OBD-II Code · Network
P0600
Serial Communication Link
Severity
high
Left alone, this one tends to take other parts with it.
Can you drive it
Only if running normally
A short trip to a shop may be reasonable if the light is steady and the car runs normally. Stop safely for a flashing light, severe shaking, overheating, loss of power, or another urgent warning. The code alone cannot confirm safety.
Indicative cost (USD)
$100–$2,000
Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
Communication link fault between modules.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then work the likely-causes list in the order shown.
That order is what a shop checks first for this code — wiring and connections before the component they run to, because a connector costs nothing to inspect and is a common answer.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Multiple CELs
- Erratic behavior
Likely causes
- WiringMost common
- Failed module
Read the full diagnostic procedureP0600 indicates a serial communication link malfunction, meaning the PCM has lost expected data traffic with one or more modules on the CAN, GMLAN, S…
P0600 indicates a serial communication link malfunction, meaning the PCM has lost expected data traffic with one or more modules on the CAN, GMLAN, SCP, or CCD bus. Start cheapest-first by scanning every module with a bidirectional tool, not just the PCM, since the missing module is the diagnostic clue. Verify battery voltage at rest above 12.4V and during cranking above 9.6V, because low system voltage is the single most common cause of phantom comm faults. Inspect the data link connector at pins 6 and 14 (CAN-H and CAN-L) with key on, engine off, looking for roughly 2.5V on each leg, and with key off across pins 6-14 you should see approximately 60 ohms (two 120-ohm terminating resistors in parallel). A reading of 120 ohms means one terminator is missing or one module is unplugged; a reading near 0 ohms is a shorted bus. Wiggle-test the harness near common chafe points (firewall pass-through, behind glovebox, near the alternator) while watching live data drop. The expensive misdiagnosis trap is replacing the PCM when the actual fault is a single corroded ground (G102/G104 on GM, G103 on Ford) or a failed module dragging the bus low — that wastes a $900+ part for a $5 fix.
Vehicle-specific patterns2003-2007 GM full-size trucks and SUVs (Silverado, Tahoe, Suburban with 4.8/5.3/6.0L) commonly throw P0600 alongside U-codes from a corroded G103 gro…
- 2003-2007GM full-size trucks and SUVs (Silverado, Tahoe, Suburban with 4.8/5.3/6.0L) commonly throw P0600 alongside U-codes from a corroded G103 ground stud near the left cylinder head or a failed instrument cluster pulling Class 2 bus low.
- 2004-2008Ford F-150 and Expedition show P0600 with U0100/U0101 from chafed CAN wiring at the engine harness pass-through behind the battery tray, addressed in TSB 08-7-6.
- 2005-2010Chrysler/Dodge/Jeep vehicles with the TIPM (300, Charger, Grand Cherokee, Ram 1500) frequently set P0600 when the TIPM internal CAN driver fails, a well-documented pattern covered by multiple FCA TSBs and the subject of class-action settlements.
- 2002-2006VW/Audi with the convenience-CAN gateway throw P0600 when the gateway module under the driver's footwell loses ground or sees water intrusion from a leaking cowl drain.
Estimated repair$40 to $1,400.
Look up another code
P0600 — frequently asked
What does a P0600 code mean?
Communication link fault between modules.
What causes a P0600 code?
Common causes: Wiring; Failed module.
What are the symptoms of a P0600 code?
Typical symptoms: Multiple CELs; Erratic behavior.
Is it safe to drive with a P0600 code?
Only if running normally. A short trip to a shop may be reasonable if the light is steady and the car runs normally. Stop safely for a flashing light, severe shaking, overheating, loss of power, or another urgent warning. The code alone cannot confirm safety. Estimated repair: $100-$2,000.
How do I diagnose a P0600 code?
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed. 1. Note every code that is set, not just this one. 2. Read the freeze frame — the conditions the fault was recorded under. 3. Confirm the fault is current rather than history. 4. Then work the likely-causes list in the order shown.
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