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.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSGMC2024SIERRA 2500 HD DENALI ULTIMATEREPAIR AND DIAGNOSISBODY & FRAMEIGNITION SWITCH/STEERING LOCKIMMOBILIZER SYSTEMDIAGNOSTIC INFORMATION AND PROCEDURESDTC P1649CIRCUIT/SYSTEM DESCRIPTION
2024 GMC Sierra 2500 HD Denali Ultimate
Circuit/System Description
2024 GMC Sierra 2500 HD Denali UltimateSECTION Circuit/System Description
For an overview of the component/system, refer to: Immobilizer Description and Operation
| Component | Description |
|---|---|
| K9 Body Control Module | Depending on the version, the control module can support different functions:
The control module also reads various switches and sensors and makes their values available via serial data. |
| K20 Engine Control Module | The control module contains a microprocessor used to process input data to control outputs. The control module controls a series of actuators to ensure optimal engine performance. The control module does this by reading values from a variety of sensors, interprets the data and adjusts the engine actuators accordingly. |
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.