Engine Control Module (ECM) Connectors

WARNING: This page is about a different variant/trim than selected.

Engine Control Module (ECM) C1

Courtesy of GENERAL MOTORS CORP.
Connector Part Information		OEM: 34566-4403 (Molex) Service: See Catalog 73-Way F MX123 Harness Connector Assembly (BK)
Pin	Wire Color	Circuit No.	Function
1-3	-	-	Not Used
4	PU/WH	1035	Starter Relay Coil Supply Voltage
5	-	-	Not Used
6	GY	48	CPP Switch Signal
7-8	-	-	Not Used
9	WH	17	Stop Lamp Switch Signal
10	PU/WH	1668	HO2S High Signal Bank 1 Sensor 2
11	TN/WH	1669	HO2S Low Signal Bank 1 Sensor 2
12	OG/BK	380	A/C Refrigerant Pressure Sensor Signal
13	BK/WH	2751	Low Reference
14-15	-	-	Not Used
16	D-BU	1936	Fuel Level Sensor Signal - Secondary
17	-	-	Not Used
18	YE	43	Accessory Voltage
19	PK	1439	Ignition 1 Voltage
20	RD/WH	2440	Battery Positive Voltage
21-22	-	-	Not Used
23	PU	1272	Low Reference
24	D-GN	890	Fuel Tank Pressure Sensor Signal
25-26	-	-	Not Used
27	TN	2501	ECM High Speed GMLAN Serial Data Bus -
28	TN/BK	2500	ECM High Speed GMLAN Serial Data Bus +
29	D-BU	1161	APP Sensor 1 Signal
30	BN	1271	Low Reference
31	TN	2759	Low Reference
32	L-BU	1162	APP Sensor 2 Signal
33	GY	2709	5-Volt Reference
34	GY	2700	5-Volt Reference
35	-	-	Not Used
36	TN	1274	5-Volt Reference
37	TN	472	IAT Sensor Signal
38	TN	2760	Low Reference
39-40	-	-	Not Used
41	YE	492	MAF Sensor Signal
42-46	-	-	Not Used
47	PK	439	Ignition 1 Voltage
48	WH	121	Engine Speed Signal
49	TN	1671	HO2S Low Signal Bank 2 Sensor 2
50	D-GN/WH	465	Fuel Pump Relay Control
51-55	-	-	Not Used
56	WH/BK	1164	5-Volt Reference
57	D-GN/WH	817	Vehicle Speed Signal
58	D-GN	335	Cooling Fan Relay Control
59	WH/BK	448	Ignition 1 Relay Control
60	-	-	Not Used
61	WH	1310	EVAP Canister Vent Solenoid Control
62	-	-	Not Used
63	D-GN/WH	459	A/C Compressor Clutch Relay Control
64	OG/WH	3223	HO2S Heater Low Control Bank 2 Sensor 2
65	BN	2391	HO2S Heater Low Control Bank 1 Sensor 2
66	GY	587	Skip/Shift Solenoid Control
67	YE/BK	625	Starter Enable Relay Control
68	BN/WH	419	MIL Control
69	PU	1670	HO2S High Signal Bank 2 Sensor 2
70	L-BU	1937	Fuel Level Sensor Signal - Right
71	YE	400	VSS High Signal
72	PU	401	VSS Low Signal
73	BK/WH	451	Ground

Engine Control Module (ECM) C2

Courtesy of GENERAL MOTORS CORP.
Connector Part Information		OEM: 34566-4503 (Molex) Service: See Catalog 80-Way F MX123 Harness Connector Assembly (GY)
Pin	Wire Color	Circuit No.	Function
1	-	-	Not Used
2	L-GN	1867	5-Volt Reference
3	L-BU/BK	1688	5-Volt Reference
4	-	-	Not Used
5	BN	582	TAC Motor Control - 2
6	YE	581	TAC Motor Control - 1
7	-	-	Not Used
8	D-GN/WH	428	EVAP Canister Purge Solenoid Valve Control
9-10	-	-	Not Used
11	L-GN	1652	Reverse Lockout Solenoid Control
12	GY/WH	3113	HO2S Heater Low Control Bank 1 Sensor 1
13	L-GN	3212	HO2S Heater Low Control Bank 2 Sensor 1
14-16	-	-	Not Used
17	D-BU/WH	878	Fuel Injector 8 Control
18	TN/WH	845	Fuel Injector 5 Control
19	YE/BK	846	Fuel Injector 6 Control
20	TN	1744	Fuel Injector 1 Control
21	YE	410	ECT Sensor Signal
22	TN	2761	Low Reference
23	TN/WH	585	Transmission Fluid Temperature Sensor Signal
24	OG/BK	586	Transmission Fluid Temperature Sensor Low Reference
25	-	-	Not Used
26	D-BU	496	Knock Sensor 1 Signal
27	GY	1716	Low Reference
28	-	-	Not Used
29	L-BU	1876	Knock Sensor 2 Signal
30	GY	2303	Low Reference
31	-	-	Not Used
32	GY	23	Generator Field Duty Cycle Signal
33	-	-	Not Used
34	BK	2755	Low Reference
35	TN/WH	1704	Low Reference
36	-	-	Not Used
37	L-GN/BK	1745	Fuel Injector 2 Control
38	PK/BK	1746	Fuel Injector 3 Control
39	L-BU/BK	844	Fuel Injector 4 Control
40	OG/BK	877	Fuel Injector 7 Control
41	GY	2705	5-Volt Reference
42	-	-	Not Used
43	GY	2704	5-Volt Reference
44	OG	631	5-Volt Reference
45-49	-	-	Not Used
50	TN/WH	331	Oil Pressure Sensor Signal
51-52	-	-	Not Used
53	OG/BK	469	Low Reference
54-55	-	-	Not Used
56	TN	1664	HO2S Low Signal Bank 1 Sensor 1
57	PU/WH	1665	HO2S High Signal - Bank 1 Sensor 1
58	L-GN	432	MAP Sensor Signal
59	PU	1666	HO2S High Signal Bank 2 Sensor 1
60	TN	1667	HO2S Low Signal Bank 2 Sensor 1
61	OG	225	Generator Turn On Signal
62	-	-	Not Used
63	PU	486	TP Sensor 2 Signal
64	BN/WH	633	CMP Sensor Signal
65	D-GN	485	TP Sensor 1 Signal
66	PK/BK	632	Low Reference
67	-	-	Not Used
68	D-BU/WH	1869	CKP Sensor Signal
69	YE/BK	1868	Low Reference
70	PU	2121	IC 1 Control
71	PU/WH	2128	IC 8 Control
72	OG	2127	IC 7 Control
73	OG/WH	2122	IC 2 Control
74	L-BU/WH	2126	IC 6 Control
75	D-GN	2125	IC 5 Control
76	D-GN	2124	IC 4 Control
77	L-BU	2123	IC 3 Control
78	BN	2129	Low Reference
79	BN/WH	2130	Low Reference
80	-	-	Not Used