DTC C1745: Exhaust Solenoid Valve Circuit Malfunction [08/2015 - 08/2019]: Description

The suspension control ECU operates the exhaust solenoid valve (height control compressor), releases the air from the height control cylinder assembly (pneumatic cylinder), and lowers vehicle height.

When the vehicle height is lowered, the suspension control ECU opens the height control valve and then operates the exhaust solenoid valve to release the compressed air to the outside.

The exhaust solenoid valve is on the compressor unit and has only one valve.

DTC Code	Detection Condition	Trouble Area
C1745	When either of the following is detected: With the exhaust valve not activated, an open signal of the exhaust valve is detected for 1 second or more. With the exhaust valve activated, a short signal of the exhaust valve is detected 8 times successively.	Wire harness or connector Exhaust solenoid valve (No. 1 height control compressor) Suspension control ECU

HINT:

Once the ECU stores DTC C1745 in the memory, the vehicle height control is suspended until a normal signal is input to the ECU from the exhaust solenoid valve. However, control is resumed if the ignition switch is turned off, then to ON again.
Malfunction in the exhaust solenoid valve:
The height control indicator light "N" comes on or blinks, and "HI" and "LO" do not come on by operating the height control switch "UP" or "DOWN".