P0600 Code: Serial Communication Link — Causes & Fix
P0600 means a fault in the serial communication link between control modules — the network (often CAN bus) modules use to talk to each other.
- Applies to
- All OBD-II vehicles (any make or model)
- Est. repair cost
- $50 – $600
- Time to fix
- 30 minutes – 2 hours
What it means
Causes include CAN bus wiring faults, a failing module, connector corrosion, or ground issues. P0600 is a generic OBD-II powertrain code defined in the SAE J2012 standard, so it applies to virtually any 1996-or-newer petrol car or light truck regardless of make. Fix the underlying fault, then clear the code with an OBD-II scan tool — it will return if the problem isn't resolved.
Symptoms
- Check engine light on
- Multiple unrelated warning lights
- Erratic gauges or features not working
How to fix it
- 1
Inspect the bus wiring and grounds
1. Check the communication (CAN) wiring and connectors for damage. 2. Verify module grounds and power.
- 2
Diagnose the network
1. Scan all modules for communication faults. 2. Repair the wiring or replace the failing module, then clear the code.
Frequently asked questions
Why do I have lots of warning lights with P0600?
A communication fault can knock out data several modules rely on, so many systems flag errors at once. Fix the network fault first.
Last updated July 19, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.