P0600 code meaning

What P0600 means

P0600 means a serial data link that the module relies on has failed. At Ford it is the internal link between the main processor and the monitoring processor ('quizzer') of the electronic throttle safety concept: if data cannot be exchanged or check bytes are invalid, the code sets within about a second (diesel: 5 s), usually with the check engine and wrench lamps and a throttle failure mode such as an RPM limit. Subaru (also sold as Saab 9-2X) uses it for the dedicated serial line between engine and transmission module. GM does not use P0600. Lost CAN messages from a named module are reported separately as U0100 and following. Before replacing anything: check battery, grounds and supply, look for a software bulletin, reprogram with a stable power supply, and replace the module only if the code returns.

P0600 at a glance

• Check engine lightYes, usually on
• Emissions testCan fail
• Limp modePossible
• Repair difficultyHard
• Typical labor1 to 4 hours
• Clears after repairWhen cleared with a scanner

Symptoms of P0600

• Check engine light, at Ford also the wrench lamp
• Reduced power or RPM limit (throttle failure mode)
• Harsh shifts or transmission limp mode where the line links engine and gearbox
• Other monitors such as the catalyst monitor do not run

Common causes of P0600

• Most likelyInternal module fault in the processor-to-processor link
• PossibleFaulty module software (update available)
• PossibleOpen or short in a dedicated serial line between engine and transmission module (e.g. Subaru)
• PossibleLow voltage, voltage dips or a poor ground or supply at the module
• Less likelyFault in the transmission module at the other end of the line

Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.

Parts involved

Engine control moduleTransmission control moduleSerial data line

What each part of P0600 means

What to do next

• Note P0600 and any other codes stored with it: several codes together often point to one cause.
• Check for loose connectors and damaged wiring around the parts the code names.
• Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
• Clear the code only after the repair. If it comes back, the fault is still there.

Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.

Codes often seen with P0600

• P0606 Control Module Processor
• P060A Internal Control Module Monitoring Processor Performance
• P0607 Control Module Performance
• P060C Internal Control Module Main Processor Performance
• U0100 Lost Communication With ECM/PCM A
• U0101 Lost Communication With TCM

Questions about P0600

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