P0600 Fault Code in Land Rover: Causes, Symptoms, and Fixes

This is a generic OBD-II code that points to a communication failure between the Engine Control Module (ECM) and other control modules in the vehicle. The ECM communicates with various modules (such as TCM, ABS, BCM) via a data bus. If it detects that the serial communication link is broken, corrupted, or intermittent, it sets code P0600.

Possible Causes

1. Loose, damaged, or corroded wiring/connectors in the communication harness
2. Faulty ECM/PCM (internal failure or software issue)
3. Faulty module (e.g., TCM, ABS, BCM not responding)
4. CAN bus or serial bus faults – open circuit, short to power/ground
5. Aftermarket devices (alarms, trackers, remote starters) interfering with communication

Symptoms

1. Check Engine Light ON
2. Other warning lights (ABS, traction, transmission, etc.) may appear
3. Vehicle may go into limp mode
4. Poor drivability: misfiring, stalling, no start (in some cases)
5. Inconsistent or no data communication when scanning with OBD-II tool

Diagnosis & Fix

1. Visual inspection – Check harnesses, grounds, fuses, connectors for looseness or corrosion.
2. Scan tool check – If multiple modules cannot communicate, suspect wiring/CAN issue.
3. Check for related codes – Often P0600 comes with other communication or module-specific codes.
4. Wiggle test – Move harness/connectors to see if code reappears.
5. Check ECM power and grounds – weak ground or low voltage can trigger this code.
6. If wiring is fine → suspect faulty ECM/PCM or another control module.
7. In rare cases, a software update/reflash may resolve it.