GM Service Manual Online
For 1990-2009 cars only

DTC

Diagnostic Procedure

Module

U1000 and U1255

DTC U1000 and U1255

HVAC control module, QS4, SCM, ATC, EBCM, PCM, TCSCM, VIU, BCM, IPC, DIC, MMM, MSM, SDM

U1001 through U1254

DTC U1001-U1254

HVAC control module, QS4, SCM, ATC, EBCM, PCM, TCSCM, VIU, BCM, IPC, DIC, MMM, MSM, SDM

U1300

DTC U1300

HVAC control module, QS4, SCM, ATC, EBCM, PCM, TCSCM, VIU, BCM, IPC, DIC, MMM, MSM, SDM

U1301

DTC U1301

HVAC control module, QS4, SCM, ATC, EBCM, PCM, TCSCM, VIU, BCM, IPC, DIC, MMM, MSM, SDM