ihiryu

iTrader: (7)

So my never ending quest on P0500.

Replaced TCM ECU
Replaced Speed Sensor number 1 (in transmission)
Transmission Fluid change (while doing the last one)

Still nothing.

Code shows P0500

I checked the wiring by the book from the transmission harness up to TCM plugs, and they show good. Book tells you to replace both (which I have).

Check the ECU to the cluster, tells you the replace engine ecu and cluster (replaced cluster).

At this point, I'm not sure what else to do. I doubt it's an ECU, but that's the only thing left. I just don't want to shell out anymore money.

I am an experienced mechanic, I've followed everything to the T, but can't figure this one out. As a last ditch effort I took it to the dealer who charged me $125, just to tell me that I have too many mods, and they don't want to touch it.

(but they did kindly print out information on how to diag the P0500).

I talked to my wife, and remembers that I had already done the coils and speakers, and everything was fine until we took a family trip to Dallas in the F.
So I know none of the aftermarket is causing it.

On the techstream, I can go to live data, and it clearly shows that there is not a speed signal. The gauge cluster speed works fine, and if I cleared the code and keep it under 2000 RPM's the code will never come on (these are parameters for the speed sensor code). I'm just really at a loss.

I8ABMR

Damn, man. If I had hair Id pull it out after all that. Hope you get it sorted. What mods do you have ??

RedlineAZ

iTrader: (5)

Dang bro, sorry to hear all this I would be totally frustrated too. I hope you figure it out. I haven't the slightest clue about how to help, but maybe call another dealer (one of the first dealers competitors) and tell them you brought it in, and they charged you a fee and did nothing, and ask them if they will do you a courtesy diagnosis because you are at a loss. Or speak to the service manager at the dealer you first went to and ask them if they can recheck it free, and have their master tech look it over to figure it out. Last option is flood the beesh in the nearest lake. LOL jk

ihiryu

iTrader: (7)

I still have a full set of hair! I'm not pulling these beauties out for nothin!

Bought the car with custom exhaust (no cats) and it already had the O2 simulators done.
I added coilover, wheels, spoiler, LC2i (with sub and amp), and did the DVD override.

The thing is, is that I had forgotten how long it's been since I had done the mods. But I talked to my wife and asked her if she remember when I put new wheels on (since I did everything else within the same time). She said, "I remember you put the wheels on (she can't tell the difference after I lowered it lol), and you were happy, then we went to Dallas and you got butt hurt. So maybe three weeks?)

I've thought about this too actually, the problem is the closest dealer is in Austin (one hour) then then San Antonio (two and a half), then Dallas (three hours).

lobuxracer

iTrader: (2)

The biggest problem with ECM swaps is having to rewrite the VIN.

Have you identified the pin on the ECM for the speed signal and popped it out of the connector to examine its condition? I had to do this with my Supra to fix a really annoying intermittent issue.

At this point in troubleshooting, it is a bad idea to assume all connections in your connectors are good.

RSXiMUS

iTrader: (7)

What does the DVD override entail?

Doesn't that somehow fool the car into thinking the car is stopped so you can have full functionality? Maybe that has something to do with your vehicle speed sensor malfunction? Just a wild guess here.

ihiryu

iTrader: (7)

I have. I took a look at each and every one of the connectors. I didn't pop them out of place (because I couldn't really figure out how, but nothing seems bent out of place.

ihiryu

iTrader: (7)

Hey Lance,

Would you happen to have the diagram for the Skid ECU and it's location?

Thanks,
Steve

lobuxracer

iTrader: (2)

Hopefully you have what you need now.

lance

ihiryu

iTrader: (7)

I went ahead and checked a few things over again.

Here's my assumption and let me know if this sounds correct to you guys.

I have a p0500 (no speed sensor), BUT gauge cluster displays speed. So here's the deal, the Skid Control ECU, collects all the data from the wheel speed sensors (rear ones really) and send it to the gauge cluster/combination meter.

From the cluster, it goes to engine ECU.

So assumingly, the wiring, skid, and wheel sensors are good (since they are reporting to the cluster).

The issue arise from the cluster, and circuit to the ECU.

Testing the wiring from the ECU to the gauge cluster checks good, and have replaced the cluster. That only leaves one thing, and that's the ECU itself.

I took a look at the pins (thanks again Lance), and the pin for the ECU is a little wallowed out (mainly because of my tester probes), and I've bent the pin back into place.

Also while I was at it, I rewired the O2 sensor simulator deal. I don't know who made the unit, but it was wired differently from how Sikky wired theirs. The only difference in wiring was the ground (Sikky wants it all on A6, but this one had the ground tapped on the last connector which is E4?).

I moved the ground, and am currently waiting on my new wheels.

lobuxracer

iTrader: (2)

Sometimes it's all in the details. I hope the problem is solved now.

ihiryu

iTrader: (7)

Le (Sigh)

Twas not the problem

Only thing left is the ECU

lobuxracer

iTrader: (2)

Just to be clear - you probed the wire from the cluster to the speed pin on the ECM, and got continuity. Did you remove the cover from the ECM and check from the backside of the connector soldered onto the PCB? It's the only way to be sure the connection is solid at the ECM connector and the cluster. Ideally you'd check from the cluster PCB to the ECM PCB on the solder joints with a very sharp probe to pierce the conformal coating on the PCBs..

lobuxracer

iTrader: (2)

Also, you are aware there is a junction connector where the yellow green wire connects (the wire to the ECM) to the pink wire coming out of the combination meter, correct? The speed signal is also input to the navigation system. This junction wire connector is where the pink wire from the combination meter splits into the pink wire going to the nav system and the yellow and green wire going to the ECM.

Have you put your nav system into diagnostic mode and checked the speed signal there? I'm really thinking RSXiMUS is on the money with your bypass device being the root of the problem.

I am extremely skeptical the ECM is bad. It is super rare unless something happened when the DVD bypass was installed - like an ESD event on the speed wire when this device got plugged in.

ihiryu

iTrader: (7)

Correct, I only did it from the connector side, and not from the interals (PCB) side.

I was not aware there was a junction. I'm going to check the bypass. But that doesn't explain why it would be good for weeks before the light came on.

Don't know how to do navi diagnostic, but will look into it. Thanks for the recommendations!