Start-Up Relay Check; Starter Command; Electrical Errors - APRILIA RS4 125 Service Station Manual

Electrical system
START- UP RELAY CHECK
•
To check relay operation:
•
Supply 12 V voltage to the two male
terminals (85 - 86).
•
Use a tester (in Ohm meter function) to
check the circuit continuity between
the other two terminals (87 - 30).
Correct value with powered relay: 0 Ohm
Correct value with non-powered relay: infinite
Ohm
•
Replace the relay involved if the result-
ing values do not correspond to those
specified.

STARTER COMMAND

Function
Commands engine starting through the injection control unit.
Operation / Operating principle
The starter button, the brake switches, the No. 25 starter command relay and the injection control unit
between PIN 5 and 10 are involved.

ELECTRICAL ERRORS

Starter command P0170 - shorted to positive.
Error cause
Shorted to positive: excessive voltage at PIN 10 of the control unit connector.
Troubleshooting
Shorted to positive:
•
This malfunction is detected with a brake activated and the starter button pressed (voltage
of 12V read at PIN 5).
•
If the battery voltage does not drop (thanks to the absorption of the No. 25 starter command
relay excitation coil) the control unit understands that PIN 10 is shorted to battery.
•
Restore the cabling (if the short is in the cabling) or the relay (if the short is in the relay).
NOTE
IN CASE OF SHORT TO GROUND / OPEN CIRCUIT NO ERROR WILL APPEAR: SEE THE TROU-
BLESHOOTING CHAPTER, THE ENGINE DOES NOT START.
ELE SYS - 104
RS4 125