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U0073 on Chrysler 300

Control Module Communication Bus A Off

Factory diagnostic protocol and troubleshooting wire for fault code U0073 specifically for the Chrysler 300 (2020–2025, 3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8)).

Verified OEM Telemetry & Field Repair Tree
Chrysler 3002020–2025
Chrysler 300
Sedan3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8)
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
300 SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Not Recommended
Critical urgency level
Est. Repair Cost
$150 - $850 (DIY: $40 - $200)
Parts & Labor DIY
Check U0073 On Another Chrysler Model:
Diagnose U0073 on Specific 300 Model Year:

1. Symptoms of U0073 on Chrysler 300

When the Engine Control Module (ECM/PCM) on your Chrysler 300 (3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8)) logs fault code U0073, drivers commonly observe:

StabiliTrak / Traction / ABS / Engine warning lights lit on Chrysler 300 (3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8))
Transmission shifting harshly or refusing to shift out of 2nd gear on Chrysler 300 (3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8))
No communication with TCM, ABS, or BCM on Chrysler 300 (3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8))
Engine may refuse to crank on Chrysler 300 (3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8))
Chrysler 300 OBD-II Port Location
The 16-pin diagnostic connector is located Under driver side dash near left knee panel. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Chrysler 300

Historical warranty claims and technical repair bulletins for Chrysler 300 point to the following failure distribution:

55%
Loose or corroded ground connection on transmission or frame (Chrysler OEM Part)
25%
Faulty Transmission Control Module (TCM) or ABS module pulling bus down (Chrysler OEM Part)
12%
Poor connection at large body-to-chassis pass-through harness connector (Chrysler OEM Part)
8%
Aftermarket accessory (remote starter, GPS tracker, cheap OBD scanner) broadcasting invalid data (Chrysler OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Chrysler 300.

3. Step-by-Step DIY Repair Guide for Chrysler 300

01
Unplug All Aftermarket OBD-II Devices

Remove any aftermarket insurance dongles, GPS trackers, or scan tools plugged into the DLC port. on the Chrysler 300 equipped with 3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8).

Required Tool: None
02
Inspect Frame and Transmission Ground Straps

Inspect braided ground straps on engine and transmission. Clean all contact surfaces to bare metal. on the Chrysler 300 equipped with 3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8).

Required Tool: Wire Brush, Sockets
03
Perform Full Vehicle Network Topology Scan

Scan all modules on vehicle. Note which modules are online and which are offline to pinpoint the break in the network daisy-chain. on the Chrysler 300 equipped with 3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8).

Required Tool: Full-System OBD-II Diagnostic Scanner
04
Check Terminating Resistance (60 Ohms)

Verify 60 ohms across Pins 6 and 14 with battery disconnected. on the Chrysler 300 equipped with 3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8).

Required Tool: Multimeter
05
Clear All System DTCs & Road Test

Clear DTCs from all modules and road test to verify error-free network transmission. on the Chrysler 300 equipped with 3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8).

Required Tool: Scan Tool
Recommended Parts & Testing Tools

Equipment for Diagnosing Chrysler 300 (U0073)

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Direct-Fit Replacement Part

Chrysler 300 OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for Chrysler 300.

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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.

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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.

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Other Common Fault Codes on Chrysler 300

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Chrysler 300:

4. Chrysler 300 U0073 FAQs

What causes code U0073 to trigger on a Chrysler 300?

On the Chrysler 300 (3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8)), U0073 is most frequently caused by Loose or corroded ground connection on transmission or frame or Faulty Transmission Control Module (TCM) or ABS module pulling bus down.

Where is the OBD-II port located on my Chrysler 300?

On the Chrysler 300, the 16-pin DLC diagnostic connector is located Under driver side dash near left knee 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 Chrysler 300 with code U0073?

No. Bus is shut down due to excessive transmission errors, leaving vehicle in unpredictable limp mode. Given that U0073 carries a Critical severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.