GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2003 🢒 TopKick C-Series (Conventional) C6/C7/C8 🢒 Engine 🢒 Engine Controls - 7.2L (Caterpillar) 🢒 Engine Controls Component Views
Figure 1:

Engine Harness to Engine (LG5), Right Side
Object Number: 689981 Size: LF
(1)Engine Coolant Temperature (ECT) Switch (UER)
(2)Generator
Figure 2:

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 3:

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 4:

Automatic Transmission Harness --Typical-- without MTW/MX4/MWF
Object Number: 689497 Size: MF
(1)To Backup Lamp Switch
(2)Vehicle Speed Sensor (VSS)
(3)Automatic Transmission Modulator
(4)Neutral Safety Switch
(5)C408/C409
Figure 5:

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 6:

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 7:

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 8:

Lower Left Side of Cab Interior
Object Number: 689894 Size: SF
(1)Instrument Panel
(2)Accelerator Pedal Position (APP) Sensor
Figure 9:

Instrument Panel Harness to Instrument Panel, Right Front View
Object Number: 689889 Size: LF
(1)Ignition Switch
(2)Park Brake Switch (JE3/J71)
(3)Turn Signal/Multifunction Switch C3
(4)Turn Signal/Multifunction Switch C2
(5)Turn Signal/Multifunction Switch C1
(6)Headlamp Dimmer Switch
(7)Turn Signal/Hazard Flasher Module
(8)Park/Neutral (PNP) Switch C3
(9)Park/Neutral (PNP) Switch C2
(10)Park/Neutral (PNP) Switch C1
(11)Accelerator Pedal Position (APP) Sensor
(12)Low Air Pressure Switch
(13)Stop Lamp Switch
Figure 10:

IP Harness to Components, Right View
Object Number: 689511 Size: MF
(1)Stop Lamp Switch Interface Module
(2)Convenience Center
(3)SERVICE TRANS FILTER Indicator Lamp
(4)Seat Belt Indicator Lamp
(5)Upfitter Accessory Feed Connector
(6)C210
(7)Upfitter AUX WRG Connector, Interior
(8)Daytime Running Lamps (DRL) Diode
(9)Blower Motor C1
(10)Blower Motor C2
(11)C208
(12)G210
(13)Speaker - RF
Figure 11:

Instrument Panel Harness to Components, Left Side of Cab
Object Number: 689891 Size: MF
(1)Multifunction Alarm Module
(2)Park Brake Control Module (PBCM)