Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the logical successor to CHARM, I recommend you try it!

Link: lemon-manuals.la

Reference Value Parameter Identification (PID)/Measured Signal Chart

REFERENCE VALUE PARAMETER IDENTIFICATION (PID)/MEASURED SIGNAL CHART

The following listing reflects PIDS and/or measured values which may reveal a possible concern within each system shown. Match the category number with the related PID/measured signal and go to the Typical Diagnostic Reference Value Charts. Typical Diagnostic Reference Values












Some signals can only be measured and require the use of a digital multimeter (DMM).