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.
Pass-Key(R) System Check
- Install scan tool. Establish communication with BCM and check for DTCs. If communication cannot be established, see appropriate BODY CONTROL MODULES article. If DTC B2721, B2722, B2723 or B2735 is stored, see SELF-DIAGNOSTIC SYSTEM . If no DTCs are stored, go to next step.
- Turn ignition switch to ON position. Using scan tool, select BCM INPUT DATA 1 and display PASS-Key(R) state. If scan tool displays PASS-Key(R) state as MONITOR PASS-KEY(R), go to step 5 . If scan tool does not display PASS-Key(R) state as MONITOR PASS-KEY(R), go to next step.
- Using scan tool, select BCM INPUT DATA 1 and display PASS-Key(R) state. Check for the following PASS-Key(R) states:
- Normal Decision
- Fail Enable
- Fail Enable Decision
- Tamper
If scan tool displayed any of these states, go to step 8 . If scan tool did not display any of these states, go to next step.
- Using scan tool, select BCM INPUT DATA 1 and display PASS-Key(R) state. Check for the following PASS-Key(R) states:
- Auto Lrn Pend
- Seed Lrn Pend
- Auto Learn
- Seed Key Learn
If scan tool displayed any of these states, go to step 7 . If scan tool did not display any of these states, go to step 6 .
- Place transmission in Park (A/T) or press clutch (M/T). Using a valid PASS-Key(R), attempt to start engine. If engine starts, system is okay. If engine does not crank, go to step 9 .
- Check the following for intermittent malfunctions:
- Incorrect or damaged PASS-Key(R) resistor.
- Foreign material on PASS-Key(R) resistor.
- Poor connections or contacts at lock cylinder.
- Open or short in the PASS-Key(R) circuit.
If problem was found, correct and retest system. If no problem was found, see STARTERS - CORVETTE article in STARTING & CHARGING SYSTEMS.
- Reprogram PASS-Key(R) system. See PROGRAMMING .
- Check ignition key lock cylinder. See TEST A: IGNITION KEY LOCK CYLINDER TEST under SYSTEM TESTS. If problem was not found, go to step 7 .
- Repair malfunction in engine cranking system. See STARTERS - CORVETTE article in STARTING & CHARGING SYSTEMS.
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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.