Dash2 setup and CAN

[stevieturbo]

Ive the DTA S80Pro and Dash2 runing off CAN

I dont seem to be able to get RPM via this method, although have it working via the tacho output...so thats sort of ok.

I have all other sensor outputs working ok.

Air Temp
Water Temp
TPS
Lambda
Fuel Pressure
Ign Advance displayed
Battery voltage was displaying strange numbers initially, but appears ok now

Boost/MAP
Having trouble here. It starts at circa 50000 units, and slowly counts down. It did once display the correct MAP value as per ecu of 97kpa key on, engine off.

But I think thats because the power was on for ages allowing it to count down.

Havent driven it yet, so dont know about road speed. Although oddly, sitting in the garage starting the engine and running it a few times, the odometer has increased in value.

ANy thoughts on the dodgy MAP/Boost reading on the Dash2 ? Im thinking its more a Dash issue than the CAN itself.

[HansB]

I run roughly the same set-up (S60)

The pressure could be a scaling issue. This is the case in my setup, where the CAN unit seems to assume that it is mBar.
You could check with the Lite Monitor the output. Divide by 1000 and you are ok

In my setup I have had to switch of the Ecu-RPM from CAN and use a hard wired connection. If I leave both in place, I get dodgy results (like numbers that are double the RPM, but not all off the time.
Quite some time Martin send me a mail, not to use the ecu RPM. Do not know if this is still the case.

[stevieturbo]

I run roughly the same set-up (S60)

The pressure could be a scaling issue. This is the case in my setup, where the CAN unit seems to assume that it is mBar.
You could check with the Lite Monitor the output. Divide by 1000 and you are ok

In my setup I have had to switch of the Ecu-RPM from CAN and use a hard wired connection. If I leave both in place, I get dodgy results (like numbers that are double the RPM, but not all off the time.
Quite some time Martin send me a mail, not to use the ecu RPM. Do not know if this is still the case.

ive tried various scalings...with no success.

In Lite monitor, it does display the correct units from what I recall, although the raw value does have a huge number. I just cant seem to get the Dash to display a sensible value.

Ive given up on a few CAN channels to see if that would speed the display up.
But still...the update rate for the items I want seems incredibly slow....in fact, apart from temperatures which tend to be slow anyway, they update so slow I'd deem them useless at present.

AFR's are very slow ( Lambda )
Fuel pressure is very slow, but in sensible format.

Battery Voltage is intermittent..sometimes it works, sometimes its crazy.
TPS is very slow
IGN Advance if I wish to display is slow.

On the Dash2 itself, road speed connected directly to a sensor now works fine...except its too senstive. Most of the time the display is flickering speeds. Half the time you cant see the ssecond digit. It really needs some sort of filtering or damping, but I cant see anywhere in the settings to do this ?
RPM connected to the tacho output does work fine, although perhaps a little slow too.


Im guessing most of my issues are down to the CAN interface itself though ?? As even viewing on Lite Monitor, it is very very slow.

[HansB]

I do not have the problem with the slow update rates, Lambda runs at 10Hz and is just fine. I use 12 of the DTA CAN variables.

I use the speed from the DL1, which, as soon as I have a lock on sufficient sattelites is very accurate

Have you terminated the CAN bus from DTA on the CAN convertor side with 120 ohm?

[stevieturbo]

Have you terminated the CAN bus from DTA on the CAN convertor side with 120 ohm?

Please explain ?

In Lite Monitor, my refresh rate is less than 0.55Hz

I do not use the DL1, my DTA connects directly to teh CAN interface exactly as per instructions.

Can Low goes to pin 2 of the D-sub connector supplied and Can Hi goes to pin 7 of the connector.

[stevieturbo]

bump...still need help here.

No matter what I try, Lite monitor updates very slowly. Boost value is just silly.

Ive tried turning CAN off and on with the DTA, and flashing latest firmware.

Is the problem with DTA, or the CAN adaptor ?

[Jimster]

I use the serial ecu adapter and I find most things work great, I don't have any problems with update speed, although I'm also not able to get RPM from via the adapter

[stevieturbo]

I didnt want to use serial, as I wanted to be able to use Dash, and have the laptop connected to the ecu, which currently uses the serial connection.

[Support]

It is worth checking with a multimeter that there is 60 ohms between the CAN H and CAN L lines on the interface (pins 2 and 7). If you measure 120 ohms then you need to add a 120 ohm resistor between the two pins.

The CAN interface outputs the data at the rate it is received from the CAN bus, so if the data is not being transmitted fast enough by the ECU for some reason it won’t be updated very quickly on the lite monitor or the DASH2.

[stevieturbo]

It is worth checking with a multimeter that there is 60 ohms between the CAN H and CAN L lines on the interface (pins 2 and 7). If you measure 120 ohms then you need to add a 120 ohm resistor between the two pins.

The CAN interface outputs the data at the rate it is received from the CAN bus, so if the data is not being transmitted fast enough by the ECU for some reason it won’t be updated very quickly on the lite monitor or the DASH2.

So to confirm. Measure resistance on interface only ( ie not attached to ecu ) and if resistance is 120ohm, I must install a 120ohm resistor in parallel ?


The update rate is one aspect....but the fact the channels appear and dissappear is stranger.


They arent, but what would happen if the hi and lo wires were reversed ?

[stevieturbo]

bump.

When I try to measure between the two CAN wires at my ecu ( at ecu plug, not connected to the ecu..so testing CAN interface only )

At no point do I get a resistance measured, either 60 or 120ohms.

Can someone also confirm Dash2/CAN connections ?

Seria Data In, despite its name, goes to the Dash2 ??? and I assume sends data OUT to the Dash ??

This "In" plug does work for reprogamming the unit though

Serial Data Out....likewise oddly named is terminated with supplied plug.

And ecu plug provides the 2 wires for CAN Hi and Lo ?? via an additional 9 pin plug, using pins 2 and 7 as per instructions supplied ? for Lo and Hi respectively

[stevieturbo]

And bump again.

What or where should be 120ohms ??

[Support]

The 120 ohms should be between pins 2 and 7 on the CAN interface. If the CAN H and L are reversed it won’t work at all

[stevieturbo]

I tried measuring with power off, and power on.

I didnt get any measured resistance across those pins at all ??

I opened the case up of the plug, and its a yellow and green wires attached to those pins.

[Support]

When you say no measured resistance, do you mean that the resistance is measured as infinite, or that it is a dead short circuit. This is being measured on the car end of the connection.