Vauxhall Workshop Service and Repair Manuals

Types of Faults - Important Note!

 

In the MULTEC control unit, there are two memory locations (BIT) for each trouble code.

E.g. trouble code 15, memory locations "A" and "B". There can now be four different types of faults stored in these two locations. For this, memory locations "A" and "B" are filled with the digits "1" or "0" by the MULTEC control unit.

The following combinations are possible:

 

 

TYPE OF FAULT:	Memory contents   "A"    "B":	TYPE OF FAULT:
Number		Description
1.	-                    0        0	No fault present
2.	"loose contact"          0        1	Fault present but condition for setting fault not yet
		fulfilled.
3.	"not present"             1        0	Condition for setting fault was present, fault was or is
		present but cannot be recognized under these driving
		conditions.
4.	"present"                   1        1	Fault present, condition for setting fulfilled.
		- Engine telltale "ON" -

 

 

Fault type 2 is evaluated by TECH 1 for the recognition of short-term faults (loose contacts).

 

If fault type 3 is present, it is switched back to fault type 1 after engine is started 16 times.

 

Important note:     If the customer reports that the engine telltale had illuminated while travelling, and it remains off in the workshop, fault no. 3 is present. I.e. the actual fault is in certain circumstances still present, as the conditions for setting (see Table 2) have been fulfilled, but the fault can no longer be recognized, because the driving conditions have changed so much that they no longer correspond to the conditions described in Table 2.

To check whether the fault is still present, proceed as follows:

1. Erase trouble code (F4)

2. During a test drive, maintain the conditions for setting the fault as described in the right column of Table 2 (e.g. for trouble code 24)

3. Trigger TECH 1 in mode F3 "Snapshot" onto trouble code (e.g. 24, or all)

4. If a fault occurs during the test drive, it will be displayed by TECH 1.

Regardless of whether fault type 3 (NOT PRES.) or fault type 4 (PRESENT) is displayed, the actual cause of the fault has definately not been eliminated and trouble-shooting according to FO:DATA LIST must be carried out.

 

 

Examples of TECH 1 Displays

 

If a fault is stored in the control unit, it can be displayed with TECH 1 in MODE "F2".

The fault occurring is initially displayed in detail. The following displays*, among others, are possible:

 

 

TYPE OF FAULT No. 2		TYPE OF FAULT No. 4		TYPE OF FAULT No. 3
TC:15 INTERMITTENT		TC:15 PRESENT		TC:15 NOT PRESENT
COOLANT TEMPERATURE		COOLANT TEMPERATURE		COOLANT TEMPERATURE
VOLTAGE HIGH		VOLTAGE HIGH		VOLTAGE HIGH
(YES)		(YES)		(YES)

 

 

After all trouble codes have been individually displayed by TECH 1, it shows a summary of the trouble codes sorted according to:

 

 

TROUBLE CODE PRESENT;		TROUBLE CODE LOOSE CONTACT;		TROUBLE CODE NOT PRESENT.
MULTEC		MULTEC		MULTEC
TROUBLE CODE PRESENT		TROUBLE CODE INTERMITTENT		TROUBLE CODE NOT PRESENT
15 35
SEE CHART 2 (YES)		SEE CHART 2 (YES)		SEE CHART 2 (YES)

 

 

* Only 16 characters per line can be displayed by TECH 1. In these examples, the TECH 1 displays are given in their complete form for better comprehension.