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Identifying Memory System Malfunctions

NOTE: Perform SYSTEM ID TEST 1A  before proceeding with this test. For connector terminal identification and wiring diagrams, see BODY CONTROL COMPUTER - INTRODUCTION. Perform VERIFICATION TEST: VER-2A  after each repair.
CAUTION: Always turn ignition switch to OFF position prior to disconnecting or connecting any module connector.
NOTE: If seat frame has been unbolted for accessibility, frame must be connected to ground during testing.
  1. Using scan tool, select BODY COMPUTER, then MEMORY SEAT MODULE. Read DTCs. If no codes are present, operate all seat and mirror switches while monitoring scan tool for DTCs. Operate seat heaters. Reset memory positions. If any codes are set, go to next step. If no codes are set, perform SWITCH SELF-TEST using scan tool.
  2. Record DTC(s) that are set. Using scan tool, erase DTCs. Operate all seat and mirror switches while monitoring scan tool for DTCs. Operate seat heaters. Reset memory positions. If original DTC(s) are set, see MEMORY SYSTEM DIAGNOSTIC TEST DIRECTORY  table and perform indicated test(s). If no codes reset, see MEMORY SYSTEM SYMPTOM DIAGNOSTIC TEST DIRECTORY  table.
MEMORY SYSTEM DIAGNOSTIC TEST DIRECTORY

Problem Perform MEMORY SYSTEM
EEPROM Refresh Failure (1) Replace MHSMM
Ignition Status Message Not Received (2) VEHICLE COMMUNICATION TEST 16A
PRNDL Display Message Not Received (2) VEHICLE COMMUNICATION TEST 12A
Front Riser Down Position Stuck TEST 2A 
Front Riser Up Position Stuck TEST 3A 
Front Riser Out Of Range Low TEST 4A 
Front Riser Out Of Range High TEST 5A 
Rear Riser Down Position Stuck TEST 6A 
Rear Riser Up Position Stuck TEST 7A 
Rear Riser Out Of Range Low TEST 8A 
Rear Riser Out Of Range High TEST 9A 
Horizontal Riser Down Position Stuck TEST 10A 
Horizontal Riser Up Position Stuck TEST 11A 
Horizontal Riser Out Of Range Low TEST 12A 
Horizontal Riser Out Of Range High TEST 13A 
Recliner Riser Down Position Stuck TEST 14A 
Recliner Riser Up Position Stuck TEST 15A 
Recliner Riser Out Of Range Low TEST 16A 
Recliner Riser Out Of Range High TEST 17A 
Memory Position No. 1 Stuck TEST 18A 
Memory Position No. 2 Stuck TEST 19A 
Memory Set "S" Position Stuck TEST 20A 
Left Seat Heat Output Open TEST 21A 
Left Seat Heat Output Shorted To Ground TEST 22A 
Left Heated Seat Switch Stuck In Low State TEST 23A 
Left Heated Seat Switch Stuck In High State TEST 24A 
Left Heated Seat Switch Open/shorted To Ground TEST 25A 
Left Thermistor Out Of Range Low TEST 26A 
Left Thermistor Out Of Range High TEST 27A 
Right Seat Heat Output Open TEST 28A 
Right Seat Heat Output Shorted To Ground TEST 29A 
Right Heated Seat Switch Stuck In Low State TEST 30A 
Right Heated Seat Switch Stuck In High State TEST 31A 
Right Heated Seat Switch Open/shorted To Ground TEST 32A 
Right Thermistor Out Of Range Low TEST 33A 
Right Thermistor Out Of Range High TEST 34A 
Left Mirror Horizontal sensor Out Of Range Low TEST 35A 
Left Mirror Horizontal sensor Out Of Range High TEST 36A 
Left Mirror Vertical Sensor Out Of Range Low TEST 37A 
Left Mirror Vertical Sensor Out Of Range High TEST 38A 
Right Mirror Horizontal sensor Out Of Range Low TEST 39A 
Right Mirror Horizontal sensor Out Of Range High TEST 40A 
Right Mirror Vertical Sensor Out Of Range Low TEST 41A 
Right Mirror Vertical Sensor Out Of Range High TEST 42A 
(1) Replace Memory Heated Seat/Mirror Module.
(2) See appropriate VEHICLE COMMUNICATIONS article.
MEMORY SYSTEM SYMPTOM DIAGNOSTIC TEST DIRECTORY

Problem Perform MEMORY SEAT SYSTEM
Memory Switch Inoperative TEST 43A 
Left Mirror Inoperative From Memory TEST 44A 
Right Mirror Inoperative From Memory TEST 45A 
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