P0600

What it means

P0600 is the generic code for a fault on the serial communication link between the engine control module and another control unit or internal processor. The module detected missing, corrupt or interrupted data on the link, or a fault in its own communication circuitry. What it points to depends on how the vehicle's network is arranged, which varies by model and engine.

Symptoms

• Engine warning light on
• Engine cranks but fails to start, or starts and stalls
• Reduced power or limp mode
• Other warning lights on at the same time, such as ABS, traction control or gearbox
• Rough running or poor throttle response
• Intermittent fault that comes and goes with vibration or damp weather

Possible causes

• Low battery voltage, poor battery terminals or a weak charging system causing communication dropoutslikely
• Damaged, corroded or loose wiring or connectors on the CAN or serial data lineslikely
• Poor power supply or earth connections to the engine control module or the other modules on the networklikely
• Another control module on the network faulty and disrupting the data buspossible
• Water ingress or corrosion inside the engine control module or its connectorpossible
• Outdated or faulty control module software where the manufacturer has a known fix for the modelrare
• Internal fault in the engine control modulerare

How to diagnose

1. Read all stored codes from every control module, not just the engine one, and note any communication or network codes that point to a particular module or bus.
2. Review freeze frame data to see when the fault was set, and check whether it is current or historic by clearing it and seeing if it returns.
3. Test battery condition and charging voltage, and inspect the battery terminals and main earths for tightness and corrosion.
4. Check for any recent work, aftermarket accessories or alarm and radio fitments that could interfere with the data lines.
5. Visually inspect the wiring and connectors at the engine control module and on the data bus for chafing, damp, bent pins or corrosion.
6. Check the power and earth feeds to the engine control module, including fuses and relays, using the wiring diagram for the model.
7. Test the data bus wiring for continuity, shorts and correct bus resistance, following the manufacturer's procedure for that vehicle.
8. Unplug suspect modules one at a time, as the manufacturer allows, to see whether one is pulling down the network, and check for available software updates for the model.

How to fix

• Charge or replace a weak battery and repair any charging system fault.
• Clean, tighten or replace corroded or loose battery, earth and module connections.
• Repair or replace damaged wiring or connectors on the data bus or the control module supply.
• Replace a faulty network module that is disrupting communication, then code or adapt it as the manufacturer requires.
• Update the control module software where a known fault exists for that model and engine.
• Replace the engine control module only after wiring, power and earths are proven good, and then program it to the vehicle.

Can I keep driving?

This code for other makes

• P0600AudiDefective PCM (Power Train Control Module), Defective PCM data bus wiring/connections, Defective PCM data bus ground circuit(s), Defective PCM or other control module controlled output devices, Defective CAN bus communication

Nearby codes

• P05FFGenericBrake Pressure Sensor / Brake Pedal Position Sensor Correlation
• P0601GenericInternal Control Module Memory Checksum Error