LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Saturn >> 2002 >> L100 L4-2.2L VIN F >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Information Bus >> Testing and Inspection >> Symptom Related Diagnostic Procedures >> Scan Tool Does Not Communicate With Keyword Data Line
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Scan Tool Does Not Communicate With Keyword Data Line



SCAN TOOL DOES NOT COMMUNICATE WITH KEYWORD DATA LINE






Circuit Operation
Modules connected on the keyword 2000 data line are the engine control module (ECM), electronic brake traction control module (EBTCM), and transaxle control module (TCM). The keyword protocols utilize a single wire bi-directional data line between the modules and the scan tool. The message structure is a request and response arrangement. Keyword 2000 is used for scan tool diagnostic only.

Diagnostic trouble codes (DTCs) may be set due to this symptom and during this diagnostic procedure. Complete the diagnostic procedure in order to ensure all the DTCs are diagnosed and cleared from memory.

Diagnostic Aids
If the malfunction is intermittent, check for poor connections at the suspect module. Wiggling the harness wiring may help in locating the fault.