GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 GMC K Pickup - 4WD 🢒 Engine 🢒 Engine Controls - 7.4L 🢒 Engine Controls Component Views
Figure 1:

Underhood Fuse/Relay Center
Object Number: 209017 Size: LF
(1)AUX B
(2)AUX A
(3)AUX B (30 amp)
(4)Lighting (50 amp)
(5)AUX A (30 amp)
(6)Battery (50 amp)
(7)Spare (10 amp)
(8)Fuse Puller
(9)Spare (20 amp)
(10)Spare (30 amp)
(11)Ignition A (40 amp)
(12)ECM B (20 amp)
(13)Horn (20 amp)
(14)Air conditioning (10 amp)
(15)Ignition B (50 amp)
(16)Rear defog (30 amp)
(17)Aux fan (30 amp)
(18)ABS (60 amp)
(19)Ignition E (20 amp)
(20)ECM 1 (20 amp)
(21)Engine 1 (20 amp)
(22)Blower (50 amp)
(23)Spare (10 amp)
(24)Stop/Hazard (30 amp)
(25)Spare (10 amp)
(26)Diode 1
(27)Diode 2
(28)Horn relay
(29)Fuel pump relay
(30)A/C relay
(31)A.I.R. relay
(32)Spare
(33)Brake lamp relay
Figure 2:

Data Link Connector (DLC)
Object Number: 542437 Size: MF
(1)Data Link Connector (DLC)
Figure 3:

Vehicle Speed Sensor (4WD)
Object Number: 209620 Size: SF
(1)Vehicle Speed Sensor (VSS)
(2)Transfer case
Figure 4:

Vehicle Speed Sensor (4L80E)
Object Number: 537877 Size: MF
(1)Vehicle Speed Sensor (VSS)
Figure 5:

Fuel Filter
Object Number: 542484 Size: MF
(1)Fuel Filter
Figure 6:

Auxliary Fuel Tank (Dual Tank)
Object Number: 405475 Size: MF
(1)Tail Lamp, LH
(2)Rear Lamp Extension Harness
(3)Balance Pump
(4)Fuel Sender
(5)Fuel Sender connector
(6)Fuel Tank, Rear
Figure 7:

Fuel Tank Pressure Sensor and Fuel Tank Sender Assembly (Utility side tank)
Object Number: 209633 Size: MF
(1)Fuel Tank Pressure Sensor
(2)Fuel Tank Sender Assembly
Figure 8:

Fuel Tank Pressure Sensor and Fuel Tank Sender Assembly (Pick-up side tank)
Object Number: 404292 Size: LF
(1)Fuel Tank Pressure Sensor
Figure 9:

Fuel Tank Pressure Sensor and Fuel Tank Sender Assembly (rear tank)
Object Number: 209630 Size: MF
(1)Fuel Tank Sender Assembly
(2)Fuel Tank Pressure Sensor
Figure 10:

Idle Air Control (IAC) and Throttle Position (TP) Sensor
Object Number: 404301 Size: MF
(1)Idle Air Control (IAC) Valve
(2)Throttle Position (TP) Sensor
(3)Engine Coolant Temperature (ECT) Sensor
(4)Manifold Absolute Pressure (MAP) Sensor
(5)Accelerator Control Cable
Figure 11:

Idle Air Control, Manifold Absolute Pressure, Engine Coolant Temperature, Throttle Position Sensors
Object Number: 214402 Size: LF
(1)Idle Air Control (IAC) Valve Motor
(2)Engine Coolant Temperature (ECT) Sensor
(3)Manifold Absolute Pressure (MAP) Sensor
(4)Crankshaft Position (CKP) Sensor
(5)Throttle Position (TP) Sensor
Figure 12:

Knock Sensors
Object Number: 404291 Size: MF
(1)Knock Sensor (left side)
(2)Knock Sensor (right side)
Figure 13:

Ignition Control Module,Camshaft Position Sensor,Knock Sensor
Object Number: 214403 Size: MF
(1)Ignition Control Module
(2)Camshaft Position Sensor
(3)Engine Oil Pressure Switch
Figure 14:

Intake Air Temperature, Mass Air Flow Sensors
Object Number: 214404 Size: MF
(1)Intake Air Temperature (IAT) Sensor
(2)Mass Air Flow (MAF) Sensor
Figure 15:

Canister Purge, Linear EGR, Knock Sensor
Object Number: 214405 Size: LF
(1)Linear Exhaust Gas Recirculation (EGR) Valve
(2)Canister Purge Valve Solenoid
Figure 16:

EVAP Canister, EVAP Vent Valve
Object Number: 214406 Size: MF
(1)Evap Canister Vent Valve
(2)Evap Canister
Figure 17:

VCM, Auxiliary Electric Cooling Fan, Underhood Electrical Center
Object Number: 214407 Size: MF
(1)Auxiliary Electric Cooling Fan Relay
(2)Underhood Electrical Center
(3)Vehicle Control Module (VCM)
Figure 18:

Heated Oxygen Sensors
Object Number: 404297 Size: SF
(1)HO2S Bank 2 Sensor 2
(2)HO2S Bank 1 Sensor 2
(3)HO2S Bank 1 Sensor 1
(4)HO2S Bank 2 Sensor 1
Figure 19:

Air Injection Reaction (AIR) Pump
Object Number: 404290 Size: MF
(1)Air Injection Reaction (AIR) Pump
Figure 20:

Auxillary Cooling Fan
Object Number: 404302 Size: MF
(1)Auxillary Cooling Fan