B318A Cadillac 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 Cadillac 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 Cadillac 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 Cadillac?
- 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 Cadillac?
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 Cadillac 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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Frequently Asked Questions about B318A Cadillac Code
1. What does OBDII code B318A mean on a Cadillac?
B318A indicates a fault related to the left rear window switch, typically involving a communication issue or malfunction in the switch circuitry.
2. What are the symptoms of code B318A in a Cadillac?
Common symptoms include the left rear window not responding to switch commands, inconsistent operation, or the switch being completely unresponsive.
3. What causes the B318A code to trigger?
The code can be caused by a faulty left rear window switch, damaged wiring or connectors, or a malfunction in the power window control module.
4. Can a blown fuse cause the B318A OBDII code?
Yes, a blown fuse in the power window circuit may prevent the switch from functioning and trigger the B318A code.
5. How can I diagnose the B318A code on my Cadillac?
Diagnose by inspecting the left rear window switch for visible damage, checking the wiring and connectors, testing the switch for continuity, and verifying power and ground at the circuit.
6. Is it safe to drive with the B318A code active?
Yes, it’s generally safe to drive with this code, but the left rear window may not function, which could be inconvenient or a safety issue in some situations.
7. How do I fix the B318A code on a Cadillac?
Repairs may involve replacing the left rear window switch, repairing damaged wiring, or resetting the power window control module.
8. Can I reset the B318A code without fixing the issue?
You can clear the code with an OBDII scanner, but if the underlying problem isn’t fixed, the code will likely return.
9. How much does it cost to repair the B318A code?
Repair costs vary but typically range from $50 to $200, depending on whether the issue is with the switch, wiring, or control module.
10. Can a software update fix the B318A code?
In rare cases, a software update to the power window control module might resolve the issue, but this is less common than physical repairs.
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