GM Service Manual Online
For 1990-2009 cars only

DTC

Description

12

Diagnostic system check

21/31

Courtesy lamps feed (circuit shorted to ground)

22/32

Courtesy lamps return (circuit shorted to B+)

23/33

Retained accessory power (circuit shorted to ground or B+)

24/34

FASTEN SEATBELT indicator lamp (circuit shorted to ground or B+)

41

Last transmitter message received valid

42

Last transmitter message received had invalid ID

43

Last transmitter message received had sumcheck error

44

Last transmitter message received had encryption error

45

Receiver processing currently in 20 second lockout

55

Begin configuration display