XJ-S V12-5.3L (1982)
Trip Computer: Technical Service Bulletins
Trip Computer - More In Depth Checking Procedures
DATE . . . JULY, 1985
NUMBER . . . J85/50
MODEL: XJ6 & XJ-S
SUBJECT:
TRIP COMPUTER CHECKING
KEY POINTS:
STRESSING THE IMPORTANCE OF CHECKING TRIP COMPUTERS BEFORE MAKING A REPLACEMENT.
A test procedure for all trip computers returned under warranty has recently been introduced. This procedure includes installation of units in the
company vehicle fleet and testing under normal driving conditions. The results have indicated a very high percentage of No Fault Found (NFF) units.
We stress the importance of carrying out checks on any trip computer that is not performing correctly.
We have recently completed a modification program for the trip computer testers and all dealers should now have these modified units in their
possession. Bear in mind that the tester can check the signal inputs to the computer. In addition, it is also able to test the operation of a computer unit
removed from a vehicle.
If a doubt still exists, the ease of removal and replacement of the unit provides an opportunity to actually test the unit in another vehicle.
Particular attention must be paid to the plug connections of the computer and the interface unit as poor connections are the main cause of operating
faults. The miles/kilometer switch should be checked for correct selection.
