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U0104 on RAM: Symptoms, Causes & Fix

Lost Communication with Cruise Control Module

Official technical diagnostic wire for fault code U0104 specifically affecting RAM vehicles (1500, 2500, 3500, TRX).

Sensor Voltage Ref
0.1V – 5.0V Ref
RAM Factory Standard
CAN Bus Speed
500 kbps CAN-FD
ISO 15765-4 Diagnostic Bus
Drivability Status
Not Recommended
Low urgency level
Est. Repair Cost
$100 - $450 (DIY: $0 - $150)
Parts & Labor DIY
Model-Specific Diagnostic Wires

Select Your RAM Model for U0104:

5 Models Available

1. Common Symptoms on RAM Vehicles

When RAM Engine Control Modules (ECM) trigger fault code U0104, drivers typically report:

Adaptive Cruise Control (ACC) disabled on RAM Powertrains
Pre-Collision System warning light on on RAM Powertrains
Check Engine Light on on RAM Powertrains

2. Root Causes on RAM Engines

Historical diagnostic claims across RAM engines point to the following failure distribution:

55%
Blocked or dirty front radar sensor in grille/bumper (RAM OEM Part)
25%
Blown radar module fuse (RAM OEM Part)
12%
Faulty radar cruise control module (RAM OEM Part)
8%
Misaligned radar sensor following minor bumper bump (RAM OEM Part)

3. Step-by-Step Fix Protocol for RAM

01
Clean Front Radar Sensor in Grille

Clean snow, ice, mud, or dead bugs off front radar emblem. on RAM engines.

Required Tool: Microfiber Towel
02
Check ACC / Radar Fuse

Verify power feed to radar sensor. on RAM engines.

Required Tool: Test Light
03
Perform Radar Aiming Calibration

Execute optical/radar alignment procedure if bumper was removed. on RAM engines.

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

Clear DTCs and test cruise on highway. on RAM engines.

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

Equipment for Diagnosing RAM (U0104)

Prime Fast Delivery & Verified Fitment
Direct-Fit Replacement Part

RAM OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for RAM.

$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 RAMVerified 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.

4. RAM U0104 Frequently Asked Questions

What does code U0104 mean on a RAM?

On RAM vehicles, U0104 indicates that the Engine Control Module (ECM) detected lost communication with cruise control module. This typically points to Blocked or dirty front radar sensor in grille/bumper or Blown radar module fuse.

Can I continue driving my RAM with code U0104?

Yes. Normal driving is unaffected, but Adaptive Cruise Control will not engage. Because this code carries a Low severity rating on RAM powertrains, we recommend scanning live data values promptly to prevent secondary damage.

How much does it cost to fix code U0104 on a RAM?

Estimated DIY parts cost ranges from $100 - $450 (DIY: $0 - $150), while professional shop repairs at an authorized RAM dealership or independent specialist typically range from $180 to $380 including diagnostic labor.