So I changed out the relays under the battery in hopes that my TCS Off/Slip lights would go off, but that didn't happen. So I checked the codes on the TCS in the trunk and I noticed it blinked 13 times. So now I'm supposed to check the blinks on the TCM, but I cannot find it anywhere. I've read a bunch of threads where people say its "near the brake pedal" (it's not) or "under the steering wheel" (where?), but I cannot find it anywhere. I removed the black plastic panel above the brake pedal and below the steering wheel, stuck my head underneath with a flashlight and could not find anything even remotely resembling the TCM box. So if anyone has done this before on their '94, could you please tell me where I should be looking for this thing? Does code 13 on the TCS usually mean that one or both of the throttle position sensors need to be replaced? Any help would be appreciated!

Thanks

There's a decent diagram of it's location on BR-57 in the FSM. It looks like you might take the radio and climate control head out to get to it?

Heath

Assuming your talking about the Throttle Control Module and not the (Automatic) Transmission Control module or the Traction Control Module. Then it under the dashboard. The glove box must be removed to gain access to it as it is near the passenger side air bag.

Check the harness to the secondary Throttle Position Sensor. The wiring or the sensors itself could be the issue.

Q451990 wrote:There's a decent diagram of it's location on BR-57 in the FSM. It looks like you might take the radio and climate control head out to get to it?

Heath

Thanks. I checked the diagram and it would appear based on that diagram that it would be, but I don't see it.

Infinitiguy19 wrote:Assuming your talking about the Throttle Control Module and not the (Automatic) Transmission Control module or the Traction Control Module. Then it under the dashboard. The glove box must be removed to gain access to it as it is near the passenger side air bag.

I'm talking about the TCM that is supposed to have an LED blinking light to tell you what might be faulty after checking the number of blinks on the TCS in the trunk. My TCS is blinking 13 times, so as per the FSM and various threads on here suggest, I should then check the TCM to see how many blinks are on there to guide me into the direction of how to fix this issue. But I can't seem to find it. Making it more difficult, there are (3) different TCMs aparently, so I'm not even sure what I'm supposed to be looking for. Based on what I read in the FSM, it would seem like the TCM that has the blinking LED lights is located near the brake pedal somewhere, which it's not cuz I looked everywhere underneath the steering wheel and nothing under there resembles that box at all.

Infinitiguy19 wrote: Check the harness to the secondary Throttle Position Sensor. The wiring or the sensors itself could be the issue.

Is my problem most likely the secondary throttle position sensor in your opinion? At this point I think I'd rather start throwing money at taking a logical guess at what might be causing the problem than looking for a box that isn't anywhere to be found.

Did you drive the car 19 MPH to get the code 13?

Are you sure you counted the number of blinks correctly?

Were the TCS and SLIP light blinking as well?

I would say check the connection to the secondary TPS Sensor first, make sure its clean....

Infinitiguy19 wrote:Did you drive the car 19 MPH to get the code 13?

Are you sure you counted the number of blinks correctly?

Were the TCS and SLIP light blinking as well?

I would say check the connection to the secondary TPS Sensor first, make sure its clean....

Well, I drove it. I parked it, went into the trunk, pulled down the back part, and counted the blinks - twice. Both times it ran as 13 blinks. My TCS & Slip lights have never blinked. As soon as you turn the car on, they just stay on. Do you know where the TPS connector is located? The FSM has a diagram and again, at least to me, it doesn't look like anything underneath my hood.

See page BR-57 for the location of the secondary TPS.

If you drive the car at 19 MPH for at least a minute. I am fairly certain the two dashboard lights will blink.

It appears the TCM is next or very near to the instrument cluster. Lucky for you I guess. When you get to it check the wiring to the TCM as well.

Ok, found it. Connection looks secure. I pulled it out and looks totally clean.

Infinitiguy19 wrote:See page BR-57 for the location of the secondary TPS.

If you drive the car at 19 MPH for at least a minute. I am fairly certain the two dashboard lights will blink.

It appears the TCM is next or very near to the instrument cluster. Lucky for you I guess. When you get to it check the wiring to the TCM as well.

So I found the TCM. I pulled the black plastic cover underneath the dash off and stuck my head all the way underneath and with a flashlight i was able to find it. But here's the thing, the LED on the TCM is not blinking. Based on what I read in the FSM, after you check the TCS control unit and count the number of blinks (in my case it was 13), you are supposed to then check the TCM and count the LED blinks on there. But my TCM isn't blinking, so what am I supposed to do? The FSM doesn't mention anything about what to do in that situation. Any ideas?

From what I have read, the TCM module is supposed to blink two sets of 5 if all is good for 55 and blink whatever the problem code is. If it is steady red then it sounds like the TCM itself may be bad. One of the descriptions mentioned for code 13 of the TCU is if the TCM has entered fail-safe mode (TCM has failed) you will get a 13. You will also get a code 13 if there is a problem with the secondary throttle opening signal or primary throttle signal between the TCS and TCM.

mattd1979 wrote:From what I have read, the TCM module is supposed to blink two sets of 5 if all is good for 55 and blink whatever the problem code is. If it is steady red then it sounds like the TCM itself may be bad. One of the descriptions mentioned for code 13 of the TCU is if the TCM has entered fail-safe mode (TCM has failed) you will get a 13. You will also get a code 13 if there is a problem with the secondary throttle opening signal or primary throttle signal between the TCS and TCM.

Hmm, interesting. So if mine isn't blinking or showing any lights at all, is it safe to assume that the TCM is dead and that's what's causing the TCS OFF/Slip lights? If you're saying it should be blinking 55 or showing a steady red and mine isn't showing anything, then that cant be good.

The way I understand it is the TCM should always be blinking a code 55 repeatedly if it is good. If there is a problem with something else then it would blink the specified number for a particular sensor or problem area. I read that for code 13 that it is one of three things. It is either the secondary throttle opening signal, primary throttle signal between the TCS and TCM, or the TCM has failed.

mattd1979 wrote:The way I understand it is the TCM should always be blinking a code 55 repeatedly if it is good. If there is a problem with something else then it would blink the specified number for a particular sensor or problem area. I read that for code 13 that it is one of three things. It is either the secondary throttle opening signal, primary throttle signal between the TCS and TCM, or the TCM has failed.

Thanks for your input. So is it safe to assume the TCM unit itself has failed since it's not blinking it all? I just don't want to have to buy another unit, plug it in and have the same problem. The FSM is pretty clear that if the TCS is blinking 13 times, it's one of those three possibilities as you said. So if it was your car, would you just replace the TCM unit to start with since it appears to not even be working?

One last thing I would do is verify that there is power and a good ground getting to the TCM. If you happened to know someone else that has a G50 with TCS close by then I would ask them if they were willing to put yours in to see if the problem moved to their car. If it came down to it, you could ship it to one of the members here and see if they are willing to try it in their car. Maybe elwesso might be willing. Or you could send it to me and I could try it in our '91.

On page 99 of the BR section it explains what to do if you get code 13 on the TCU but 0 blinks on the TCM. It is "Diagnostic Procedure 20". It sounds exactly like what you are having so follow that procedure and see what you get. Also in the 1995 FSM in the BR section on page 112 there is a diagram of the TCM connector explaining the voltages that you should get for each pin on the input side apparently of the TCM. Try to take measurements of those pins and see if they match what is on the page if you don't get anywhere with "Procedure 20" mentioned above.

Hey, thanks for all your help and your offer to check my TCM. I'm gonna try to do that procedure you pointed out first, cuz it seems like it would rule out the harness. If the harness checks out ok, I'll probably just go buy another TCM or see if mine can be repaired somehow. Unfortunately I don't know anyone local that has a Q with TCS. But either way, whether its the harness or the TCM, it's gonna be a b**** to replace because of the awkward location it's in. In the FSM, it seems like it comes out with ease, but it doesn't seem that way in person. To be honest, not sure it's even in my skill set to be able to remove it by myself, but I will certainly give it a shot.

Not a problem. Just follow "diagnostic procedure 20" and let us know what you find.

Matt

Well I tried to remove the harness for the TCM today and honestly, it's just not doable. I have relatively small hands and even i couldn't get in there to get any kind of grip on the harness to even pull it out to test it. I gotta say, this TCM has got be in the worst location possible. I can't see how it's even possible to remove without taking the entire dash apart. So I'm not quite sure what to even to do at this point. I'd like to have a working traction control system, but i can see that the only way to test and/or replace the TCM is to bring it to the stealership or somewhere that has the expertise to be able to remove it successfully. I'm wondering if anyone on here has even tried to remove the TCM or harness before? I just don't see how it's possible without taking the whole dash apart.

Can you post a picture of it? I might be able to give you some ideas if I can see it.

Heath

Any resolution on this at all? Im trying to debug the exact same issue with my 93. Got the car with the TCS off light on only, slip is not lit, finally checked blinks the other day. 13 blinks. Checked the secondary TPS connections and it is solid, all contacts are clean. Ive swapped all the typical fuses and relays, alt and battery are new. I also noticed that after I disconnected and checked the tps or after the battery is disconnected for a while, the tps light is dimmly lit but not off? I can see the light flutter as I press the tcs button in the car upon starting it up. Eventually it becomes solid after about a minute.

Really want to get this stinkin light off, annoying the crap out of me as it is the last warning light I have yet to clear.

marcyprojects wrote:Any resolution on this at all? Im trying to debug the exact same issue with my 93. Got the car with the TCS off light on only, slip is not lit, finally checked blinks the other day. 13 blinks. Checked the secondary TPS connections and it is solid, all contacts are clean. Ive swapped all the typical fuses and relays, alt and battery are new. I also noticed that after I disconnected and checked the tps or after the battery is disconnected for a while, the tps light is dimmly lit but not off? I can see the light flutter as I press the tcs button in the car upon starting it up. Eventually it becomes solid after about a minute.

Really want to get this stinkin light off, annoying the crap out of me as it is the last warning light I have yet to clear.

Sorry so late to respond to this thread, but I had put this issue on ice for a moment. I'm taking my dash apart again sometime this weekend for the 1,836,873rd time and if I can somehow access the TCM from above, I will let you all know. I'll even take pics since apparently no one in the history of this board has ever had this issue but me. I did read something in the FSM that indicated that the TCM gets power from the secondary throttle position sensor (even though that doesn't seem to make any sense whatsoever), so perhaps my sensor has failed, thus causing no lights on my TCM. I really don't know. If I can't gain access to my TCM to remove it, then maybe I will just buy a new secondary throttle position sensor and see if that fixes it. If not, I really don't know what I'm going to do.

I honestly just wish I had bought a Q without TCS, because I swear, every Q with TCS I've looked at has the TCS OFF/Slip lights illuminated. This was obviously a very unreliable system from Infiniti as there are apparently so many issues with the TCS. If you just browse through this forum, it becomes quite obvious very quickly. I'm not so sure it's even worth investing money to fix to be honest. It'll probably cost me less money to buy a whole nother Q without TCS than to fix my current Q with TCS