GM Service Manual Online
For 1990-2009 cars only
Figure 1:

Front Chassis Harness to Brake Components (JE3)


Object Number: 231487  Size: LF
(1)Brake Fluid Flow Switch
(2)Electronic Brake Control Module (EBCM) (JE3) Connecor C2 (2 cavities)
(3)Electronic Brake Control Module (EBCM) (JE3) Connector C1 (24 cavities)
(4)Electronic Brake Control Module (EBCM) (JE3)
Figure 2:

Front Chassis Harness to Relay Bracket (JE3) (LG4)


Object Number: 513404  Size: LF
(1)Trailer Stop Relay
Figure 3:

Front Wheel Speed Sensor (WSS)


Object Number: 231740  Size: LF
(1)Wheel Speed Sensor (WSS) - RF (LF Similar)
Figure 4:

Instrument Panel Switches, Center Forward View


Object Number: 1400889  Size: LF
(1)Outside Heated Mirror Switch (DNN)
(2)High Idle Switch (UF3) or Power Take-Off (PTO) Switch
(3)Exhaust Brake Switch (K40)
(4)Rear Axle Driver Control Switch - Two Speed (HPZ and Automatic Transmission)
(5)Traction Control Switch (NW9)
(6)Overdrive (OD) Defeat Switch (Allison® LCT)
(7)Marker Lamp Switch (JE4, RQ2 and U86, or JE4 and RQ3)
Figure 5:

Park Brake


Object Number: 231691  Size: LF
(1)Park Brake Lever
(2)Park Brake Switch (Hydraulic Brakes)
Figure 6:

Rear of Frame, Right Rear View


Object Number: 231761  Size: MF
(1)Wheel Speed Sensor (WSS) -- LR (RF Symilar)