Starting

A customer complaining of a no start may actually have a security fault that purposely disables the vehicle. It is important to understand how the security system disables the vehicle so you can assess the situation and provide a rapid diagnosis. The security system works by comparing the security code sent out from the alarm ECU to the GEMS ECU and the confirmation that it is correct is by illuminating the check engine light. The alarm ECU senses that the check engine light is illuminated and then enables the cranking of the engine. If the code is not correct the check engine light will not illuminate, the injectors will not be enabled and the engine will not be allowed to crank, thus disabling the vehicle. For additional information concerning P1621,P1622 fault codes, check the Security Link section of this document.

On New Range Rover check the following, see if:

^ Battery ground loose.

^ GEMS ground under fusebox loose.

^ Harness connections under fusebox loose/not latched.

^ Sticking starter solenoids.

^ Crank sensor mounting loose causing intermittent signal from crankshaft sensor.

On Discovery check the following, see if:

^ Any of the GEMS connectors are latched properly.

^ Starts but delayed cranking (> 5 secs) the connectors behind washer bottle (C1027-black contains the link between GEMS and the instrument pack - check engine light) are properly latched.

^ No start/delayed cranking; the connectors behind washer bottle (C1026-blue contains the link between GEMS and the alarm ECM) are properly latched.

^ GEMS body grounds (see ETM section Y5) are secured.

^ Crank sensor mounting loose causing intermittent signal from crankshaft sensor.

^ The alarm unit is properly programmed to the American market (no check engine light after new alarm ECU fitted).