TROUBLESHOOTING USING GSC FAULT CODES - Continued
CORRECTIVE ACTION - Continued
Compare voltages between GSC control panel reading and A5. If they match,
troubleshoot wiring harness between TB1 and GSC for loose connection,
corrosions, and broken wires. Repair and replace, as necessary (WP 0090).
If GSC voltage and A5 voltage do not match, check continuity of wires between
A5P1 and GSCP7 (FO-1, sheet 5).
If continuity is present, replace A5 module (WP 0041).
Verify that problem is resolved. If problem still exists, check all GSC fuses
(FO-4, Sheets 3 and 5).
If GSC fuses are ok, replace GSC (WP 0040).
Verify the problem is resolved.
The bus transformer box isolates and reduces the load bus voltages for use by the GSC. The
GSC uses the reduced value of L1 (Phase A) to determine the voltage level on the load bus. The
GSC uses the reduced value of L3 (Phase C) to measure the frequency of the voltage on the load
CID 1170 FMI 02
CID 1170 FMI 04
CID 1170 FMI 08
FMI 02 - Erratic, Intermittent, or Incorrect Signal.
FMI 04 - Voltage Below Normal.
FMI 08 - Abnormal Frequency, Pulse Width, or Period.
Set Battery Disconnect Switch to OFF.
Check BTB A6 fuses A6F1 and A6F2 per FO-4, sheet 3. Replace BTB A6 fuses,
Remove BTB A6 fuses A6F1 and A6F2. Measure resistance between wires B11
and B12 connected to A6 fuse block. Resistance should be 2140 + / - 400 ohms.
If A6 is replaced, verify that problem is resolved.
Set Battery Disconnect Switch to ON. Set DEAD CRANK SWITCH to NORMAL.
Turn the ENGINE CONTROL switch to MANUAL START. Set the GSC to
display L to L voltage. Adjust voltage to 208 voltage.