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GRT EIS/EFIS CHT & EGT Values "Frozen" in Flight

JHill

I'm New Here
RV-ers,

I recently purchased a RV-8 with two GRT Horizon Series I WS displays. I generally fly with the PFD on the top and Engine Display on the bottom screen. The engine information on the Horizon is fed through a the GRT EIS system.

On two flights, I noticed the EGT and CHT values were "Frozen" as in they wouldn't change. On one flight we were an hour and a half in at 12.5k and the values were frozen at the previous cruise power settings. On a recent flight practicing touch and go's I noticed the same issue but the values were stuck somewhere around a taxi setting or just after takeoff.

I called GRT and they haven't seen this issue previously. Next time I see this, I will verify if the EIS values are frozen as well. I've only noticed it on the Horizon GRT and didn't think to check the EIS values. I reloaded the software on the top and bottom Horizon's yesterday and will check them on the next flight.

Has anyone seen this type of issue? If so, what was the fix?
 
frozen

...Has anyone seen this type of issue? If so, what was the fix?
I have not heard of this issue or seen it either.

No doubt you are in good hands if you are talking to GRT. I assume that they asked you activate the data logging feature and see if the numbers are "stuck" there too?

You can also see if the EIS is sending data on the serial interface counter in the setup screens. Are all values from the EIS stuck or just some?
 
First, confirm that the EIS unit is accurately dislaying real time info when the PFD is not.. If that is the case, I would expect a loose wire or pin crimp between the eis and pfd. The data flows across an RS-232 connection. There are DB 25 connectors on each unit.
Larry
 
If everything else is displaying as usual on the Horizon (rpm, pressures etc), the RS232 connection between the EIS and Horizon is working correctly.

All the CHT and EGT thermocouples connect to EIS in one connector. All other inputs are on the second connector. Perhaps your thermocouple connector is loose. It is the vertical DB-25 connector with red, yellow and white wires.

Jim Butcher
 
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