LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Cadillac >> 1990 >> Allante F7/ME9 >> Repair and Diagnosis >> Body & Frame >> Body, Cab Control Systems >> Body Computer Module >> Diagnostic Tests >> DTC L202: OSM Number 2 Communications Problem >> Description
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC L202: OSM Number 2 Communications Problem: Description

DTC L202 indicates the BCM has been unable to correctly communicate information to OSM No. 2. This fault could affect the operation of the lamps shown in the circuit.

NOTE: The following numbered steps refer to circled numbers on diagnostic chart. See Fig 1 . For circuit identification, see Fig 2 .
  1. System misdiagnosis may result if the proper diagnostic sequence is not followed.
  2. A visual inspection of connector cavities and OSM pins for obvious connection problems may result in identification of the fault without further diagnosis.
  3. Assure proper power supply to OSM.
  4. Assure proper ground to OSM.
  5. Assure proper OSM address.
  6. Hazard flashers will increase data line activity, typical voltages will be between 0 and 5 volts and constantly changing. This will help identify if the OSM or data line is the problem.
Fig 1: Identifying DTC L202: OSM No. 2 Communications Problem Flow Chart
G00103605Courtesy of GENERAL MOTORS CORP.
Fig 2: Identifying DTC L202: OSM No. 2 Communications Problem Flow Chart Circuit
G00103606Courtesy of GENERAL MOTORS CORP.