Built-In Test Equipment - Husqvarna PT26D Workshop Manual

Built-in test equipment

The electrical system is equipped with BITE (Built In Test Equipment) in the form of LEDs on the circuit
card and in the sensors. The LED on the circuit card for each circuit comes on when a function is activated.
The circuit card diodes can emit the following signals:
• Green, circuit OK
• Red, circuit short circuited
• Red and green, open circuit.
Most diodes work in pairs as set out in the table below. Some circuits lack the red LED. This entails another
troubleshooting method, described in chapter Troubleshooting.
LED function table
Detailed table, see "Trouble shooting table LEDs" on page 128.
LED Colour
LD1 Green
LD14 Red
LD2 Green
LD13 Red
LD3 Green
LD12 Red
LD4 Green
LD15 Red
LD5 Green
LD16 Red
LD6 Green
LD17 Red
LD7 Green
LD18 Red
Fault LD8 Green
LD19 Red
LD9 Green
LD21 Red
LD10 Green
LD22 Red
LD11 Green
LD20 Red
LD23 Green
LD24 Green
LD25 Green
LD26 Green
LD27 Green
LD28 Green
DESIGN AND FUNCTION
Valve blade Voltage out
Valve 1 V blade Fault
Valve 6 extra equipment A-side Voltage out
Valve 6 extra equipment A-side Fault
Valve 5 extra equipment B-side Voltage out
Valve 5 extra equipment B-side Fault
Switch weight transfer Voltage out
Switch weight transfer Fault
Valve 2 lift function Voltage out
Valve 2 lift function Fault
High speed Voltage out
High speed Fault
Diff lock.Voltage out
Diff lock Fault
Solenoid clutch Voltage out
Solenoid clutch Fault
Flasher right Voltage out
Flasher right Fault
Flasher left Voltage out
Flasher left Fault
Injection pump Voltage out
Injection pump Fault
Starter motor Voltage out
Glow plug heating Voltage out
High beam voltage out
Low beam Voltage out
Cooling fan Voltage out
+ 12 V Voltage out
Function
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English-