Home ECU Pinouts LS1 ECU Pinout – 1999-2002

LS1 ECU Pinout – 1999-2002

September 15, 2014

This LS1 ECU pinout reference is intended for 1999–2002 Camaro and Firebird (F-body) LS1 applications with cable-operated throttle. It does not cover Corvette, 1998 F-body, truck PCMs or electronic-throttle conversions. Transmission, emissions equipment and harness modifications can change which circuits are present.

Updated November 10, 2026: Four joined pin entries have been separated and both legacy lists have been reformatted as tables. Wire colors, circuit numbers and function assignments have been preserved. This formatting repair is not a full factory-diagram validation.

Connector orientation and how to read the tables

The photographs below show the harness connectors from the wire-entry side, attached to the PCM. They are reference photographs, not numbered terminal-face diagrams. Do not count cavities from a photograph or assume that a terminal-face illustration has the same left-to-right order as the wire side. Match the molded cavity numbers and the viewing direction in the exact-year service connector end view before probing or moving a terminal.

The pin column identifies the PCM connector cavity. A component terminal such as CKP pin “C” in the function column refers to the sensor or component connector, not another PCM cavity. Grouped ranges retain the original article’s entries; “Not Used” is not proof that the cavity is unused in every 1999–2002 configuration.

Service information and known year differences

Use GM/ACDelco Technical Delivery System for the matching vehicle’s service-information offering. Confirm the model year, engine, transmission, PCM identification and connector end view. The service documents themselves were not accessed during this repair.

For a separate specialist cross-check, LT1Swap’s 1999–2002 F-body reference identifies C1 as blue and C2 as red and agrees with the four separated entries. It also lists EGR-related circuits at blue cavities 47 and 55, while the legacy table below marks them “Not Used.” Treat those two legacy entries as application-dependent and verify them against exact-year factory information before use. The source is a specialist reference, not a GM service document.

Let’s start with the BLUE connector found on your LS1 Powertrain Control Module (PCM) and work our way through all the ECU pinouts.

Make sure to check out our related LS1 articles below as well.

Blue PCM connector — legacy pin assignments

Legacy blue PCM connector assignments — confirm exact-year service information
Pin	Wire color	Circuit number	Function / component terminal
1	BLK	451	PCM Ground
2	LT GRN	1867	12 Volt Reference- CKP Pin “C”
3	PNK/BLK	1746	Fuel Injector 3 Control
4	LT GRN/BLK	1745	Fuel Injector 2 Control
5-7	—	—	Not Used
8	GRA	596	5 Volt Reference TPS Pin “A”
9-10	—	—	Not Used
11	LT BLU	1876	KS [2] Signal Rear Sensor Pin “B”
12	DK BLU/WHT	1869	CKP Sensor Signal Pin “A”
13-16	—	—	Not Used
17	DK BLU	1225	Transmission Fluid Pressure Switch Signal B Pin “R”
18	RED	1226	Transmission Fluid Pressure Switch Signal C Pin “P”
19	PNK	439	Ignition 1 Voltage
20	ORN	340	Battery Positive Voltage
21	YEL/BLK	1868	Low Reference CKP Pin “B”
22	—	—	Not Used
23	GRA	720	Low Reference Fuel Level Sensor (Factory)
24	—	—	Not Used
25	TAN	1671	HO2S Low Signal [Bank 2 Sensor 2]
26	TAN	1667	HO2S Low Signal [Bank 2 Sensor 1]
27	—	—	Not Used
28	TAN/WHT	1669	HO2S Low Signal [Bank 1 Sensor 2]
29	TAN/WHT	1653	HO2S Low Signal [Bank 1 Sensor 1]
30-31	—	—	Not Used
32	GRA	48	CPP Switch Signal (Manual Trans.)
33	PPL	420	TCC Brake Switch Signal (Auto. Trans)
34	ORN/BLK	434	Neutral Safety Switch Signal
35	—	—	Not Used
36	BLK	1744	Fuel Injector 1 Control
37	YEL/BLK	846	Fuel Injector 6 Control
38-39	—	—	Not Used
40	BLK	451	Ground
41	—	—	Not Used
42	DK GRN	335	Low Speed Cooling Fan Relay Control (Primary fan)
43	RED/BLK	877	Fuel Injector 7 Control
44	LT BLU/BLK	844	Fuel Injector 4 Control
45	GRA	474	5 Volt Reference (A/C Refrigerant Pressure Sensor) (Factory)
46	GRA	474	5 Volt Reference (Fuel Tank Pressure Sensor) (Factory)
47	—	—	Not Used
48	GRA	416	5 Volt Reference (MAP Sensor) Pin “C”
49-50	—	—	Not Used
51	DK BLU	496	KS [1] Signal Front sensor Pin “A”
52	—	—	Not Used
53	BLK	407	Low Reference (Transmission Temperature Sensor) Pin “M”
54	BLK	407	Low Reference (MAP Sensor Ground) Pin “A”
55	—	—	Not Used
56	—	—	Not Used
57	ORN	340	Battery Positive Voltage
58	DK GRN	1049	ECM/PCM/VCM Class 2 Serial Data
59	—	—	Not Used
60	BLK	452	Low Reference TPS Pin “B”
61	PNK/BLK	632	Low Reference (Camshaft Position Sensor) Pin “B”
62-64	—	—	Not Used
65	PPL	1670	HO2S High Signal [Bank 2 Sensor 2]
66	PPL	1666	HO2S High Signal [Bank 2 Sensor 1]
67	—	—	Not Used
68	PPL/WHT	1668	HO2S High Signal [Bank 1 Sensor 2]
69	PPL/WHT	1665	HO2S High Signal [Bank 1 Sensor 1]
70	BRN	1174	Oil Level Switch Signal
71-72	—	—	Not Used
73	BRN/WHT	633	CMP Sensor Signal Pin “A”
74	YEL	410	ECT Sensor Signal Pin “B”
75	—	—	Not Used
76	BLK/WHT	845	Fuel Injector 5 Control
77	DK BLU/WHT	878	Fuel Injector 8 Control
78	—	—	Not Used
79	GRA or WHT	587 or 687	Skip Shift Solenoid Control (M/T) or 3-2 Shift Solenoid Control (A/T) Pin “S”
80	BLK	407	Low Reference ECT Pin “A”

Red PCM connector — legacy pin assignments

Legacy red PCM connector assignments — confirm exact-year service information
Pin	Wire color	Circuit number	Function / component terminal
1	BLK	451	Ground
2	BRN	418	TCC Solenoid – Output – PWM Pin “U”
3	—	—	Not Used
4	PNK/BLK	429	Air Injection Reaction Solenoid Relay – Coil – Control
5	—	—	Not Used
6	RED/BLK	1228	PC Solenoid Valve High Control (Sol.A) Pin “C”
7	—	—	Not Used
8	LT BLU/WHT	1229	PC Solenoid Valve Low Control (Sol.A) Pin “D”
9	DK GRN/WHT	465	Fuel Pump Relay Control [Primary]
10	WHT	121	Engine Speed Signal- Tachometer
11-12	—	—	Not Used
13	WHT	85	Cruise Control Engage Signal
14	RED/BLK	380	A/C Refrigerant Pressure Sensor Signal
15	RED	225	Generator Turn ON Signal
16	—	—	Not Used
17	DK GRN/WHT	762	A/C Request Signal
18	DK GRN	59	A/C Compressor Clutch Supply Voltage
19	—	—	Not Used
20	LT GRN/BLK	822	VSS Low Signal
21	PPL/WHT	821	VSS High Signal
22-23	—	—	Not Used
24	DK BLU	417	TPS Sensor Signal Pin “C”
25	TAN	472	IAT Sensor Signal Pin “B”
26	PPL	2121	IC 1 Control
27	RED	2127	IC 7 Control
28	LT BLU/WHT	2126	IC 6 Control
29	DK GRN/WHT	2124	IC 4 Control
30	DK BLU	229	Fuel Enable Control
31	YEL	492	MAF Sensor Signal Pin “A”
32	LT GRN	432	MAP Sensor Signal Pin “B”
33	DK BLU	473	High Speed Cooling Fan Relay Control
34	DK GRN/WHT	428	EVAP Canister Purge Solenoid Control
35	—	—	Not Used
36	BRN	436	AIR Pump Relay Control
37	DK GRN	83	Cruise Control Inhibit Signal
38	—	—	Not Used
39	RED	631	12 Volt Reference CMP Pin “C”
40	BLK	451	Ground
41	—	—	Not Used
42	TAN/BLK	422	TCC Solenoid Valve Control Pin “T”
43	DK GRN/WHT	459	A/C Clutch Relay Control
44	LT GRN	1652	Reverse Lock Out Solenoid Control
45	WHT	1310	EVAP Canister Vent Solenoid Control
46	BRN/WHT	419	MIL Control
47	YEL/BLK	1223	2 – 3 Shift Solenoid Valve Control Pin “B”
48	LT GRN	1222	1 – 2 Shift Solenoid Valve Control Pin “A”
49	—	—	Not Used
50	DK GRN/WHT	817	VSS Signal
51	YEL/BLK	1227	TFT Sensor Signal Pin “L”
52	—	—	Not Used
53	GRA/BLK	1687	Ignition Retard Signal EBCM only (Factory)
54	PPL	1589	Fuel Level Sensor Signal (Factory)
55-56	—	—	Not Used
57	PPL	719	Low Reference IAT Pin “A”
58-59	—	—	Not Used
60	BRN	2129	Low Reference Ignition Coils bank 1 (1-3-5-7)
61	BRN/WHT	2130	Low Reference Ignition Coils Bank 2 (2-4-6-8)
62	—	—	Not Used
63	PNK	1224	Transmission Fluid Pressure Switch Signal A Pin “N”
64	DK GRN	890	Fuel Tank Pressure Sensor Signal (Factory)
65	—	—	Not Used
66	PPL/WHT	2128	IC 8 Control
67	RED/WHT	2122	IC 2 Control
68	DK GRN	2125	IC 5 Control
69	LT BLU	2123	IC 3 Control
70-75	—	—	Not Used
76	LT GRN/WHT	1749	IAC Coil B High Control Pin “B”
77	LT GRN/BLK	444	IAC Coil B Low Control Pin “A”
78	LT BLU/BLK	1748	IAC Coil A Low Control Pin “C”
79	LT BLU/WHT	1747	IAC Coil A High Control Pin “D”
80	—	—	Not Used