Engine Control Module Connector End Views

Connector 1:	Engine Control Module (ECM) C1
Connector 2:	Engine Control Module (ECM) C2
Connector 3:	Engine Control Module (ECM) C3

Engine Control Module (ECM) C1

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Connector Part Information

OEM: 12582680
Service: 88988373
Description: 56-Way F (BU with BK case)

Terminal Part Information

Pins: 6, 7, 9, 12, 13, 18, 19, 20, 33, 34, 35, 36, 37, 40, 44, 47, 48, 49, 53, 54, 55, 56
Terminal/Tray: See Terminal Repair Kit
Core/Insulation Crimp: See Terminal Repair Kit
Release Tool/Test Probe: See Terminal Repair Kit

Engine Control Module (ECM) C1

Pin	Wire Color	Circuit No.	Function
1-5	--	--	Not Used
6	BN/WH	379	CPP Switch Signal (MA5)
7	L-BU	20	Stop Lamp Supply Voltage
8	--	--	Not Used
9	TN	2759	Low Reference
10-11	--	--	Not Used
12	BN/WH	419	MIL Control
13	D-GN/WH	465	Fuel Pump Relay Control
14-17	--	--	Not Used
18	BN	4	Accessory Voltage
19	PK	1039	Ignition 1 Voltage
20	RD/WH	840	Battery Positive Voltage
21-32	--	--	Not Used
33	WH/BK	1164	5-Volt Reference
34	GY	2709	5-Volt Reference
35	TN	1274	5-Volt Reference
36	BN	1271	Low Reference
37	PU	1272	Low Reference
38-39	--	--	Not Used
40	BN	5069	Main Relay Control
41-43	--	--	Not Used
44	PU	1589	Fuel Level Sensor Signal
45-46	--	--	Not Used
47	D-BU	1161	APP Sensor 1 Signal
48	D-GN	890	Fuel Tank Pressure Sensor Signal
49	L-BU	1162	APP Sensor 2 Signal
50-52	--	--	Not Used
53	D-GN/WH	459	A/C Compressor Clutch Relay Control (C60)
54	D-BU	473	High Speed Cooling Fan Relay Control
55	WH	1310	EVAP Canister Vent Solenoid Control
56	YE	447	Starter Relay Coil Control

Engine Control Module (ECM) C2

Connector Part Information

OEM: 12582677
Service: 88988931
Description: 73-Way F (BK)

Terminal Part Information

Pins: 1, 2, 3, 4, 5, 8, 9, 11, 12, 13, 14, 17, 20, 23, 27, 29, 30, 32, 33, 35, 36, 39, 42, 43, 44, 46, 48, 50, 53, 56, 59, 62, 63, 64, 66, 67, 68, 69, 71, 72
Terminal/Tray: See Terminal Repair Kit
Core/Insulation Crimp: See Terminal Repair Kit
Release Tool/Test Probe: See Terminal Repair Kit

Pins: 73
Terminal/Tray: 7116-4152-02/9
Core/Insulation Crimp: 2/5
Release Tool/Test Probe: 12094430/J-35616-35 (VT)

Engine Control Module (ECM) C2

Pin	Wire Color	Circuit No.	Function
1	PU	2121	IC 1 Control
2	TN/WH	3111	HO2S Low Reference Sensor 1
3	PU/WH	3110	HO2S Reference Voltage Sensor 1
4	PU/WH	1668	HO2S High Signal Sensor 2
5	TN/WH	1669	HO2S Low Signal Sensor 2
6-7	--	--	Not Used
8	D-BU	496	Knock Sensor 1 Signal
9	GY	1716	Knock Sensor Signal Return
10	--	--	Not Used
11	YE	581	TAC Motor Control - 1
12	BN	582	TAC Motor Control - 2
13	PK/BK	5290	Ignition 1 Voltage
14	PU	5284	Camshaft Phaser Intake Solenoid (1)
15-16	--	--	Not Used
17	L-BU	2123	IC 3 Control
18-19	--	--	Not Used
20	GY	5296	Low Reference
21-22	--	--	Not Used
23	TN	5301	Low Reference
24-26	--	--	Not Used
27	PU	574	Low Reference
28	--	--	Not Used
29	TN	2752	Low Reference
30	L-GN	5282	Camshaft Phaser Exhaust Solenoid (1)
31	--	--	Not Used
32	L-GN/BK	1745	Fuel Injector 2 Control
33	D-GN/WH	2124	IC 4 Control
34	--	--	Not Used
35	BN	2129	Low Reference
36	YE/BK	5297	5-Volt Reference
37-38	--	--	Not Used
39	D-BU	5300	5-Volt Reference
40-41	--	--	Not Used
42	BK	2760	Low Reference
43	L-GN	2867	5-Volt Reference
44	GY	2701	5-Volt Reference
45	--	--	Not Used
46	TN	2199	Low Reference
47	--	--	Not Used
48	PK/BK	1746	Fuel Injector 3 Control
49	--	--	Not Used
50	TN	452	Low Reference
51-52	--	--	Not Used
53	OG/WH	2122	IC 2 Control
54-55	--	--	Not Used
56	D-GN	5273	Camshaft Position Exhaust Sensor (1)
57-58	--	--	Not Used
59	OG	5275	Camshaft Position Intake Sensor (1)
60-61	--	--	Not Used
62	TN	472	IAT Sensor Signal
63	YE	573	CKP Sensor 1 Signal
64	D-GN	485	TP Sensor Signal
65	--	--	Not Used
66	PU	486	TP Sensor 2 Signal
67	YE	492	MAF Sensor Signal
68	GY/WH	3113	HO2S Heater Low Control Sensor 1
69	GY/WH	3122	HO2S Heater Low Control Sensor 2
70	--	--	Not Used
71	L-BU/BK	844	Fuel Injector 4 Control
72	BK	1744	Fuel Injector 1 Control
73	BK/WH	451	Ground

Engine Control Module (ECM) C3

Connector Part Information

OEM: 12582678
Service: 15497996
Description: 73-Way F MX 123 Harness Connector Assembly (GY with BK case)

Terminal Part Information

Pins: 7, 21, 23, 28, 29, 33, 35, 37, 39, 44, 46, 47, 48, 49, 53, 55, 57, 59, 65, 66, 67
Terminal/Tray: See Terminal Repair Kit
Core/Insulation Crimp: See Terminal Repair Kit
Release Tool/Test Probe: See Terminal Repair Kit

Engine Control Module (ECM) C3

Pin	Wire Color	Circuit No.	Function
1-6	--	--	Not Used
7	OG	225	Generator Turn On Signal
8-20	--	--	Not Used
21	BK/WH	2751	Low Reference (C60)
22	--	--	Not Used
23	OG/BK	469	Low Reference
24-27	--	--	Not Used
28	TN/WH	1704	Low Reference
29	GY	23	Generator Field Duty Cycle Signal
30-32	--	--	Not Used
33	TN	2501	High Speed GMLAN Serial Data Bus (-)
34	--	--	Not Used
35	TN	2761	Low Reference
36	--	--	Not Used
37	GY	2700	5-Volt Reference (C60)
38	--	--	Not Used
39	GY	2704	5-Volt Reference
40-43	--	--	Not Used
44	L-BU/BK	1688	5-Volt Reference
45	--	--	Not Used
46	OG/BK	1786	Transmission Park/Neutral Signal (1) (M82)
47	D-GN	1433	PNP/Clutch Start Switch Signal
48	D-GN/WH	428	EVAP Canister Purge Solenoid Control
49	D-GN	335	Low Speed Cooling Fan Relay Control
50-52	--	--	Not Used
53	TN/BK	2500	High Speed GMLAN Serial Data Bus (+)
54	--	--	Not Used
55	YE	410	ECT Sensor Signal
56	--	--	Not Used
57	OG/BK	380	A/C Refrigerant Pressure Sensor Signal (C60)
58	--	--	Not Used
59	L-GN	432	MAP Sensor Signal
60-64	--	--	Not Used
65	TN/BK	231	Oil Pressure Switch Signal
66	YE	400	VSS High Signal (MA5)
67	PU	401	VSS Low Signal (MA5)
68-73	--	--	Not Used