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.
On-Board System Readiness (OSR) Test Mode
OSR test mode indicates OBD II system operating status by indicating status of each system monitor (complete or incomplete). There are 2 types of system monitors. Misfires, fuel system and comprehensive components are continuous monitoring-type functions and will be identified by a CONT message on the scan tool. Catalyst, EGR system, EVAP system and oxygen sensor are monitored during each drive cycle only. When the drive cycle sensor monitor is complete, a YES message will display.
Apply parking brake. Place shift lever in Park (A/T) or Neutral (M/T). Block wheels. Turn off all electrical accessories. Ensure engine is at normal operating temperature.
Perform visual inspection. Ensure air cleaner and inlet ducts are clean, and system wiring harness is properly connected. Check for bent or broken connector terminals and corroded or loose wires. Check Powertrain Control Module (PCM), sensors and actuators for physical damage. Check engine coolant for proper level and mixture. Check for proper transmission fluid level and quality.
Turn ignition off. Ensure proper memory (EPROM) card is inserted into NGS scan tool. Connect service connections of adapter cable to vehicle Data Link Connector (DLC) and the NGS scan tool. See Figure and Figure . Connect NGS scan tool power supply cable to power and listen for a double beep to indicate that scan tool is on.
To enter OSR test mode, program scan tool using the following steps:
- Select GENERIC OBD II FUNCTIONS.
- Select TESTS.
- Press CANCEL key repeatedly to return to main menu.
- Select GENERIC OBD II FUNCTIONS.
- Select CONT.
- Select CLEAR DIAGNOSTIC CODES.
- Select START and follow scan tool prompts.
Use the Manual With the Right Hardware
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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.