Mercedes-Benz W204 will not start: steering lock and ignition switch
W204 will not start and there is no click from the ignition switch, what is wrong?
Often the fault is in the electric steering lock and not in the ignition switch. A typical part is the steering lock motor. Symptoms can be that the key does not click, the power does not come on or the key does not turn. The cause can vary, so the fault is confirmed by diagnosis.
Which fault codes are related to the W204's steering lock?
The codes A25464 (illogical signal) and A25407 (control unit faulty) have been seen in the steering lock control unit. The fault can be intermittent and does not always show as a code. Replacing the battery does not remove the symptom.
How is a faulty steering lock repaired?
The repair is replacing the steering lock. If the fault remains unclear, first check the key and its battery, the fuses and the dirty infrared lens of the key or the ignition switch. It is not worth greasing the ignition switch, because it cannot be made to work better that way. The steering lock is tied to the immobiliser and the steering, so replacing and activating it is a job for a workshop.
How can the steering lock getting stuck be avoided?
Do not pull on the steering wheel or hold it while switching the car off. The power steering then presses the lock bolt tight, and the bolt can get stuck or the lock motor can burn out.