Clock - Inaccurate
Group 62
Instruments
Bulletin Number
62 03 98
343
Woodcliff Lake, NJ
May 1998
Product Engineering
SUBJECT:
Clock Inaccurate
MODEL:
5 Series (E39), 7 Series (E38)
Complaint:
Clock Inaccurate.
General Information:
The Time of Day function on E38 and E39 may be displayed on the instrument cluster, MID, or Board Monitor. However, in all cases, this clock
function is controlled by the Instrument Cluster or IKE.
Clock accuracy is precisely calibrated by a quartz crystal in the Instrument Cluster / IKE, to maintain acceptable accuracy over its entire operating
environment. Two factors external factors influence clock accuracy:
1) Voltage supply less than 9 volts
2) Temperature extremes. (See chart)
Procedure:
In case of a customer complaint, confirm that there are no fault codes set in the Instrument Cluster / IKE for "Voltage Supply". If there are, correct
the cause of the low battery voltage first, as this is the likely reason for the customer complaint.
In cases where clock accuracy needs to be checked, a two-step procedure should be followed:
Step 1
Set the clock to "Radio time", advise your customer to recheck the time by the same method after a minimum of (1) week. If the customer confirms
the inaccuracy, arrange for the vehicle to be booked in for repair. Continue to Step 2 below.
Step 2
Set the clock to "Radio time", and refer to chart to estimate a reasonable time period for the test considering the likely temperatures of the instrument
cluster/IKE during the test. For example, for instrument cluster temperatures between -4锟斤拷F and +86锟斤拷F, the clock accuracy should not gain more than
0.2 seconds per day, or lose more than 0.3 seconds per day (see chart). Use "Radio time" to recheck the time at the end of the test.
