MG PTC Cabin Air Heater

Overview
PTC Air heater assembly found in MG EVs (ZS, MG4, MG5).
Heater is controlled by LIN.
Dimensions are WxLxD 160 x 220 x 33mm for the active part with the control box adding another 30mm in length.
Part Numbers
| MG Part Number | Vehicles Used it | Tested? |
|---|---|---|
| 10606761 | ZS | No |
LIN Control
- no timers, counters or CRC are needed, but there is a delay of about 3 seconds until settings are applied
- Bytes 2E and 2F contain the control messages, 3A has the responses
- Control is in byte 0+1 of 0x2E Scaling = x25 Little endian So if you want 20% power you need to send decimal 500 which is hex 01F4 So then Byte 0 = 0xF4 and Byte 1 = 0x01 Byte 4 looks to be on/off with 0x96 = ON and 0x00 = Off but it does not fully turn off. I kept seeing a current draw on the bench power supply of 0,07A at 300V. When requesting power 0% this does drop to 0A.
- Feedback Message 0x3A Byte 5 and 6 contain the actual consumption in W as little endian. So if Byte 5 = CF and Byte 6 = 04 that is 04CF in hex which is 1,2 kW.
- Below about 250V it stops working. Then 0x3A sends 00 00 00 08 00 00 00 20
- Above 150 degrees it stops working. Then 0x3A sends 00 00 00 00 01 00 00 20
Connectors

Low Voltage/Control
KET part number MG644145-5
Hyundai part number 1879002605as
Pinout
| Pin | Cross Section | Colour | Function |
|---|---|---|---|
| 2 | 0.35 | Green/White | + fused with 5A |
| 3 | 0.35 | Pink/Black | LIN |
| 4 | 0.35 | Black | GND |
High Voltage
Pinout
| Pin | Cross Section | Colour | Function |
|---|---|---|---|
| 1 | 3.00 | Orange | HV+ fused with 40A |
| 2 | 3.00 | Orange | HV- |
