View Full Version : Using the AC relay output to control a second fuel pump
ttls1
December 28th, 2013, 10:56 PM
Hi, Just wondering if anyone has used the AC relay output to control a second fuel pump depending on RPM or TPS? Looking at the wiring diagram and parameters in efilive it may be doable. Would have to use the NC contacts on a relay and have the "AC Disable RPM" or "AC Disable TPS" actually turn the pump on. Will probably have to bridge the AC transducer input also. I was considering using the shift light output but as my setup is an auto it is used for a shift solenoid.
gmh308
December 29th, 2013, 05:58 PM
Hi, Just wondering if anyone has used the AC relay output to control a second fuel pump depending on RPM or TPS? Looking at the wiring diagram and parameters in efilive it may be doable. Would have to use the NC contacts on a relay and have the "AC Disable RPM" or "AC Disable TPS" actually turn the pump on. Will probably have to bridge the AC transducer input also. I was considering using the shift light output but as my setup is an auto it is used for a shift solenoid.
The AC on command comes via the CAN from the BCM. So might work with AC switched on :).
ttls1
December 31st, 2013, 11:13 PM
Cheers, I forgot to mention that this is in a conversion so I don't use the PCM for AC control. Also realised I should have posted under the genIII topic as its an LS1 ecu and it has an input on the pcm for AC request. Will try and give it a go
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