B3717 - Front Wiper Relay Drive Circuit Low (BCM)

Introduction:

The B3717 diagnostic trouble code (DTC) indicates a problem within the front wiper relay control circuit, specifically a low voltage or resistance condition detected by the Body Control Module (BCM). This code suggests the BCM is not receiving the expected feedback voltage when attempting to activate the front windshield wipers, hinting at a potential issue with the wiring, relay, or even the BCM itself. Addressing this code promptly is important for safety, as malfunctioning windshield wipers can severely impair visibility during inclement weather.

Table: B3717 - Front Wiper Relay Drive Circuit Low (BCM)

Category	Description	Possible Causes
General Information	Definition of B3717	BCM detects a low voltage or resistance in the front wiper relay drive circuit when attempting to activate the wipers.
	Affected System	Windshield Wiper System
	Controlling Module	Body Control Module (BCM)
Symptoms	Common Symptoms	Front wipers may not function at all, function intermittently, or operate at incorrect speeds. Wiper motor may be unresponsive. DTC B3717 is stored in the BCM memory.
	Secondary Symptoms	Other electrical issues may be present, depending on the vehicle's electrical system design. Check engine light may illuminate (though less common with BCM-related codes).
Possible Causes	Wiring Issues	Open circuit in the wiring between the BCM and the wiper relay. Short to ground in the wiring between the BCM and the wiper relay. High resistance in the wiring due to corrosion or damage. Damaged or corroded connectors.
	Relay Issues	Faulty front wiper relay. Relay contacts are burned or corroded. Relay coil is open or shorted. Relay not properly seated in its socket.
	BCM Issues	Faulty BCM. Internal BCM failure affecting the wiper relay drive circuit. BCM programming error.
	Wiper Motor Issues	While less likely to directly trigger B3717, a failing wiper motor can draw excessive current and indirectly affect the relay circuit, potentially causing the BCM to misinterpret the signal.
	Power Supply Issues	Low voltage to the BCM or wiper system due to a weak battery or faulty alternator (though this usually triggers other codes first).
Troubleshooting Steps	Initial Steps	Visually inspect the wiring, connectors, and relay associated with the front wipers. Check for corrosion, damage, or loose connections.
	Relay Testing	Test the front wiper relay using a multimeter or relay tester. Verify proper operation of the relay coil and contacts.
	Wiring Testing	Use a multimeter to check for continuity, shorts to ground, and voltage drop in the wiring between the BCM and the wiper relay.
	BCM Testing	Check BCM power and ground connections. Use a scan tool to monitor the BCM's output signal to the wiper relay. Consult the vehicle's service manual for specific BCM testing procedures.
	Wiper Motor Testing	Test the wiper motor separately to ensure it is functioning correctly. Check for excessive current draw.
Tools Required	Diagnostic Tools	Scan tool capable of reading and clearing DTCs, and monitoring BCM data. Multimeter. Wiring diagram for the vehicle's wiper system.
	Other Tools	Wire strippers, crimpers, connector cleaning tools, relay tester (optional).
Repair Procedures	Wiring Repair	Repair or replace damaged wiring. Clean corroded connectors. Ensure proper connections.
	Relay Replacement	Replace the faulty front wiper relay with a new one. Ensure the replacement relay is the correct type for the vehicle.
	BCM Replacement/Reprogramming	In rare cases, BCM replacement or reprogramming may be necessary. This should be performed by a qualified technician with the appropriate tools and software.
Related DTCs	Other Wiper System Codes	Codes related to the rear wiper system, wiper motor speed control, or other BCM-related issues.
Safety Precautions	General Safety	Disconnect the negative battery cable before working on the electrical system. Use caution when working with electrical components.
	Specific Precautions	Avoid shorting circuits when testing wiring. Consult the vehicle's service manual for specific safety precautions related to the wiper system and BCM.
Typical Repair Costs	Relay Replacement	$20 - $100 (depending on relay cost and labor).
	Wiring Repair	$50 - $300 (depending on the extent of the damage and labor).
	BCM Replacement/Reprogramming	$300 - $1500 (depending on the vehicle and labor). BCM reprogramming alone can be less expensive.
Importance	Safety	Properly functioning windshield wipers are crucial for safe driving in inclement weather.
	Preventative Maintenance	Regularly inspect and clean the windshield wiper blades and ensure the wiper system is functioning correctly.

Detailed Explanations:

Definition of B3717: This code signifies that the Body Control Module (BCM) has detected a low voltage or resistance condition in the circuit that controls the front wiper relay. Essentially, the BCM is sending a signal to activate the wipers, but the feedback it's receiving from the circuit is not what it expects.

Affected System: The B3717 code directly affects the windshield wiper system, specifically the front wipers. This system is crucial for maintaining visibility during rain, snow, and other adverse weather conditions.

Controlling Module: The Body Control Module (BCM) is the primary electronic control unit responsible for managing various body-related functions in the vehicle, including the windshield wipers, lights, and power windows. It monitors and controls the wiper relay circuit.

Common Symptoms: The most noticeable symptom is the front wipers failing to operate correctly. They might not work at all, operate intermittently, or function at the wrong speed. The wiper motor itself may be unresponsive. The B3717 DTC will be stored in the BCM's memory and can be retrieved using a scan tool.

Secondary Symptoms: Depending on the vehicle's design and electrical system integration, other electrical issues might be present. While less common for BCM-related codes, the check engine light could illuminate.

Wiring Issues: Problems with the wiring connecting the BCM to the wiper relay are a common cause. This includes:

Open circuit: A break in the wire preventing the signal from reaching the relay.
Short to ground: The wire is making unintended contact with the vehicle's chassis, causing a low resistance path.
High resistance: Corrosion or damage increases the resistance in the wire, hindering the signal flow.
Damaged or corroded connectors: Poor connections can also impede the signal.

Relay Issues: The front wiper relay itself can be faulty. Common relay problems include:

Faulty front wiper relay: The internal components of the relay have failed.
Relay contacts are burned or corroded: This prevents the relay from properly switching the circuit.
Relay coil is open or shorted: The coil that actuates the relay is not functioning correctly.
Relay not properly seated in its socket: A loose connection can prevent the relay from working.

BCM Issues: Although less frequent, a faulty BCM can cause the B3717 code. This can be due to:

Faulty BCM: An internal failure within the BCM affecting the wiper relay drive circuit.
BCM programming error: Incorrect or corrupted software within the BCM.

Wiper Motor Issues: While a failing wiper motor is less likely to directly trigger the B3717 code, it can contribute. A motor drawing excessive current can indirectly affect the relay circuit, potentially leading the BCM to misinterpret the signal.

Power Supply Issues: Low voltage to the BCM or wiper system due to a weak battery or faulty alternator could, in theory, contribute. However, this usually triggers other, more specific voltage-related codes first.

Initial Steps: Begin by visually inspecting all wiring, connectors, and the relay associated with the front wipers. Look for obvious signs of damage, corrosion, or loose connections.

Relay Testing: The front wiper relay can be tested using a multimeter or a dedicated relay tester. Verify that the relay coil has the correct resistance and that the contacts switch properly when the coil is energized.

Wiring Testing: Use a multimeter to check the wiring between the BCM and the wiper relay. Test for continuity (to ensure the wire is intact), shorts to ground (to check for unintended contact with the chassis), and voltage drop (to measure the resistance in the wire).

BCM Testing: Check the BCM's power and ground connections to ensure it's receiving adequate power. Use a scan tool to monitor the BCM's output signal to the wiper relay. Consult the vehicle's service manual for specific BCM testing procedures.

Wiper Motor Testing: Test the wiper motor separately to ensure it is functioning correctly. Check for excessive current draw, which could indicate a failing motor.

Scan tool capable of reading and clearing DTCs, and monitoring BCM data: A scan tool is essential for retrieving the B3717 code and monitoring the BCM's behavior.

Multimeter: A multimeter is used to test wiring, relays, and other electrical components.

Wiring diagram for the vehicle's wiper system: A wiring diagram is crucial for understanding the circuit layout and identifying the correct wires to test.

Repair or replace damaged wiring: If wiring is found to be damaged, it must be repaired or replaced to restore the circuit's integrity.

Clean corroded connectors: Corrosion can impede electrical flow. Clean corroded connectors to ensure a good connection.

Replace the faulty front wiper relay with a new one: If the relay is found to be faulty, it should be replaced with a new one of the correct type.

In rare cases, BCM replacement or reprogramming may be necessary: If the BCM is determined to be faulty, it may need to be replaced or reprogrammed. This should be performed by a qualified technician.

Codes related to the rear wiper system, wiper motor speed control, or other BCM-related issues: Be aware of other related DTCs that may provide additional clues about the problem.

Disconnect the negative battery cable before working on the electrical system: This is a crucial safety precaution to prevent electrical shock or damage to the vehicle's electrical system.

Avoid shorting circuits when testing wiring: Use caution when testing wiring to avoid accidentally shorting circuits, which can damage electrical components.

Regularly inspect and clean the windshield wiper blades and ensure the wiper system is functioning correctly: Preventative maintenance can help prevent problems with the wiper system.

Safety: Having properly functioning windshield wipers is essential for safe driving, especially in inclement weather.

Preventative Maintenance: Regularly inspect and maintain your windshield wipers to prevent issues. This includes checking the blades for wear and tear and ensuring the washer fluid reservoir is full.

Frequently Asked Questions:

What does B3717 code mean? It indicates a low voltage or resistance problem in the front wiper relay drive circuit, detected by the BCM.
Can I fix the B3717 code myself? If you are comfortable working with electrical systems and have the necessary tools, you can attempt to diagnose and repair the issue. However, if you are unsure, it's best to consult a qualified technician.
What are the symptoms of a bad wiper relay? The wipers may not work at all, work intermittently, or function at incorrect speeds.
Will a bad BCM always cause a B3717 code? No, a bad BCM is only one potential cause of the B3717 code. Wiring issues and a faulty relay are more common.
How much does it cost to fix a B3717 code? The cost varies depending on the cause of the problem, but it can range from $20 for a relay replacement to $1500 for BCM replacement and reprogramming.

Conclusion:

The B3717 DTC signals a problem within the front wiper relay control circuit, requiring systematic diagnosis to pinpoint the root cause. Addressing this issue promptly is crucial for maintaining safe driving conditions, particularly during inclement weather. Start with basic checks of wiring and the relay, and if necessary, consult a qualified technician for further diagnosis and repair, especially if BCM involvement is suspected.