Released today on GTR site, haven't seen anything similar reported on the forum yet, but just in case:
SSM 42955
Models
LM - New Range Rover
LS - Range Rover Sport
LA - Discovery 4
Title 10MY Smart Key Not Found
Last Modified 13-JAN-2010 11:51
Category Electrical
Symptom 203000 Basic Electrical
Content
Issue
The Ignition will not turn on / Engine will not start and the message 'Smart Key Not Found' is the displayed on the Instrument Pack message centre.
Cause
Currently Engineering has identified several concerns with regards to this message and in order to help correct the concern the following steps must be performed.
The problem is identified as Transponder Lock Up, in this scenario the Transmitter within the Smart Key is blocked from making the appropriate transmission to the vehicle. The failure mode is intermittent and therefore it is not always repeatable.
Action
1. Determine if the concern is a result of Medium Speed CAN. Can you communicate to the vehicle's Medium Speed CAN using SDD?
a. YES – The Medium Speed CAN is operating properly. Continue to step 2.
b. NO – Proceed with diagnosing why the Medium Speed CAN is not responding.
2. Remove fuse 17P (5amps) from the Passenger Compartment Fuse Box. Wait one minute. Insert fuse 17P (5amps) into the Passenger Compartment Fuse Box. Has the 'Smart Key Not Found' message cleared?
a. YES – STOP. At this point you've diagnosed a concern with the KVM's software. Engineering is currently looking into this condition to understand what is causing the KVM to enter this locked state. A further communication will follow once the root cause has been determined. Furthermore, the concern could happen again and it is advisable to alert the customer that if the condition occurs they will need remove fuse 17P (5amps) from the Passenger Compartment Fuse Box in order to recover the KVM. Make the customer aware that we are working on a resolution and will deliver one ASAP.
b. NO – Continue to step 3.
3. If steps 1 and 2 have not rectified the concern, then the problem is identified as Transponder Lock Up, in this scenario the transmitter within the Smart Key is blocked from making the appropriate transmission to the vehicle. The failure mode is intermittent and therefore it is not always repeatable. Replace the original two and any subsequent keys the customer has for the vehicle. Updated keys are available, under the following numbers via a Critical Parts Order.
Range Rover and Range Rover Sport.
433 MHz LR020366
315 MHz LR020365
Discovery4 and LR4
433 MHz LR020364
315 MHz LR020363