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 AWDSECTION Diagnostic Procedures
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2002 GMC Sonoma, 2002 GMC Safari, 2002 GMC Jimmy, 2002 Chevrolet S10 Pickup, and 2002 Chevrolet Blazer. 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 STARTING & CHARGING SYSTEMS. 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 ON the ignition, with the 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.
- Vehicle Theft Deterrent (VTD).
- Instrument Panel (IP) cluster.
- Electronic Brake Control Module (EBCM).
- Heating, Ventilation, and Air Conditioning (HVAC).
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, VTD, IP Cluster, EBCM, HVAC. 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-P0607, P1600, P1621, P1627, P1680, P1681 or P1683? If yes, see DTC P0601-P0607, P1600, P1621, P1627, P1680, P1681 & P1683: PCM MEMORY (ASTRO & SAFARI) or DTC P0601-P0607, P1600, P1621, P1627, P1680, P1681 & P1683: PCM MEMORY (BLAZER, JIMMY CANADIAN, SONOMA & S10 PICKUP) under DIAGNOSTIC TESTS. If no, go to next step.
- Does the scan tool display DTC P0562, P0563, P1637 or P1638? If yes, see appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS. 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 INSPECTION/MAINTENANCE PROCEDURES.
- Review the following symptoms. Hard start, surges/chuggles, lack of power, sluggishness, sponginess, detonation/spark knock, hesitation, sag, stumble, cuts out, misses, poor fuel economy, poor fuel fill quality, rough, unstable, or incorrect idle and stalling, dieseling, run-on and backfire. See appropriate TROUBLE SHOOTING - NO CODES article. 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.