TPS Communication Timeout

General Topics for configuring, operating and tuning the Megajolt. Also see the <a href="http://www.autosportlabs.net/MJLJ_V4_Operation_Guide">Operation Guide</a>

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didly
Posts: 17
Joined: Thu Jul 12, 2007 7:41 am

TPS Communication Timeout

Post by didly »

Hello all, I have come across a small issue concerning the TPS calibration. Every thing seems to be fine until i try to calibrate the TPS. Have had no problems with communications between MJLJ and laptop, have spark (engine has not yet been started and run), TPS values on screen ramp up and down all be it a little jumpy (small throttle movements = large numeric increases) and runtime values seem to be fine. The MJLJ at the moment is powered by a 9Vbattery and the laptop is running XP. The problen arises when i try to calibrate TPS, open load axis calibration, press calibrate TPS and press OK with throttle closed, wide open throttle and press ok returns a message (Communication Timeout) and this automaticlly drops the link between the MJLJ and laptop and must be reset. The map that is installed is from the library and belongs to Darren Brightman.

Anyone got any ideas ??

Mik

brentp
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Post by brentp »

Hi Mik,

Interesting problem. What happens if:

- You calibrate the TPS without moving the throttle?
- You calibrate the TPS with the TPS disconnected?
- You calibrate the TPS with the throttle only partly open when it instructs you to fully open it?
- You fully depress the throttle when you are in the main configurator window (look for a 'timeout' message)

Regards,
Brent Picasso
CEO and Founder, Autosport Labs
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Oliver Sedlacek
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Post by Oliver Sedlacek »

I would double check the TPS connections. The large TPS signal changes for small throttle openings might be a clue.

didly
Posts: 17
Joined: Thu Jul 12, 2007 7:41 am

Post by didly »

Hi Brent, answers follow

(1) open throttle value (0) must be greater than closed throttle value (0)
(2) open throttle value (16) must be greater than closed throttle value (16)
(3) could not communicate with controller (communications timeout occoured)
(4) works as per original post BUT ramps from 0 to 100 in the scaled value column from position 0 to 31, these values changed after completing Q (3), values are static at 36 to position 112 then alternate between 83 and 86 to the end of the column.

As per Olivers question i should have mentioned this yesterday

The throttle position sensor that i am using is a standard 98 2.0L mondeo unit. i have attached a pic to hopfully help with explanation. If the TPS is wired as per instillation quide (yellow wire being on the right) the values run backwards, changing just the MJLJ wires the values tick between 83 and 86 from closed throttle to wide open. To get the TPS to work with increasing values it was wired, BROWN to earth, YELLOW to lower MJLJ connection, WHITE to top MJLJ connection.
Any one else running zetecs got a wiring diagrm for these TPS wire values
Thanks

Mik
Attachments
From top down, Yellow, White, Brown
From top down, Yellow, White, Brown
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rbalmford
Posts: 33
Joined: Thu Feb 26, 2004 1:19 pm
Location: Southampton, U.K.

Post by rbalmford »

Mik,

Not 100% sure what you mean by 'top' and 'bottom' MJ connection, but sounds like it's not quite right. Going from your pic, the centre WHITE wire needs to go to the 'TPS INPUT' terminal, and the outer 2 wires YELLOW and BROWN should go to EARTH and the 'TPS VREF' pins, swapping just these two around if you need to reverse the 'sense'.

Rich.

didly
Posts: 17
Joined: Thu Jul 12, 2007 7:41 am

Post by didly »

Hi rbalmford, should have been a little more clear with my post. But its getting late here in Aus ( 10:30 in the evening) and being Bathurst 1000 race weekend i have run out of time to have a look today. Will check after work tomorrow. But just to let people no about the upper and lower MJLJ connections and how the TPS is currantly connected. The WHITE wire (centre) is connected to TPS input, YELLOW (top) is connected to TPS (Vref) and BROWN (bottom) is connected to EARTH. I take it that the Vref connection on the MJLJ is a second earth connection ??? and it is these two wires that you say to change if needed to change the "sense". I will try these changes tomorrow but as i have a increasing TPS value i think that i have this the right way round (might be wrong thou).

Anyway Food for Thought

Mik

brentp
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Post by brentp »

What originally concerned me was the 'timeout' message after the last step of calibration. I believe it's happening when the controller goes to write the flash after calculating the table.

Can you read/write ignition configurations, including writing the flash?

On the right side of the calibration window, there are the "read calibration"/"write calibration" buttons. Without moving the throttle, press the 'read calibration' button' and then the 'write calibration button'. Let us know what the response is.

Are you still powering the unit with a 9V battery? if so, try switching to the auto's battery and retry the calibration.

For the other questions- The VREF output is +5v. (Voltage reference). When connected correctly the voltage on the TPS input should scale somewhere between 0 and 5v, increasing as you open the throttle. Wire it per Rich's description- assuming the center wire is indeed the TPS wire.

With question #4- holding the throttle open and watching the screen for timeout messages- I wanted to see if holding the the throttle open caused the same timeout behavior, but in a different area (runtime data). Seems like it doesn't...
Brent Picasso
CEO and Founder, Autosport Labs
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didly
Posts: 17
Joined: Thu Jul 12, 2007 7:41 am

Post by didly »

Hi Brent, First of the easy answer TPS connections.

Plugged + connection of volt meter into white wire of TPS with a value of 0.51V at closed throttle and 3.82V throttle wide open.
changed wires around as per Rich's post and values reversed. So TPS is connected OK.

plugged laptop to MJ and tried the read and write callibration buttons, response for both were (Communication Error) could not read calibration data from controller, a communications timeout occoured.
Tried to write a new ingnition map to MJ ( this is where things went a little crazy) when i tried to retrieve the new map from the MJ i recieved a message reading (Failed To Read Ignition Configuration) Ignition advance value specified (86) must be between 0 and 59. pressed ok to close this window.
I then noticed at the bottom of the screen two messages one would quickly appear and then change to (timeout reading runtime data), the one that would appear for a split second read (timeout writing ignition configuration).

A couple of crazy thing happened that i think should be mentioned. after i tried to write a new map to MJ the RPM dial at the botton read (28598) and the ignition advance box read 85 then changed to 36 also some of the "outputs" lights at the bottom were on with none of the outputs on the MJ connected ??????????.

Didnt get around to trying the question 4 issue as i was getting a little confused. Also have hooked MJ to 12V auto Battery with 5 amp inline fuse.

Cheers
Mik

didly
Posts: 17
Joined: Thu Jul 12, 2007 7:41 am

Post by didly »

Ok so whats the verdict brent ??, i can take the bad news :( , you dont have to be gentle. :D


Mik

MartinM
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Post by MartinM »

New facts make it look like a PC comms issue - maybe the TPS is a red herring...

...but I'm a bit confused as your 1st post says it all worked fine, but now you indicate that you've seen all sorts of strange values.

So if it's PC a comms issue now, then:
- if you go back to basics (just your PC, the MJLJ and a 9v battery on the bench) does it still work flawlessly in terms of reading/writing maps (it should do!)
- if not, real serial port or USB adapter? - if the latter, what sort?..
- ....and then there will be some more questions

didly
Posts: 17
Joined: Thu Jul 12, 2007 7:41 am

Post by didly »

Hi MartinM, I will try to explain this as best i can as im not the electrical wizz ide like to be. I have been converting the zetec engine into my mk1 escort for the last few months and had finally got around to hooking up the Edis and the MJ to do its first start up. I had loaded a map onto the MJ (connected to a 9V battery) using my desktop Pc (real serial port) and loaded a map no worries. Installed MJ into car (still hooked to 9V) and connected to laptop via usb serial adapter. I then opened the configurator options and matched the com port number (com port 9) and ticked the automatically read config at start up. didnt notice any issues at this stage. Disconnected the link between the MJ and laptop then re connected. the map that i had loaded via desktop Pc came up screen. At this stage i was only looking to calibrate TPS 'prier' to start up. This is where my first post starts. When i state that the 'runtime values seem to be fine' the green advance line was static at 3 degrees RPM at 457 and was showing a rise and fall in TPS white line. It was not until i tried to load another map, one of brents questions "can you read/write ignition configurations, including writing the flash" that all the crazy values started to appear
Am currantly hooking all concerned including TPS to desktop Pc will post when finished.

Cheers

Mik

PS/ the usb lead is of the 'prolific' type

brentp
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Post by brentp »

Based on your description, it seems that your problem isn't related to TPS calibration per se, but serial communications in general..

You're on the right path to test it on a bench with a good power supply- at least use a *fresh* 9V battery, and if possible, on a desktop PC which has a standard serial port. Once you can verify everything works- read/write/flash ignition configurations- and read/write TPS calibration tables then take it back to your car for additional troubleshooting.

The prolific USB lead should work well as I've developed against this type of adapter- however you might have a variant that is causing problems. we'll see.

Ideally you could test on your other computer with the standard serial port *and* the usb adapter and see what results you get.

Regards,
Brent Picasso
CEO and Founder, Autosport Labs
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didly
Posts: 17
Joined: Thu Jul 12, 2007 7:41 am

Post by didly »

Hi. Took brents advice and spent a couple of days trouble shooting throu the USB lead problem. Have MJ and TPS hooked up on the desk using a new 9V battery. First of hooked the MJ to Desktop Pc throu a 'real' com port(1) cable , and all works fine!. read/write ignition maps and config TPS no worries.
Next i unpluged the com(1) cable from both Pc and MJ and closed MJ config software, plugged in the USB lead (with 9 pin extension cable between usb and MJ) and opened the MJLJ configurator, changed port to com(7) then plugged in at MJ end. The timing advance number appears, rpm dial reads correct and the TPS dial is stuck at 36. Lights on the USB lead are flashing, Runtine screen lines correspond to set values. It is only when you try to callibrate TPS or write a new map to MJ that you recieve the message at the bottom of the screen 'timeout reading runtime data' or a window appears with connot communicate with controler a communication timeout occured and the MJ config software locks up and some strange values appear. (bugger). MJ software must be closed. Now, if i close the software and unplug the lead (MJ end only), then reconnect, the comfig software will change back to the values at the time of the lock up. Nothing has changed. If you repeat this sequance along with turning off/on of power to MJ, you return to the original point of having some control. I have also repeated this quite a few times with the same results.
Bloody annoying it only half works!
Just a couple of ideas that seen to be common on the web concerning USB adapters problems. 1/ make sure the com port 'properties' setting for comport(7) in my case are suitable. Any figures ?. 2/ 'You will need to download the driver and remove any "changeto" text from the file extension(s) to make them useable. Not sure on this one??.

Food For Thought

Mik

didly
Posts: 17
Joined: Thu Jul 12, 2007 7:41 am

Post by didly »

Howdy all, ya its been a while but thought i should explain the outcome of my problem for others searching the forum with similer problem. 'My' cable just would not work full stop.!! the cable worked fine on every thing else i tried it on but not the MJ. I tried that many differant things to get it to work it wasnt funny. Anyway, looked at a few differant options and decided the bluetooth would be best. Went to my local electronic specialest with the posts from this thread http://www.autosportlabs.org/viewtopic.php?t=1095 and asked can you help. Cost me $60 AUS and works fine the USB lead cost me $50. A much better option in my opinion in all aspects.

Mik

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