I have a Deere 210l ep Gannon serial x06934 with a yanmar 4tnv98ct. Machine runs perfectly fine but will randomly throw a 2798-06 code Injection Valve Supply Voltage 2, Resistance Too Low and it will cut out injectors 2 and 3 I can shut unit off and machine will run fine again for a little while. Could not find much information on the internet about this code. I’m assuming is talking about injector #2. Checked resistance of all injectors all tested the same. Ran machine with injector #2 disconnected to see if it would still throw the code and shut off injector #3. Machine did the same thing. Any help be appreciated don’t have service manual or schematics so troubleshooting this one has been a pain
Welcome to HEF Jcontreras ! Please post the entire serial number so we can look up accurate information. Did you check for continuity of the injector wires to ground with the ECU and injectors unplugged?
Full serial 1T8210ELUKG896204 Yes I have checked for short to ground and I tested all individual wires while wiggling the harness no issues found
While the schematic (check your messages) does not show it, I bet the power wires for the #2 and 3 injectors come from the same driver and #1 and 4 from another driver. I can't be sure with the Yanmar. Deere engines pair up injectors on power wires and control the ground to each individual injector. If Yanmar does this, the driver might be defective, which would kill two injectors.
is that internal to the ecm ? Any idea how I could verify the driver is bad.
Not sure if the Drivers are like on Caterpillar engines at 110 volts to injector on some. Because of the high speed that injuectors are firing at, my guess is that you would need a scope like a Pico 4425A to record if the power is getting there. I could be wrong, mg2361 has a smaller version scope I believe and may help get you the procedure. Simon C
Yes, the drivers are internal to the ECU. I can confirm they use one driver for two injectors because the troubleshooting procedure says to test both injector #2 and 3 resistances for that code. If you do not have a scope, then it is basically troubleshooting by the process of elimination. If all the wires are proving to be of sound condition, and the injectors are not shorted to ground, or have too low of a resistance, then the only thing left is the ECU. As far as the injectors are concerned, if a key cycle allows them to work for a while, then I do not suspect an injector issue. Did you measure their resistance immediately after the issue appears? The ECU will shut down a driver if it detects a short and will not turn the driver back on until a key cycle. That short could be external, or internal. On Deere engines, it is 90 volts (see below for an example of a good Deere injector in a no start condition). I have not done the voltage on a Yanmar yet, but I have done the amperage on a Yanmar injector. I have to work on getting a pattern. I work on plenty of the suckers, but have yet to play with the scope in detail.
Good explanation of how it all works. Simon C