I am surprised that no one has picked this up yet and made their own CANbus to e30 box. What is the GPeterson box actually doing? I am assuming that it is sending the MSS54 the 0x615 CAN message that the e46 IKE would send. 0x615 is below, or at least what I think people have figured out from it.
-Byte 0
--bit 0-4 - A/C compressor Torque
--bit 5-6 - unknown
--bit 7 - A/C Turn on Signal - 1 is requested and 0 not requested
-Byte 1
--bit 0-1 unknown
--bit 2 - headlights on
--bit 3 - hood switch
--bit 4-7 - A/C fan speed request from 0-15
-Byte 2
-Byte 3
-- Outside Air Temperature in Deg C
-Byte 4
--bit 0 = driver door open
--bit 1 = handbrake engaged
-Byte 5
--bit 1 - left turn signal
--bit 2 - right turn signal (both for hazard)
--bit 3-4 - CAN_EKP_CRASH (probably whether or not the car is crashed and whether or not fuel pump should be turned off).
-Byte 6
-Byte 7
--bit 1 - Key Information (if 1, key information available)
--bits 2 - 3 - Key number (00 = Key 1, 01 = Key 2, 10 = Key 3, 11 = Key 4)
It would seem like the portions bolded and in red above were probably what Garry was modifying? Maybe more. If I had to guess when you hit the snowflake button and the evap temp switch, high pressure cutoff switch, and low pressure cutoff switch were all closed he would flit Byte0, bit 7 to 1. This would let the MSS54 know you wanted A/C and then the MSS54 would decide when to turn on the compressor with an added compressor relay based on WOT, engine temp, etc. One of this issues I think with these boxes being flaky is that the A/C circuit in the e30 is one of the ones that changed the most from year to year and engine to engine in the e30. The wiring diagrams provided I don't think would work for every e30 version. Also there seemed to be a huge amount of variability of what components people were using, e36 compressor, s54 compressor, e46 sensor, e30 switches, e36 switches, etc. and I'm sure that didn't help.
What he was doing with the e46 pressure switch I am not sure but his comments make it seem like it was only for the fan request. I would imagine that he varied Byte 1, bits 4-7 based on the pressure sensor to request the fan for A/C? I am not sure how the MSS54 takes that request into account along with the temp tables for the radiator outlet sensor. It may not be necessary. in other threads people mentioned using the e36 or e30 pressure switch and it sounded like the he would just make the fan turn on all the way so probably set this value to either 0 or 15 instead of an intermediate value based in a sensor.
The other functions that were implemented were based on the CAN messages from the ECU.
I don't have one of these boxes to test anymore. and I don't run a/c in my s54e30 If someone could confirm what it is doing I think that would go along way to recreating something that actually works and possibly could support more functions to simplify the swap.
-Byte 0
--bit 0-4 - A/C compressor Torque
--bit 5-6 - unknown
--bit 7 - A/C Turn on Signal - 1 is requested and 0 not requested
-Byte 1
--bit 0-1 unknown
--bit 2 - headlights on
--bit 3 - hood switch
--bit 4-7 - A/C fan speed request from 0-15
-Byte 2
-Byte 3
-- Outside Air Temperature in Deg C
-Byte 4
--bit 0 = driver door open
--bit 1 = handbrake engaged
-Byte 5
--bit 1 - left turn signal
--bit 2 - right turn signal (both for hazard)
--bit 3-4 - CAN_EKP_CRASH (probably whether or not the car is crashed and whether or not fuel pump should be turned off).
-Byte 6
-Byte 7
--bit 1 - Key Information (if 1, key information available)
--bits 2 - 3 - Key number (00 = Key 1, 01 = Key 2, 10 = Key 3, 11 = Key 4)
It would seem like the portions bolded and in red above were probably what Garry was modifying? Maybe more. If I had to guess when you hit the snowflake button and the evap temp switch, high pressure cutoff switch, and low pressure cutoff switch were all closed he would flit Byte0, bit 7 to 1. This would let the MSS54 know you wanted A/C and then the MSS54 would decide when to turn on the compressor with an added compressor relay based on WOT, engine temp, etc. One of this issues I think with these boxes being flaky is that the A/C circuit in the e30 is one of the ones that changed the most from year to year and engine to engine in the e30. The wiring diagrams provided I don't think would work for every e30 version. Also there seemed to be a huge amount of variability of what components people were using, e36 compressor, s54 compressor, e46 sensor, e30 switches, e36 switches, etc. and I'm sure that didn't help.
What he was doing with the e46 pressure switch I am not sure but his comments make it seem like it was only for the fan request. I would imagine that he varied Byte 1, bits 4-7 based on the pressure sensor to request the fan for A/C? I am not sure how the MSS54 takes that request into account along with the temp tables for the radiator outlet sensor. It may not be necessary. in other threads people mentioned using the e36 or e30 pressure switch and it sounded like the he would just make the fan turn on all the way so probably set this value to either 0 or 15 instead of an intermediate value based in a sensor.
The other functions that were implemented were based on the CAN messages from the ECU.
I don't have one of these boxes to test anymore. and I don't run a/c in my s54e30 If someone could confirm what it is doing I think that would go along way to recreating something that actually works and possibly could support more functions to simplify the swap.
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