B318A 2017 GMC Sierra Code - Left Rear Window Switch
Quick Answer
The driver and passenger window motors supply 12 V signal circuits to their respective window switches, when a window switch has been activated, a switch closes providing a ground to the appropriate signal circuit causing the voltage to drop to 0 V. Common causes include Faulty Left Rear Window Switch, Left Rear Window Switch harness is open or shorted, Left Rear Window Switch 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
- B318A 2017 GMC Sierra indicates Left Rear Window Switch.
- Common causes
- Common causes include Faulty Left Rear Window Switch, Left Rear Window Switch harness is open or shorted, Left Rear Window Switch 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 B318A 2017 GMC Sierra Description
The driver window master control switch also contains control switches for the passenger, left rear and right rear window functions. When a window switch is pressed, a serial data message is sent to the Body Control Module (BCM). The BCM examines the request and checks for messages from other power window motors that may prohibit window movement. If no prohibitive messages have been received, the BCM will send a serial data message to the passenger window motor or to the appropriate rear window switch which will perform the command as requested.
What are the Possible Causes of the DTC B318A 2017 GMC Sierra?
- Faulty Left Rear Window Switch
- Left Rear Window Switch harness is open or shorted
- Left Rear Window Switch circuit poor electrical connection
- Faulty Body Control Module (BCM)
How to Fix the DTC B318A 2017 GMC Sierra?
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 B318A 2017 GMC Sierra 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 B318A 2017 GMC Sierra code?
Need more information on how to fix the B318A 2017 GMC Sierra code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the B318A 2017 GMC Sierra code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about B318A 2017 GMC Sierra Code
What does OBDII code B318A mean for a 2017 GMC Sierra?
B318A indicates a problem with the left rear window switch, which may affect the operation of the window.
What symptoms might I experience with code B318A?
Symptoms include the left rear window not functioning, intermittent operation, or the window switch not responding.
What could cause the B318A code to trigger?
Possible causes include a faulty left rear window switch, wiring issues, or a problem with the body control module.
How can I diagnose the issue related to code B318A?
Start by checking the left rear window switch for proper operation, inspecting the wiring for any damage, and using a multimeter to test for continuity.
Can a bad window motor cause OBDII code B318A?
While the window motor could cause operational issues, code B318A specifically refers to the window switch. However, it’s important to check all related components.
What repairs are typically needed to fix code B318A?
Repairs may involve replacing the left rear window switch, repairing any damaged wiring, or reprogramming the body control module if necessary.
Is it safe to drive a vehicle with code B318A?
While it may be safe to drive, the left rear window may not operate, which could be a safety concern if you need to use it.
Can I reset the code B318A myself?
Yes, you can clear the code using an OBDII scanner, but it’s advisable to diagnose and fix the underlying issue first.
Should I take my GMC Sierra to a dealership for this code?
While dealerships have specialized knowledge, a qualified mechanic can also diagnose and repair issues related to code B318A effectively.
Discuss the causes and fixes for B318A 2017 GMC Sierra OBDII Code
Code B318A 2017 GMC Sierra 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.
