Code 16 (Ignition 3 Fuse Open)
- This code will always appear as history code. If Central Control Module (CCM) 3 fuse is blown, CCM will not receive IGN 3 power and will not enter diagnostic mode. If CCM reads ignition 3 fuse circuit has low voltage for more than 3 seconds when CCM expects high voltage, History Code 16 will set.
- If CCM 3 fuse is blown, ensure ignition is off. Replace fuse and turn ignition on. If fuse blows again when ignition is turned on, repair short to ground in Brown wire between CCM Green connector and CCM 3 fuse. See Fig 1
. If newly installed fuse did not blow, clear codes and re-enter diagnostic mode. If Code 16 is still set, go to next step.
- If CCM 3 fuse is not blown (or if Code 16 is still set), turn ignition off. Connect jumper between Data Link Connector (DLC) terminals No. 12 and 5. See Figure
. Turn ignition on. If CCM enters automatic display mode, system is functioning properly. Wiggle connections and wiring to locate intermittent fault.
- If CCM does not enter automatic display mode, measure voltage between backprobed terminal E4 (Brown wire) of CCM Green connector and ground. If voltage reading is not about 12 volts, repair open in Brown wire between CCM Green connector and CCM 3 fuse.
- If voltage reading is about 12 volts, turn ignition off. Disconnect CCM Green connector. Using Terminal Adapter Kit (J-35616), connect DVOM between terminal E4 (Brown wire) of CCM Green connector and ground. Turn ignition on. If voltage reading is about 12 volts, wiggle connections and wiring to check for intermittent faults. If no faults are found, clear code and check if code resets. If code resets, replace CCM.
- If voltage reading not is about 12 volts, repair poor connection at terminal E4 (Brown wire) of CCM Green connector. When repairs are completed, clear codes and verify operation.
Courtesy of GENERAL MOTORS CORP.