Subject: 2014 Chevrolet Cruze Diesel Noises When Vehicle is Turned Off
Models: 2014 Chevrolet Cruze
Equipped with the 2.0L (RPO-LUZ) 4-cyl Diesel Engine
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Some customers may comment on noises that are heard shortly after the vehicle is turned off.
A dealer may encounter a customer concern of a squeak, chirp, moan, whine or buzz type noises heard shortly after the vehicle has been turned off.
There are several components that may produce noises shortly after the engine has been turned off. The noises below are considered to be normal operating characteristics of the vehicle.
The Throttle Body/Throttle Valve may be heard cycling or sweeping after the engine is shut down. This may last about 15 seconds and may be heard cycling or sweeping between 5 and 10 times. The throttle body performs a self-cleaning followed by an offset learn procedure after the engine is shut off.
The Exhaust Gas Recirculation (EGR) Valve may be heard opening and closing after the engine is shut down. This may last about 15 seconds and may be heard about 5 times. The EGR valve is opening and closing to learn the position offset.
The Intake Manifold Runner Control Valve Actuator may be heard cycling. This may last about 5 seconds. This is done as an integrity check and to confirm that the mechanical link between the actuator and the intake manifold runner is still connected.
The Fuel Rail Pressure Control Valve may be heard making a whining noise. This may last about 15 seconds. The Fuel Rail Pressure Control Valve is pressurizing/controlling the flow of the fuel.
The Diesel Exhaust Fluid (DEF) Pump and DEF Reverting Valve may be heard from the rear of the vehicle. This may last about 45 seconds. When the vehicle is turned off the DEF pump and reverting valve operate to relieve the DEF system pressure and to clear the lines of DEF. The reverting valve is opened to relieve the pressure and send the fluid back to the DEF tank, and then the reverting valve is closed once the DEF lines are clear.
The Air Conditioner (A/C) Compressor Electronic Control Valve may be heard making a whining noise. This may last about 5 minutes. The electronic control valve inside the air conditioner compressor may remain energized after the engine is shut down.
The Service Personnel should communicate to the customer that this is a normal operating characteristic of their vehicle. It will not impact the designed performance or reliability of the vehicle. Please share this information with the customer, including a copy of this message.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.