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.
Test Description
2004 Oldsmobile Bravada RWDSECTION Test Description
WARNING: This page is about a different car, the 2002 Oldsmobile Bravada, 2002 GMC Envoy XL, 2002 GMC Envoy, and 2002 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers on the diagnostic table.
- 4: Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
- 5: The symptom list in Symptoms will determine the correct diagnostic procedure to use.
- 6: The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.
Diagnostic System Check - Engine Electrical
| Step | Action | Yes | No |
|---|---|---|---|
| 1 | Perform the Battery Inspection/Test. Does the battery pass the test? |
Go to Step 2 | Go to Battery Inspection/Test (Non-HP2) |
| 2 | Install a scan tool. Does the scan tool power up? |
Go to Step 3 | Go to SCAN TOOL DOES NOT POWER UP |
| 3 |
IMPORTANT:
The engine may start during the following step. Turn OFF the engine as soon as you have observed the Crank power mode.
|
Go to Step 4 | Go to POWER MODE MISMATCH in Body Control System |
| 4 |
|
Go to Step 5 | Go to SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 Device (W/O Immobilizer) |
| 5 |
|
Go to Step 6 | Go to Symptoms - Engine Electrical |
| 6 | Does the scan tool display any DTC beginning with "U"? | Go to DIAGNOSTIC TROUBLE CODE (DTC) LIST | Go to Step 7 |
| 7 | Does the scan tool display any DTC beginning with "P"? | Go to DIAGNOSTIC TESTS | Go to Step 8 |
| 8 | Does the scan tool display any DTC beginning with "B"? | Go to Scan Tool Data Definitions | Go to Diagnostic Trouble Code (DTC) List |
RENDER: 1.0x
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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.