My Chevy SS won't start and the electrical stuff acts weird. What should I check?

Short answer: Start with voltage. Charge and load-test the AGM battery in the trunk, then clean and tighten both battery cables and the engine and body grounds. Owners found that new parts didn't help until the connections were good. If you see Service Theft Deterrent, put the key fob in the console key pocket and try again, and replace the fob battery.

Symptom: The SS won't crank or start, the lights flicker, or it only refuses to start with the A/C on. You might see a Service Theft Deterrent message.

What to check first

1. Measure battery voltage with the car off. About 12.6 volts is full. Have it load-tested.
2. Check both battery terminals and the ground straps for corrosion or looseness.
3. Put the fob in the console key pocket and try to start.
4. Have the codes read, including any that flash briefly when it won't start.
5. Run your VIN at nhtsa.gov/recalls.

Likely causes

1. Loose or corroded battery or ground connections. A bad connection acts like a dead battery under load. Owners said that if a new battery and alternator didn't help, connections are the next suspect.
2. Weak AGM battery in the trunk. The SS battery lives in the trunk. Low voltage makes GM cars do strange things, such as refusing to crank with certain switches on.
3. Key fob not being read (immobilizer). A Service Theft Deterrent message means the car may not be recognizing the key. A weak fob battery or a reader problem can block the start.

What it usually costs

A battery and cable cleaning are the cheap end. Owners who replaced the battery and alternator first still had the problem, so diagnose before buying parts.

Is it safe to keep driving?

Flickering lights while driving can mean the charging system is failing and the car may stall. Get it checked before long drives.

DIY or shop?

Battery, terminals, grounds and fob battery are all DIY. Charging-system and immobilizer faults may need a shop scan tool.

Recalls, bulletins and complaints in plain words

• Recalls: NHTSA lists 10 recall(s) for the Chevrolet SS in these years, and none match this problem. Check your VIN at nhtsa.gov/recalls. If your car is part of a recall, the dealer fixes it for free.
• Plain words: The complaint count below shows how often owners reported problems that mention these words to NHTSA. A count is not proof of a defect.
• NHTSA complaints: 38 keyword-matched complaints for Chevrolet SS 2014–2017 (of 99 unique complaints queried, NHTSA complaints API by model year, queried 2026-11-01; keywords: start, crank, battery, stall, electrical, suspension, stabilitrak) (NHTSA returned no data for 1 model-year queries). This counts complaints that mention these words. It is not a defect finding.

What owners report

• In Car wont start on Reddit r/ChevySS, an SS owner's lights flickered on the freeway, and after replacing the battery and alternator the car still wouldn't start, even on a jump. Replies pointed to a loose connection. One noted the Service Theft Deterrent message suggests an immobilizer problem, and another said putting the fob in the key pocket in the console gets the car to start.
• In No start while a/c is on on Reddit r/ChevySS, an owner's SS wouldn't start when the A/C button was left on but started right away with it off. Replies said to read the code that flashed, make sure the AGM battery in the trunk is tight and fully charged, and that low voltage on GM cars causes lots of odd electrical problems.

Quick tip

Before you buy an alternator, put a voltmeter on it and wiggle the cables. A 'dead alternator' is often really a loose ground.

Vehicle focus: Chevrolet SS sedan with the 6.2L V8, 2014-2017.

Safety / mechanic note

A failing charging system can stall the car in traffic. Verify with a mechanic.