Fan runs with key on, and Communication dropped.

[Buzda]

Hi,

Hardware: MS3 v3.57 with MS3X.

I have been in the middle of configuring the car from a C3I ignition to individual coils, and have gone through numerous key on events without starting the engine.

The communication problem started when I had TS open and was viewing the diagnostics tab before keying on. When I turned the ignition key on it briefly switched from offline to online, then back offline and the fan started running. I keyed off, the fan stopped running, keyed on fan started running but MS would not go back online even after removing the check from the Work Offline box.

I removed the MS from the vehicle and powered it up on the bench with the JimStim. Still could not get it to go online. When running the Port Detect it fails, but the SPKA thru SPKF LEDs and the TACHO LED glow dim for a bit then go out during certain times, see below.

The fan no longer comes on during a Key on event now that MS is removed from the vehicle.

The following are selected in communications settings:

Driver: USB and Wireless (USB cable is used between the MS and Laptop, and it used to run fine on this same USB jack which is COM3)
Connection Type: FTDI - D2XX Driver
Device Serial #: Auto
Baud Rate: 115200

When I click on TEST PORT, I get a Failed! message.
When I click on DETECT, it scrolls through and tries to detect but is unsuccessful. The LED lights mentioned above do briefly light when it scrolls through some of the tests, but they go out.

Anyone have suggestions on things to try on the bench to get the MS to communicate?

Thanks,
-john

1.4_Coil_Pack_2016-02-13_12.47.03.msq

[billr]

With it out on the bench and connected to the JimStim, remove the MS3 daughter-card and make all the voltage checks at the 40-pin connector, as specified in the assembly instructions. If those are all OK,re-install just the MS3 card, leave the MS3X disconnected and try connecting to TS again, and read the Vref voltage at the mainboard DB37 pin 22.

[Buzda]

Thanks for the reply.

I disconnected the daughter board and ran the voltage test on the 40 pin daughter board connection per section 13.5 of the MS3X/v3.57 Hardware Guide and here are the results.

Pin 1 - Should be 5v - initial power on ~3.8v slowly climbs to ~4.2v over about twenty seconds and then drops to zero

Pin 2 - Should be 0v - measured 0v

Pin 16 - Should be 12v - initial power on ~4v climbs to ~4.2v over about 20 seconds then drops to 2.2v

Pin 19 - Should be 0v - measured 0v

Pin 20 - Should be 5v - initial power on ~3.8v slowly climbs to ~4.2v over about twenty seconds and then drops to zero

Pin 31 - Should be 5v - initial power on ~3.8v slowly climbs to ~4.2v over about twenty seconds and then drops to zero

Pin 32 - Should be 0v - measured 0v

What do these results mean?

Thanks in advance,
-john

[billr]

I gotta go, can study the schematic until later, but that may be good news. There is a chance that an inexpensive component needs to be replaced on the mainboard, but the MS3 is OK. Replacement of SMD on the V3.57 isn't as easy for a DIYer, but it can be done.

[Buzda]

Thanks for the reply.

Are there any other troubleshooting checks that I can do to help identify what's going on?

Thanks,
-john

[shainiac]

I've had the same problem with a corrupted firmware. I reflashed the firmware with the boot-jumper and it fixed the issue.

[billr]

This one seems to have a failure of the power-supply on the mainboard. I don't think a FW re-load is going to be even possible. Yeah there are trouble-shooting steps, I just need to get time to research it to advise correctly...

[billr]

Okay, when you made those voltage tests at the 40-pin socket, was the MS mainboard disconnected from everything except 12V power and ground? Did the "raw 12V," at the mainboard DB37 pin 28, stay up at an acceptable value, like 9V or better?

Assuming your answer to both above is "yes", then I would like to focus on the 12V. If there is a jumper between S12 and S12C, removed it and check for 12V again at the 40-pin socket. If the 12V still doesn't come up, then disconnect one end of D10 (either end) and check for 12V at the pad for the "A" terminal (anode, non-banded end). Post what you find.

I am suggesting a very methodical way to trouble-shoot, going to take you step-by-step through the circuit, but it may require more disconnecting of components than necessary. If somebody else (like Matt at DIY) joins in and suggests something different, I would be inclined to follow their lead...

PS: If any of those components, like D9-13, C16-19, F1, or U5 are getting too hot to touch... let us know!

[Buzda]

Thanks for the help. BTW I have ordered a serial cable from EFI-Analytics in hopes that I'll be able to communicate with it rather than the USB cable.

The JIMStim was connected to the main board because it provides the path for the power, the MS3X board and stim for it was also connected.

I checked the voltage at the 12v port on the X3 terminal block which is I believe as close to pin 28 on the DB37 as I can get with the stim plugged in, and voltage there is roughly 2.5v.

I checked the incoming voltage from the power supply and it is 12v.

Thanks in advance for any info you can provide.


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[billr]

"The JIMStim was connected to the main board because it provides the path for the power, the MS3X board and stim for it was also connected. "

Whoa! If the MS3X was connected, that implies the MS3 was still in place. You want to disconnect everything except power (pin 28) and ground until the readings at the 40-pin socket are verified as being correct. As useful as the JimStim is, I would set it aside until you are past this. Let there be no doubt about what voltage you are supplying to pin 28. Do use a fuse, like 1/2 amp, in the power feed!

[Buzda]

Thanks for the pointers. Below is an update.

I don't have a low amp fuse on-hand at the moment so I didn't wire a 12v source direct to pin28 yet, however I did find the following of interest:

I disconnected the JimStim from the main board and placed DMM leads onto JimStim sockets for pin 28 and pin 19 for what should be 12v and ground. With the switch off it was 0v as expected, and when I turned the switch on it started at ~4v and climbed to ~4.2v over about 20 seconds then drops to 2.2v, just like what I saw on pin 16 of the daughter board socket. That tells me that the main board wasn't getting a 12v source from the JimStim.

The serial cable arrived today, so I put the MS back together and installed it in the car where it likely gets fed a 12v power source. Same results, fan runs whenever the key is in the on position and I cannot establish an online connection with TS.

[billr]

I would investigate that JimStim first, it should be fairly easy to determine why the 12V isn't getting over to pin 28. I think there is just one diode there, to protect against a reversed-polarity raw input. if you really want to focus on the MS first, get a fuse! It's much easier to do that, so as to eliminate any chance of a problem in the external wiring as you try to get the MS alive.

[Buzda]

I decided to set the JIMStim problems aside for now and concentrate on the main board.

With the main board on the bench, disconnected from everything but a 12v source to pin 28 and a ground to pin 19 the voltage check on the 40-pin connector per the manual checked out okay.

I then connected to the serial port and attempted to connect to TS, but failed.

The voltage on pin 22 is zero.

TIA for the guidance for next steps.


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[billr]

Pin 22 of the DB37 goes to zero, correct? Was the MS3X disconnected? I assume still just power and ground to the main DB37. Remove the MS3, verify the 5V is OK again, then load it with a 20-50 ohm resistor; see if it remains close to 5V with that load. You can use a small (1/4 - 1/2W) resistor for the load. It will warm up quickly, but won't burn-up in the time it takes to check voltage.

[Buzda]

Pin 22 of the DB37 is zero with or without the 12v source connected.

The MS3X is disconnected.

Power and ground are the only things connected to the main board.

Can you please verify what MS3 is when you say 'Remove the MS3'. Is this a component on the main board? The main board that I have was purchased pre-assembled.

Thanks!


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[wes kiser]

The MS3 is the white board with the SD card on it. Carefully remove it, as it is VERY easy to break the pins. The MS3X or expander is the small green board that bolts to the case on one end, and connects to the MS3 with ribbon cables.

[Buzda]

Got it, thanks for the clarification.

There are three 5v sockets on the 40 pin connector, #1, #20, and #31 which do I install the load resistor on?

Thanks.


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[billr]

I wouldn't tease any of those sockets on the 40-pin connector; connect the load to the DB37 pin 26 (Vref).

Edit: Wait, I am wandering in the weeds here, probably leading you astray. DB37-22 is the TPS input, it should be at zero if the TPS isn't connected (just power and ground to the MS). What does the Vref (DB37-26) read when you have the MS in and out?

[Buzda]

DB37 Pin 26 is 5v, with and without MS3 board connected.


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[slow_hemi6]

Something wrong with that MSQ you have in the first post. It is comming up as a blank/garbled tune like if you started a new tune from scratch rather than from an example tune. If that is what is on the ECU I don't doubt it is giving very strange behaviour. Did you ever try to reload your firmware with/without the boot jumper on the MS3?