U1158: Antenna Module Communication Lost
The U1158 code indicates that the Body Control Module (BCM) or Audio Control Module (ACM) has detected a loss of communication or invalid data from the antenna module (or integrated antenna tuner) over the SCP (Standard Corporate Protocol) bus, Ford's proprietary implementation of SAE J1850 VPW. This means periodic status or data messages from the antenna are missing, corrupted, or have an incorrect identifier.
1. Commonly Affected Makes
2. Most Common Causes
- Open, short to ground/battery, or high resistance in the SCP bus (+/-) wiring to the antenna module
- Internal failure of the antenna module or antenna amplifier
- Internal failure of the Audio Control Module (ACM) or BCM
- Loose, corroded, or damaged connectors on the SCP bus
- Excessive electromagnetic interference (EMI) on the communication harness
- Software configuration error or incompatible module version after replacement
3. Symptoms You Will Notice
- Radio or audio system malfunction (no sound, poor reception, or intermittent operation)
- Possible issues with keyless entry, remote start, or other antenna-dependent features
4. Step-by-Step Diagnosis
Scan for other related codes and check for communication faults on the SCP bus
Inspect the SCP bus wiring and connectors for damage, corrosion, or loose connections
Test the antenna module power, ground, and bus signals with a multimeter or oscilloscope
Check for software updates or module configuration issues using a factory-level scan tool
If wiring is intact, substitute the antenna module with a known-good unit to isolate the fault
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, the vehicle is generally safe to drive, but you may experience audio system issues and possibly other antenna-related functions. The severity is medium, so it's advisable to diagnose and repair soon to avoid further electrical problems.
How much does it cost to fix?▼
The cost can range from $100 to $500 depending on the root cause. Simple wiring repairs may cost $100-$200, while replacing an antenna module or ACM can run $300-$500 including labor.