Operating instructions

5.4 Reading a Fault Code with 1531 “Comfort” Timer
Installed
Where the Thermo 90 S installation includes the model 1531 “Comfort”
Digital Timer, you will be able to read the current failure fault code
directly from the timer display.
For example: fault code “07" (fuel pump) will be visible on the timer display.
Once the failure has been corrected, and the heater successfully starts and
runs, the error code will no longer be visible on the timer
display.
5.4.1 Storing a Fault Code in Memory
Once the Thermo 90 S completes the after run (cool down) period
initiated by a failure event, the current flash code will be downloaded
(stored) in memory.
The Thermo 90 S can store up to four fault codes.
Once the memory is “full”, any additional fault code will replace the
earliest code stored thereby continually updating the fault codes
stored in memory with the four most recent faults.
5.4.2 Reading and Removing Fault Codes Stored in Memory
using PC Diagnostics Kit P.N.9009064C
It is possible to read and remove (reset) stored fault codes from the Thermo 90 S memory.
This is achieved through the use of a diagnostic interface kit
connected to the Thermo 90 S and an IBM compatible computer
having the necessary software installed.
The PC Diagnostic Interface Kit comes complete with instructions,
software and several interface connectors for use with Webasto
heaters equipped with internal diagnostics capabilities such as the
Thermo 90 S. (Order PC Diagnostics Kit under part number 9009064C)
Kit does not include required computer.
In addition to working with stored fault codes, the PC Diagnostics Kit allows you to do several other
functions such as reading values while the heater is in operation or testing individual components.
Printing out of fault codes is also available (User supplied printer required).
For further capabilities and instructions for use with the Thermo 90 S heater, see instruction manual
supplied with the PC Diagnostics Kit.
604
6 Basic Troubleshooting Thermo 90 S
CAUTION
Troubleshooting re-
quires profound knowl-
edge about structure
and theory of
operation of the heater
NOTE
After any correction of
a defect a functional
test has to be per-
CAUTION
Diagnostics equipment
is intended for use by
Webasto trained per-
sonnel at authorized
Webasto