power mode still/again

[Trevor]

Originally Posted by spinn360

svxistentialist I have two TPS's one I opened up and cleaned both cause the tcu to put the tranny in power mode. So it has to be either the wire, or the part you didnt mention, the TCU itself. I am getting a used TCU soon. I am going to replace this and if the symptoms percist I am going to re-wire the wire that goes from the tcu to the tps. I thought the o2 sensors wiring and the wiring from the tps might run along with eachother some where. And that possibly something rubbed or somehow removed the plastic over the wires exposing them to eachother, causing the car to malfunction in each place that the wires corrosponded with. Since the o2 Sensors came on at the same time the power mode started happening, that is why I thought the two were connected.

As I pointed out way back in the thread, the TCU is now the most likely culprit. Don't hack any wiring about until you have tried the used TCU replacement AND do not rule out the prospect that this also could be faulty. I hope you are sure it perfomed properly during its earlier history. Fault finding by way of substitution, requires caution in this respect.

[svxistentialist]

Originally Posted by spinn360

svxistentialist I have two TPS's one I opened up and cleaned both cause the tcu to put the tranny in power mode. So it has to be either the wire, or the part you didnt mention, the TCU itself. I am getting a used TCU soon. I am going to replace this and if the symptoms percist I am going to re-wire the wire that goes from the tcu to the tps. I thought the o2 sensors wiring and the wiring from the tps might run along with eachother some where. And that possibly something rubbed or somehow removed the plastic over the wires exposing them to eachother, causing the car to malfunction in each place that the wires corrosponded with. Since the o2 Sensors came on at the same time the power mode started happening, that is why I thought the two were connected.

OK man

It sounds sensible enough what you are trying. If the TCU sorts it, you are laughing. While you are installing the TCU [difficult to get at] have a good look at the three black connectors that plug into the side of it. Make sure all the wires are in place, and not stripped or damaged. Sometimes those connectors need replacing, and it would mean a lot of stripping and splicing.

Joe

[spinn360]

I drove the car the last two days in D again. And yesterday the power mode was on almost the whole time. It went off when I gave the car full throttle though and it hasnt come back on. I dont know why. I did move the wires around for the o2sensors but the CE is still coming on for them and I move another set of wires that were by the o2 wires and I also wiggled the wires coming off the tranny just to see if they would fall out. and I had the power mode come on while I drove after all that but not at all today other then the CE 02 sensor code the driving was fine.


Hey Black betty had a child
and it was a pearly/black SVX

maybe she had been messin round with some cracker.<-----this is a joke you know so laugh. its ok

[spinn360]

I got my tcu yesterday I am going to put it in a little later and then I will post on if I have anymore powermode problems. thanks

[spinn360]

Put the TCU in and worked for a day then the power mode came back on. I hate this car sometimes. Ok so I looked at the tps and I checked the volt it was way off. I cant set this thing. Everytime that I set it it changes. (no its not loose snug as a bug). I think the butterfly valves arent closing the same everytime. or I am losing my mind. I have cleaned it several times with intake manifold cleaner. I will take it apart this weekend and see if I cant figure it out. and if that doesnt work then I guess I will try re-wiring the TPS to tcu wire.

[Trevor]

Originally Posted by spinn360

Put the TCU in and worked for a day then the power mode came back on. I hate this car sometimes. Ok so I looked at the tps and I checked the volt it was way off. I cant set this thing. Everytime that I set it it changes. (no its not loose snug as a bug). I think the butterfly valves arent closing the same everytime. or I am losing my mind. I have cleaned it several times with intake manifold cleaner. I will take it apart this weekend and see if I cant figure it out. and if that doesnt work then I guess I will try re-wiring the TPS to tcu wire.

If every time you set it, it changes the wiper and resistace element contact is intermittent. ( Unless there is a faulty connection.) This a positive indication of a fault.

Inside there is a rotary potentiometer comprising a conductive plastic element around which a wiper turns. Unfortunately the thing can not be taken apart and it is difficult to get cleanibg fluid into it. You could try completely immersing it while turning it. CRC type fluid would be best. It is not possible to accurately measure minor contact interruptions without a scope, or meter with a bargraph instant response read out.

Best of luck, but you may be stuck with purchasing a replacement.

[spinn360]

Originally Posted by Trevor

If every time you set it, it changes the wiper and resistace element contact is intermittent. ( Unless there is a faulty connection.) This a positive indication of a fault.

Inside there is a rotary potentiometer comprising a conductive plastic element around which a wiper turns. Unfortunately the thing can not be taken apart and it is difficult to get cleanibg fluid into it. You could try completely immersing it while turning it. CRC type fluid would be best. It is not possible to accurately measure minor contact interruptions without a scope, or meter with a bargraph instant response read out.

Best of luck, but you may be stuck with purchasing a replacement.

Actually trevor the thing can be taken apart and put together although rather ugly afterwards. The tps is not my problem by itself, there has to be either a wire or something else that is causing my problem. Here are a couple of pics of the TPS apart.

[Trevor]

Originally Posted by spinn360

Actually trevor the thing can be taken apart and put together although rather ugly afterwards. The tps is not my problem by itself, there has to be either a wire or something else that is causing my problem. Here are a couple of pics of the TPS apart.

Good on you for attacking it. I trust you have some good glue on hand.
The configeration of the elements is rather more complictaed than I had expected. It would appear that the moving contact bridges between two wafers. Am I correct? This would eliminate a central contact on the rotor, which is a good design point.

Please have a look at the thread I have posted regarding TPS testing. You may be the one who could experiment.

Why are you sure that there is a separate issue involved in your problem, unless you have first completely ruled out the TPS ?

Congratulations regarding your confidence in getting inside the thing. I have an affinity for those who have a go.

[spinn360]

I am pretty sure its not the tps. I just dont want to fork out the 200 dollars as I am cheap cheap cheap, and not to mention poor. I actually saw a member of the xt6 site I goto do a write up on cleaning the tps(rather then shelling out about 200 dollars). The XT6 tps while different in design slightly is almost the same to tear apart. And I figured that since I had two and both of them caused me the same prob I my as well experiment. So just to be sure that the inside was good I took one apart and cleaned it with electrical parts cleaner and a good eraser. I tried that one out to no avail the same problem. Then I switched the TCU again with the same results. The power mode seems to come on all the time, and then will stop for a day or two or maybe just an hour. The fact that it came on while stopped once was what leads me to believe the wire(especially since the TCU's werent bad). I am leaning towards bad ground or bad wire to and from the tps-tcu. I think that I am almost there. I dont want to waste more money swapping. When I can try a few things first. I will post back after I have reground the TCU. I believe the ground wires are B68 #10 Black wire, and B66 #1 Black wire. I could be wrong as I suck at reading wiring diagrams, but I think thats right. Someone correct me if I am wrong please. Thanks


Oh and yes I had glue and silicone.

[Trevor]

Originally Posted by spinn360

I am pretty sure its not the tps. I just dont want to fork out the 200 dollars as I am cheap cheap cheap, and not to mention poor. I actually saw a member of the xt6 site I goto do a write up on cleaning the tps(rather then shelling out about 200 dollars). The XT6 tps while different in design slightly is almost the same to tear apart. And I figured that since I had two and both of them caused me the same prob I my as well experiment. So just to be sure that the inside was good I took one apart and cleaned it with electrical parts cleaner and a good eraser. I tried that one out to no avail the same problem. Then I switched the TCU again with the same results. The power mode seems to come on all the time, and then will stop for a day or two or maybe just an hour. The fact that it came on while stopped once was what leads me to believe the wire(especially since the TCU's werent bad). I am leaning towards bad ground or bad wire to and from the tps-tcu. I think that I am almost there. I dont want to waste more money swapping. When I can try a few things first. I will post back after I have reground the TCU. I believe the ground wires are B68 #10 Black wire, and B66 #1 Black wire. I could be wrong as I suck at reading wiring diagrams, but I think thats right. Someone correct me if I am wrong please. Thanks


Oh and yes I had glue and silicone.

You have reported cleaning the TCU but this does not mean that there is not a fault in the conductive plastic elements or a lack of contact pressure. I hope you used the cleaning solution after the eraser, as any rubber on the surface would be bad news. Unless you test it properly you can not rule it out. I presume you have tested it with an ohmeter. (Refer my thread on a suggested improved test.)

As you have an intermittent fault you must proceed in logical steps. You are up against the worst possible problem. If it would only break and stay broken you would be away laughing. I will also do some swearing if that will help.

The rule of thumb appears to be always suspect a ground fault, but I do not go along with such a simple approach. Surely if the TCU was not properly grounded several associated faults would show up.

N. B. ---- You are correct with the ground connections. The TCU is grounded via a black lead which goes all the way back to a common point within the transmission housing. This is done to prevent an earth loop which could otherwise result in interference signals on the high impedence input circuits. Do NOT attach a direct ground wire from the TCU to any other place.

I am swearing for you, Trevor.

[spinn360]

Hey thanks for swearing for me and thanks for the advice of grounding the tcu to the tranny.

[svxistentialist]

Originally Posted by b3lha

Joe,

The JDM and Euro TCUs are probably the same hardware, but the software is different. Pin 4 signals the TCU to change shift maps. On a Euro TCU, you ground pin 4 to enable Economy mode. On a JDM car, you ground pin 4 to enable Power mode.

There are two ways you can make a power switch on a car with a Euro TCU:

1) Mess with the TPS signal as per the FAQ.
2) Swap in a JDM TCU and then remove the bulb from the Econ light on the dash. This will make your Econ switch into a Power switch. AFAICT the JDM TCU should work fine with the Euro transmission.

Phil.

Hi Phil

This week, I put the TCU in, the JDM one I bought while I had ICBM[aka Plum]

It worked precisely as you said. When I put on the Econ switch on the gear lever, it lights up the Power light AND the Econ light on the dashboard.

I'm presuming I have switched on Power mode, so I will remove the Econ bulb later, if I retain the JDM TCU.

I still have not solved the speed signal conundrum. I am still stuck in 1 range, and no speed showing on the speedo.

Joe

[b3lha]

Originally Posted by svxistentialist

It worked precisely as you said. When I put on the Econ switch on the gear lever, it lights up the Power light AND the Econ light on the dashboard.

That's nice to know.

Originally Posted by svxistentialist

I'm presuming I have switched on Power mode, so I will remove the Econ bulb later, if I retain the JDM TCU.

Correct. The power light is on because the TCU is in power mode. The Econ light is on because it's wired directly to the switch.

I still have not solved the speed signal conundrum. I am still stuck in 1 range, and no speed showing on the speedo.

I don't recall the exact details of your problem. Will have to search for it.

I was thinking the other day that it might be possible to use a pair of headphones to check for the presence or absence of the speed sensor signal. The frequency of the signal should be in the audible range. It would produce a low tone which would become higher pitched as speed increases. But I wouldn't recommend trying it without running it past an electronics guru first. Maybe Trevor can advise.

[svxistentialist]

That would be interesting Phil if it worked.

My problem is the tranny is stuck in 1 range, won't change up. In addition [part of the problem, probably?] no speed shows on the speedo.

In the past two weeks I have gone to an aching lot of trouble to check that all signal and earth circuits have continuity. Being a Euro box, my VSS 2 is inside the gearbox, not in the diff like JDM and US ones.

There are two looms coming from the transmission to two connectors T1 and T2. T1 carries info from the inhibitor side, while T2 carries the info from the internal sensors, including the two speed sensors. Initially, I ran the check showing that the impedance across both sets of speed sensor wires was in range, an indicator that the sensors may be OK.

Then, I checked continuity between the output connectors [as joined up to T1 and T2] and the TCU. Everything is connecting. Next step, I checked that all joined up earth wires and so on were interconnected as they should be, that was all OK.

Next, I checked up that the output wires from the tranny were actually connected across when plugged into the respective connectors. T2 was all OK. I found a loose wire in T1, which I fixed. Plugged everything back together, still showing the same problem.

With one significant difference This time around, it was throwing a tranny code. EUREKA!!, I thought. eureka! indeed It pulled up code 13, which is for solenoid 3, works the over-running clutch. Zilch to do with the speed signal, back to the drawing board.

My next move is to jack up the car and check for a pulse [I'm sounding like Mr Bean here ] I need to run with the wheels spinning, and check that the speed sensors are outputting a signal.

Any advice on where to tap into this signal, and what to expect?

Joe

[b3lha]

From looking at the diagrams, you should be able to test using a digital meter set for low voltage AC.

To test sensor 1, measure the voltage across pins 9 (black) and 16 (white) of plug T2.

To test sensor 2, measure the voltage across pins 14 (black) and 15 (white) of plug T2.

In actual fact, pins 9 and 14 are grounds and are connected together, so you can measure 14-16 and 14-15 if it's easier.

The book says the voltage should be > 1 volt AC. I wouldn't expect it to be much more than that.

I think I asked you this before: Have you checked the "shield joint connector" B69 that connects all the transmission signal earths together.