B3708 - Front Washer Motor Input High (BCM)

This article delves into the diagnostic trouble code (DTC) B3708, specifically focusing on "Front Washer Motor Input High (BCM)." This code indicates a fault within the vehicle's Body Control Module (BCM) related to the voltage signal received from the front windshield washer motor circuit. Understanding this code is crucial for diagnosing and resolving issues with the windshield washer system, which is essential for safe driving visibility.

B3708 DTC: A Comprehensive Overview

Detailed Explanations

Definition: This refers to the specific meaning of the diagnostic trouble code B3708. It clearly states that the BCM has detected an unusually high voltage coming from the front washer motor circuit. This is an abnormal condition that needs investigation. The BCM monitors various electrical components within the vehicle, and the washer motor circuit is one of them. When the voltage exceeds a pre-defined threshold, the BCM registers the B3708 code.

Symptoms: These are the observable signs that a vehicle owner or technician might notice when this code is present. The most obvious symptom is a malfunctioning windshield washer system. This can manifest as the washer not working at all, working only sometimes, or even running continuously without being activated. Other symptoms can include issues related to the BCM's overall functionality, other electrical problems, and the illumination of the Check Engine Light on the dashboard.

Possible Causes: This is the most crucial part, as it lists potential reasons why the B3708 code might be triggered. These range from simple issues like a short circuit in the wiring to more complex problems like a faulty BCM. Each possible cause needs to be investigated systematically to pinpoint the root of the problem. It's important to note that this list is not exhaustive, but it covers the most common scenarios. A thorough diagnostic process is always necessary.

• Short to Voltage in Washer Motor Circuit: This is a common cause. It occurs when a wire in the washer motor circuit accidentally comes into contact with a source of power, such as a live wire. This creates an unintended electrical path, resulting in excessive voltage in the circuit.

• Faulty Washer Motor: The washer motor itself could be defective. A malfunctioning motor might send an incorrect voltage signal back to the BCM, triggering the B3708 code. Internal shorts or other electrical failures within the motor are possible causes.

• BCM Malfunction: While less frequent, the BCM itself could be faulty. If the BCM is misinterpreting the voltage signal or generating the incorrect code, it will need to be diagnosed and potentially replaced. This is usually considered after other potential causes have been ruled out.

• Wiring Issues: Damage to the wiring, corrosion on the connectors, or loose connections in the washer motor circuit can all contribute to the problem. Damaged wires can short to ground or to other wires, while corroded or loose connectors can disrupt the flow of electricity.

• Contaminated Washer Fluid: Although uncommon, heavily contaminated washer fluid could potentially create electrical issues. Impurities in the fluid could affect the conductivity and lead to electrical problems within the washer system.

• Incorrect Washer Motor Installation: If the washer motor has been recently replaced, improper installation or the use of an incompatible motor could cause problems. Ensure the motor is correctly installed and meets the vehicle's specifications.

• Internal Short in Washer Motor Switch: The switch that activates the washer motor could have an internal short, sending an erroneous signal to the BCM.

• High Resistance in Ground Circuit: A poor ground connection can cause voltage to backfeed into the system, leading to a high voltage reading at the BCM.

• Aftermarket Accessories: Improperly installed aftermarket accessories could interfere with the washer motor circuit and cause voltage irregularities.

• Software Glitch in BCM: A temporary software glitch in the BCM could trigger the code, although this is less likely. Clearing the code and re-evaluating after a drive cycle can sometimes resolve this.

Frequently Asked Questions

What does the B3708 code mean? It means the Body Control Module (BCM) has detected a higher than expected voltage in the front windshield washer motor circuit.

Can I fix this problem myself? Depending on your mechanical skills, you may be able to diagnose and fix some issues, such as loose connections or damaged wiring. However, more complex problems may require professional diagnosis and repair.

Will this code affect my vehicle's performance? While the code itself might not directly impact engine performance, a non-functional windshield washer system can compromise visibility and safety.

How do I clear the B3708 code? Using an OBD-II scanner, you can clear the code after addressing the underlying problem. Keep in mind that the code will reappear if the issue persists.

How much does it cost to fix this issue? The cost varies depending on the cause of the problem. A simple wiring fix might be inexpensive, while replacing the BCM could be more costly.

Conclusion

The B3708 code, indicating a high voltage input from the front washer motor to the BCM, signifies a problem within the windshield washer system. Thoroughly diagnosing the potential causes and addressing them promptly is crucial for ensuring safe driving conditions and preventing further electrical issues.