P1631: Theft Deterrent Start Enable Signal Not Correct
1 vehicles · 1 makes · $150-$600 repair
P1631 is an OBD-II diagnostic trouble code meaning “Theft Deterrent Start Enable Signal Not Correct.” GM-specific code. The anti-theft system is not sending the correct signal to enable the starter. This code appears across 1 vehicle models from 1 manufacturers, with repair costs ranging from $150 to $600.
Common Causes
Typical Repair Cost
Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P1631, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
Vehicles Affected (1)
FAQ
What does P1631 mean?
P1631 stands for "Theft Deterrent Start Enable Signal Not Correct." GM-specific code. The anti-theft system is not sending the correct signal to enable the starter.
What are the most common causes of P1631?
The most common causes of P1631 are: Passlock sensor failure, BCM fault, Key cylinder issue, Wiring damage, Reprogramming needed. The specific cause varies by vehicle.
How much does it cost to fix P1631?
Repair costs for P1631 range from $150 to $600, depending on the vehicle and root cause.
Which vehicles are affected by P1631?
Au7o has documented P1631 across 1 vehicle models from 1 manufacturers: Chevrolet.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.