Tesla Model S/X A/C Compressor
Overview
There are two known variants of A/C compressors used in Model S & X. The first generation is a unit by Denso which can be controlled via PWM. Later units built by HVCC and Hanon are CAN-controlled. This page deals with gen 1 units, details for controlling the gen 2 CAN variants are found here.
Early years of Model S (2013-2014) used an ES34C by Denso with part number 6007380-00-D.
Later models (2015+) used a HVCC ESC33 with Tesla part number 1028398-00-E, 1028398-00-F and 1028398-00-J. Tesla also used the Hanon HES33 and is found with number 1063369-00-D, 1063369-00-E, 1063369-00-F and 1063369-00-G.
Gen 1 Unit (Denso ES34C)
Power Draw
As per: https://www.diyelectriccar.com/threads/tesla-a-c-compressor-questions.189978/post-1061852
Current draw at maximum load is in the neighbourhood of 12 amps @ 360V, so somewhere around 4.5kW draw.
Control/Pinouts
| pin | function |
|---|---|
| 1 | GND |
| 2 | On/Off |
| 3 | Diagnostics |
| 4 | Not connected |
| 5 | Power feedback |
| 6 | PWM in |
| 7 | 12V in |
| 8 | Not connected |
As mentioned above, the Denso ES34C can be controlled using a PWM signal.
As per: https://www.evcreate.nl/using-tesla-thermal-management-system-parts/#tesla-ac-compressor
Connect 12V + in to pin 7 and provide chassis ground to pin 1. Pin 4 and 8 are not connected (don’t even have a male terminal in the compressor connector). You can leave the power feedback (pin 5) and diagnostics (pin 3) unconnected too.
The compressor is enabled by grouding pin 2 (active low) and speed control via a PWM signal on pin 6.
As per: https://www.diyelectriccar.com/threads/tesla-a-c-compressor-questions.189978/post-1029299
Success! I got the ES34C running. It is very easy to control and very tolerant of input conditions. It takes a PWM signal anywhere from 35 to 400 hz. Control range is from 5% (max speed) to 85% (min speed) duty cycle.
I supplied 12V to Pin 7 (VIgn), Grounded pins 1 (Gnd) and 2 (On/Off), and left pins 3 (Diag) and 5 (Power (FB)) unconnected. The 12V PWM signal was input to pin 6 (PWMin).
Wiring/Connectors
HV
Polarity of the HV connector (as looking into the connector):
Details of the connector itself are currently unknown, though an HV cable from a Lexus hybrid (i.e. GS450H) A/C compressor has been known to work if a Tesla assembly can't be sourced.
LV
As per: https://www.diyelectriccar.com/threads/tesla-a-c-compressor-questions.189978/post-1062935
Female connector for control signals is Sumitomo P/N: 6189-1240
Controller
An Arduino MEGA-based controller has been developed by DIYEC user Classic Style. Details here: https://www.diyelectriccar.com/threads/tesla-a-c-compressor-questions.189978/post-1067794
Integration with aftermarket HVAC
It has been pointed out that a typical HVAC trinary switch will provide a 12V signal to enable (might be typical on ICE compressors), however, in this case the Denso ES34C is looking for a GND signal to enable (pin 2 - ON/OFF). As per: https://www.diyelectriccar.com/threads/tesla-a-c-compressor-questions.189978/post-1075637, DIYEC users jsimonkeller and DANTM managed this simply by using a typical automotive relay to invert the signal and switch GND instead of 12V.