U1164

SCP (J1850) Invalid or Missing Data for Tuner / Receiver

Network / Communication Network/Communication J1850 SCP Bus 🟡 Moderate — Fix within a week ⚠️ Drive with Care
💬

What This Actually Means

In plain language — no jargon

Your vehicle's communication network isn't receiving proper data from the radio/tuner module over the SCP bus. Think of it like a phone call where one person isn't transmitting their voice clearly—the other end hears silence or garbled messages.

⚡

Symptoms You May Notice

3 known symptoms for this code
Radio or infotainment system malfunction or display errors
Loss of audio or tuner functionality
Check Engine Light illuminated
🔬

How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ECU monitors the SCP (J1850) serial communication bus for valid data packets from the tuner/receiver module at regular intervals. When expected messages fail to arrive or contain invalid checksums within the timeout window, the ECU logs this fault. The system expects periodic heartbeat signals and command responses from the radio module.

Voltage & Parameter Thresholds

ParameterNormal RangeFault Condition
SCP Message Timeout Valid data received every 10-100ms No valid message received for >500ms
Data Checksum Validity Checksum matches expected value Checksum mismatch or corrupted packet
🔧

Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex
1
OBD-II Scanner
Clear the fault code and observe if it returns; transient communication errors may self-resolve.
2
SCP Bus Wiring/Connectors
Inspect radio module connectors and J1850 bus wiring for corrosion, loose pins, or damaged insulation and clean or reseat as needed.
3
Radio/Tuner Module
If wiring is sound, the radio module itself may be faulty and require replacement or reprogramming by dealer.
⚠️

When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code U1164 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.

Safety note: OBD-II codes identify the system or circuit where a fault was detected — they do not always identify the exact failed component. A professional mechanic using live sensor data will diagnose the root cause more accurately than replacing parts based on the code alone.
🔄

How to Clear Code U1164

What happens after you fix the fault

Once the fault is repaired, U1164 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.

The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.

✅ Safe to Clear When
  • Fault has been diagnosed and repaired
  • You want to confirm the repair worked
  • Code appeared after a sensor was cleaned
⚠️ Do Not Clear When
  • Preparing for an emissions/PUC test
  • Root cause is still undiagnosed
  • Check engine light is flashing
Emissions test note: Clearing codes resets OBD readiness monitors. Most vehicles need 50–100 km of mixed driving before monitors complete. Do not clear codes immediately before an emissions or PUC inspection.