Your Infiniti Q45 engine control system detects a problem, the computer stores the diagnostic trouble
code U3523 in its memory.
To figure out what is wrong with your vehicle you must first extract the U3523 DTC For Infiniti Q45.
On 1999 and later U3523 Infiniti Q45 engines, the instrument cluster has a built-in self-diagnostic mode that can be accessed by pressing and holding the instrument cluster SELECT/RESET button. Insert the ignition key and turn to the RUN position (but don't crank or start engine). Continue to press and hold the SELECT/RESET button (for 5 seconds) until the word TEST is displayed by the odometer. Release the SELECT/RESET button within three seconds after the word TEST is displayed to begin the self-diagnostic mode.
U3523 Infiniti Q45 DTC Meaning
Network Code - Problem is climate control system, lighting, airbags, etc.
SAE - Generic
Auxiliary Emission Controls
Cruise Control Servo Indicates Low
TFP Valve Position Switch-Drive Without Drive Ratio
While fuel economy was increased, acceleration was seriously compromised, and the loss of engine vacuum led to a dangerous loss of braking assist when the U3523 Infiniti Q45 code system was in four-cylinder mode. In addition to these issues, while the company proposed a hydraulically controlled system that could be switched from within the car, the version they implemented had to be manually changed in the engine compartment using hand tools.