TM 10-3930-675-20-1 0016 00-11 INPUT AND OUTPUT SIGNALS FOR STEERING ECU (792) TROUBLESHOOTING - CONTINUED 0016 00 Table 16. Error Code 427 - Tophandler Work Light Switch, Circuit Failure Troubleshooting Procedures. MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION Error   Code   427   -   Tophandler   Work   Light Switch, Circuit Failure 1.  Check  for  a  tripped  circuit breaker F-17 (WP 0073 00). Reset circuit breaker. 2.  Check  voltage  at  tophandler work  light  switch  connector 106-2  pin  5.  Voltage  should be 22-26V. If  voltage  is  not  as  specified, check  wires  A678  and  678  for damage.     Repair     or     replace connectors (WP 0111 00). 3.  Check  voltage  at  tophandler work  light  switch  connector 106-2  pin  1.  Voltage  should be 22-26V with switch activated and 0V with switch not activated. If  voltage  is  not  as  specified, replace   tophandler   work   light switch (WP 0072 00). 4.  Check    continuity    between tophandler work light switch connector   106-2  pin   1   and connector X67 pin 9. a.  If  continuity  between  pins, repair  or  replace  connectors (WP 0111 00). b. If continuity (short) to chassis,    repair    or    replace connectors (WP 0111 00). c.  If continuity is present, notify SRA. 5.  Check    continuity    between connector   X67   pin   9   and connector X46 pin 6. a.  If  continuity  between  pins, repair  or  replace  connectors (WP 0111 00). b. If continuity (short) to chassis,    repair    or    replace connectors (WP 0111 00). c.  If continuity is present, notify SRA. 6.  Check    continuity    between connector   X46   pin   6   and connector X174 pin 11. a.  If  continuity  between  pins, repair  or  replace  connectors (WP 0111 00). b. If continuity (short) to chassis,    repair    or    replace connectors (WP 0111 00). c.  If continuity is present, notify SRA. 7.  Check    continuity    between connector  X174  pin  11  and steering ECU (792) connector pin 102. a.  If  continuity  between  pins, repair  or  replace  connectors (WP 0111 00). b. If continuity (short) to chassis,    repair    or    replace connectors (WP 0111 00). c.  If   problem   persists,   notify SRA.