B318A 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 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 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?
- 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?
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 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.
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Information for Specific Makes
- B318A Buick — Left Rear Window Switch
- B318A Cadillac — Left Rear Window Switch
- B318A Chevrolet — Left Rear Window Switch
- B318A GMC — Left Rear Window Switch
Frequently Asked Questions about B318A Code
1. What does OBDII code B318A indicate regarding the Left Rear Window Switch?
- OBDII code B318A indicates an issue with the Left Rear Window Switch in the vehicle.
2. What are the common symptoms of OBDII code B318A related to the Left Rear Window Switch?
- Common symptoms include the left rear window being unable to open or close using the switch, or erratic behavior of the window when the switch is used.
3. What are the possible causes of OBDII code B318A for the Left Rear Window Switch?
- Possible causes include a faulty window switch, damaged wiring or connectors, or an issue with the window regulator or motor.
4. How can I diagnose the problem with the Left Rear Window Switch causing OBDII code B318A?
- To diagnose the issue, you can perform a visual inspection of the switch and wiring, test the switch for continuity, and check the window regulator and motor for proper function.
5. What are some tips for repairing OBDII code B318A related to the Left Rear Window Switch?
- Repair tips include replacing the faulty switch, repairing any damaged wiring or connectors, and addressing any issues with the window regulator or motor.
6. Can OBDII code B318A be cleared after fixing the issue with the Left Rear Window Switch?
- Yes, after repairing the issue causing the code, you can clear OBDII code B318A using an OBDII scanner or by disconnecting the vehicle's battery for a few minutes.
7. Is it safe to continue driving with OBDII code B318A triggered by the Left Rear Window Switch problem?
- It is generally safe to continue driving with this code, but it is recommended to address the issue promptly to avoid further inconvenience or potential safety concerns.
8. How much does it typically cost to repair OBDII code B318A associated with the Left Rear Window Switch?
- Repair costs can vary depending on the specific cause of the issue, but it may range from a simple switch replacement to more extensive repairs involving the regulator or motor.
9. Can I fix OBDII code B318A for the Left Rear Window Switch myself, or should I take it to a professional mechanic?
- If you have experience with automotive repairs and the necessary tools, you may be able to fix the issue yourself. Otherwise, it is recommended to consult a professional mechanic for assistance.
10. Are there any preventive measures to avoid encountering OBDII code B318A related to the Left Rear Window Switch in the future?
- Regularly checking the functionality of all window switches, addressing any issues promptly, and ensuring proper maintenance of the window system can help prevent the recurrence of this code.
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