Coolant Fan Control

[Rex-Racer]

If using the M1 output control via Can Bus to a PDM using PDM Byte x Mask xx, does the PMW control and duty cycle and all those settings translate to the CAN state being switched on and off? Thus allowing all the control settings in the M1 and the PDM simply listening for the CAN message and controlling the output accordingly?

[adrian]

No the CAN message is just a status. Any duty cycle above 0 will be on and duty cycle of 0 will be off. The reason for this is that the PDM cannot PWM it's outputs so there is no point in sending it a duty cycle.

[Rex-Racer]

Thanks, that was the info I was looking for. Sounds like the M1 might have a little more sophisticated control over the coolant fan than the PDM. What is the current capability of the half bridge or low side outputs that can PWM in the M1?

TIA
Jay

[David Ferguson]

According to the M1 ECU Hardware manual Half Bridge Outputs: 12 Amp low side driver and 9 Amp high side driver.

Here is the manual:

https://www.motec.com.au/filedownload.p ... docid=4487

BTW this is hard to find. Look in the Tech Notes section of this page:

https://www.motec.com.au/downloads/down ... pdrawings/

[Rex-Racer]

Thanks David, that is THE file I've been looking for specifying the technical nature of the input and outputs.

[adrian]

Just be aware those current ratings David has mentioned are the maximum values. The continuous current rating is 4A. If you want to use a half bridge to PWM a fan you need to use a solid state relay.

[Rex-Racer]

Glad you mentioned that.

Thanks