U1165: Lost Communication with Tuner Module
The U1165 code indicates that a control module (typically the Audio Control Module or Front Control/Display Interface Module) has detected invalid data or a complete lack of expected messages from the radio tuner/satellite receiver over the SCP (Standard Corporate Protocol) bus, which is based on SAE J1850. This fault represents a loss of one-way or two-way communication on the low-speed bus dedicated to the infotainment system.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty tuner/satellite radio module
- Open circuit, short to ground, or short to battery on the SCP bus (+/-) to the tuner
- Damaged connectors, loose pins, or corrosion in the tuner harness
- Internal failure of the receiving module (ACM/FCDIM) that processes the SCP signal
- Missing or incorrect termination resistors on the SCP bus
- Low battery voltage or voltage spikes after jump-starting
3. Symptoms You Will Notice
- No audio from radio or satellite radio
- Infotainment system display shows 'No Signal' or communication error
4. Step-by-Step Diagnosis
Check for technical service bulletins (TSBs) related to U1165 for the specific vehicle
Inspect the SCP bus wiring and connectors for damage, corrosion, or loose pins
Test the tuner module power and ground circuits
Verify SCP bus voltage and resistance with a multimeter (typically 2.5V and 60 ohms)
Perform a network communication test using a scan tool to isolate the fault
If wiring is okay, replace the tuner module or the receiving module (ACM/FCDIM) as needed
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, the vehicle is generally safe to drive, but you may lose audio and some infotainment functions. The issue does not affect critical drivetrain or safety systems.
How much does it cost to fix?▼
Diagnosis typically costs $100-$150. Repair costs vary: a new tuner module can range from $200 to $600 plus labor, while wiring repairs are usually $100-$300.