Mode 6 Data Retrieval - Data Link Diag. Comm. Tool (98-T-75)

MODE 6 DATA RETRIEVAL - DATA LINK DIAG. COMM. TOOL

TECHNICAL SERVICE BULLETIN

USE OF SERIAL DATA LINK DIAGNOSTIC COMMUNICATION TOOLS TO RETRIEVE MODE 6 DATA (REQUEST ON-BOARD MONITORING TEST RESULTS BY TEST ID)

APPLICATION

Model(s): 1996-98 Saturn Models

Group/Seq. No.: General Info - 01

Corporation No.: 99-06-04-003

Bulletin No.: 98-T-75

Date: December, 1998

VEHICLES AFFECTED

All 1996-1998 Saturn Vehicles

PURPOSE

Federal emission regulations require that a vehicle be able to display certain data when interrogated using an off-board tool. One group of data that must be displayed is Mode 6 Data. Within Mode 6 Data is a section that requests EGR flow test results. The following is a description of the EGR flow test results:

• Test ID - $07 Request EGR flow test results
• Comp ID - $0D Request for deceleration test only
• Test Value - (OD) Scaling of the test value is a 2's complement signed number: QEMDSTHR E=(N) counts (2 byte)
• Test Limit - (OD) Scaling of the test value is a 2's complement signed number: QEMDSEWN E= (N) counts (2 byte)

On all 1996-1998 Saturn vehicles, the EGR flow test results are incorrectly displayed in the reverse order. Instead of the test results being displayed Test Value first and Test Limit second, the Test Limit is displayed first and Test Value is displayed second. This must be taken into consideration when displaying Mode 6 Data or when developing communication tools that use Mode 6 Data communication.