Max EV Speed Threshold
 

Finally have the new ScanGuage connected to the new MMH, and am able to coax it up to about 29 mph in EV on a level entrance road to where I live. Have not yet found the right X Guage to determine what trips the ICE back on ( I've looked at MxD but that is obviously not the answer ). Seems like I read posts about traction motor current draw from the HV Battery, but cannot find that data item within the list of X Guages on the Scan Guage web site. Any ideas from the experts?

Thanks,
John Dixson

Re: Max EV Speed Threshold
 

I never gave Ron the AMP add-a-gauges because I thought the large positive numbers when charging would confuse people, but I guess people can learn to live with that untill a method of dealing with scaled 2's complement PIDs can be found.

I'm not sure amps alone determine when to turn the ICE on. I suspect it is torque demanded compared to torque available. This assures that the generator can spin the engine over at the speed and SoC, etc. Knowing Ford, they were probably very conservative in this respect so that in worst case conditions they would have plenty of margin to spin the engine without a large drop in speed or SoC or without a large jolt. On a recent cold morning, I got up to 45MPH solely on electric power while the ICE idled in warm-up mode. My SoC went from about 42% to 32%. In this case the ICE is already running so obviously no need to start it.

Total torque desired is PID 4974 from the TCM but I'm not positive on the scaling. The add-a-gauge below assumes Nm with a scaling of 0.1 (?)

Anyway, current from the HV battery can be coded as follows:

TXD: 0745224915
RXF: 046285490615
RXD: 3010
MTH: 027108000000
NAM: Amp

Current from the TCM is:

TXD: 07E122496E
RXF: 04628549066E
RXD: 3010
MTH: 027102000000
NAM: AMP

A guesstimate for Torque desired is:

TXD: 07E1224974
RXF: 046285490674
RXD: 3010
MTH: 000100010000
NAM: TqD

Re: Max EV Speed Threshold
 

Congrats on the new MMH. I have copied and pasted a previous post concerning current draw from traction motor, and the parameters to program it in on your new SGII. On a warm day, my 08 FEH AWD can reach 59.x AMP before ICE cuts on. That value is lower when temperatures are lower, because the HV battery charge is dependent on temp. If you are going down a slight incline, you can exceed > 29mph. You see this speed because you are reaching the max AMPerage limit. Also, SoC, CHT, & fWT are contributing factors. That's all described in the FEH/MMH section of this website. The water temp (fWT), and SoC are pretty hard/fast rules, so monitoring fWT, SoC, and AMP can help you pinpoint almost to the second when EV stops and engine kicks on.

Good Luck.
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Current from TCM:
TXD: 07E122496E
RXF: 04628549066E
RXD: 3010
MTH: 027102000000
NAM: AMP

You need to watch AMP and not exceed about 50 amps to stay in EV.
I say about, because in warm weather you can exceed 50 amps in EV, but in cold, you may only get about 40 amps.
I can't give an exact value on this, but it's a good guide to start with.

Note: You get small positive numbers from 0 to ~75 amps when drawing power out... you get large postive numbers when putting amps in.

Amps in = 1445 - value on display. If you get 1400 on the display, you are putting 45 amps in. This is due to the fact that the raw data is in hexidecimal 2's complement format, and the math conversion does not do negative numbers easily.

Just remember a small number = actual value out ( discharge )
A large number is 1445 - xxxx = actual value in ( charge )

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Re: Max EV Speed Threshold
 

Thanks, Ken E and Desert Dog. I'll try these approaches. I appreciate your timely responses. With level terrain and moderate temperatures, I've been able to do pretty well with initial mpg numbers, but it is still fun to try and maximize the hybrid benefits.

Thanks,
John Dixson

Re: Max EV Speed Threshold
 

John,
I don't know how long you've had your MMH, but don't be surprised if your numbers are very different until you get about 3,000-5,000 miles on the vehicle. During the break-in/learning phase the vehicle will jump out of EV mode sooner and at far lower speeds. Judging by the fact that you can only get to 29mph in EV I would say your MMH is still very new. As the vehicle learns driving patterns and the battery gets conditioned you will see that change. Eventually you should be able to stay in EV mode longer and drive faster....but as I said don't expect that until you hit at least 3,000 miles on the ODO.

Re: Max EV Speed Threshold
 

Thanks and you are quite right: I only have 500 miles on the vehicle. My driving habits are best described as "docile" and I can eke out 4-5 mpg more than my spouse in the diesel we own.

Re: Max EV Speed Threshold
 

I like "docile". My 08 FEH AWD has abt 3100 miles now, and I can attest to the fact that EV is better now than the beginning. However, on day of purchase in Oct. 07', the temperatures have been gradually declining. So cold wx is a negative influence while the break-in is a positive.

I won't be able to testify with absolute certainty until ambient temps start averaging what the did in mid Oct.:)