DIY: How to Install an AEM 1101 EMS into OBD-1 SC300

[CleanSC]

First post over here so it should be a good one, eh? ;)

The following is what I had to do to install the 1101 AEM EMS (Speed Density) on my 1992 SC300 5-speed that AEM did *NOT* cover in their instructions. So this is all supplemental to the install instructions provided by AEM.

For the record, the 1101 box is NOT plug and play for this application. More like plug and play with your soldering iron. :D

Some of my sensors you may not want to use so substitute as you see fit. Wiring should remain the same.

MAP Sensor: GM 3-Bar
Part Numbers:
GM P/N: 12223861
Aftermarket P/N: D21 213 101
Pigtail P/N: KEM 350 259

Wiring:
Pin A: Ground (brown wire) (E)
Pin B: Signal (yellow/green wire) ECU Pin 66B-->62B (KS)***
Pin C: +5V Reference (blue/red wire) ECU Pin 41B (VC)

***Move signal wire Pin 66B (MAF Input - obsolete) to Pin 62B (MAP Input) on the ECU connector. This saves you from running a separate wire into the cabin by just using the old MAF input wire.

Intake Air Temperature Sensor:
Part Numbers:
Aftermarket P/N: KEM 139 202
Pigtail P/N: KEM 148 018

Wiring:
Polarity doesn't matter:
Brown Wire ECU Pin 65B (E2)
Yellow/Black Wire ECU Pin 45B (THA)

Your a/c will not run so install the following:

Air Conditioning: Pull-Up Resistor
Wire in 1k ohm resistor between pins:
ECU Pin 34A (A/C) blue/red wire (a/c request input)
ECU Pin 33A (BATT) black/yellow wire (Battery Voltage)
Resistor Specs:
Resistance: 1,000 (1k) Ohms
Part Number: Radio Shack #271-153
Color Bands: Brown-Black-Red

Set the following in the A/C options menu:
A/C Request Input: "Switch #6 Ground = ON"
A/C Output #1: LS6
A/C Output #2: Disable

This should set you up pretty good. Have fun. ;)

[Kirk]

Thanks!! I added it to the technical forums

[CleanSC]

No probs! ;)

I figure I might save future AEM users from that headache. :thumbup:

[scnat]

don't forget to tell them who taught you about the resistor on the request line :ugh2:

[Bean]

No probs! ;)

I figure I might save future AEM users from that headache. :thumbup:


CleanSC!!! Glad to have you on here! Thanks for the writeup on the AEM.... after doing a lot of research on the AEM installs on SCs, I was aware of the A/C rewiring and I had guessed that one could use the MAF signal wire for the MAP sensor... but that took a lot of reading. Its nice to have it here and definitive :)

[CleanSC]

don't forget to tell them who taught you about the resistor on the request line :ugh2:

Yes, Dave, thanks for the resistor lead. Don't forget the props you got on the AEM forums and CL. ;)

And thanks for the welcome, Bean. Glad to be aboard. :D

[calvinx408]

does these direction only apply to sc300 or is for the na supra also? Im about to switch from vpc+afc combo to aem so im trying to get the most information that i can. Thanks

[CleanSC]

does these direction only apply to sc300 or is for the na supra also? Im about to switch from vpc+afc combo to aem so im trying to get the most information that i can. Thanks

I'd assume it's the same but obviously I'd have no way of telling since I haven't tried it. You can double check everything beforehand by verifying the wire colors and pin locations with your electrical manual. Do a dry run on paper and see if it all matches up.

It should all check out since the box is for both cars but you never know. ;)

[craaaazzy]

bringing back an old thread. hopefully someone can help me.

my sc300 is running well with the 1101. only issue is the a/c. we've done the resistor addition but now, the compressor is always on. when i open the vents (instead of recirculating), i get cold air. when i turn on the fans and try heat, no deal, only cold air. any ideas? all settings done as described above. thanks guys.

[greenzombie2]

I did all of this but the car will only sputter not start :( any ideas?