OBD Code B1470: Lamp Outage Module Communication Error – Causes, Symptoms & Fixes

Q: How do I know if the problem is the module itself or just a wiring issue?

Start with simple checks: inspect connectors for corrosion, verify ground connections with a multimeter, and clean connector pins. If the code returns after these steps, the problem is likely the module itself. A professional diagnostic scan can also help pinpoint whether the module is responding to communication attempts.

Quick Answer: Code B1470 indicates a communication failure between your vehicle’s lamp outage module and other control modules. This is typically caused by wiring issues, corroded connectors, or a faulty lamp outage module itself. Start by checking the module’s electrical connections and wiring for damage.

Code B1470 is a body code (indicated by the “B” prefix) that signals a communication problem between your vehicle’s lamp outage module and the rest of the vehicle’s control systems. The lamp outage module is responsible for monitoring your vehicle’s lighting system and detecting when bulbs have burned out. When this module can’t communicate properly with other modules, your vehicle stores this diagnostic trouble code and may trigger warning lights on your dashboard.

What Does B1470 Mean?

B1470 stands for “Lamp Outage Module Communication Error.” This code is set when the vehicle’s body control module (BCM) or other primary control modules fail to establish or maintain proper communication with the lamp outage module. The lamp outage module is a specialized component that monitors the status of exterior lighting (headlights, taillights, turn signals, etc.) and alerts the driver or the vehicle’s systems when a bulb has burned out.

The communication error typically occurs over the vehicle’s CAN bus (Controller Area Network), which is the communication backbone connecting all of the vehicle’s electronic modules. When this communication link fails or becomes intermittent, the B1470 code is triggered. This is a relatively serious code because it prevents the vehicle from properly monitoring its lighting system, which has safety implications.

Common Symptoms

Check Engine or Warning Light: A warning light or check engine light illuminates on the dashboard
Lamp Outage Indicator Malfunction: The lamp outage indicator or “bulb out” warning light doesn’t function correctly
No Bulb Failure Detection: The vehicle fails to alert you when exterior lights burn out
Intermittent Warning Lights: Dashboard warnings appear and disappear sporadically
Communication Issues: Other module communication errors may appear alongside B1470
Lighting System Problems: Exterior lights may flicker or operate intermittently
Dashboard Display Errors: Information displays or cluster warnings may malfunction
No Obvious Lighting Issues: Exterior lights may function normally despite the code being present

Possible Causes (Ranked by Frequency)

Corroded or Loose Connector Pins (Most Common): The lamp outage module or its communication connectors may have corroded, loose, or damaged pins that prevent proper electrical connection. This is the most frequent cause of communication errors.
Damaged Wiring Harness: The wiring harness connecting the lamp outage module to the CAN bus or other modules may be damaged, pinched, or broken. Water intrusion or rodent damage can cause this issue.
Poor Ground Connection: A loose or corroded ground connection for the lamp outage module can prevent proper communication and electrical function.
Faulty Lamp Outage Module: The lamp outage module itself may be defective or failing, preventing it from communicating with other vehicle systems.
Body Control Module (BCM) Issues: The primary BCM that communicates with the lamp outage module may have a software glitch or hardware failure.
CAN Bus Termination Problems: Issues with the CAN bus termination resistors or the bus itself can prevent proper module-to-module communication.
Water Intrusion or Moisture: Water or moisture in electrical connectors or the module itself can cause intermittent communication failures.
Software or Firmware Issues: Outdated or corrupted module firmware may prevent proper communication protocols from functioning.

Diagnostic Steps

Step 1: Scan for Additional Codes

Connect a diagnostic scanner to your vehicle’s OBD-II port and retrieve all stored and pending codes. B1470 often appears alongside other communication codes. Document all codes present, as they may provide additional clues about the root cause.

Step 2: Visually Inspect the Lamp Outage Module

Locate the lamp outage module (consult your vehicle’s service manual for the exact location—it’s typically mounted in the engine bay, under the dashboard, or in the trunk). Inspect the module and its connectors for:

Visible corrosion or white/green oxidation on pins
Loose or partially disconnected connectors
Water damage or moisture inside connectors
Damaged or cracked plastic housing
Bent or broken connector pins

Step 3: Check Wiring and Connectors

Inspect the wiring harness leading to and from the lamp outage module for:

Pinched, cut, or abraded wires
Loose connections at both ends
Corrosion on connector terminals
Signs of water intrusion or moisture

Gently wiggle connectors while the ignition is on (engine off) and observe if the warning light flickers, which would indicate a loose connection.

Step 4: Clean Connectors

Disconnect the lamp outage module connector and carefully clean the pins with a contact cleaner and a soft brush or cloth. Remove any corrosion or oxidation. Reconnect the connector firmly and clear the code to see if it returns.

Step 5: Test Ground Connections

Using a multimeter, verify that the lamp outage module has a solid ground connection. Check the resistance between the module’s ground pin and a known good ground point on the vehicle (such as the negative battery terminal). Resistance should be near zero ohms.

Step 6: Check CAN Bus Voltage

Using a multimeter, measure the voltage on the CAN bus communication lines (typically labeled CAN-H and CAN-L). With the ignition on, CAN-H should read approximately 2.5V and CAN-L should also read approximately 2.5V. If voltages are significantly different, there may be a CAN bus problem.

Step 7: Verify Module Power Supply

Check that the lamp outage module is receiving proper power. Consult your service manual for the correct voltage specification (typically 12V for battery voltage). Use a multimeter to verify power at the module’s power pins with the ignition on.

Step 8: Perform a Module Reset

Disconnect the negative battery terminal for 15 minutes to reset all vehicle modules. Reconnect the battery and clear the code using your diagnostic scanner. Drive the vehicle for several miles to see if the code returns. If it does, the problem is likely hardware-related rather than a temporary glitch.

Step 9: Check for Recalls or TSBs

Consult your vehicle manufacturer’s website or a technical service bulletin (TSB) database to determine if there are known issues with the lamp outage module or related systems for your specific vehicle model and year.

Step 10: Test or Replace the Module

If all connections and wiring check out, the lamp outage module itself may be faulty. Consult your service manual for module testing procedures, or consider replacing the module with a new or remanufactured unit.

Repair Cost Estimates

The cost to repair a B1470 code varies significantly depending on the underlying cause and your vehicle’s make and model:

Connector Cleaning or Tightening: $0–$50 (DIY) or $50–$150 (professional diagnosis)
Wiring Repair or Replacement: $150–$500 depending on the extent of damage and labor hours
Ground Connection Repair: $100–$300
Lamp Outage Module Replacement: $300–$800 for the module itself, plus $100–$300 in labor
Body Control Module (BCM) Replacement: $600–$1,500+ for the module and reprogramming
Complete Diagnostic Service: $100–$200 for professional diagnosis if DIY troubleshooting doesn’t resolve the issue

Most B1470 codes are resolved with simple connector cleaning or tightening, which costs little to nothing if you perform the work yourself. However, if the module itself is faulty, replacement costs can be substantial.

Can I Still Drive?

Safety Assessment: Moderate Concern

You can typically continue driving with a B1470 code, but it’s not ideal. Here’s what you need to know:

Safe to Drive: The code itself doesn’t prevent your vehicle from operating. Exterior lights will likely still function normally, and the vehicle is generally safe to drive in the short term.

Why You Should Address It: The lamp outage module exists for safety reasons. Without proper communication from this module, you won’t receive alerts if critical exterior lights (headlights, taillights, brake lights) burn out. This could leave you driving with non-functional lights without knowing it, creating a serious safety hazard for you and other drivers.

Recommended Action: Address this code within a few days. Start with the simple troubleshooting steps (connector cleaning and inspection) before considering module replacement. If you can’t resolve it yourself, have a professional technician diagnose and repair it promptly.

Avoid Ignoring It: Don’t ignore this code for extended periods. While your lights may work fine today, a burned-out bulb tomorrow could go undetected, creating a genuine safety issue.

Frequently Asked Questions

What is a lamp outage module?

A lamp outage module is a specialized control module that monitors the status of your vehicle’s exterior lighting system. It detects when bulbs have burned out and alerts the driver through a dashboard warning light or message. This helps ensure that critical safety lights (headlights, taillights, brake lights) are always functioning. The module communicates with the body control module (BCM) and other systems via the CAN bus.

Can I drive without a working lamp outage module?

Yes, you can drive without a working lamp outage module because your lights will continue to function normally. However, you’ll lose the ability to receive alerts when bulbs burn out. This is a safety concern because you may not realize that critical lights have failed. It’s recommended to have the module repaired or replaced as soon as possible, but it’s not an emergency that requires immediate roadside assistance.

How do I know if the problem is the module itself or just a wiring issue?

Start with the simple checks: inspect connectors for corrosion, verify ground connections with a multimeter, and clean connector pins. If the code returns after these steps, the problem is likely the module itself. You can also check for CAN bus voltage and power supply to the module. If power and ground are good but communication still fails, the module is probably faulty. A professional diagnostic scan can also help pinpoint whether the module is responding to communication attempts.

Will clearing the code fix the problem?

Clearing the code alone will not fix the underlying problem—the code will return once the vehicle detects the communication failure again. However, clearing the code after performing repairs (such as connector cleaning or module replacement) is necessary to confirm that your fix was successful. If the code returns immediately after clearing it, your repair didn’t address the root cause.

Is B1470 the same as other lamp outage codes?

No, B1470 specifically refers to a communication error with the lamp outage module. Other related codes might include B1471 (Lamp Outage Module Input Error) or B1472 (Lamp Outage Module Output Error), which indicate different types of failures within the lamp outage system. Each code points to a different aspect of the lamp outage system’s function, so diagnosis should be specific to the code you’re seeing.