing an auxiliary cooler now since my issue only happens when the tranny is hot(operating temp)

I have done thru mode 4 based on Autotransdiagnosis. Everything checked out ok

 

Hi Dbeckwith

First of all, did you download the .pdf in my last link for the Auto Trans Diagnosis? I found this to be very helpful. There is a transmission oil temperature sensor which should give you a 235 code for as long as the temp remains high and it should also activate the transmission trouble light on the dash (flashing up-shift arrow). I find it curious that the trans trouble light is not flashing (maybe bulb burned out?)
There is also a procedure to actually check each sensor and component individually in a sequential manner using the diagnostic port. I have not attempted this yet, but I may need to. It seems from your post that you may have already have done all of this?

My problem - One morning, started car and up-shift arrow was flashing. Looked in owner's manual - and it said that it meant there was a trans problem and go to dealer (Gulp!) After a few miles it went away. This reoccurred every day for a week or so, then the trans light was flashing continuously. Then one day on the freeway, the car lost all power; I glided up an off-ramp where the car died. It started right up again but as soon as I re-entered the freeway it lost power again. I again barely made it off the freeway and limped home on side streets.

Once home, I researched the issue and then pulled the following codes from the diagnostic unit: 114-Mode selector switch malfunction; 223 - Throttle position sensor signal too low. Tested switch with VOM, and it tested bad; got a used one a the local Pic-A-Part rather than spend $65 for a new one. It tested ok and solved that problem.

The 223 code is the one that has me scratching my head. I removed the TCM and thoroughly cleaned all of the male connectors; bought some CRC electrical spray cleaner and cleaned the female connectors for the TCM and also the fuel and ignition ECUs (My car has the Bosch LH3.2 Jetronic with the EZ-29k Ignition, so there is a separate ECU for the ignition.) I removed the idle control valve, cleaned it and the connectors; and cleaned the connectors for the throttle position sensor. They were quite corroded on the female end, and I cleaned the males the best I code considering I couldn't see them that well. At the same time I found several bad vacuum lines and elbows and repaired them also. After a few days I put everything back together, but alas, the car wouldn't start. Realizing that I forgot to clear the codes, that was done and then after about a minute of cranking it finally started up and it felt like a new car! The idle was rock solid at 800 rpm and there was power and smoothness I hadn't felt before in the two years we've had the car! I took it out for a long test drive on a variety of roads; and after about an hour, while making a u-turn in a rural culdesac, it DIED again! No warning, it wouldn't start, just turned over and over! And, the trans and check engine lights were now lit. I pushed the car to the side of the road, pulled the codes - 223 AGAIN! Since I had no tools and it was getting dark, I could either call AAA or try a few things. I cleared the transmission trouble codes; made sure there were no more warning lights flashing, and went to start the car - It started right up and was as smooth as silk on the ride home!

Obviously, I have a questionable connection somewhere. My questions to those of you that have read this far - should I just replace the throttle position sensor or is it possible that the fault lie somewhere within the TCU? I have spent many hours on this issue already and my wife is growing impatient with not having her car and I am growing weary of being the family taxi as well as the family fleet manager! Any suggestions?

 

I wish I had some suggestions for you but I don't. You have considered swapping out the TCM to see what impact it might have? You can pick them up used on ebay for cheap. I have been considering this but now I am working on brakes and installing oil cooler. I am keeping my fingers crossed. I probably should have installed a temp gauge so I can have a baseline, but my wife already thinks I am psychotic with respect to this volvo

As for me I wish a code would get triggered. At least then I would have some kind of reference point. Being borderline OCD this trans issue pushes me to the brink of hysteria.

Yes I did investigate the diagnostic material you referenced me. I run most tests except individual pin tests(no codes) and the line pressure test. Could be the source of my problem when the trans gets hot. That is when I experience my issues.

If after installing the cooler I notice no appreciable differences I will have a line pressure test. I could do it myself but by the time I buy a gauge and fittings I might as well pay someone to do it.

Good luck with your situation and keep me posted.

 

TrueVoice1: If it were not for the codes I would think the problem was NOT related. The stall that is. Now when my car runs out of gas I get all kinds of codes (happened once or twice when I was low and on a slant). Not sure why a car would stall and not start due to anything with the transmission. Some cars stall when they spin out or something but usually start right back up. Do you think it's possible that you have a fuel relay problem?

 

Transmission fluid Temperature sensor (TFT)

This may also be known as Transmission Oil Temperature. This sensor determines the fluid temperature inside the transmission. This is often used for diagnostic purposes to check ATF (Automatic Transmission Fluid) at the correct temperature. The main use of this has been as a failsafe feature to downshift the transmission if the ATF becomes extremely hot. On more modern TCUs this input allows the TCU to modify the line pressure and solenoid pressures according to the changing viscosity of the fluid based on temperature, and also to determine regulation of the torque converter lock-up clutch.

You may already be aware of this but I found it to be interesting reading.
The more I think about it the more I think I will try replacing the temp sensor and see if I get a reaction from that

 

Hi rspi

Thanks for the suggestion. I am inclined to think that it is electrical due to the fact that when it died all of a sudden, both the trans trouble light and the check engine light came on at the same time. However, when I went to start the car again yesterday morning, it turned over and over without starting which seems like a symptom of a no fuel situation. Anyway, at the local self service wrecking yard I found a 850 with only 116k on it and I got the TPS from it and I am planning to install it later today. Hopefully that will take care of the 223 code. I just find it curious that all of a sudden several things in different areas would fail at the same time.

Question - if there is a no fuel problem, in your experience, what is the most likely culprit? I know that the fuel pumps can fail without warning and that I need to check all of the connectors, etc. DO you have any other ideas? Thanks in advance for the help!

 

Actually the fuel relay goes more often than the pump. The relay is often intermittant which sucks.

 

As it turns out, I called up a mobile Volvo mechanic, and for a while he was scratching his head also; no spark, no signal or codes from the ECUs, but their was fuel pressure. After a while he found the source of the problem. Under the battery 'flap', the positive terminal resides with several wires coming out of the terminal. There was quite a bit of corrosion, and the wire that powered the ECUs was so deteriorated that when he touched it, it fell apart! So, parts of the engine were getting juice and the ECUs were getting little, if none at all. This explains why it quit when some of the codes were displayed, there may not have been enough current to have the car go into limp home mode so it just shut down? Anyway, he removed the flap over the terminal, repaired the wire that was bad, and now all I have to do is give the terminal a good cleaning with baking soda and water. And he only charged me $60! Lesson learned - keep the battery terminals as clean as possible and for the rest of you 850 owners, get rid of that stupid flap over the positive terminal! The car is purring like a kitten now!

 

Wow! That's great news. I wish they all were that simple.