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

Engine Harness to Engine (LG5), Front View


Object Number: 689488  Size: MF
(1)Engine Coolant Temperature (ECT) Gage Sensor
(2)C115
(3)Intake Air (IA) Heater Relay Connector
Figure 2:

Engine Harness to Engine (LG5), Left Side


Object Number: 689494  Size: MF
(1)C408/C409
(2)Upfitter TO PTO Connector
(3)Upfitter TRANS OPT Connector
(4)Powertrain Control Module (PCM) Connector
(5)Engine Oil Pressure (EOP) Switch
(6)Engine Oil Pressure (EOP) Gage Sensor
(7)Fuel Heater
Figure 3:

Engine Harness to Transmission (MWF)


Object Number: 214808  Size: SF
(1)Transmission
(2)Automatic Transmission Input Shaft Speed (ISS) Sensor
(3)Vehicle Speed Sensor (VSS)
Figure 4:

Manual Transmission Harness, Left Forward View


Object Number: 689881  Size: MF
(1)Backup Lamp Switch
(2)Vehicle Speed Sensor (VSS) (JE4)
(3)Vehicle Speed Sensor (VSS) (JE3)
Figure 5:

Engine Harness to Transmission (MTW/MX4)


Object Number: 689982  Size: LF
(1)Turbine Shaft Speed (TSS) Sensor
(2)Automatic Transmission Connector
(3)Vehicle Speed Sensor (VSS)
(4)Park/Neutral Position (PNP) Switch
(5)Automatic Transmission Input Shaft Speed (ISS) Sensor
Figure 6:

Lower Left Side of Cab Interior


Object Number: 689894  Size: SF
(1)Instrument Panel
(2)Accelerator Pedal Position (APP) Sensor