Engine Control Module (ECM) C3 Connector End View

Courtesy of GENERAL MOTORS CORP.
Connector Part Information		15418476 56-Way F Micro 64 Series (GY)
Pin	Wire Color	Circuit No.	Function
1	PU	1666	HO2S High Signal - Bank 2 Sensor 1
2	TN	1667	HO2S Low Signal - Bank 2 Sensor 1
3	PU/WH	5281	HO2S Output Pump Current Bank 1 Sensor 1
4-11	-	-	Not Used
12	D-BU	1936	Fuel Level Sensor Signal - Secondary
13	YE	5036	HO2S Heater Low Control - Bank 1 Sensor 2
14	OG/BK	463	Requested Torque Signal
15	-	-	Not Used
16	PU	5035	HO2S Heater Low Control - Bank 2 Sensor 2
17	TN/BK	464	Delivered Torque Signal
18	OG/BK	1786	Ignition Lock Cylinder Control Actuator Signal
19	TN	1671	HO2S Low Signal - Bank 2 Sensor 2
20	PU/WH	1668	HO2S High Signal - Bank 2 Sensor 2
21	TN/WH	1669	HO2S Low Signal - Bank 2 Sensor 2
22	OG	5280	HO2S Input Pump Current Bank 1 Sensor 1
23	BN	1174	Oil Level Switch Signal
24	L-BU	1937	Fuel Gage Sensor - Signal - Right
25	TN/WH	331	Oil Pressure Sensor Signal
26-36	-	-	Not Used
37	TN	452	Low Reference
38	BK	2755	Low Reference
39	-	-	Not Used
40	PU/WH	5037	HO2S Heater Low Control - Bank 1 Sensor 1
41	L-BU	5038	HO2S Heater Low Control - Bank 2 Sensor 1
42	GY	2709	5-Volt Reference
43	PU	1670	HO2S High Signal - Bank 2 Sensor 2
44	D-GN	890	Fuel Tank Pressure Sensor Signal
45	PU/WH	1665	HO2S High Signal - Bank 1 Sensor 1
46	TN/WH	1653	HO2S Low Signal - Bank 1 Sensor 1
47	-	-	Not Used
48	WH	5279	HO2S Output Pump Current Bank 2 Sensor 1
49	L-GN	5278	HO2S Input Pump Current Bank 2 Sensor 1
50	-	-	Not Used
51	GY	2705	5-Volt Reference
52-56	-	-	Not Used