Gerhard

Everything You Can Do to Troubleshoot Your SS Automatic.

As many of you are probably aware, Honda has seen fit to warranty the 2000 and 2001 model year Prelude transmissions to 100,000 miles. Unfortunately, this leaves the owners of the other 3 model years of the 5th Generation of the Prelude to pay for expensive rebuilds themselves.

However, all hope is not lost! The Sequential Sportshift Automatic Transmission is an electronically controlled fluid coupled transmission, and there are many problems that can be fixed without need to replace the transmission. You need to know what can go wrong so that you are not sold a new transmission because you didn’t know what the problem really was!

Most of the user fixable transmission problems are going to be electrical (wires and solenoids).

Getting Started:

First, there are a few diagrams in the 1997-1999 Helms manual that you’ll want to look at:

1) Page 14-53 shows the external transmission components that are involved in the normal operation of the automatic trans.
2) Page 14-16 shows a list of Shift Control Solenoid Valve positions and what gears they effect. (more on this later)
3) Pages 14-102 to 14-106 show how to test all of the external components specific to the transmission.
4) Pages 14-114 to 14-117 show which components to check based on the symptoms you are experiencing.
5) Pages 14-116 and 14-117 show typical causes during rebuilding that will cause specific problems. So if you’ve had your tranny rebuilt and it’s acting up, you’ll want to check these pages.

Theory:

To figure out what type of problem you have you should know the basics of how an automatic transmission (auto trans) works.

Basically, an auto trans uses hydraulic pressure to control the functions of the transmission (trans). These functions include controlling the clutches (1st thru 4th), locking up the torque converter, cooling the trans & torque converter, and lubrication.

The fluid used in the trans is generally called Automatic Transmission fluid (ATF), and circulates through the trans via a variety of pathways cut into the various steel and aluminum components.

Flow the ATF in the various components controls exactly which gear the transmission is currently shifted into by placing ATF pressure in a series of stacked plates (clutches) that in turn put the transmission into gear. (This is a somewhat simplified explanation.)

The flow is controlled by 6 solenoids (with the help of you car’s Transmission Control Module [TCM]):

1) Shift Control Solenoid A
2) Shift Control Solenoid B
3) Shift Control Solenoid C
4) Lock-Up Control Solenoid
5) Pressure Control Solenoid A
6) Pressure Control Solenoid B

From High School physics you probably know that liquids are basically uncompressible. As such, applying pressure to the ATF causes it to flow through the pathways in the trans. The exact direction and components that the pressurized ATF is applied to are controlled by a combination of the Pressure Control Solenoids, Shift Control Solenoids, and the Lock-Up Control Solenoid.

When ATF is applied to the various internal clutches in the trans they engage and cause the vehicle to move in the corresponding gear. So, if ATF is being pumped into 1st gear clutch then the car will begin to move in 1st gear, and so on.

Knowing what kind of problem you have:

Problems with your SS auto trans are probably going to fall into one of the following categories: Mechanical, Electrical, or ATF.

ATF:

Honda recommends that you use only Honda Z1 ATF in your SS auto. This is fairly important if your ride is still under warranty.

Honestly, Honda ATF is pretty good, but it’s not so great a sub zero temperatures. I’ve been using Mobil 1 synthetic ATF for some time and it works very well. If you are facing subzero temperatures, then you may want to consider using Mobil 1 synthetic ATF. I make no warranties as to how it will work in your car, but it works fine in my 1998 Prelude.

There are a few problems that involve ATF.

First, if your car rolls in Neutral, then the problem is probably that you have TOO MUCH ATF in your trans. During a normal ATF change in the 5th Gen Prelude you can put as much as 3 QTs into the unit without any problems. More than that and the car might start to roll in Neutral.

Second, if you car doesn’t move at all when you put it into gear, then you probably don’t have enough ATF in the transmission. Check the dipstick and verify you actually have enough ATF. The ATF should be at the top of the hash marks on the dip stick.

Third, under the Shift Control Solenoid A / Lock-Up Control Solenoid assembly is a rubber gasket with two small screens embedded in it. If the ATF has not been changed regularly (every 15000 to 30000 miles), then the screens can begin to clog with small metal particles that are part of the normal wear of the transmission. Generally, these screens can be cleaned and reinstalled (though Honda indicates that they should be replaced upon inspection to prevent ATF leakage). The symptoms that this form of problem causes will vary depending on which solenoid is clogged:

Lock-Up Control Solenoid
- Low torque converter stall speed.
- Engine idle vibration
- T/C lock-up clutch does not engage / disengage.
- Lock-Up clutch does not operate smoothly.

Shift Control Solenoid A
- Vehicle does not move in the 2 position on the Shift Control Lever.
- Trans erratically fails to shift in D4 from 1st to 3rd.

Note: There is a way to monitor the health of the internals of you trans by sending your spent ATF out to a laboratory at every ATF change. Lab services will analyze your ATF and determine exactly how well it’s holding up. They will also tell you what wear metals are present. Knowing the level of wear metals will give you a heads up about any imminent mechanical failures.

Two companies of note are:

Oil Analyzers at http://www.oaitesting.com/

Blackstone Labs at http://www.blackstone-labs.com/index.html

Mechanical:

Mechanical problems with your SS Auto Trans tend to be somewhat obvious.

First, if you notice problems and then drain the ATF and find a LOT of metal in the drained ATF, then you’ve probably got a serious mechanical problem. NOTE: If the ATF also smells burnt (like a fireplace you’ve put plastic into), then you definitely have an internal mechanical problem).

Second, if you check you fluid levels and the outside temperature is not below freezing AND your tranny makes a whining or whirling noise, then it’s likely you may have a problem with your T/C.

Third, if you shift into any gear and the transmission BANGS (aka Hard Shifts) into the next gear AND you’ve checked all of the potential electrical problems, then your transmission probably has a mechanical problem. Probably either bad bearings or bad clutches. (The SS auto is known for have bad 3rd gear clutches.)

Fourth, if you shift into any gear and the transmission slips and never quite makes it into gear AND you’ve checked all of the potential electrical problems, then your transmission probably has a mechanical problem. This is likely a bad clutch.

Lastly, if you hear grinding, you’re screwed. It’s probably caused by bad bearings. You need a rebuild. (You probably saw a lot of metal in your ATF… if you have ATF Pressure.)

Gerhard

(Continued)

Electrical:

Electrical problems can cause just about every problem except grinding in you SS Auto.

(Though ignoring an electrical problem could conceivably lead to a mechanical failure of the transmission.)

It is important to note that many of the electrical problems that might be encountered with an SS Auto will not generate a Malfunction Indicator Light (MIL) on the dash board or cause the D4 light to blink once the engine is running. If you encounter a problem and are familiar with checking codes you can find out if you car’s computer has noticed any problems and stored any Diagnostic Trouble Codes (DTC’s). Page 14-54 to 14-59 of the 1997 – 1999 service manual cover how to view codes and troubleshoot them.

Shift Control Solenoids (SCS) A/B/C:

The Shift Control Solenoids (SCS for short) can cause a bunch of symptoms that generally deal with poor shifting (harsh shifts, long shifts, etc.) or a complete failure to shift into the proper gear.

The SCS’s work as 3 bit binary system that controls the flow of ATF to various parts of the transmission. The flow of ATF is controlled by the position of the 3 solenoids which in turn effect the shifts of the transmission into the different gears (via pressurized clutches). As such the smoothness of the shifts is controlled by intermediate positions of the solenoids.

Take a look at Page 14-16 in the service manual. It has a table that shows what the trans is doing in relation to the 3 SCS’s.

If your transmission is only having a problem at higher RPM’s (which would equate to higher ATF pressure), then it’s possible that you have a problem with one of the SCS’s or the ATF Pressure Control Solenoids (PCS) [we go over them next].

Use the instructions in pages 14-102 to 14-106 to check any of the solenoids.

Typical problems with the SCS’s will cause many different problems (see pages 14-114 and 14-115 in the service manual):

- Vehicle does not move in a specific gear.
- Late shifts from Neutral to D4 or D3.
- Late shifts from Neutral to R
- Fails to shift from D4, D3, or 1 – and starts out in 3rd gear.
- Excessive shock or flares while shifting to/from ANY gear.

SPECIAL NOTICE:

If you need to replace either SCS B or C, then you need to be very specific with the Honda Parts person you deal with. The 1997-1999 Helms Honda Prelude Serivce Manual shows the location of the 3 SCS’s. Unfortunately, the Honda Parts system lists the solenoids incorrectly. They show the B solenoid as A, and the C solenoid as B. The best way to insure that you get the correct one is to bring your manual and show it to them. Also, the B solenoid is BLACK and the C solenoid is BROWN. If you ask for the C solenoid (to solve harsh shifting from 3rd to 4th for instance) and they come out with a black solenoid, you’ve been given the wrong one.

Clutch Pressure Control Solenoids A / B:

The Clutch Pressure Control Solenoids (CPCS) are controlled (like all the others) by the Transmission Control Module (TCM). The TCM regulates which gear the transmission is in by activating / deactivating the CPC solenoids. The output of the CPC solenoids are moderated by the SCS’s to control the smoothness and precission of the shifts from the various gears.

Problems with the CPCS’s will cause the following issues:

- Excessive shock or flares in an ALL shift lever positions.
- Late shift from Neutral to D4, D3.
- Late shift from Neutral to R.
- Lock-up clutch does not engage, disengage, or operate smoothly.

Lock-Up Control Solenoid (LUCS):

One of the features of a modern auto trans is generally the ability to “lock� the torque converter (T/C). I’m not going to cover everything you should know about a T/C, but here is a good article on the basics of what it is and how it works. You want to pay close attention to the lock-up feature:

http://www.howstuffworks.com/torque-converter.htm

The 4 speed M6HA Honda Prelude transmission has 4 gears and a feature called “lock-up.� The T/C is connected directly to the engine. At various points in various gears the speed of the engine will begin to match the speed the 2nd half of the T/C is spinning at. At that point it becomes more efficient to have the T/C actually spinning at the same speed as the engine. When the TCM notices that the engine speed and T/C speeds are within a certain number of RPM’s of each other, it actives the Lock-Up Control Solenoid and the two halves of the T/C spin at the same speed. This is more efficient than using the normal fluid coupling of the T/C, and has the improved benefit of improving gas mileage.

One last feature of the T/C is known as Stall Speed. Stall speed is basically the number of RPM’s that the T/C needs to be rotating before the car will begin to move (aka the transmission is engaged). The optimum stall speed is determined by the horse power and torque that the engine produces coupled with the style of ride you are looking to achieve. Most vendors go for a smooth ride as opposed to an aggressive ride. (Smooth starts as opposed to abrupt starts. The T/C’s stall speed affects this.)

Failure of the LUCS causes:
- A low stall speed. (The service manual indicates it should be 2500 RPM.)
- Engine idle vibration.
- Lock-Up Clutch does not engage, disengage, or operate smoothly.*

* Honestly, it’s going to require a little bit to testing to determine that you have a LUCS issue. If the LUCS doesn’t work, you may never know. If it works poorly, then you’ll probably need to start testing all of the various components and eventually arrive at the LUCS.

One way to potentially tell if the LUCS does not work is if your gas mileage suddenly goes down dramatically, which would tell you that the T/C is not locking up like it should.

NoRice4U

this is why I love PO.com..it is so technical

__________________
CHOWWW
1999 9psi Supercharged Honda Prelude 5spd

Gerhard

Thanks, I didn't want to over do it... but I did want to get folks to check some of the simpler issues.

-Gerhard

sharkcohen

Gotta love that Helm. I've been reading the SS tranny section to try to come up with a way of controlling the lock-up system, specifically to get the converter to lock-up in first when the engine is under boost. What you have written above has given me so much of a new understanding of how this transmission works. You explain things very well. Awesome thread.

Gerhard

Thanks dude.

You could install a by pass switch that causes the coverter to lock when you press the switch.

I'm wondering if there is anything else that is involved during lock-up... but I don't think so.

Also, I think page 14-119 goes over when lock-up occurs.

This leads me to believe that you can just install a by-pass switch and try it manually.

-Gerhard

THUNDERCAT98

DOOD THIS IS LIKE MAJOR PIMP ISH!

Gerhard: Dood you always seem to out do yourself, whenever i think i've read something completely mind blowing about our year car i'm like Ok, Now i know alittle more then before..

But now! Hell I feel like i have to walk away and come back because its information overload!


WHEN ARE THEY GONNA FAQ THIS!?~! lol

****Dood, question for Almighty Gerhard****** hehhe

My car is going into the shop monday (after being in the shop 3 times without any help) But when my car comes down out of gear it makes a noise like a 5 spd. would make when your grinding gears! And when i'm in Idle and bring the car over 4 grand and let it come back down it makes the same noise...

I was maybe thinking it was the timing belt... what do you think it is?!?

Gerhard

Thanks.

Honestly, that's a though one for me.

If you can localize the sound to a side of the car, then I might be able to help you figure it out.

I know the on the left side of the engine the timing belt tensioner or the PS pump can cause a strange tapping sound.

In the center of the engine the valve train can cause a bunch of tapping noise if it they haven't been adjusted in a long time...

I suspose a seriously failed timing belt tensioner could grind... if that was the case I wouldn't drive the car...

I suppose a bad CV joints could also cause grinding noises... but that would be pretty constant...

In the tranny, it's almost always bad bearing that cause that.

I think you've got the timing belt issue....

I had my tensioner and belts replaced at 45000 miles, and at 90000 miles I started having this odd tapping noise from about 1800 to 3200 RPMS... I think it's the tensioner...

Damn honda...

THUNDERCAT98

The noise seems to be central around my foot of excelleration... like the front portion of my car... I had my GF reeve the engine as i stood underneath the hood and it seemed to be coming from near the valve cover.

It light weight scares me. But it seems to be getting worse by the day... But i need to drive it to get to work.

johnnyx25

I agree with thundercat, this has some major Pimp factor to it. I've learned alot from this and Gerhard's past posts as well.

Somebody give this guy an Emmy or something.

sharkcohen

I have an interesting problem with the tranny. My torque curve at WOT with the JRSC is not flat below 4000 rpms (as it should be with boost) and my stall speed is testing out below 2000 rpms. Either my converter one-way clutch is fried or the lockup clutch solenoid is not working properly. When I dyno'd the car it was the very first day I ever boosted on it, which leads me to believe that the problem was already resident BEFORE the JRSC installation. Here's what my torque curve is looking like:



Now, compare my torque curve below 4000 to vir2L's, who's setup is also a JRSC SS:



It could be a tuning matter, but I am not sure. Both dynos are WOT runs and I was using the WOT table in my PMS to tune it. The a/f looks good, no abrupt change compared to the dip in torque. I was running pretty much stock timing on that run, though , so it might be a matter of ignition timing. I'm not sure, but will find out soon when I get this thing back on a dyno properly tuned. Howerver, I am more inclined to think that the problematic torque curve is related to the low stall speed by a common problem.

sharkcohen

Helm page 14-102: I decided to try to diagnose the condition of the lockup solenoid. I tested the resistance of each of the terminals (one is the lockup, the other is shift A). Both came up as ~16 ohms, right within the standard range. The next step says that if the resistance checks out OK, to then hook each terminal directly to the positive terminal of the battery and listen for a click (the solenoid engaging). I am not hearing a click from either solenoid. Now, I'm not having any shifting problems, so I'm wondering if this clicking sound is supposed to be loud enough to hear with the ear, or if one needs a stethescope. I highly doubt that there is anything wrong with the shift A solenoid because, as I said, I'm having no shift problems. I'm considering removing the solenoid assembly and checking the condition of the filter screen underneath.

sharkcohen

OK, it helps to have the negative battery cable back on the battery (I removed it when I was testing the resistance of the solenoids) There is nothing physically or electrically wrong with the lockup solenoid, so unless the filter screen is so clogged that it is causing problems, I might have a serious problem, or it is just a tuning issue.

makavelli1227

man this is one hell of a thread....a Mod needs to FAQ this...thank you very much

__________________
"Drifting is a skill, much like masturbation."

Quote:

Originally posted by MR.CLIFFORD if my nuts were stored on the net I could find them anywhere

ryuryu

yes very technical indeed...

now i'll add onto with my 2 cents.

1)All the solenoids / cupplers that are attached onto the outside of the transmission is ECU controlled, where the ECU sends out certain currents during the shifting / driving in each gear. The ECU only sends out 2 different types of currents 0.2 A or 1.0 A. Most likely the soleinoids will not be the root cause of your car, because if your car was bought with a faulty peripheral item, the car will experience erratic shifting patterns from the beginning.

It's very very hard to fix a transmission, and investigate what is wrong with it, especially if it mechanical. As the thread starter said if you smell burt rubber... 'VERY STINCKY'..... your clutch and friction plates are burned..... 100% The material that has been worn off can clog the ATF strainer (basically a filter where the ATF circulates through) there by inhibiting pressure build up to each clutch, there by you might have sudden downshift, or gear slipping. The debris could also contaminate the Main Valve Body which are full of shift valves and CPC valves that control the shifting of the car. All though the valves and their counter bores have micron clearances, debris (if excessive) can manage to go into the clearance and grind up agains the valves, thereby slowing the movements, or not allowing movements.


Oh, one more cent.... as mentioned earlier......... the solenoids on the outsides are ATF flow controllers, a metal valve and a magnet. If you send a current through it, the valve moves thereby opening up a different flow path. There are filter screens in them that keeps solenoids clean.... but if they are clogged, they are clogged with clutch material and cleaning them will only help the situation for a short time. Pull the drain plug (watch out for the pouring ATF) and see if any ferrous materials is wrapped around it. The drain plug is a very strong permanent magnet, it should atleast let you know if your clutch plates are grinded down.

__________________
sporty red 2000Gen5 type SS

SS stands for spanking stock

Gerhard

Your points are excellent!

The real issue for the do it yourselfer is to check the obvious.

Solenoids can wear out or trip in sluggish manner casuing poor shifting. The TCM does sent current to activate and remove current to deactive the various solenoids to control shifting, but can also fail in manners that are not as cut and dry as not working at all.

My experience leads me to believe that many technitions would rather sell you a new tranny for $5000.00 total than fix a simpler problem.

There is no doubt that the clutch plates will wear and small metal particles will end up in your tranny. Over time the clutches will completely fail due to wear. (Except the 3rd clutch with is simply faultly to begin with.)

Do you know if ALL of the solenoids have little screens in them? (The A/B Pressure Solenoids for instance?)

Since you are knowledgable, let me ask you a question:

I was driving at 110MPH the other day and shifted from 3rd to 4th gear. The tranny somewhat hard shifted into 4th, and from that point on whenever I'm driving over 75MPH the shifts from 3rd to 4th are rough.

Changing the ATF did not yeild burnt fluid. (However, I did take a sample and send it to the lab to determine just how much metal might be in the fluid. ...and compare it to the last sample.)

I'm wondering if the tranny has higher ATF pressure at higher speeds? There must be an obvious answer as to what would cause harsh shifting from 3rd to 4th at speeds above 75MPH.

Any thoughts?

(I did swap out SCS C.)

-Gerhard

Gerhard

I'd be suprised if you did not feel or hear the clicking sound when you test the solenoids.

Also, since the car is actually shifting properly, I'd be more suspicious of the lock-up control. I think the service manual indicates that a low stall speed can be the lock-up control...

-Gerhard

sharkcohen

The solenoids are clicking (see post after the one you quoted). That leaves the following probable causes according to the Helm: defective one-way clutch, defective lock-up clutch piston, or defective lock-up shift valve. The lock-up shift valve is in the valve body. Seems to me I either have a problem with my torque converter or the valve body. Or the LUCS is operating sluggishly. Of course, the Helm does also list low engine output as a probable cause. That's definitely not the problem I still am going to try replacing the filter screen below the lock-up solenoid before I decide to replace anything else. If that doesn't work then I'm going to have to make a decision about whether or not to keep the car.

sharkcohen

I removed the LUCS/shift A solenoid assembly yesterday to have a look-see. The filter screens were absolutely clean and clear, no buildup of particles at all. This plus the fact that the LUCS is clicking when connected directly to the battery leads me to believe that the solenoid is not the problem. This, and being that it is a $130-$180 part, leaves me resigned to replacing it just to see if that solves the stall speed problem. I'm fairly certain at this point that I have an internal problem, most likely being either the torque converter one-way clutch, the lock-up clutch piston, or the lock-up shift valve.

Other than the low stall speed and the low torque output below 4500 rpm, the tranny seems perfectly fine. It shifts properly with no problems at all. I am wary about returning the car to stock and taking it in for warranty service (I have a 2000) because if they for any reason decide to check out the TCM they will unveil all the wire hacking I have done to the ECM, and then I will be screwed and probably have to fork out a lot of money for whatever they do up to that point. Being that I'm not really experiencing any trouble at this point, I'm thinking I'll just drive it till it dies and then figure out what to do from there.

Gerhard

Yeah, I wouldn't take it to Honda cause they'll note in their system that the car was moded out the wassu.

Since the tranny hasn't completely failed, you might want to try to find a honda or acura tech that works on the side.

Are you sure you don't have an electrical problem with the TCM / ECU as a result of the aftermarket electronics??