U0486

Code

Generic U — Network/User

Invalid Data Received From Antenna Control Module

Brand: Generic

Type: U — Network/User

Views: UK: 26 EN: 32 RU: 23

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Page language: EN

Causes

Faulty Antenna Control Module (ACM) firmware or hardware
Intermittent or failed power supply or ground to the ACM
Damaged, corroded, or disconnected wiring/connectors to the ACM
CAN or LIN bus wiring fault (short, open, high resistance, or improper termination)
Bus contention or excessive bus errors from another module
Module programming mismatch or corrupted software

Symptoms

Loss or intermittent operation of powered or mast antenna (no extend/retract)
Radio reception problems (AM/FM or satellite) or no antenna signal
One or more audio/radio functions inoperative or reported communication errors
Network-related warning messages in infotainment or body modules
DTC present in body or infotainment modules; possibly illuminated message on dash

What to check

Connect a scan tool and record U0486 plus any related DTCs and freeze-frame data from all modules
Check battery voltage (should be within nominal range) and look for low-voltage events during communication
Visually inspect ACM connector and wiring for corrosion, damage, water intrusion, or loose pins
Verify ACM power and ground circuits (fuse, relay, 12V feed, and at-module ground continuity/resistance)
Check CAN/LIN bus wiring continuity and for shorts to battery, ground or other circuits
Measure CAN bus voltages with a DMM (idle) and/or view waveforms with an oscilloscope to detect bus errors/noise

Signal parameters

ACM supply voltage: ~12 V nominal (verify within vehicle spec)
Ground: low resistance to chassis (typically
CAN bus recessive voltage: CAN_H ≈ 2.5 V, CAN_L ≈ 2.5 V
CAN bus dominant state: CAN_H ≈ 3.5 V, CAN_L ≈ 1.5 V (differential ~2 V)
Expected ACM message: periodic status/heartbeat at a low frequency (typically 1–10 Hz) — verify presence with scan tool
Bus termination: ~60 ohms total (two 120Ω terminators in parallel) if measuring with an ohmmeter across CAN_H/CAN_L with power off

Diagnostic algorithm

Read and record all DTCs and module addresses; note freeze frame data and related U-codes.
Inspect ACM connector and harness for water intrusion, corrosion, bent pins, or damage; repair as needed.
Verify fuses/relays supplying ACM power; measure supply voltage at the module with key on and during operation.
Check and measure module ground quality; clean/repair ground connections if high resistance.
Scan the CAN/LIN network with a capable tool: monitor for ACM messages (ID/periodicity) and for bus errors or collisions.
Measure CAN_H and CAN_L idle and dominant voltages with DMM; if suspect, view waveforms with an oscilloscope to find noise, reflections or missing frames.
Isolate the ACM from the bus (disconnect its connector) and observe bus behavior and DTC changes — note: disconnect only when safe and with procedures followed.
If ACM is not transmitting but has proper power/ground, consider reprogramming or replacing the ACM; verify software calibration matches vehicle.
After repairs or module replacement, clear codes and perform a road or function test; monitor network to ensure no recurrence.
If intermittent, wiggle test harness while monitoring to reproduce and locate intermittent wiring faults.

Likely causes

Loose, corroded, or damaged ACM connector or wiring
Failed ACM or internal electronic fault
CAN bus wiring fault (open/short/poor splice) between ACM and network
Low battery/poor supply voltage during module communication
ECU/software mismatch after module replacement or update

Fault status

⚠️ Status

Invalid or corrupted data received from the Antenna Control Module. Communication messages from the module failed validation or were not within expected parameters.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.0 hours

Repair manuals