Microsquirt based trans controller
(C) James Murray Oct 2007
The controller software in presently awaiting alpha test. Bench simulation looks promising, but until I have a transmission to test on it is only theory.
Code has been written for 4L60E and 4L80E.
The 4L60E 3-2 shift solenoid documentation I used was a little fuzzy so it is either off or 90%. No change is made during 3-2 downshift.
Download the latest firmware from http://www.jsm-net.demon.co.uk/trans/files/alpha, extract somewhere on your hard drive and read the README
Download Megatune from http://www.not2fast.com/megasquirt/mt/2.25
Microsquirt Wiring
|
Microsquirt pin number |
Signal name |
Function |
|---|---|---|
|
33 |
VR- |
VSS negative (rear /side of trans or transfer case) |
|
32 |
VR+ |
VSS positive (rear /side of trans or transfer case) |
|
8 |
FP |
Solenoid A |
|
7 |
IDL |
Solenoid B |
|
11 |
IGNOUT2 |
3-2 Solenoid (4L60E only) |
|
9 |
INJ1 |
TCC solenoid |
|
10 |
INJ2 |
EPC solenoid |
|
26 |
MAT |
TPT pin A |
|
25 |
CLT |
TPT pin B |
|
34 |
EGO |
TPT pin C |
|
19 |
GND |
Trans temp sensor ground |
|
24 |
MAP |
Trans temp sensor |
|
28 |
VREF |
Connect 2.49k resistor to pin 34. Connect 2.49k resistor to pin 24 (should be ok for GM trans) Connect 2.49k resistor to pin 29 (adjust for different sensor in engine) If standalone TPS is used, connect to TPS. DO NOT CONNECT if sharing TPS with another ECU. |
|
27 |
TPS |
TPS signal “middle wire” (0-5v input) |
|
18 |
GND |
If standalone TPS is used, connect to TPS. DO NOT CONNECT if sharing TPS with another ECU. |
|
29 |
SPAREADC |
Engine temp sensor. |
|
21,22,23 |
GND |
Connect to a good ground location |
|
1 |
+12V |
Connect to a fused 12v supply live when ignition is on |
|
6 |
FLEX |
Brake switch signal. Use a relay to connect this to ground when brake pedal is pressed. DO NOT apply 12v to this pin. |
|
16 |
VR2IN+ |
Engine speed signal. Connect to tacho or crank sensor |
|
13,14,20 |
RXOUT,TXOUT, GND |
Serial connection to computer. |
|
2,3 |
CANH,CANL |
Not used at this time. Do not connect. |
|
16,17,35,12 |
ALED,WLED,TACHOUT,IGN |
Not used at this time. Do not connect. Maybe switched outputs in the future. |
|
30,31 |
OPTOIN+,OPTOIN- |
Do not connect. |
|
15 |
BOOTLOAD |
Required during initial setup. Connect to ground to load code. NEVER apply a voltage to this pin or damage will occur. |
It should be possible to use an MS2 card as an alternative, but it will be a little more involved. Send me an email if interested.
The following diagrams and pinout lists were taken from the yahoo Megashift group and corrected from service data.
|
|
|
|
|
Early 4L80E connector |
1993 up 4L80E connector |
4L60E connector |
|
Function |
Early 4L80E |
Late 4L80E |
4L60E |
|
Sol A Switched Gnd |
A |
A |
A |
|
Sol B Switched Gnd |
B |
B |
B |
|
+12 Power |
C & K |
E |
E |
|
Press Sw A (Pin A) |
D |
N |
N |
|
Press Sw B (Pin B) |
E |
R |
R |
|
Press Sw C (Pin C) |
F |
P |
P |
|
Temp Sensor GND |
H |
M |
M |
|
Temp Sensor |
G |
L |
L |
|
LU Sol Switched Gnd |
J |
S |
T |
|
EPC +12V |
L |
C |
C |
|
EPC Switched Gnd |
M |
D |
D |
Last updated: 3rd November 2007
Email: jsm@jsm-net.demon.co.uk
