Diagnostic AIDS

A Code EO38 in conjunction with a Code EO39 or 26 would mean a problem with one or more of the following components.

Fuse or power supply circuit, brake switch or wire before the splice.
Code EO38 alone is the result of a wire or circuit problem between the splice and the control module, poor connection to the control module, or possibly the control module, itself. If brake switch has failed in an open state, TCC will not engage. Code EO38 does not turn on SERVICE ENGINE SOON light on all models.

Fig 1: Code EO38, Schematic, Brake Switch Circuit

NOTE: Scan testers display brake status in different manners depending upon manufacturer. What is important is that status changes when brake pedal is depressed.

Fig 2: EO38, Flow Chart, Brake Switch Circuit