Page F-6
Repair and Service Manual
B
ELECTRONIC SPEED CONTROL - TCT
Read all of Section B and this section before attempting any procedure. Pay particular attention to Notices, Cautions, Warnings and Dangers.
TROUBLESHOOTING DIAGRAMS
The following diagrams will assist in servicing the vehicle. By utilizing the diagnostic mode Fault Codes, considerable
time will be saved in determining the probable vehicle operating malfunction. The vehicle controller wiring diagram is
included for your convenience in tracing the electrical wiring.
1206HB-5201 Controller Faults and Troubleshooting
1311 Display
Explanation
Tested When
Controller
Response
Recover
When
Possible Cause
HW FAILSAFE
Hardware Failsafe
Error
Throttle applied to
cause contactor to
initially close
1,2,3
KSI cycled
1. Controller defective
2. Controller power cables mis-wired
FIELD MISSING
Motor Field Winding
open
Contactor closed
2,8
Condition clears
1. Field Winding or its connection
open
M- SHORTED
Armature PWM pulses
not detected
Contactor Closed
1,2
Condition clears
1. Controller defective
2. Power cables shorted
CURRENT SENSE
FAULT
Armature Current
reading at invalid Zero
Amps level
Out-of-Range value
KSI OFF -> ON,
Continuous
1,2,3
KSI OFF-> ON
when condition
cleared
1. Controller defective
2. Excessive Plug Current detected
MAIN DROPOUT 2
Contactor detected as
opening during Regen
Contactor
commanded to be
closed
3,9
Throttle reapplied
1. Contactor opened
2. Contactor coil or wiring opened
MAIN DRIVER OFF
Main Driver FET
detected as not turning
ON
Throttle applied to
cause Contactor to
close
3,8
Condition clears
1. Controller defective
MOTOR STALL
High Armature Current
when no Speed Pulses
detected
Contactor closed
6
Speed Pulses
appear
1. Motor is stalled
2. Defective speed sensor or wiring
MAIN DROPOUT 1
Contactor detected as
opening during Drive
Contactor
commanded to be
closed
3,9
Throttle reapplied
1. Contactor opened
2. Contactor coil or wiring opened
MAIN COIL OPEN
Main Contactor coil
detected as open
Continuous while
KSI ON
3
Condition clears
1. Contactor coil or wiring open
MAIN DRIVER ON
Main Driver FET
detected as ON when
commanded to be OFF
Continuous while
KSI ON and
Contactor
commanded to be
open
4
Condition clears
1. Controller defective
2. Pin 12 short to ground
SPEED SENSOR
FAULT
No speed pulses
detected
Contactor closed
4
Condition clears
1.Defective or missing speed sensor
2. Open speed sensor wiring
MAIN WELDED
Main Contactor
detected as stuck
closed
Contactor
commanded to be
Open
4
Contactor
commanded to
Open and does
Open
1. Welded Contactor
NEG IA 300
Very high Regen
Current
Continuous
No Action
Throttle reapplied 1. High Regen Current
NEG IA 250
High Regen Current
Continuous
No Action
Throttle reapplied 2. High Regen Current
MAIN DRIVER
OVERCURRENT
High Driver Current
Detected
Continuous while
Contactor is
commanded to be
closed
No Action
Throttle reapplied
1. Main Contactor coil or wiring
shorted
2. Electrical Noise