P1668: PCM - IDM Communications Error
MediumPowertrainEngine/Powertrain
What does P1668 mean?
P1668 is a diagnostic trouble code indicating "PCM - IDM Communications Error". This code relates to your vehicle's engine/powertrain and should be diagnosed to determine the root cause. The severity level helps indicate how urgently this should be addressed.
Symptoms you may notice
- Check engine light (MIL) illuminated on dashboard
- Possible issues with engine/powertrain operation
- Vehicle may enter reduced power mode (limp mode)
Estimated repair cost
Typical range in Australia (parts + labour)
$200 – $1500 AUD
Common causes
- Faulty engine/powertrain component
- Wiring or connector issue in the related circuit
- Failed sensor providing incorrect readings
- Software/calibration issue requiring ECU update
- Related component causing secondary fault
What should you do?
This code sits in a powertrain control module. The engine or transmission can drop into limp mode or cut out, which is its own hazard in traffic or on a motorway. Get it diagnosed before your next trip rather than waiting for the next service.
Get a diagnosis for YOUR car
Code P1668 can mean different things depending on your vehicle. TorqueBot gives you a diagnosis specific to your make, model, and year.