Table 3 - DTC

The Instrument Panel Cluster may, under certain circumstances, set it's own Diagnostic Trouble Codes (DTCs) over the UART Data Line. These can be found by using the "DTC" mode of the TECH 2. The first instance a DTC could be set is for Vehicle Theft Deterrent operation. Refer Antitheft and Alarm Systems for system and code diagnosis and operation. Antitheft and Alarm Systems

The second instance is when there is a loss of serial data with one or more of the Modules on the UART Data Line. Such a loss could be the result of an open or short in the UART Data Line or CKT 800. These codes can be especially useful when diagnosing an intermittent problem. An explanation of these are given below in TABLE #3. Refer to Data LinkConnector, CHART #1 for UART Serial Data Line diagnosis. Data Link Connector

TABLE #3 - DIAGNOSTIC TROUBLE CODES (DTC)
DIAGNOSTIC TROUBLE CODE EXPLANATION

DTC - B1021 LOSS OF PCM SERIAL DATA The IPC is having trouble communicating with the Powertrain Control Module (PCM).

DTC - B1022 LOSS OF SIR SERIAL DATA The IPC is having trouble communicating with the Sensing Diagnostic Module (SDM).

DTC B1023 LOSS OF ABS SERIAL DATA The IPC is having trouble communicating with the Electronic Brake Control Module (EBCM).