Gen2 Prius: Custom PIDs for Torque (Android App) with formulas

When you change screens you quit writing to the fan speed and the normal temperature control takes back over.

Whether SGII, Torque or Engine Link you have to continuously overwrite fan speed command or it reverts back to temperature control.

 

The normal Prius HV fan control is best observed/monitored using the torque pid that displays fan voltage.
The positive side of the blower get 13 volts applied through blower relay when battery temp2 gets to 96.6 degrees.
The negative terminal of the blower is connected to the HV speed controler.
Thus the speed controller varies the ground potential applied to the negative terminal of the blower motor.

So when torque app displays 7 blower volts it really means the the blower negative terminal is 7 volts above ground potential.
Therefor the true HV blower voltage would be 6 volts.
Or said better torque app pid for fan voltage is incorrect in its math.
The torque app blower voltage needs to be subtracted from the aux battery voltage (13.8 volts) to show the correct voltage across the blower motors terminals.

You will notice when monitoring blower motor voltage with the torque app (currently incorrect math) that the blower voltage decrease with vehicle speed, which is backwards.
You can actually hear the blower speed increase as the vehicle speed increases.

All the information is from removing HV blower from my Prius last summer for cleaning an then reinstalling blower motor but connecting it to a variable power supply.

I varied the voltage to the blower while stationary and listening from the drivers seat.

I determined that the first speed the Prius selects at battery temp2 of 96 degrees (while stationary ) is about 3.5 volts.

This is hard for me to explain all the parameters I've observed. Regarding the HV battery cooling blower .

You will definitely want to set up a gauge on the torque app to monitor HV blower voltage to answer all your questions. The pid nessary should be available in your current extended pid list.

 

I have monitored all of battery fan gauges on both SGII and Engine Link, including voltage. I see no link between fan speed and vehicle speed. What I see is that fan speed is controlled by battery temp starting where you indicate at 96F. The fan voltage goes up proportional to fan speed mode.

 

I'm the developer of OBD Fusion for iOS and TouchScan for Android. I'm working on adding support for custom PIDs for OBD Fusion and am looking for beta testers. This will support custom PIDs like Torque and Engine Link. If anyone is interested in beta testing, let me know and I can provide OBD Fusion for free. This will be first come, first serve, and the number of testers will be limited.

 

If you manually set fan speed . Fan voltage will remain constant.
If you let the Prius control fan speed. The fan voltage will vary with road speed.

This is applicable to genII and genIII. And confirmed thru different methods and Prius chat sources.

The only thing I can think is your monitoring air conditioner blower. Not HV battery blower.
Or your monitor program is faking the reading based on temperature only.
Or you have manual blower speed setting.

What voltage readings are you seeing, first speed, second speed, approximately?

If the Prius blower control worked the way you say. We wouldn't need external speed control and we wouldn't have battery heat problems.

 

Usbseawolf there is a mistake in the math for both genII and genIII blower voltage.
(VMF fan motor voltage)
GenII math displays voltage output of the speed controller which varies the ground potential applied to the blower's negative terminal. The motors positive terminal is connected to the aux battery through blower control relay.
So the right math should be something like;
aux_bat - ((.2 * c) - 25.6) ) or
13.8 - ((.2 * c) -25.6))
Or (((.2*d) -25.6)) - ((.2 * c) - 25.6))) I am thinking this could be simplified? Help!
Or the gauge could be simply retitled to blower ground voltage.

Gen III MATH ag / 5 instead of ag / 10 .
ag / 10 produces reading as low as 1.5 volts which could not sustain rotation of a 12 volt motor.

With these changes both genII and gen III produce very similar readings.
I have both prius's . I have only altered the genIII pid code.

For the genII I subtract the torque reading from 13 volts in my head.
I think the genII code should be corrected by someone who knows which variable contains the aux battery voltage.

 

I am monitoring HV battery blower motor for heavens sake. Unless the Gen II is totally different than the Gen III the battery blower fan speed has absolutely nothing to do with vehicle speed. If the battery temp is below 97F the fan speed mode is 0, no matter what speed you are running.

 

Here is some testing I did by forcing the fan speed with SGII:

BFM = 1, CF0 = 34% and VMF = 1.3V​

BFM = 2, CF0 = 41% and VMF = 2.0V​

BFM = 3, CF0 = 48% and VMF = 2.5V​

BFM = 4, CF0 = 55% and VMF = 3.0V​

BFM = 5, CF0 = 63% and VMF = 3.5V​

BFM = 6, CF0 = 72% and VMF = 4.0V​

​

As you can see at the highest battery fan speed at BFM (battery fan mode) = 6, the voltage to the blower fan is only 4.0V. I am not sure what connecting 12V directly to the blower fan motor would do. I am sure it would be extremely loud since at BFM=6 the fan was pretty loud.​

​

Of course this assumes that the SGII XGauge feedback is correct. ​

​

 

If those % and voltage readings are from the scanguage. The math for the voltage is wrong just like the torque genIII APP fan voltage is wrong. Those need to be more than doubled to match your percentages.

I guess cfo is cooling fan output?
How were the cfo percentages obtained they seem accurate compaired to the inacurate voltages.
As I stated in my previous post 1.3 and even 1.5 volts will not sustain rotation of hv blower motor.

4 volts divided by 12 volts would be 33% of the blower motors capability.
Obviously your setup is using different math for voltage and cfo.

Oh I did put 12.6 volts on the hv blower motor last year when it was removed for cleaning. It pulled 5.75 amps and produced about 9 pounds of thrust out the nozzle.
It was unbelieveable! Even at 6 volts it produces a heck of alot of force.

 

The SGII XGauge parameters were taken from a spreadsheet started by Adrian Black and updated by vincent1449p. In the 2010 Repair Manual it only gives one fan speed setting and normal range:

VMF Fan Motor Voltage1
Battery blower motor monitoring voltage/ Min.: 0 V, Max.: 25.5 V
Fan mode 1 with READY indicator ON and park (P) selected: 1.0 to 1.4 V
Battery cooling fan circuit

In Battery Fan Mode 1 my SGII VMF reading was 1.3V, which fits the manual's range of 1.0 to 1.4V.

There is also a test procedure for testing the different speed modes:

(h) Select each air volume mode (1 to 6) in the "Driving the Battery Cooling Fan" active test to operate the battery cooling blower assembly.
(i) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection S14-2 (VM0) - S14-4 (GND0)
Condition Specified Battery cooling blower is operating
Condition Below 5 V

 

Can you comment about cfo percentage being much higher than the voltage percentage (4/12 = 33%).
Is the cfo % from the scaguage? Is it one scanguage function thats reports both cfo% and fan voltage?

 

From the Repair Manual the voltage range to the blower motor is not 0-12V but less than 0-5V. The SGII readings indicated 0-4V. So try doing the percentage based on 0-4V and see what you get. Closer but not exact.

The BFM, CFO and VMF are separate XGauges.

I was surprised to find that the voltage range to the blower motor was 0-4V rather than 0-12V. I have not been able to find anything that states the nameplate voltage of the blower motor.

 

The blower from gen II is marker as 12 volts.
A government testing lab reported genI blower current as 5.75 amps at 12 volts. My genII blower pulls the same current at 12 volts..
I assume all prius use same blower even at 5 volts produce plenty air.

 

OK thanks. That is the first time I have seen where the rated voltage was listed. My feeling was that the fan could move sufficient air at BFM 6 and 4.0V so did not need to go any higher at this time.

 

I,m unable to find CFO OR VMF on the genIII Scanguage master list.
Can you paste those txd's rxf's rxd's and mth. That will allow me to determine why your readings are not changing with vehicle speed.

 

I will get them when I get home tonight.

Why are you still convinced that the fan speed changes with vehicle speed? Why would it? One more time the fan speed is controlled by battery temperature.

 

Once again, from the Repair Manual:

The speed of the battery cooling blower assembly is controlled by the power management control ECU.
Battery cooling blower assembly power is supplied when the FCTL terminal of the power management control
ECU turns on the battery blower relay. The power management control ECU sends command signals (SI) to the
battery cooling blower assembly to get the fan speed corresponding to the HV battery temperature. Information about the voltage applied to the battery cooling blower assembly (VM) is sent to the power management control ECU as a monitor signal using serial communication via the battery smart unit.

How about sharing some data with me where there is any indication that the battery blower motor speed has anything to do with vehicle speed.

 

Ok
I'ts very easy to hear the blower speed increase (with good hearing). Especally in the genIII .
The torque app takes bytes a and g (bytes 1 and 7) to compute blower voltage.
A scanguage cannot do the same calculation. There for your xgauges for CFO and VMF are bogus!

Oops its not byte a and g it is byte ag (byte 32) that should be blower fan voltage.
And the scanguage should be able to read byte 32 ( if someone would count in out corectly).

 

You trust your gauges and I will trust mine, especially since they match the Repair Manual sensor ranges. Besides I have no use for monitoring CFO and VMF. I monitor battery temp and BFM to tell when the fan is running and when it is not. I can assure you in my car the fan runs on temp and not speed.

If you are so hung up on believing that yours changes with vehicle speed, knock yourself out.

Show me supporting "data" that supports the vehicle speed controlling fan speed.

 

I agree with jd. The HV battery fan runs based on traction battery temp, not vehicle speed.

I started using torque for android this winter. I witnessed the fan speed change for the first time from 0 to 1 (and 2) this past weekend when the ambient air temps in suburban Chicago reached the high 70s. The HV battery temp exceeded 97 in the center of the pack and that's when the HV fan came on (or at least that what was indicated on the gauge - I didn't actually check the fan for operation by putting my ear up to the inlet in the back seat). Once the temp dropped below 95, the HV fan speed went back down to 0.