The USDM Evo VIII ECU uses a four-plug harness, with two rows of pins for each plug. The factory service manual refers to these plugs as C-121, C-119, C-117, and C-115.
For a picture of the ECU-side of the harness, see Road Race Engineering's EVO VIII pinout page.
Complete harness
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13
|
14 |
15 |
16 |
17 |
18 |
19 |
20 |
21 |
22 |
23 |
24 |
25 |
26
|
|
31 |
32 |
33 |
34 |
35 |
36 |
37 |
38
|
39 |
40 |
41 |
42 |
43 |
44 |
45 |
46
|
|
51 |
52 |
53 |
54 |
55 |
56
|
57 |
58 |
59 |
60 |
61 |
62
|
|
71 |
72 |
73 |
74 |
75 |
76 |
77 |
78 |
79 |
80 |
81
|
82 |
83 |
84 |
85 |
86 |
87 |
88 |
89 |
90 |
91 |
92
|
|
C-121
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13
|
14 |
15 |
16 |
17 |
18 |
19 |
20 |
21 |
22 |
23 |
24 |
25 |
26
|
Pin |
Description
|
1 |
Injector #1
|
2 |
Injector #3
|
3 |
Fuel pressure solenoid
|
4 |
Idle air control motor, coil A1
|
5 |
Idle air control motor, coil B1
|
6 |
Exhaust gas recirculation solenoid relay control, ground
|
7 |
|
8 |
A/C compressor clutch control, ground
|
9 |
Evaporative emission purge solenoid
|
10 |
Ignition coil, cylinder #1 and #4
|
11 |
Turbocharger wastegate solenoid
|
12 |
12V power (through MFI relay)
|
13 |
Chassis ground
|
14 |
Injector #2
|
15 |
Injector #4
|
16 |
|
17 |
Idle air control motor, coil A2
|
18 |
Idle air control motor, coil B2
|
19 |
Volume airflow sensor reset (MAF filter?)
|
20 |
|
21 |
A/C condenser fan control
|
22 |
Fuel pump relay
|
23 |
Ignition coil, cylinder #2 and #3
|
24 |
A/C control (?)
|
25 |
12V power (through MFI relay)
|
26 |
Chassis ground
|
C-119
31 |
32 |
33 |
34 |
35 |
36 |
37 |
38
|
39 |
40 |
41 |
42 |
43 |
44 |
45 |
46
|
Pin |
Description
|
31 |
|
32 |
A/C condenser fan relay (high)
|
33 |
Alternator voltage regulator, ground
|
34 |
A/C condenser fan relay (low)
|
35 |
Charge air cooler water spray fluid meter
|
36 |
Check-engine light
|
37 |
Power steering pressure sensor signal
|
38 |
MFI relay control, ground
|
39 |
Fuel pump relay control, ground
|
40 |
Sensor ground (IAT, cam position, fuel tank pressure, MDP, TPS)
|
41 |
Alternator voltage regulator signal
|
42 |
Aftermarket use: ADC 0F, typically used for map switching in TephraMod
|
43 |
Clutch pedal position switch
|
44 |
Charge air cooler water spray switch (auto control)
|
45 |
A/C control (?)
|
46 |
Fuel level sender signal (gauge)
|
C-117
51 |
52 |
53 |
54 |
55 |
56
|
57 |
58 |
59 |
60 |
61 |
62
|
Pin |
Description
|
51 |
Engine immobilizer system
|
52 |
|
53 |
|
54 |
Rear O2 sensor signal
|
55 |
Evaporative emission ventilation solenoid
|
56 |
|
57 |
Charge air cooler water spray relay control
|
58 |
Engine speed (RPM)
|
59 |
|
60 |
Front O2 sensor signal
|
61 |
Fuel tank differential pressure sensor signal
|
62 |
Data link (OBD-II/MUT-III comms, pin 7 on OBD-II port, C-14)
|
C-115
71 |
72 |
73 |
74 |
75 |
76 |
77 |
78 |
79 |
80 |
81
|
82 |
83 |
84 |
85 |
86 |
87 |
88 |
89 |
90 |
91 |
92
|
Pin |
Description
|
71 |
Starter relay signal
|
72 |
Intake air temperature sensor signal
|
73 |
MAP sensor signal
|
74 |
Fuel level sender signal (low-fuel light)
|
75 |
Rear O2 sensor heater control
|
76 |
Front O2 sensor heater control
|
77 |
Fuel temperature sensor signal
|
78 |
Knock sensor signal
|
79 |
Data link (flash signal, pin 26 on diagnostic port, C-15)
|
80 |
12V power (backup ECU power, wired directly from battery)
|
81 |
Throttle position sensor power (+5V)
|
82 |
Ignition switch IG1 (power when ignition in postion "ON" and "START")
|
83 |
Coolant temperature sensor signal
|
84 |
Throttle position sensor signal
|
85 |
MAF barometric pressure sensor signal
|
86 |
Vehicle speed sensor signal
|
87 |
|
88 |
Intake cam position sensor signal
|
89 |
Crankshaft position sensor signal
|
90 |
MAF sensor signal
|
91 |
Charge air cooler water spray switch (manual control)
|
92 |
Sensor ground (O2 heaters, coolant temp, tps signal, MAP, fuel tank pressure signal)
|