Pcm Code E90, VCC Brake Switch Input Problem: Action

PCM will set Code E90 and turn on SERVICE VEHICLE SOON light.

NOTE: Test number refers to number on diagnostic chart.

When test is successfully completed, Fuel Data Center (FDC) will alternately display E.7.1 and 00.
Check VCC brake switch. Repair or replace as necessary.

Fig 1: PCM Code E90, Schematic, VCC Brake Switch Input Problem

Courtesy of GENERAL MOTORS CORP.

Fig 2: PCM Code E90, Flow Chart, VCC Brake Switch Input Problem

Courtesy of GENERAL MOTORS CORP.

Fig 3: PCM Code E90