Permanent and Cheap Fix for the Dreaded Steering Lock (Key will not turn in the ignition)

Twice in the last 12 months I've been stranded in my 2007 L322 TDV8, both times due to the key not turning in the barrel. At the time I assumed the key was at fault, or maybe the ignition barrel, but actually the fault lies with the steering lock. You may hear some clicks from the dash/steering column when it tries to unlock - some people refer to it as the "three dreaded clicks".

Firstly, a quick overview on how it is meant to work. Pre-2008 cars have a motorised steering lock, with a Kuhnke solenoid with inbuilt hall sensor. Behind the traditional "ignition barrel" is a transponder which reads the key (to disarm the immobiliser), a sensor to pick up when the key is inserted along with a locking pin (another solenoid), and finally a switch to actually turn on the ignition and crank the engine.

When the key is inserted, a signal is sent from the key-in sensor to the steering lock ECU. This small module is located within a security sealed aluminium casing on the underside of the steering column. You can get into it with a bit of force and by drilling out the locking pins. Many people do this in an attempt to lubricate the solenoid with WD40. This didn't work for me, the solenoid had failed. I was able to get it actuate with a bit of helping push and a 12V feed, but it wasn't operating whilst in the vehicle.

If steering lock fails, any garage will tell you need an upper steering column. This is a JLR part only, and currently costs £3.5k. Ouch. Second hand columns often go for £400-£900 on eBay. There was no way I was going to pay that, so I looked for a bypass. Kuhnke are not allowed to sell the solenoid to anyone except JLR - many people have asked!

Luckily, my steering lock failed open. You can of course check by simply moving the steering wheel and checking whether or not it hits the lock. If this is the case, you're in luck - there's an extremely simple fix available. If it's failed in a locked position, you may need to get into the alloy box by drilling pins and driving the motor into the release position with a 12V feed to the motor. Once your steering lock is released, you can completely remove the steering lock module from the system. If you haven't prised open the alloy box, simply remove the connector C2055:

Removing this connector will completely isolate the module. The steering lock can no longer function.

The next challenge is to send the signal to the key-in sensor to allow the key to turn. Following the diagram below, we can see that there are three wires between the two modules:

By using a multi-meter, you can measure the resistance of these wires to ground. You'll find the resistance of C2055-1 to earth is about 80 ohms. This indicates it's likely a solenoid. More precisely, it's the locking pin solenoid which is preventing the key from turning.

If you send 12V down pin 1, for example by shorting the battery live pin (pin7), the locking pin will release, and the key will turn. As the immobiliser operates from the transponder, the car will finally start.

As a temporary measure, placing two sewing needles into 1 and 7 allows you to touch them together and turn the key. A more permanent fix of course is to wire a push switch to these two wires. Like a valet switch, you'll then need to depress it to turn the key. If you want to keep the "normal" behaviour, a timer relay wired to the interior lights would be your best bet. 

You do not need to buy a new steering column. Simply short two wires and you'll be mobile again.

Enjoy....

L322 Nut