1999 4T65EHD transmission has acted up twice now. The first time I was heading to a car show. Service Engine Soon light came on and as I was getting close to the museum the trans would shift real hard and the engine seemed to run funny. When I got to the museum I checked the trans fluid and it was low. Found a store put some trans fluid in and it has been doing great for the last almost 2 months. I have consistently checked the fluid to ensure the level was where it should be. This evening left work and went to the car show. I was almost there, got off the expressway and on city streets when the I noticed the transmission seemed to shift funny. Then the Service Engine Soon light came on and the trans shifted hard. Like it had a shift kit installed. I let the it set for a while then stated the engine up and let the trans get to operating temperature checked and it seemed to be at the proper level. Drove the car home after show and no problems. Checked the level and it is were it should be.
It does get hot in the engine compartment.
Is this transmission run by the computer? I wonder if that could possibly be the problem. The terminal by the cigarette lighter doesn't seem to work. I tried several different testers a couple of years ago when I was working at a dealership. I could not get any of them to work. This past winter I had OleJoedad try one of their testers and they could not get it to work on the plug. PO says Sinister programed the computer. Not sure what tester to use. PO had some kind of scan tool that he ran all the time.
That is everything I could think of about the history and build of the vehicle.
Low fluid will cause the transmission to act up. The wrong fluid may do it too. The recommended fluid for your transmission is Dextron VI which is a synthetic fluid. Putting regular Dextron III in it may upset performance and change shift points. Also check the fluid level only when the engine is hot. If your fluid has been mixed with Dextron III and VI I suggest that you flush it out it and replace it.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Dennis, PO put Dexron VI Valvoline Full Synthetic in and that is what I use. I do recall after I purchased the car I checked all the fluids and found many low. The trans was almost a quart low. That was about 2-1/2 years ago. The event about a month and a half ago, I had left the "performance switch" on and I think that caused the fluid to disappear and the associated problems. I again used Valvoline Dexron VI, it took about 1/2 to 3/4 quart. What is puzzling is there wasn't any leakage on the garage floor. As you suggested, I always check it hot and level.
[This message has been edited by solotwo (edited 06-24-2015).]
Dennis, PO put Dexron VI Valvoline Full Synthetic in and that is what I use. I do recall after I purchased the car I checked all the fluids and found many low. The trans was almost a quart low. That was about 2-1/2 years ago. The event about a month and a half ago, I had left the "performance switch" on and I think that caused the fluid to disappear and the associated problems. I again used Valvoline Dexron VI, it took about 1/2 to 3/4 quart. What is puzzling is there wasn't any leakage on the garage floor. As you suggested, I always check it hot and level.
Sounds like you are doing everything right and this is puzzling. If the transmission fluid continues to disappear and no external leaks are conformed, then check your coolant for traces of fluid. It is possible but unlikely that the internal radiator trans cooler sprung a tiny leak. Again rare but it has happened before. If you are getting DTC's get them read. If you don't have a scanner or code reader, Autozone offers a courtesy trouble code retrieval.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Sounds like you are doing everything right and this is puzzling. If the transmission fluid continues to disappear and no external leaks are conformed, then check your coolant for traces of fluid. It is possible but unlikely that the internal radiator trans cooler sprung a tiny leak. Again rare but it has happened before. If you are getting DTC's get them read. If you don't have a scanner or code reader, Autozone offers a courtesy trouble code retrieval.
I will try to get to a autozone type place and get the codes checked, If they can. I notice bubbles on the dip stick when checking the fluid level. Normal? Oh the car was a manual transmission car so PO installed a tranny cooler next to the transmission. When I first bought the car I had that 4 week flu that was going around, so I didn't check the car out like I should have. When I was better I noticed a trans line leaking where it was attached to cooler. The Ideal clamp was loose. I tightened it up of course and installed extra ideal clamps on all the external transmission hoses.
bubbles ? I wonder if the Filter/pickup is not sealed and is sucking AIR ? 4t65e-HD trans is Definitely computer controlled. you said the plug for Checking codes Does NOT work ? It should be a OBD2 plug. are all the electrical PLUGS tight , especially the round one?
bubbles ? I wonder if the Filter/pickup is not sealed and is sucking AIR ? 4t65e-HD trans is Definitely computer controlled. you said the plug for Checking codes Does NOT work ? It should be a OBD2 plug. are all the electrical PLUGS tight , especially the round one?
I tried two different scanners when I was working at a GM dealership. I also had Joe try with his scanner and he mentioned that I may have to get a hold of Ryan @ Sinister to see how the computer was programed to see what type of scanner I may need to get codes. I am going to see if a autozone type store can get the codes from the computer. PO presumably had a scanner hooked up all the time. I will check my notes to see what the name of it is.
You need a 12V supply on the OBDII connector for it to pull codes. Whoever did the swap may have taken the supply from the cigarette lighter circuit. If the cigarette lighter fuse is burned, replace it and see what happens,
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
I would first check to make sure you have no restrictions in your cooler lines. Have seen many hoses separate on the inside. Overheated fluid will expand, puke out of the vent, and then get bubbles when the level gets low. Not to mention, smokes wet clutches. Does your cooler get good air flow? If you can't get it to the front, at least get the cooler where it can get air flow. 4T65e uses a pressure control solenoid instead of a modulator valve to control shift pressure. They don't like to get hot. Seen them fail both ways. Full pressure/shifts hard, Low pressure/slips, shutter when shifting. Better fluids and better cooling do help greatly. 90% of the time if you can't get a scanner to come up it is no power to the ODBII connector. As many have said this normally comes from the lighter or ctsy fuse, but that depends on how it was wired. Can't count the times I can't get a scanner to come up due to someone pushing a crappy USB adapter into the lighter.
You need to get codes. Bet it has P1811(maximum adapt and long shift). The car shifts hard when the code sets because the computer commands maximum line pressure. Marc
Cigarette lighter works. Bubbles are a few on the dip stick. Cooler seems to be in a good area. I'll take pics. PO pulled some extra wiring when he sold it to me. He had it wired for computer hook up. Plus some other stuff. May be in his haste he pulled the power to the obd connector.
I took some pictures this evening of the cooler and the dip stick, but in my haste to get a picture before the bubbles were gone, all I got were pictures of the drive way. LOL The cooler looking down from the top of the engine.
From the ground. Sorry it is a little blurry.
I will try tomorrow to take pictures of the bubbles.
I would first check to make sure you have no restrictions in your cooler lines. Have seen many hoses separate on the inside. Overheated fluid will expand, puke out of the vent, and then get bubbles when the level gets low. Not to mention, smokes wet clutches. Does your cooler get good air flow? If you can't get it to the front, at least get the cooler where it can get air flow. 4T65e uses a pressure control solenoid instead of a modulator valve to control shift pressure. They don't like to get hot. Seen them fail both ways. Full pressure/shifts hard, Low pressure/slips, shutter when shifting. Better fluids and better cooling do help greatly. 90% of the time if you can't get a scanner to come up it is no power to the ODBII connector. As many have said this normally comes from the lighter or ctsy fuse, but that depends on how it was wired. Can't count the times I can't get a scanner to come up due to someone pushing a crappy USB adapter into the lighter.
Lighter works. I charged cell phone on the way to work this AM. On lunch today went to OReillys and had them try to scan. No work! Something is a miss somewhere.
When the transmission starts shifting hard, it's a good bet the PCM has set a transmission related code and caused it to do that. It would be very helpful to know what trouble code or codes are setting in the PCM.
------------------ OVERKILL IS UNDERRATED Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com
When the transmission starts shifting hard, it's a good bet the PCM has set a transmission related code and caused it to do that. It would be very helpful to know what trouble code or codes are setting in the PCM.
I AGREE! But I cant get them! The connecter isn't working! So what's next? I have tried for the 2 years I have owned it!!
The PCM is programmed to increase shift pressures when it starts to see problems. It is basically supposed to be a 'limp mode' to get you home. This results in the hard shifting. It is a common symptom especially in higher mileage transmissions.
One of the things that can do this is a worn valve body. But the thing as Darth said is to read the codes before speculating too much.
[This message has been edited by phonedawgz (edited 06-26-2015).]
Pin 16 needs to be connected to constant 12v + battery power protected by a 10 amp fuse.
Pins 4 & 5 need to be connected to ground.
Pin 2 needs to be connected to 3800 Series 2 PCM terminal C1-59.
I just took the console off, it doesnt look good(as in ut oh something is missing) as far as wires coming out the back. I think a ground is missing. I am going back to the garage and look at it again. Tying to do this and clean the carpet for the wife. I'll take pictures.
Ok got some pictures and you will see no ground wires just 2 wires going to the ecm/pcm. So now I need to unravel the tape to make sure the pins and wires match up. And install some ground wires.
Found some extra wires here are a couple.
These must be wires not needed in for the 3800 & PCM
And am I safe in assuming this is the proper wiring for the connector?
In looking at the wiring and the extra wires I know how this came about. Jesse was under a time constraint to take off the wiring I didn't want- as he said" They power an extra switched power point in the car, under the dash I used an RF transmitter. Plus an always on micro USB port and a full size USB port which come out under the center console. I used them for my phone and iPod charger." plus load up the extra parts and body parts. Then load the car on a dolly and drive it up to Michigan. So the extra wiring was removed and more than likely unintentionally the ground wires. I am sure the question all are asking, why didn't I do this earlier and take the console off? Well I didn't have any real codes to check , just wanted to see what I could find and sometimes you just get tired of Always working on the Fiero. LOL
The Purple wire as it plugs into the pcm
The tan wire as it plugs into the pcm
[This message has been edited by solotwo (edited 06-27-2015).]
Bingo I think I found the problem. No 12Volt power and no ground.
I numbered the wires according to this print;
Number 16 has a red wire spliced on and cut off. Grounds 4 & 5 not attached. 4 had a black wire spliced and cut off. So this evening my son stopped over to chat and gave ole dad a hand while we talked. Nice to have a son who is an automotive engineer. Just lives a little to far to run over to his place for help. He lives in the metro Detroit.
[This message has been edited by solotwo (edited 06-27-2015).]
Ok I think the Problem is solved. I installed a new trans filter and wasnt happy with the way it installed. Talked with 2 Seat Garage and took their suggestions. Installed the new bushing and now filter sits level in the trans. When I took the pan off the filter that was installed was hanging down so much that it was resting in the pan. My finger is pointing to the spot. Not sure if it has been that way for 2 years or not. Though it seems like I have seen bubbles for a long time. Could have been a bad install or could have been our crappy roads in Grand Rapids!
Now the filter sets like it should.
[This message has been edited by solotwo (edited 06-29-2015).]
It is shifting better. Best since I have owned the car. Fixed the OBD connecter problem. I had ORiellys scan it and three codes showed up, two that that I knew would show up I had the O2 sensor unplugged and forgot to plug it back in, and the same for the sensor in the air intake, and the third was a transmission code. P0742. More than likely from the lock up last week and or from last month. I am glad that I caught the problem, thanks to the great people here on the forum. Two items checked of the long list of things that need repair on the car.
[This message has been edited by solotwo (edited 06-29-2015).]
P0742 is for the TCC stuck on. Now that you've fixed the filter issue, I recommend clearing codes and see if this one (or any others) return. Let us know.
P0742 is for the TCC stuck on. Now that you've fixed the filter issue, I recommend clearing codes and see if this one (or any others) return. Let us know.
I went to ORiellys at lunch today and got the codes. I hope they cleared them.
Thanks for the info. Oh on the way home I noticed the transmission seems to be shifting soother and goes into 4th torque clutch lock up sooner and is less noticeable. It is definitely better than when I purchased the car.
[This message has been edited by solotwo (edited 06-29-2015).]
Well I encountered it again to a lesser degree. In heavy construction traffic. Stop and go traffic, acted up just as I was getting back to work. No light or codes. I think I will install new rubber lines. May be install an air scoop to direct air to the cooler better.
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