Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2008 Hummer H3 L5-3.7LFACTORY OEM SERVICE PROCEDURE
Powertrain Component Views
Powertrain Component Views
Left Front of the Engine Components (LLR)
1 - Evaporative Emission (EVAP) Canister Purge Soleniod Valve
2 - Starter Motor
3 - Knock Sensor (KS)
4 - Crankshaft Position (CKP) Sensor
5 - G102
6 - G103
7 - Engine Block Heater (K05)
8 - Camshaft Position (CMP) Sensor
9 - Camshaft Position (CMP) Actuator Solenoid Valve
Right Rear of the Engine Components (LLR)
1 - Manifold Absolute Pressure (MAP) Sensor
2 - Throttle Body
3 - Ignition Coil 3
4 - Ignition Coil 2
5 - Ignition Coil 1
6 - Camshaft Position (CMP) Actuator Solenoid Valve
7 - Engine Oil Pressure (EOP) Switch
8 - Heated Oxygen Sensor (HO2S) 1
9 - Engine Coolant Temperature (ECT) Sensor
10 - Engine Coolant Temperature (ECT) Sensor Connector
11 - X101
12 - Ignition Coil 5
13 - Ignition Coil 4
Upper Left Side of the Engine Components (LLR)
1 - Fuel Injector 1
2 - Fuel Injector 2
3 - Fuel Injector 3
4 - Fuel Injector 4
5 - X101
6 - Fuel Injector 5
Top of the Engine Components (K18)
1 - Secondary Air Injection (AIR) Pump Solenoid
2 - Secondary Air Injection (AIR) Pump Relay
3 - Secondary Air Injection (AIR) Pump
Engine - Front (LH8)
1 - Throttle Body
2 - Camshaft Position (CMP) Sensor
Engine - Left (LH8)
1 - Engine Coolant Temperature (ECT) Sensor
2 - Generator
3 - Ignition Coil 1
4 - Evaporative Emission (EVAP) Canister Purge Solenoid Valve
5 - Ignition Coil 3
6 - Ignition Coil 5
7 - Ignition Coil 7
8 - Engine Oil Pressure (EOP) Sensor
9 - Park/Neutral Position (PNP) Switch (M30)
10 - Knock Sensor (KS) 1
11 - Engine Block Heater Connector (K05)
Engine - Left Side (LH8)
1 - Crankshaft Position (CKP) Sensor
2 - Ignition Coil 8
3 - Ignition Coil 6
4 - Ignition Coil 4
5 - Manifold Absolute Pressure (MAP) Sensor
6 - Ignition Coil 2
7 - A/C Compressor Clutch
8 - Knock Sensor (KS) 2
9 - Starter Motor
Engine - Top View (LH8)
1 - Fuel Injector 1
2 - Fuel Injector 4
3 - Fuel Injector 6
4 - Fuel Injector 8
5 - Fuel Injector 7
6 - Fuel Injector 5
7 - Fuel Injector 3
8 - Fuel Injector 1
Left Side of the Transmission Components (M30)
Park Neutral Position (PNP) Switch:
1 - Automatic Transmission
2 - Park/Neutral Position (PNP) Switch
Inside the Transmission Components (M30)
36 - Vehicle Speed Sensor (VSS)
66 - Torque Converter Clutch (TCC) Solenoid Valve
69 - Automatic Transmission Fluid Pressure Manual Valve Position Switch
367a - 1-2 Shift Solenoid (SS) Valve
367b - 2-3 Shift Solenoid (SS) Valve
377 - Pressure Control (PC) Solenoid Valve
394 - 3-2 Shift Solenoid (SS) Valve
396 - Torque Converter Clutch (TCC) Pulse Width Modulation (PWM) Solenoid Valve
Rear of the Transmission and Transfer Case Components (M30)
Engine Harness - Rear (M30):
1 - Transmission
2 - X175
3 - Heated Oxygen Sensor (HO2S) 2 Connector (LLR)
4 - Transfer Case Encoder Motor Connector
5 - Vehicle Speed Sensor (VSS) Connector
6 - Park/Neutral Position (PNP) Switch
Rear of the Transmission and Transfer Case Components (MA5)
Engine Harness - Rear (MA5):
1 - Transmission
2 - Backup Lamp Switch
3 - Heated Oxygen Sensor (HO2S) 2 Connector (LLR)
4 - Transfer Case Encoder Motor Connector
5 - Vehicle Speed Sensor (VSS) Connector
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.
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