B2325 – LIN communication bus (Toyota)

Last updated: March 28, 2026

What Does B2325 Mean?

DTC B2325 – LIN communication bus (Toyota) is a Manufacturer Specific diagnostic trouble code for the Body system with a General fault type. The official meaning is: LIN communication bus.

Definition source: Toyota factory description. Diagnostic guidance is based on factory-defined fault logic for this code.

This code indicates the vehicle has detected a fault condition associated with the LIN (Local Interconnect Network) communication bus. LIN is a low-speed, single-wire communication network used to exchange data between a controlling module and one or more connected components. When B2325 is set, the control module that monitors the LIN bus has determined that bus communication is not occurring as expected. The code is a network-level indicator: it identifies a problem related to the LIN communication bus itself, rather than naming a specific component as failed.

Because B2325 is defined only as LIN communication bus, correct diagnosis focuses on determining (1) which module reported the DTC, (2) whether the bus shows signs of an open circuit, short circuit, excessive resistance, or unstable electrical conditions, and (3) whether any connected device is disrupting communication.

Quick Reference

• Code: B2325
• Official Title: B2325 – LIN communication bus (Toyota)
• Official Meaning: LIN communication bus
• Fault Type: General
• Standard Classification: Manufacturer Specific
• System: Body
• What it points to: A fault affecting LIN bus communication (signal integrity and/or the electrical circuit that supports communication)
• What it does not guarantee: A specific component is defective

Symptoms

When B2325 is present, symptoms are typically related to the Body system features that rely on LIN communication and to diagnostic observations indicating communication instability. The exact affected functions depend on the vehicle configuration and how the LIN network is arranged.

• DTC storage: B2325 stored as current, pending, or history in the reporting module
• Intermittent behavior: Some body functions may operate inconsistently, such as working at times and failing at other times
• Inoperative functions: One or more body-related features associated with LIN may stop operating
• Delayed or erratic responses: A function may respond slowly or not match the command state due to missing communication
• Additional diagnostic trouble codes: Other communication- or body-related DTCs may be present alongside B2325
• Scan tool observations: Data items may not update, show implausible states, or indicate communication disruption for devices related to LIN

Common Causes

B2325 indicates a fault related to the LIN communication bus. Common root causes generally fall into wiring/circuit faults, connection faults, power/ground problems that prevent a device from participating in communication, or a device that disrupts the bus electrically.

• Open circuit in the LIN bus wire: A break in the single-wire LIN communication path preventing messages from being transmitted or received
• Short to ground on the LIN bus wire: The LIN line is forced low, preventing proper signaling
• Short to voltage on the LIN bus wire: The LIN line is forced high, preventing proper signaling
• High resistance in the LIN circuit: Excess resistance from damaged wiring, poor terminal contact, or degraded splices affecting signal integrity
• Connector/terminal issues: Loose connections, backed-out terminals, bent pins, contamination, moisture intrusion, or corrosion
• Power supply problem at a LIN device or the controlling module: A device may drop off the bus if its power feed is missing or unstable
• Ground circuit problem at a LIN device or the controlling module: Poor ground can prevent reliable communication or cause resets that interrupt bus activity
• A device on the LIN bus disrupting communication: An internal fault can load the bus, interfere with signaling, or prevent normal communication timing
• Harness damage: Pinched, chafed, or water-damaged harness sections affecting the LIN wire or related power/ground circuits

Diagnosis Steps

The goal of diagnosis is to confirm that B2325 is set due to a LIN bus communication fault and to identify whether the issue is caused by the LIN circuit (open/short/high resistance), a connection problem, a power/ground issue, or a device that is disrupting the LIN bus. Use appropriate service information for connector pin identification, network layout, and safe disconnection procedures.

1. Confirm the code and identify the reporting module
   • Perform a full vehicle scan.
   • Confirm B2325 is present and recorded as LIN communication bus.
   • Note which module reports B2325.
   • Record associated DTCs and any stored snapshot/freeze-frame-like data available for the Body system.
2. Check whether the fault is current or intermittent
   • Clear DTCs.
   • Cycle ignition and re-check for B2325.
   • If the code returns immediately, treat it as an active fault.
   • If it does not return immediately, plan to reproduce conditions while monitoring status/data related to LIN communication.
3. Verify power supply and ground integrity for the reporting module
   • With the module connected and operating, verify power and ground using voltage drop testing (preferred over unloaded resistance checks).
   • Address any abnormal voltage drop, unstable supply, or poor ground before further LIN signal diagnosis.
   • Inspect related fuses and power distribution paths as indicated by service information.
4. Perform a targeted visual inspection of wiring and connectors
   • Inspect the reporting module connector(s), focusing on the LIN circuit pin(s) and any shared power/ground pins.
   • Inspect accessible harness routing for pinching, abrasion, or evidence of repairs.
   • Check for connector damage, moisture, contamination, corrosion, or terminal fit issues.
5. Use scan tool data to look for communication loss indicators
   • Review data lists and communication-related status items associated with LIN.
   • Look for signs such as missing updates, “communication stop,” or non-updating inputs/outputs that may indicate a device is not participating in LIN communication.
   • Compare current readings to expected behavior based on commanded inputs (switch operation) and system state.
6. Check the LIN bus electrical behavior with the system awake
   • With the ignition ON and the network awake, measure the LIN circuit at an accessible point.
   • Look for conditions consistent with a short to ground, short to voltage, or an open circuit.
   • If available, use an oscilloscope to verify that the LIN line shows switching activity rather than a constant level.
   • Do not rely on ignition-OFF readings alone, as LIN biasing and activity depend on the system being powered and awake.
7. Isolate the problem by controlled disconnection (when appropriate)
   • Follow service information for safe disconnect procedures and ignition state requirements.
   • If the LIN line appears stuck or overloaded, disconnect LIN-connected devices one at a time (with the system powered down as required), then re-check bus behavior.
   • If communication returns after disconnecting a particular device, that device, its connector, or its local wiring may be disrupting the bus.
8. Test the LIN circuit for continuity and shorts (power OFF)
   • Power down the vehicle as required and allow modules to sleep if specified.
   • Check continuity of the LIN wire between the reporting module and the relevant sections of the harness.
   • Check for short-to-ground and short-to-voltage conditions as directed by service information.
   • Identify and repair opens or high-resistance points by segmenting the circuit (connector-to-connector testing).
9. Verify power and ground at any suspected device
   • If scan data or isolation points to a specific device, confirm it has correct power and ground at its connector under operating conditions.
   • A device that loses power or ground may stop communicating and trigger a LIN communication bus DTC.
10. Confirm the repair
    • Reconnect all components and restore original wiring routing and connector locking.
    • Clear DTCs and re-test.
    • Re-scan to verify B2325 does not return.
    • Operate the affected Body system functions to confirm proper behavior and stable communication.

Possible Fixes

Repairs for B2325 should be based on test results that confirm the root cause of the LIN communication bus fault. Possible fixes include:

• Repair an open circuit in the LIN communication wire (restore continuity and correct any damaged harness sections)
• Repair a short to ground on the LIN line (locate chafed insulation, crushed wiring, or connector damage and restore proper insulation/routing)
• Repair a short to voltage on the LIN line (identify contact with a power feed and correct harness routing or connector faults)
• Correct high resistance in the LIN circuit (repair splices, terminals, or damaged conductors that increase resistance)
• Service connectors and terminals (clean contamination, address corrosion, repair/replace damaged terminals, ensure correct pin fit and connector locking)
• Restore proper power supply to the module/device involved (repair power feed issues and replace failed fuses only after identifying the cause)
• Restore proper ground integrity (repair ground points, ground wires, or terminal integrity as indicated by voltage drop testing)
• Replace a LIN-connected device only when isolation/testing shows that device disrupts the LIN bus and wiring/power/ground are confirmed good
• Repair/replace the reporting module only after confirming the LIN circuit and connected devices are not the cause and the module has verified correct power/ground

Can I Still Drive With B2325?

B2325 indicates a fault related to the LIN communication bus within the Body system. Whether driving is advisable depends on what Body system functions are affected and whether the fault creates unsafe operating conditions.

• If the vehicle remains controllable and essential safety functions are unaffected: driving may still be possible, but the fault should be diagnosed and repaired to restore proper system communication and to prevent escalation of electrical issues.
• If any required road-legal or safety-related Body functions are impaired: limit driving and address the problem promptly.
• If the fault is accompanied by widespread electrical malfunctions: treat it as a higher risk condition and perform diagnosis before extended driving.

The code itself communicates that the LIN communication bus is not operating correctly; it does not specify which functions are affected. Verification of affected systems should be part of the diagnostic process before deciding on continued operation.

Repair Costs

Network and communication fault repairs vary by root cause — wiring/connectors are often the source, but module-level repairs or replacements can be significantly more expensive.