Vauxhall Workshop Service and Repair Manuals

Test	TECH 1	Notes	Nominal Values	Pin	Possible
Step	Display				Trouble
No.					Codes
08	IDLE CO POT.	Ignition ON	0.1 to 4.2 V*)	43/26	65, 66
		Open loop systems:	Normally approx. 2.5 V
		Closed loop systems:	C 24 NE MY '89: 0 or 2.6 V
			MY '90: NOT PRES.

 

 

Note:

 

On engines as catalytic converter version, any CO potentiometer which may be present is generally not effective.

 

*)The IDLE CO POT. has a permissible adjustment range of 0.1 to 4.2 V; the value is dependent on the adjusted CO value.

If the value is outside this range, a trouble code can be set.

 

With the IDLE CO POT., the injection period can be directly influenced over the entire load range.

If there are deviations, observe the O2 INTEGRATOR as well.

Turn potentiometer to right (increase voltage) means increase injection period (CO content increases), to left means decrease injection period (CO content decreases).

 

Example:

Adjustment to 0.1 V: injection period is decreased by 0.25 ms

Adjustment to 4.0 V: injection period is increased by 0.25 ms

 

The result of this is a total injection period adjustment range of max. 0.5 ms.

 

IMPORTANT:

With open loop systems, a CO exhaust gas gauge must be used.

Maximal CO content 1 % » 2.5 volts

The exhaust gas value is the determining factor for the adjustment of the IDLE CO POT.

 

 

Trouble-shooting:                                      Nominal Value:                       Cause of Fault:

(If nominal value is not attained)

 

First try to adjust to the nominal value using a screwdriver.

 

· Ignition ON

 

· Remove AFM plug                                                      0.1 V                                                   · Control unit defective

· Display:                                                                                                                                      · Short circuit between signal lead Ter.1

and voltage supply Ter. 3

 

· Bridge Ter. 1 (signal lead) with Ter.                     4.9 to 5 V                                               · Lead interruption

3 (+) at air flow meter plug using                                                                                              - From control unit Ter. 43 to AFM Ter. 1

adapter cable from KM-609                                                                                                       - From control unit Ter. 12 to AFM Ter. 3

Display:                                                                                                                                      · Poor plug connection (loose

contact caused by pushed-back pin)

· Control unit defective

 

The relevant terminal designations are located under the rubber grommet of the AFM plug.

 

If nominal values are attained          · AFM defective

 

Checking values

Ter. 3 (+)/Ter. 4 (-):                                                     300 to 550 W

Measure Ter. 1 (sign.:)/Ter. 4 (-)                              Note value 1        ---------->          values 1 + 2 » 700 W

Measure Ter. 1 (sign.:)/Ter. 3 (+)                             Note value 2        ---------->                                   (600 to 900 W)