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.
Diagnostic Procedures
2004 Oldsmobile Bravada RWDSECTION Diagnostic Procedures
WARNING: This page is about a different car, the 2003 Cadillac Seville and 2003 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Do not perform this diagnostic if there is not a driveability concern, unless another procedure directs you to this diagnostic. Before you proceed with diagnosis, search for applicable service bulletins. Unless a diagnostic procedure instructs you, DO NOT clear the DTCs. If there is a condition with the starting system, see appropriate STARTERS article in ELECTRICAL. Ensure the battery has a full charge. Ensure the battery cables are clean and tight. Ensure the PCM grounds are clean, tight, and in the correct location.
- Install a scan tool. Does the scan tool turn ON? If yes, go to next step. If no, see SCAN TOOL DOES NOT POWER UP in appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
- Turn ignition on, with engine off. Attempt to establish communication with the listed control modules. If you are using a Tech 2, obtain the information using the Class 2 Message Monitor feature:
- PCM.
- Electronic Brake Control Module (EBCM).
- Vehicle Theft Deterrent (VTD).
Does the scan tool communicate with all the listed control modules? If yes, go to next step. If no, see SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE in appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
- Attempt to start the engine. Does the engine start and idle? If yes, go to next step. If no, see ENGINE CRANKS BUT DOES NOT RUN in appropriate TROUBLE SHOOTING - NO CODES article.
- Select the DTC display function for the following control modules: PCM, EBCM and VTD. Does the scan tool display any DTCs? If yes, go to next step. If no, go to step 9.
- With a scan tool, select Captured Info in order to store the powertrain DTC information. When complete, go to next step.
- Does the scan tool display DTCs which begin with a "U"? If yes, see appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT. If no, go to next step.
- Does the scan tool display DTC P0601, P0602, P0603, P0604, P0606, or P1621? If yes, see DTC P0601-P0607, P1600, P1621, P1627, P1680, P1681, P1683 & P2610: PCM MEMORY under DIAGNOSTIC TESTS. If no, go to next step.
- Does the scan tool display DTC P0560, P0562, P0563, P0621, P0622? If yes, see appropriate GENERATORS & REGULATORS article in ELECTRICAL. If no, see DIAGNOSTIC TROUBLE CODE DEFINITIONS .
- Is the customer's concern with the automatic transmission? If yes, see appropriate DIAGNOSIS article in AUTOMATIC TRANSMISSIONS. If no, go to next step.
- Is the customer's concern with Inspection and Maintenance (I/M) testing? If yes, see INSPECTION/MAINTENANCE SYSTEM CHECK under DRIVE CYCLES. If no, go to next step.
- Review the following symptoms. See appropriate TROUBLE SHOOTING - NO CODES article.
- Hard start.
- Surges and/or chuggles.
- Lack of power, sluggishness or sponginess.
- Detonation and/or spark knock.
- Hesitation, sag or stumble.
- Cuts out or misses.
- Poor fuel economy.
- Poor fuel fill quality.
- Rough, unstable, or incorrect idle and stalling.
- Dieseling.
- Run-on and backfire.
Did you find and correct the condition? If yes, system is okay. If no, see INTERMITTENT CONDITIONS .
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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.