MazicBay Diagnostics
MAZICBAYDiagnostics
FTC Reader Disclosure: When you purchase or register through links on our site, we may earn an affiliate commission at no extra cost to you. Read our Editorial & Advertising Policy.
U0102LexusLexus IS HubAll Lexus U0102Medium Severity

U0102 on Lexus IS

Lost Communication with Transfer Case Control Module (TCCM)

Factory diagnostic protocol and troubleshooting wire for fault code U0102 specifically for the Lexus IS (2020–2026, 2.0L Turbo / 3.5L V6 (IS 350 311HP) / 5.0L Naturally Aspirated V8 (IS 500 472HP)).

Verified OEM Telemetry & Field Repair Tree
Lexus IS2020–2026
Lexus IS
Sedan2.0L Turbo / 3.5L V6 (IS 350 311HP) / 5.0L Naturally Aspirated V8 (IS 500 472HP)
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
IS SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Drivable (Short Trip)
Medium urgency level
Est. Repair Cost
$150 - $650 (DIY: $50 - $220)
Parts & Labor DIY
Check U0102 On Another Lexus Model:
Diagnose U0102 on Specific IS Model Year:

1. Symptoms of U0102 on Lexus IS

When the Engine Control Module (ECM/PCM) on your Lexus IS (2.0L Turbo / 3.5L V6 (IS 350 311HP) / 5.0L Naturally Aspirated V8 (IS 500 472HP)) logs fault code U0102, drivers commonly observe:

'Service 4WD' or '4WD System Error' message on dash on Lexus IS (2.0L Turbo / 3.5L V6 (IS 350 311HP) / 5.0L Naturally Aspirated V8 (IS 500 472HP))
4WD selector switch unresponsive (lights out on switch) on Lexus IS (2.0L Turbo / 3.5L V6 (IS 350 311HP) / 5.0L Naturally Aspirated V8 (IS 500 472HP))
Vehicle stuck in 2WD or last selected 4WD mode on Lexus IS (2.0L Turbo / 3.5L V6 (IS 350 311HP) / 5.0L Naturally Aspirated V8 (IS 500 472HP))
Lexus IS OBD-II Port Location
The 16-pin diagnostic connector is located Driver A-pillar base kick panel. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Lexus IS

Historical warranty claims and technical repair bulletins for Lexus IS point to the following failure distribution:

55%
Corroded TCCM power/ground wiring under vehicle (Lexus OEM Part)
25%
Blown 4WD / TCCM fuse in engine fuse panel (Lexus OEM Part)
12%
Faulty Transfer Case Control Module (Lexus OEM Part)
8%
Faulty transfer case shift encoder motor (Lexus OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Lexus IS.

3. Step-by-Step DIY Repair Guide for Lexus IS

01
Check 4WD / TCCM Fuses

Inspect ATC / 4WD fuses with test light. on the Lexus IS equipped with 2.0L Turbo / 3.5L V6 (IS 350 311HP) / 5.0L Naturally Aspirated V8 (IS 500 472HP).

Required Tool: Test Light
02
Inspect TCCM Connector

Check module under driver dash or seat for water intrusion. on the Lexus IS equipped with 2.0L Turbo / 3.5L V6 (IS 350 311HP) / 5.0L Naturally Aspirated V8 (IS 500 472HP).

Required Tool: Flashlight
03
Test CAN Bus Wires at TCCM

Verify 2.5V CAN signals reach the module. on the Lexus IS equipped with 2.0L Turbo / 3.5L V6 (IS 350 311HP) / 5.0L Naturally Aspirated V8 (IS 500 472HP).

Required Tool: Multimeter
04
Replace TCCM & Clear Codes

Install replacement module and clear trouble codes. on the Lexus IS equipped with 2.0L Turbo / 3.5L V6 (IS 350 311HP) / 5.0L Naturally Aspirated V8 (IS 500 472HP).

Required Tool: Socket Set, Scan Tool
Recommended Parts & Testing Tools

Equipment for Diagnosing Lexus IS (U0102)

Prime Fast Delivery & Verified Fitment
Direct-Fit Replacement Part

Lexus IS OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for Lexus IS.

$45 – $95 Prime
Check Fitment on Amazon
Sensor Signal Voltage Meter

AstroAI Auto-Ranging Digital Multimeter

4.6 / 5.0 (Best Seller)

Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.

$29.99 Prime
View on Amazon
Top Mobile OBD-II Scanner

BlueDriver Bluetooth Pro OBDII Scan Tool

4.7 / 5.0 (50,000+ Reviews)

Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.

Compare OEM & Aftermarket Replacement Sensors for Lexus ISVerified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
Find Parts on Amazon
* As an Amazon Associate, MazicBay earns from qualifying purchases. Prices & availability subject to change.

Other Common Fault Codes on Lexus IS

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Lexus IS:

4. Lexus IS U0102 FAQs

What causes code U0102 to trigger on a Lexus IS?

On the Lexus IS (2.0L Turbo / 3.5L V6 (IS 350 311HP) / 5.0L Naturally Aspirated V8 (IS 500 472HP)), U0102 is most frequently caused by Corroded TCCM power/ground wiring under vehicle or Blown 4WD / TCCM fuse in engine fuse panel.

Where is the OBD-II port located on my Lexus IS?

On the Lexus IS, the 16-pin DLC diagnostic connector is located Driver A-pillar base kick panel. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Lexus IS with code U0102?

Yes, in 2WD. 4WD and Auto 4x4 functions will be inoperative. Given that U0102 carries a Medium severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.