Diagnostic System Check

Install scan tool. If scan tool powers up, go to next step. If scan tool does not power up, perform appropriate diagnostic procedure. See SELF-DIAGNOSTIC SYSTEM in appropriate BODY CONTROL MODULES article.
Turn ignition on, engine off. Following scan tool manufacturer's instructions, attempt to establish communication with Body Control Module (BCM). If communication with BCM, go to next step. If communication with BCM is not established, diagnose communication problem with class 2 device. See SELF-DIAGNOSTIC SYSTEM in appropriate BODY CONTROL MODULES article.
Select display DTC function for BCM. Record all displayed DTCs and status of displayed DTCs. If DTCs are displayed, go to next step. If no DTCs are displayed, diagnose by symptom. See SYMPTOM TESTS .
Retrieve DTCs and perform appropriate test. See DIAGNOSTIC TROUBLE CODE INDEX table.

DIAGNOSTIC TROUBLE CODE INDEX

DTC

Description

B1000 & B1001

⁽¹⁾

Door Lock Switch Circuit Low

Door Lock Switch Circuit High

Passenger Door Unlock Switch Circuit Low

Passenger Door Unlock Switch Circuit High

UXXXX

⁽²⁾

⁽¹⁾	See appropriate BODY CONTROL MODULES article.

⁽²⁾	For any DTC beginning with the letter "U", diagnose communication problem with class 2 device. See SELF-DIAGNOSTIC SYSTEM in appropriate BODY CONTROL MODULES article.