Test M: The Driver Temperature Control Seat Module Does Not Respond To The Diagnostic Tool

PINPOINT TEST M: THE DRIVER TEMPERATURE CONTROL SEAT MODULE DOES NOT RESPOND TO THE DIAGNOSTIC TOOL

M1-M3:

M4-M6:

M7-M9:

Normal Operation
The driver temperature control seat module communicates with the diagnostic tool through the universal asynchronous receiver-transmitter (UART)-based protocol (UBP) communications network circuit 4-HC21 (GY/OG). If circuit 4-HC21 (GY/OG) becomes open or shorted to ground, communications to that module are not possible. Check circuit 4-HC21 (GY/OG) between the temperature control seat module and the data link connector (DLC) C251. The total resistance value must not be more than 5 ohms. If the resistance is more than 5 ohms, there is either an open in circuit 4-HC21 (GY/OG), damage to the DLC C251, damage to the driver temperature control seat module C3031a, or a problem with in-line C213, in-line C315 or joint connector No. 1 C261.

Possible Causes
- UBP circuit 4-HC21 (GY/OG) open
- joint connector No. 1 C261
- in-line C213
- in-line C315
- driver temperature control seat module C3031a
- driver temperature control seat module