Diagnostic Aids

WARNING: This page is about a different car, the 2003 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

If there is an open or a short on the PASS-Key® signal or ground circuit, the BCM will be unable to accept a valid PASS-Key® code when the program mode is activated. The vehicle will also exhibit a no crank condition.
Diagnose all other theft deterrent DTCs before attempting to diagnose DTC B2735, as this will affect the BCM's ability to properly read a PASS-Key® resistance value.
Clean the key resistor contacts of any foreign material. The foreign material could interfere with the key detection circuit, causing the BCM to be unable to program the PASS-Key® system and to set a DTC B2735.

Fig 1: DTC B2735

Courtesy of GENERAL MOTORS CORP.