USDM Evo 9 pinout according to USDM Evo 9 Factory Service Manual*
* The unused pins were examined as follows with ignition "on" and engine "off"
1) The voltage was measured across all unused pins.
2) 1.7 V was applied to most of the unused pins to determine which if any were ADC inputs.
plug C-121 = "A" plug on GEMs pinout, pins 1-8, 9-23, 24-35
plug C-119 = "B" plug on GEMs pinout, pins 41-47, 48-59, 60-68
plug C-117 = "C" plug on GEMs pinout, pins 71-77, 78-90, 91-100
Pin Color USDM Description
1 Injector #1
2 Injector #4
3 Front O2 heater control
4 not used, 0 V
5 not used, 0 V, probably a relay (secondary air solenoid control on JDM Evo IXs)
6 EGR solenoid relay ground (control)
7 not used, 0 V
8 Alternator control ground
9 Injector #2
10 not used, 0 V
11 Ignition coil cyl #1, #4
12 Ignition coil cyl #2, #3
13 not used, 0 V
14 Idle air control
15 Idle air control
16 Evaporative purge solenoid relay ground (control)
17 not used, 0 V
18 Cooling fan relay ground (control)
19 MAF signal filter?
20 A/C compressor clutch ground (control)
21 Fuel pump relay ground (control)
22 CEL ground (control)
23 not used, +5 V (load capacity unknown)
24 Injector #3
25 not used, 0 V
26 Rear O2 heater control
27 not used, 0 V
28 Idle air control
29 Idle air control
30 A/C condenser fan control high
31 A/C condenser fan control low
32 MIVEC valve control
33 not used, 0 V
34 Sensor ground
35 Evaporative ventilation solenoid relay ground (control)
Pin Color Description
41 Waste gate solenoid relay ground (control)
42 TPS power (+5 V)
43 Crankshaft position sensor signal
44 Coolant sensor signal
45 RPM
46 Ground to Chassis
47 12 V Power (via MFI relay, likely follows IG1)
48 Fuel pressure solenoid ground (control)
49 Sensor ground
50 Exhaust cam position sensor signal
51 MAF barometric pressure sensor signal
52 Alternator signal?
53 Intake cam position sensor signal
54 Power steering pressure sensor signal
55 Fuel pump relay ground (control)
56 not used, relay (ICS relay ground on JDM Evo IXs)
57 MFI relay ground (control)
58 Ground to chassis
59 12 V Power (via MFI relay, likely follows IG1)
60 Power from battery (always live)
61 MAF sensor signal
62 IAT sensor signal
63 not used, 0 V
64 not used, ADC 0F, 5 V = 255 (read by ECU but unused in code)
65 A/C control
66 not used, active +11.75 V power out (ICS power on JDM Evo IXs)
67 not used, active +11.75 V power out (ICS power on JDM Evo IXs)
68 Starter relay signal
Pin Color Description
71 Front O2 sensor signal
72 not used, causes ADC 08 to flip from 0 to 1 when 1.7 V applied
73 Rear O2 sensor signal
74 not used, 0 V
75 not used, 0.51 V
76 not used, 0 V
77 not used, 0 V
78 TPS signal
79 ACD
80 Vehicle Speed Sensor signal
81 not used, 0 V
82 not used, 0 V
83 A/C control
84 not used, +4.6 V
85 Data link
86 not used, 0 V
87 not used, 0 V
88 Clutch pedal
89 not used, 0 V
90 not used, relay, (ICS relay ground on JDM Evo IXs)
91 Knock sensor signal
92 MAP sensor signal
93 Fuel tank differential pressure sensor signal
94 not used, 0 V
95 Fuel level sensor signal (main)
96 Fuel temperature sensor signal
97 Fuel level sensor signal (low fuel)
98 Immobilizer
99 Ignition Switch IG1 (power during ignition "ON" and "START")
100 Data link
