The B1335 Diagnostic Trouble Code (DTC) indicates a fault within the Rear Right (RR) door ajar circuit of a vehicle's body control system. This circuit is responsible for informing the vehicle's computer when the rear right door is not fully closed. A malfunctioning circuit can lead to incorrect illumination of the door ajar warning light, potential battery drain, and other associated issues. Understanding the causes, diagnosis, and potential solutions for a B1335 code is crucial for effective vehicle maintenance and repair.
The B1335 code is a common issue that can arise in many modern vehicles, particularly those equipped with advanced body control modules. Addressing this problem promptly can prevent further complications and ensure the proper functioning of the vehicle's safety systems.
| Component/Symptom | Possible Cause | Troubleshooting Steps |
|---|---|---|
| Illuminated Door Ajar Light | Faulty Door Ajar Switch | Inspect the door ajar switch for physical damage, corrosion, or loose connections. Test the switch's continuity using a multimeter when the door is open and closed. Replace if faulty. |
| Wiring Harness Damage | Visually inspect the wiring harness leading to the door ajar switch for cuts, abrasions, or pinched wires. Use a multimeter to check for continuity and shorts to ground. Repair or replace damaged wiring. | |
| Connector Corrosion | Check the connectors for the door ajar switch and the body control module (BCM) for corrosion. Clean corroded terminals with a wire brush or electrical contact cleaner. Apply dielectric grease after cleaning. | |
| Body Control Module (BCM) Malfunction | Perform a scan of the BCM for other related DTCs. If other BCM faults are present, the BCM itself may be faulty. Consult a qualified technician for BCM diagnosis and reprogramming or replacement. | |
| Battery Drain | Stuck Door Ajar Switch | If the door ajar switch is stuck in the "open" position, it can continuously signal the BCM, leading to parasitic battery drain. Manually manipulate the switch to see if it releases. Replace if necessary. |
| BCM Keeping Systems Active | A faulty BCM might misinterpret the door ajar signal and keep interior lights or other systems active, causing battery drain. Diagnose the BCM's operation and look for other related codes. | |
| Intermittent Door Ajar Warning | Loose Connection | Check all connections in the door ajar circuit, including the switch, wiring harness, and BCM connectors. Secure any loose connections. |
| Environmental Factors | Extreme temperatures or humidity can affect the resistance of the circuit, leading to intermittent faults. Inspect the circuit under different environmental conditions. | |
| Door Doesn't Latch Properly | Misaligned Door Latch | A misaligned door latch can prevent the door ajar switch from fully engaging, triggering the B1335 code. Adjust the door latch as needed to ensure proper engagement. |
| Obstruction in Door Latch Area | Debris or obstructions in the door latch area can prevent the door from closing completely. Clean the latch area and remove any obstructions. | |
| BCM Software Glitch | Corrupted Software | In rare cases, a software glitch in the BCM can cause false door ajar readings. Check for software updates for the BCM and reprogram it if necessary. |
| Security System Issues | Faulty Alarm System Integration | If the vehicle's security system is integrated with the door ajar circuit, a fault in the security system can trigger the B1335 code. Disconnect or reset the security system to see if the problem resolves. |
| Door Ajar Switch Adjustment | Incorrect Gap | The gap between the door and the switch might be too large, preventing proper closure. Adjust the switch position. |
Detailed Explanations
Illuminated Door Ajar Light: The most obvious symptom of a B1335 code is the constant or intermittent illumination of the door ajar warning light on the vehicle's dashboard. This light indicates that one or more doors are not properly closed, but in the case of B1335, the issue is specifically related to the rear right door circuit. The light can be distracting and, more importantly, mask other potential door issues.
Faulty Door Ajar Switch: The door ajar switch is a simple electromechanical device that detects whether the door is open or closed. It's typically located on the door frame or the door itself, near the latch. Over time, these switches can fail due to wear and tear, corrosion, or physical damage. A faulty switch will not properly signal the BCM about the door's status.
Wiring Harness Damage: The wiring harness that connects the door ajar switch to the BCM is susceptible to damage, especially in areas where the wiring flexes with the opening and closing of the door. Cuts, abrasions, or pinched wires can disrupt the electrical signal and trigger the B1335 code. Rodent damage is also a common cause of wiring harness issues.
Connector Corrosion: Corrosion on the electrical connectors can create resistance in the circuit, leading to inaccurate readings. This is especially common in areas exposed to moisture or road salt. Cleaning and protecting the connectors is crucial for maintaining a reliable electrical connection. Dielectric grease helps prevent future corrosion.
Body Control Module (BCM) Malfunction: The BCM is a central computer that controls various functions in the vehicle, including the door ajar warning system. In rare cases, a malfunction within the BCM itself can cause the B1335 code. This could be due to internal component failure or corrupted software.
Battery Drain: A stuck door ajar switch, or a BCM that continuously monitors the door ajar status, can lead to parasitic battery drain. This occurs when the vehicle's electrical system remains active even when the engine is off, draining the battery over time.
Stuck Door Ajar Switch: If the door ajar switch becomes stuck in the "open" position, it will continuously signal the BCM, potentially keeping interior lights or other systems active and causing battery drain. This can happen due to dirt, debris, or a mechanical failure within the switch.
BCM Keeping Systems Active: Even if the switch itself isn't stuck, a faulty BCM might misinterpret the door ajar signal and keep interior lights or other systems active, leading to battery drain. This requires further diagnosis of the BCM's operation.
Intermittent Door Ajar Warning: An intermittent door ajar warning, where the light comes on and off sporadically, often indicates a loose connection or a wiring issue. This can be difficult to diagnose because the problem may not be present during testing.
Loose Connection: A loose connection in the door ajar circuit can cause intermittent signals, triggering the B1335 code. This can be due to vibration, corrosion, or improper installation of connectors.
Environmental Factors: Extreme temperatures or humidity can affect the resistance of the circuit, leading to intermittent faults. For example, a connection that is slightly corroded might only cause problems when the humidity is high.
Door Doesn't Latch Properly: If the rear right door does not latch properly, the door ajar switch may not be fully engaged, leading to the B1335 code. This could be due to a misaligned door latch or an obstruction in the latch area.
Misaligned Door Latch: A misaligned door latch can prevent the door ajar switch from fully engaging, triggering the B1335 code. This can happen due to wear and tear, or after a collision.
Obstruction in Door Latch Area: Debris or obstructions in the door latch area can prevent the door from closing completely. This can be anything from small rocks to pieces of trim.
BCM Software Glitch: In rare cases, a software glitch in the BCM can cause false door ajar readings. This is more common in vehicles with complex electronic systems.
Corrupted Software: Corrupted software within the BCM can lead to a variety of issues, including false door ajar readings. This can happen due to electrical surges, or during a software update.
Security System Issues: If the vehicle's security system is integrated with the door ajar circuit, a fault in the security system can trigger the B1335 code. This is because the security system might be monitoring the door ajar status for alarm purposes.
Faulty Alarm System Integration: A faulty alarm system can interfere with the normal operation of the door ajar circuit, causing the B1335 code. This can happen if the alarm system is improperly installed or if it is malfunctioning.
Door Ajar Switch Adjustment: The gap between the door and the switch needs to be within a specific range for proper operation.
Incorrect Gap: If the gap between the door and the switch is too large, the switch won't fully engage when the door is closed.
Frequently Asked Questions
What does the B1335 code mean? The B1335 code indicates a fault in the rear right door ajar circuit, meaning the vehicle's computer is detecting an issue with the signal indicating whether the door is open or closed.
What are the common symptoms of a B1335 code? The most common symptoms include an illuminated door ajar light, intermittent door ajar warnings, and potential battery drain.
Can a faulty door ajar switch cause a B1335 code? Yes, a faulty door ajar switch is a common cause of the B1335 code, as it can send an incorrect signal to the BCM.
How do I diagnose a B1335 code? Diagnosing the code involves inspecting the door ajar switch, wiring harness, connectors, and the BCM, using a multimeter to check for continuity and shorts.
Can I fix the B1335 code myself? Depending on the cause, you may be able to fix the code yourself by cleaning connectors, repairing wiring, or replacing the door ajar switch. However, BCM issues may require professional assistance.
Will a B1335 code cause my battery to drain? Yes, a stuck door ajar switch or a faulty BCM can keep systems active, leading to parasitic battery drain.
How much does it cost to fix a B1335 code? The cost varies depending on the cause. Replacing a door ajar switch is relatively inexpensive, while BCM repairs or replacements can be more costly.
Conclusion
The B1335 code, indicating a fault in the rear right door ajar circuit, can stem from various issues ranging from a faulty switch to BCM malfunctions. Thorough diagnosis and systematic troubleshooting are key to resolving this issue and preventing potential battery drain or inaccurate warning lights.