B1380

What Does Code B1380 Mean?

DTC B1380 signifies an electrical fault within the circuit dedicated to the oil change reset button. This code is typically stored in the Body Control Module (BCM), Instrument Cluster (IC), or a dedicated oil life monitor module, rather than the Engine Control Module (ECM) or Powertrain Control Module (PCM) directly, though the PCM may report its presence via network communication. The oil change reset button is a momentary contact switch designed to send a signal to its corresponding control module, informing it to reset the calculated engine oil life or maintenance interval. The control module detects a B1380 code when it observes an electrical condition on this circuit that deviates from expected parameters. This could be a constant open circuit (no signal when the button should be pressed), a constant short to ground or power (signal always present or incorrect voltage), or abnormally high resistance preventing a clear signal transition. This subsystem is crucial for accurate vehicle maintenance reminders and proper operation of the oil life monitoring system.

Common Symptoms

• Inability to reset the Oil Life Monitor or Maintenance Required indicator after an oil change.
• The Maintenance Required light or message may remain continuously illuminated on the instrument cluster.
• A persistent Service Due message displayed on the driver information center.
• Other related dashboard warning lights or messages may appear, depending on the vehicle’s specific system integration.
• The Check Engine Light (CEL) is generally not illuminated for this B-code, as it is related to a body electrical function rather than powertrain emissions.

What Causes the Code B1380?

• Faulty Oil Change Reset Button Switch: Internal electrical or mechanical failure of the momentary contact switch itself, preventing proper signal transmission.
• Open Circuit in Wiring Harness: A break or discontinuity in the electrical wire connecting the oil change reset button to its control module. This can be caused by physical damage, corrosion, or a compromised terminal.
• Short Circuit in Wiring Harness: The signal wire for the oil change reset button circuit shorting to ground, a power source, or another signal wire.
• Corroded or Loose Electrical Connectors: Poor electrical contact at the connector terminals between the switch and the wiring harness, or between the wiring harness and the control module, due to corrosion, bent pins, or insufficient seating.
• Internal Fault within the Instrument Cluster or Body Control Module: While less common, a failure within the input circuit of the control module responsible for reading the switch’s signal can also trigger this code.

How to Diagnose and Troubleshoot

A systematic diagnostic approach is essential for accurately identifying the root cause of DTC B1380:

1. Verify Symptoms and Scan for Codes: Use an advanced OBD-II scanner or manufacturer-specific diagnostic tool to confirm the presence of B1380 in the BCM or IC. Note any other related diagnostic trouble codes (DTCs) that might offer additional clues. Confirm the customer’s complaint regarding the inability to reset the oil life monitor.
2. Perform a Thorough Visual Inspection:
   • Locate the oil change reset button (commonly found on the instrument cluster, steering wheel, or center console).
   • Carefully inspect the visible wiring leading to the button and any accessible connectors for signs of physical damage, chafing, pinching, corrosion, or signs of rodent activity.
   • Disconnect the appropriate electrical connectors (starting with the button’s connector) and inspect the terminals for bent pins, corrosion, or loose fitting.
3. Electrical Circuit Testing with a Digital Multimeter (DMM):
   • Isolate the Switch: Disconnect the electrical connector from the oil change reset button.
   • Test the Switch: Set your DMM to continuity or resistance mode. With the switch disconnected, place the DMM probes across the switch terminals. The DMM should indicate an open circuit (OL or very high resistance) when the button is not pressed and near 0 ohms (continuity) when the button is pressed and held. If the switch shows continuity all the time, or never shows continuity when pressed, the switch is faulty.
   • Test the Wiring for Open Circuit: With both the switch and the control module connector (e.g., BCM or IC) disconnected (if safely accessible per service manual), use your DMM to test for continuity between the appropriate signal wire pin at the switch harness connector and its corresponding pin at the control module harness connector. A reading near 0 ohms indicates good continuity. An open circuit (OL) indicates a break in the wire.
   • Test the Wiring for Short Circuit: With both the switch and control module disconnected, test for continuity between the signal wire and vehicle ground, and between the signal wire and any adjacent power wires within the harness. Any continuity (low resistance) indicates a short circuit.
   • Test Voltage/Ground at Switch Connector: Reconnect the control module and turn the ignition to the ON position (engine off). With the switch still disconnected, use your DMM to measure voltage at the switch’s harness connector. Depending on the circuit design (pull-up or pull-down), you should observe either a reference voltage (e.g., 5V or battery voltage) or ground on the signal wire. This confirms the module’s ability to provide power/ground to the switch circuit.
4. Control Module Input Test (Advanced): If the switch and wiring test good, and if the control module’s input pin is accessible, use a lab scope or an advanced diagnostic tool with live data capabilities to monitor the signal input at the module while the button is pressed. This can confirm if the module is receiving the correct signal but failing to process it internally.

Recommended Repairs and Solutions

Once the faulty component has been identified through diagnosis, the following repairs are typically recommended:

• Replace Faulty Oil Change Reset Button Switch: If the switch tested bad during the DMM checks, replace the switch. This often requires careful removal of dashboard trim, steering wheel components, or instrument cluster to access and replace the unit.
• Repair or Replace Wiring Harness: If an open circuit, short circuit, or high resistance is found in the wiring, repair the damaged section of the harness. Use appropriate automotive-grade wiring, solder, heat shrink tubing, and loom for a durable repair. In cases of extensive damage, replacing a section of the harness or the entire harness may be necessary.
• Clean and Secure Electrical Connectors: If corrosion or loose pins were identified, meticulously clean the terminals using electrical contact cleaner and a small brush. Ensure all pins are straight and make solid contact. Apply a small amount of dielectric grease to the terminals to prevent future corrosion and ensure a robust connection before reassembly.
• Replace Instrument Cluster or Body Control Module: This is a last resort repair. If the switch and all associated wiring and connectors have been thoroughly tested and confirmed to be in good working order, and diagnostic steps point to an internal module fault (e.g., faulty input driver), then replacement of the BCM or IC may be necessary. Be aware that module replacement often requires programming or calibration with a factory-level diagnostic tool to function correctly in the vehicle.
• Post-Repair Verification: After completing any repairs, clear the B1380 DTC using an OBD-II scanner. Then, attempt to reset the oil life monitor and cycle the ignition to verify that the button functions correctly and the “Maintenance Required” light or message extinguishes as expected.