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 Driver Door Module (DDM) and Powertrain Control Module (PCM). If communication with DDM and PCM is established, go to next step. If communication with DDM and PCM 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 DDM and PCM. 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, B1004, B1007, B1009, B1327 Or B1328

⁽¹⁾

B2757, B2762 Or B2772

⁽²⁾

Left Unlock Switch Circuit Low

Passenger Unlock Switch Circuit Low

Left Lock Switch Circuit Low

Passenger Lock Switch Circuit Low

PXXXX

⁽³⁾

U1161, U1162, U1163 Or U1170

⁽⁴⁾

UXXXX

⁽⁵⁾

⁽¹⁾	See appropriate BODY CONTROL MODULES article.

⁽²⁾	See appropriate POWER SEAT article.

⁽³⁾	See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.

⁽⁴⁾	See DIAGNOSTIC TESTS in POWER WINDOWS - BONNEVILLE & LESABRE article.

⁽⁵⁾	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.