B1971 GMC Code - Inadvertent Power Fault
Quick Answer
If interior lights are accidentally left on, a Delayed Interior Lighting (DIL) feature provides automatic shutoff. Common causes include Faulty Inadvertent Power Relay, Inadvertent Power Relay harness is open or shorted, Inadvertent Power Relay circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- B1971 GMC indicates Inadvertent Power Fault.
- Common causes
- Common causes include Faulty Inadvertent Power Relay, Inadvertent Power Relay harness is open or shorted, Inadvertent Power Relay circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code B1971 GMC Description
- A door is opened or closed, or driver door unlock message is received.
- The trunk is opened or closed.
- Interior lights are turned on. When DIL relay is energized, power is supplied to interior lights and high side of the interior light relay coil.
The BCM continuously monitors output to DIL relay. The Diagnostic Trouble Code (DTC) B1971 will set when output is commanded on or off, and short or open is detected for at least 2 seconds. When DTC B1971 is set, BCM will continue to command the requested state of relay until it is achieved or no longer necessary. DTC B1971 will clear when conditions for fault no longer exist or when scan tool is used. A history DTC will clear after 50 consecutive ignition cycles if conditions for fault no longer exist.
What are the Possible Causes of the DTC B1971 GMC?
- Faulty Inadvertent Power Relay
- Inadvertent Power Relay harness is open or shorted
- Inadvertent Power Relay circuit poor electrical connection
How to Fix the DTC B1971 GMC?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the B1971 GMC code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
Need more information about the B1971 GMC code?
Need more information on how to fix the B1971 GMC code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the B1971 GMC code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about B1971 GMC Code
1. What does the OBDII code B1971 mean on a GMC vehicle?
The code B1971 indicates an "Inadvertent Power Fault," meaning there’s an issue with the circuit that controls power to certain interior components like lights or accessories when the vehicle is off.
2. What are common symptoms of the B1971 code in a GMC?
Symptoms may include interior lights staying on, lights not turning on at all, battery drain, or accessories malfunctioning when the vehicle is off.
3. What causes the B1971 code to appear on a GMC?
Common causes include a short circuit, faulty wiring, a defective inadvertent power relay, or issues with the body control module (BCM).
4. How is the B1971 code typically diagnosed?
A technician will inspect the wiring for damage, test the inadvertent power relay, and check the BCM for proper function using a diagnostic tool.
5. Can a drained battery cause the B1971 code?
A drained battery is more likely a symptom than a cause of B1971, as the code typically stems from a fault in the power circuit that may lead to continuous current draw.
6. Is it safe to drive a GMC with the B1971 code?
Yes, it’s generally safe to drive, but ignoring the issue could lead to battery drainage or electrical problems, which might leave you stranded.
7. How can the B1971 code be fixed on a GMC vehicle?
Repairs may involve replacing a faulty relay, repairing damaged wiring, or reprogramming or replacing the body control module (BCM).
8. Can the B1971 code clear itself?
The code will not usually clear itself; the underlying issue must be resolved, and the code may need to be cleared with an OBDII scanner.
9. How much does it cost to repair a GMC with a B1971 code?
Repair costs vary depending on the exact issue, ranging from $50 to $300 for wiring or relay fixes, or more if the BCM requires replacement.
10. Can I fix the B1971 code on my GMC myself?
If you’re experienced with electrical systems, you can inspect and repair wiring or replace the relay. However, BCM issues may require professional diagnostics and repair.
Discuss the causes and fixes for B1971 GMC OBDII Code
Code B1971 GMC comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
