Transfer Case Shift Control Module - C1

Courtesy of GENERAL MOTORS CORP.
Connector Part Information		12052107 32-Way F Micro-Pack 100 Series (ORN)
Pin	Wire Color	Circuit No.	Function
E1	TAN	1569	Lock Solenoid Control
E2	-	-	Not Used
E3	PNK	1561	AWD Indicator Control
E4	LT GRN/BLK	1563	2 HI Indicator Control
E5	BRN/WHT	1555	Channel P Encoder Signal
E6	RED/WHT	1556	Channel C Encoder Signal
E7	YEL/BLK	1558	Channel B Encoder Signal
E8	DK BLU/ WHT	1557	Channel A Encoder Signal
E9	DK GRN/ WHT	1133	ATC Class 2 Serial Data
E10	BRN	241	Ignition 3 Voltage
E11	PPL	806	Crank Voltage
E12	YEL	400	Signal High - Front
E13	PPL	401	Signal Low - Front
E14	BLK/WHT	1695	Axle Switch Signal
E15	-	-	Not Used
E16	BLK/WHT	451	Ground
F1	PPL/WHT	1565	4 LO Indicator Control
F2	TAN/BLK	1566	4 HI Indicator Control
F3	BRN	1560	Neutral Indicator Control
F4	GRY/BLK	1570	Axle Actuator Control
F5	LT BLU	2221	Signal High - Rear
F6	DK GRN	2222	Signal Low - Rear
F7	GRY/BLK	1694	4WD Low Signal
F8- F11	-	-	Not Used
F12	BLK/WHT	1554	Encoder Signal Ground
F13	LT GRN/BLK	431	8 Volt Reference
F14	LT GRN/BLK	431	8 Volt Reference
F15	-	-	Not Used
F16	LT BLU	1693	Switch Signal

Transfer Case Shift Control Module - C2

Courtesy of GENERAL MOTORS CORP.
Connector Part Information		12052856 4-Way F Metri-Pack 280 Series (BLK)
Pin	Wire Color	Circuit No.	Function
A	BLK	1552	Motor Control A
B	RED	1553	Motor Control B
C	BLK	1050	Ground
D	ORN	1640	Battery Positive Voltage

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Transfer Case Shift Control Module Connector End Views