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U0104 on Toyota RAV4

Lost Communication with Cruise Control Module

Factory diagnostic protocol and troubleshooting wire for fault code U0104 specifically for the Toyota RAV4 (2020–2026, 2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP).

Verified OEM Telemetry & Field Repair Tree
Toyota RAV42020–2026
Toyota RAV4
SUV2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
RAV4 SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Not Recommended
Low urgency level
Est. Repair Cost
$100 - $450 (DIY: $0 - $150)
Parts & Labor DIY
Check U0104 On Another Toyota Model:
Diagnose U0104 on Specific RAV4 Model Year:

1. Symptoms of U0104 on Toyota RAV4

When the Engine Control Module (ECM/PCM) on your Toyota RAV4 (2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP) logs fault code U0104, drivers commonly observe:

Adaptive Cruise Control (ACC) disabled on Toyota RAV4 (2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP)
Pre-Collision System warning light on on Toyota RAV4 (2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP)
Check Engine Light on on Toyota RAV4 (2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP)
Toyota RAV4 OBD-II Port Location
The 16-pin diagnostic connector is located Driver footwell directly above brake pedal arm. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Toyota RAV4

Historical warranty claims and technical repair bulletins for Toyota RAV4 point to the following failure distribution:

55%
Blocked or dirty front radar sensor in grille/bumper (Toyota OEM Part)
25%
Blown radar module fuse (Toyota OEM Part)
12%
Faulty radar cruise control module (Toyota OEM Part)
8%
Misaligned radar sensor following minor bumper bump (Toyota OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Toyota RAV4.

3. Step-by-Step DIY Repair Guide for Toyota RAV4

01
Clean Front Radar Sensor in Grille

Clean snow, ice, mud, or dead bugs off front radar emblem. on the Toyota RAV4 equipped with 2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP.

Required Tool: Microfiber Towel
02
Check ACC / Radar Fuse

Verify power feed to radar sensor. on the Toyota RAV4 equipped with 2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP.

Required Tool: Test Light
03
Perform Radar Aiming Calibration

Execute optical/radar alignment procedure if bumper was removed. on the Toyota RAV4 equipped with 2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP.

Required Tool: Calibration Target, Scan Tool
04
Clear Trouble Codes

Clear DTCs and test cruise on highway. on the Toyota RAV4 equipped with 2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP.

Required Tool: OBD-II Scanner
Recommended Parts & Testing Tools

Equipment for Diagnosing Toyota RAV4 (U0104)

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Direct-Fit Replacement Part

Toyota RAV4 OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for Toyota RAV4.

$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 Toyota RAV4Verified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
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Other Common Fault Codes on Toyota RAV4

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Toyota RAV4:

4. Toyota RAV4 U0104 FAQs

What causes code U0104 to trigger on a Toyota RAV4?

On the Toyota RAV4 (2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP), U0104 is most frequently caused by Blocked or dirty front radar sensor in grille/bumper or Blown radar module fuse.

Where is the OBD-II port located on my Toyota RAV4?

On the Toyota RAV4, the 16-pin DLC diagnostic connector is located Driver footwell directly above brake pedal arm. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Toyota RAV4 with code U0104?

Yes. Normal driving is unaffected, but Adaptive Cruise Control will not engage. Given that U0104 carries a Low severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.