Engine Control Module (ECM) X1 (LS4)

WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Engine Control Module (ECM) X1 (LS4) Connector End View

Courtesy of GENERAL MOTORS CORP.

Pin	Wire	Circuit	Function
1-6	-	-	Not Used
7	0.5 WH	17	Stop Lamp Switch Signal
8	-	-	Not Used
9	0.35 BK	2759	Low Reference
10-11	-	-	Not Used
12	0.35 BN/WH	419	MIL Control
13	0.35 D-GN/WH	465	Fuel Pump Relay Control
14-15	-	-	Not Used
16	0.35 D-GN	1049	ECM Class 2 Serial Data
17	-	-	Not Used
18	0.35 BN	1141	Accessory Voltage
19	0.5 PK	439	Ignition 1 Voltage
20	0.5 OG	540	Battery Positive Voltage
21-24	-	-	Not Used
25	0.35 WH	121	Engine Speed Signal
26-28	-	-	Not Used
29	0.5 GY	1884	Cruise Control Switch Signal
30-31	-	-	Not Used
32	0.35 GY	6031	5-Volt Reference 2
33	0.35 WH/BK	1164	5-Volt Reference 1
34	0.35 GY	2709	5-Volt Reference 1
35	0.35 TN	1274	5-Volt Reference 2
36	0.35 BN	1271	Low Reference
37	0.35 PU	1272	Low Reference
38	-	-	Not Used
39	0.35 D-GN	389	Vehicle Speed Signal
40	0.35 BN	5069	Powertrain Relay Control
41-43	-	-	Not Used
44	0.35 PU	1589	Fuel Level Sensor Signal
45	-	-	Not Used
46	0.35 OG	6030	Brake Booster Vacuum Signal
47	0.35 D-BU	1161	APP Sensor 2 Signal
48	0.35 D-GN	890	Fuel Tank Pressure Sensor Signal
49	0.35 L-BU	1162	APP Sensor 1 Signal
50-52	-	-	Not Used
53	0.35 D-GN/WH	459	A/C Compressor Clutch Relay Control
54	0.35 D-BU	473	High Speed Cooling Fan Relay Control
55	0.35 WH	1310	EVAP Canister Vent Solenoid Control
56	0.35 YE/BK	625	Starter Enable Relay Control

Connector Part Information

OEM: 13583475
Service: See Catalog
Description: 56-Way F MX123 Series (BK)

Terminal Part Information

Pins: 7, 9, 12, 16, 18-20, 25, 29, 31-37, 39, 40, 44, 46-49, 53-56
Terminal/Tray: See Terminal Repair Kit
Core/Insulation Crimp: See Terminal Repair Kit
Release Tool/Test Probe: See Terminal Repair Kit