Plausibility Checking
The TCM detects a fault if an excessive voltage jump is identified between any two consecutive measurements. Also, with the engine started from cold the TFT will start to rise. Therefore the substrate or fluid temperature will also start to rise because the TCM is surrounded by transmission fluid. If the engine and OSS is higher than a set threshold for a predetermined length of time without the substrate temperature rising above a set threshold a fault will be detected.
NOTE:
Unless specifically included in the tables below, IAT, ECT, vehicle speed and time after start up are not critical to enable these monitors.