Faulty Glow Plug Control Module
Glow Plug Control Module harness is open or shorted
Glow Plug Control Module circuit poor electrical connection
Engine Light ON (or Service Engine Soon Warning Light)
Code P163D Buick Description
The Glow Plug Control Module (GPCM) has the ability to perform internal diagnostics for the voltage and output state of the glow plugs. If the GPCM receives a command to turn on the glow plugs, and Ignition 1 Signal voltage is low this code will set. If the GPCM detects voltage on the glow plug circuits while glow plugs are not commanded on this code will set. If the GPCM detects a ground offset of 1.5 volts between the GPCM ground and the glow plug ground circuit this code will be set. The GPCM will send a message to the Engine Control Module (ECM) to set this Diagnostic Trouble Code (DTC).
P163D Buick Code – Glow Plug Control Module Secondary Circuit