Buzzer Problems; Telltale Indicators; Testing The Telltale Bulbs; Telltale Bulb Signal Flow Diagram - Volvo VNL Service Manual

Group 38 Instrumentation, VNL, VNM

Buzzer Problems

The buzzer can be tested by performing the Buzzer Test
in the Cluster Self Test Mode of the Diagnostics Menu.
Buzzer Signal
Turn signal beep (momentary beep)
Clock reminder (double beep every other second)
Warning signal (two beeps every second)

Telltale Indicators

Telltale indicators are lighted by bulbs positioned across
the bottom of the instrument cluster.

Testing the Telltale Bulbs

Test the telltale bulbs by using the Bulb Test function in
the Cluster Self Test Mode of the Diagnostics menu.
1
CAUTION
When probing connector terminals, do not insert
probes into the terminals. This will spread the ter-
minals apart, causing permanent damage. Probe
the insertion side of the connector.
If none of the telltale bulbs light during the Bulb Test
function, check for +12 volts between LY-3 and LY-4
during the Bulb Test function. If missing, replace the
cluster.
40
The buzzer is not serviceable. If it fails to sound, replace
the cluster.
Fig. 40: Telltale bulb signal flow
2 If the suspect bulb lights during the self test, the
problem is not in the cluster. Check the signal
source for individual telltale bulbs.
3 If the suspect bulb fails but other bulbs light during
the self test, replace the suspect bulb.
4 If none of the bulbs in the center section light during
the Bulb Test function, check for
+12 volts between CY-5 and CY-6,
or between CY-19 and CY-20.
If missing, there is an open wire in the wiring har-
ness.
5 If none of the bulbs in the right section light during
the Bulb Test function, check for +12 volts between
RX-18 and RX-19. If missing, there is an open wire
in the wiring harness.
For more information, refer to the VNL, VNM Electrical
Schematics.
Troubleshooting
W3000986