LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> GMC >> 2002 >> Jimmy 2D Utility, Part Time, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 1256 (Cellular Communication System) >> Diagnostic Information and Procedures >> Diagnostic System Check - Cellular Communication >> Test Description
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Test Description

WARNING: This page is about a different car, the 2003 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

  1. 2. Lack of communication may be due to a partial malfunction or a total malfunction of the class 2 serial data circuit. The specified procedure will determine the condition.
  2. 4. The presence of DTCs which begin with "U" indicate some other system control module is not communicating.
Fig 1: Cellular Communication System Diagnostic Table
G01503418Courtesy of GENERAL MOTORS CORP.