P0600 Serial Communication Link
OBD-II Trouble Code Technical Description
Generic: Serial Communication Link Malfunction
Chrysler: PCM Fault, SPI Communications Conditions
GM: Loss of Serial Communication Link Conditions
Infiniti: AT communication - circuit malfunction
Nissan: ECM/TCM - communication malfunction
What does that mean?
This is a generic powertrain diagnostic trouble code (DTC), which means it covers all makes/models, 1996-newer. However, specific troubleshooting steps will vary depending on the vehicle.
This code indicates a malfunction in the wiring link between the electronic control module (ECM) and one of its supporting control modules. On board diagnostics (OBD) trouble code P0600 is generic by design and encompasses all computer-controlled vehicles.
Explanation of OBD code P0600
Your vehicle's ECM or powertrain control module (PCM) has lost its control over one or more actuator modules. Most vehicles have as many as 18 actuators that the primary ECM controls. It does so through a controller area network (Can Bus Automotive Network), which is a series of wiring harnesses from the ECM to the controllers.
The controllers operated by the ECM, known as modules, control the majority of the functions of your vehicle. The code P0600 was set when the ECM recognized a loss of communication and control over one or more of these modules for eight consecutive starts.
ECM and associated control modules
This is a list of the primary control modules operated by the ECM:
Fuel injection system Ignition system Variable camshaft timing Turbo charger Emission systems Air conditioning Transmission shift points Body ride control ABS brakes Cruise control Anti-theft Sunroof and seat position Power windows Traction control systems Proximity alertsThese are just a few, not to mention all the available computer controlled options available today.
Symptoms
This is a commonly misdiagnosed code inasmuch as it may cause a deceptive symptom. Always bear in mind that the code P0600 indicates a communication failure. For instance -- an ignition system failure or a failed fuel injector can cause a misfire.
An inexperienced technician may begin by attempting to diagnose the affected system rather than the loss of communication. If the ECM is not controlling the ignition control module or grounding the fuel injector, a misfire will occur.
This is not a fault with the system, but with control of the system itself. Depending on the location of the failure, the following symptoms may be present:
Check engine light illuminated accompanied by an additional code, ABS light illuminated, Transmission light illuminated (vehicle may not shift properly), Big drop in fuel economy, Driveability problems may occur, such as stalling at an idle, rough running and poor acceleration, or Problems with a particular system indicating a possible communication loss in this area.Potential Causes
Experience has proven that a poor connection or failed ECM driver is the root cause of this code. For the most part, the ECM acts as a ground to control these components and modules as opposed to supplying power to them.
A loose or corroded connector is more likely than a frayed or broken wire between both devices. Poor grounds are another plausible cause. The ECM, as well as the activator module, need a good ground to operate.
The wiring harness or Can Bus may be defective and have a short to ground or an open wire.
Diagnostic and Repair Procedures
The best advice concerning the diagnosis and repair of this particular code is to take the vehicle to a professional technician that has a Autohex or Tech II diagnostic computer.
If you unplug the ECM or the associated wiring and then probe the terminals, your bank account could suffer extreme consequence
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