GM Service Manual Online
For 1990-2009 cars only

DTC

Diagnostic Procedure

Module

U1000

Class 2 Communication Malfunction. Refer to DTC U1000 and U1255 .

EBCM, PCM, PK3, SDM

U1016

Lost Communication with PCM. Refer to DTC U1001-U1254 .

DIC, EBCM, IPC, Radio, SDM

U1040

Lost Communication with EBCM. Refer to DTC U1001-U1254 .

DIC, IPC, PCM, SDM

U1088

Lost Communication with SDM. Refer to DTC U1001-U1254 .

VIU

U1096

Lost Communication with IPC. Refer to DTC U1001-U1254 .

DIC, MSM, PCM, PK3, SDM

U1192

Lost Communication with PK3. Refer to DTC U1001-U1254 .

IPC

U1255

Class 2 Communication Malfunction. Refer to DTC U1000 and U1255 .

DIC, IPC, MSM, Radio, VIU

U1300

Class 2 Data Link Low. Refer to DTC U1300 .

EBCM, PCM, Radio, SDM, VIU

U1301

Class 2 Data Link High. Refer to DTC U1301 .

EBCM, PCM, Radio, SDM, VIU

U1305

Class 2 Data Link Low or High. Refer to DTC U1305 .

DIC, MSM