Engine Control Module (ECM) Connectors

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Engine Control Module (ECM) - C1

Courtesy of GENERAL MOTORS CORP.
Connector Part Information		15357147 56-Way F Micro 64 (BLU)
Pin	Wire Color	Circuit No.	Function
1	YEL	2361	SAE J1939 Serial Data Bus +
2	DK GRN	2362	SAE J1939 Serial Data Bus -
3-4	-	-	Not Used
5	ORN	440	Battery Positive Voltage
6	-	-	Not Used
7	ORN/BLK	1057	Low Reference
8	PNK/BLK	632	Low Reference
9	BLK/WHT	451	Ground
10	PNK	439	Ignition 1 Voltage
11-12	-	-	Not Used
13	YEL	492	MAF Sensor Signal
14	BRN/WHT	5763	EGR Valve Position Signal
15	DK GRN	1049	Class 2 Serial Data
16	YEL	710	Class 2 Serial Data
17	TAN	1274	5-Volt Reference
18	PNK	1020	Ignition 0 Voltage (M74)
19	PNK	439	Ignition 1 Voltage
20	ORN	440	Battery Positive Voltage
21	GRY	2700	5-Volt Reference
22	-	-	Not Used
23	ORN/BLK	5929	5-Volt Reference
24-25	-	-	Not Used
26	DK BLU	507	Wait to Start Indicator Control
27	-	-	Not Used
28	LT BLU	1162	APP Sensor 2 Signal
29	-	-	Not Used
30	PPL/WHT	1589	Fuel Level Sensor Signal - Primary
31	WHT/BLK	2932	5-Volt Reference
32	WHT/BLK	1164	5-Volt Reference
33	TAN	2917	5-Volt Reference
34	GRY	2705	5-Volt Reference
35	-	-	Not Used
36	YEL/BLK	1275	5-Volt Reference
37	YEL	2834	Fuel Pressure Regulator Solenoid Control
38	-	-	Not Used
39	GRY	597	5-Volt Reference
40	PPL/WHT	2530	Fuel Pressure Regulator Solenoid Supply Voltage
41	GRY	23	Generator Field Duty Cycle Signal
42	PNK	1039	Ignition 1 Voltage
43	DK BLU	1936	Fuel Level Sensor Signal - Secondary
44	DK GRN/WHT	465	Fuel Pump Relay Control
45	-	-	Not Used
46	YEL/BLK	1827	Vehicle Speed Sensors
47	GRY	2703	5-Volt Reference
48-49	-	-	Not Used
50	RED	631	5-Volt Reference
51	YEL	2834	Fuel Pressure Regulator Solenoid Control
52	GRY/BLK	2219	FICM Relay Control
53	DK GRN/WHT	817	Vehicle Speed Signal
54	PPL/WHT	2530	Fuel Pressure Regulator Solenoid Supply Voltage
55	-	-	Not Used
56	PNK	1039	Ignition 1 Voltage

Engine Control Module (ECM) - C2

Courtesy of GENERAL MOTORS CORP.
Connector Part Information		15357131 73-Way F Micro 64 (BLK)
Pin	Wire Color	Circuit No.	Function
1	-	-	Not Used
2	ORN/BLK	2919	Low Reference
3	-	-	Not Used
4	BRN	25	Charge Indicator Control
5-6	-	-	Not Used
7	GRY/BLK	1694	4WD Low Signal
8	BLK	2754	Low Reference
9-12	-	-	Not Used
13	BLK	2751	Low Reference
14	GRY	720	Low Reference
15-16	-	-	Not Used
17	YEL/BLK	508	Water in Fuel Indicator Control
18	-	-	Not Used
19	DK BLU	1161	APP Sensor 1 Signal
20	-	-	Not Used
21	DK BLU	2466	Trans MIL Request
22	-	-	Not Used
23	LT GRN	432	Turbocharger Boost Sensor Signal
24	DK GRN	1163	APP Sensor 3 Signal
25	TAN/WHT	332	Oil Pressure Sensor Signal
26	BRN	1174	Oil Level Switch Signal
27	YEL	1578	Fuel Temperature Signal
28	LT GRN	1867	12-Volt Reference
29	GRY/BLK	2931	Low Reference
30	ORN/BLK	469	Low Reference
31	YEL	5775	Turbocharger Vane Position Sensor Signal
32	-	-	Not Used
33	ORN/BLK	5764	EGR Motor High Control
34	-	-	Not Used
35	LT GRN/ BLK	5746	EGR Motor Low Control
36	BLK/WHT	451	Ground
37	-	-	Not Used
38	LT GRN	1478	Coolant Level Switch Signal
39	BLK	2755	Low Reference
40	BRN	1271	Low Reference
41	-	-	Not Used
42	YEL	2918	FRP Sensor Signal
43	-	-	Not Used
44	TAN	5928	Low Reference
45	-	-	Not Used
46	GRY/BLK	433	Baro Sensor Signal
47-48	-	-	Not Used
49	DK BLU	5930	Turbocharger Vane Position Control Solenoid Valve High Control
50	WHT	5931	Low Reference
51	-	-	Not Used
52	PNK/BLK	1746	Fuel Injector 3 Control
53	ORN/BLK	5764	EGR Motor High Control
54	PPL	1272	Low Reference
55	LT GRN/ BLK	5746	EGR Motor Low Control
56	GRY	1273	Low Reference
57	BRN	2524	Generator 2 Turn on Signal (K65 or 8X5)
58	BLK	552	Low Reference
59	-	-	Not Used
60	LT BLU	1320	CHMSL Supply Voltage
61	PPL	420	TCC Brake Switch/Cruise Control Release Signal
62	-	-	Not Used
63	LT BLU	2832	Engine Speed Signal
64	BLK	470	Low Reference
65	LT GRN/BLK	1745	Fuel Injector 2 Control
66	RED/BLK	877	Fuel Injector 7 Control
67	YEL	410	ECT Sensor Signal
68	DK BLU/WHT	878	Fuel Injector 8 Control
69	LT BLU/BLK	844	Fuel Injector 4 Control
70	BLK/WHT	845	Fuel Injector 5 Control
71	YEL/BLK	846	Fuel Injector 6 Control
72	BLK	1744	Fuel Injector 1 Control
73	BLK/WHT	451	Ground

Engine Control Module (ECM) - C3

Courtesy of GENERAL MOTORS CORP.
Connector Part Information		15357148 56-Way F Micro 64 (GRY)
Pin	Wire Color	Circuit No.	Function
1	LT BLU	494	PTO Engine Kill Signal (PTO)
2-4	-	-	Not Used
5	GRY/BLK	5765	Fuel Filter Pressure Switch Signal
6	LT GRN	488	PTO on Switch Signal (PTO)
7	-	-	Not Used
8	BLK/WHT	1695	Front Axle Switch Signal
9	-	-	Not Used
10	PNK	1039	Ignition 1 Voltage
11	-	-	Not Used
12	PPL/WHT	821	VSS High Signal (ML6)
12	YEL	400	VSS High Signal (M74)
13	-	-	Not Used
14	PNK	1039	Ignition 1 Voltage
15-16	-	-	Not Used
17	YEL	2522	PTO Engage Signal (PTO)
18	PPL	806	Crank Voltage
19	DK BLU	84	Cruise Control Set/Coast Switch Signal (K34)
20-21	-	-	Not Used
22	GRY/BLK	87	Cruise Control Resume/Accel Switch Signal (K34)
23	LT GRN/BLK	822	VSS Low Signal (ML6)
24	TAN	472	IAT Sensor Signal
25-29	-	-	Not Used
30	GRY	397	Cruise Control on Switch Signal (K34)
31	ORN/BLK	1786	Park/Neutral Signal
32	-	-	Not Used
33	RED/BLK	380	A/C Refrigerant Pressure Sensor Signal
34	-	-	Not Used
35	YEL/BLK	625	Starter Enable Relay Control
36	-	-	Not Used
37	WHT	121	Engine Speed Signal
38	-	-	Not Used
39	PPL	2562	PTO Control (PTO)
40	BRN/WHT	419	MIL Control
41	DK GRN/WHT	459	A/C Compressor Clutch Relay Control
42	-	-	Not Used
43	YEL/BLK	1868	Low Reference
44	BLK/WHT	451	Ground
45	GRY	1524	Backup Lamp Supply Voltage
46	-	-	Not Used
47	GRY	48	CPP Switch Signal (ML6)
48	BRN	718	Low Reference
49-50	-	-	Not Used
51	BRN/WHT	633	CMP Sensor Signal
52	DK BLU/WHT	1869	CKP Sensor Signal
53	YEL	505	Glow Plug Control
54-56	-	-	Not Used