Vauxhall Workshop Service and Repair Manuals

No.

TECH 1 Display

Conditions for Checking

Nominal Value

Trouble Codes

Terminal

39

02

X 20 SE engine only:

13, 38, 39

-

INTEGRATOR

Engine running at idle speed, operating temperature

Switch off all consumers

115 to 141 steps

Note:

The 02 INTEGRATOR can be used to evaluate the air / fuel mixture correction of the oxygen sensor regulation.

If, for example, the air / fuel mixture is too lean, the value of the 02 INTEGRATOR and thus also the injection period is increased in steps until the oxygen sensor signals that the mixture is too rich.

The 02 INTEGRATOR is then decreased in steps and thus the injection period shortened again until the oxygen sensor displays that the mixture is too lean (closed loop only).

02 INTEGRATOR = 128 means either:          Stochiometric air / fuel ratio of approx. 14.7 parts by volume air to one part by volume fuel, i. e. one fuel particle is available for each air particle for combustion.

or:                                                                       the circuit has been opened by the control unit, as a fault is present (e. g. oxygen sensor defective) or the conditions for closed loop have not yet been attained.

02 INTEGRATOR less than 128 means:         System becomes leaner, mixture too rich (injection period is reduced).

02 INTEGRATOR greater than 128 means:    System becomes richer, mixture too lean (injection period is increased).

Note:

The 02 INTEGRATOR affects the injection period and thus also the amount of fuel injected. As the amount of fuel depends on the fuel pressure, incorrect fuel pressure can be detected as follows:

·   Fuel pressure too high:           02 INTEGRATOR and thus injection period is reduced in steps (system becomes leaner).

·   Fuel pressure too high:           02 INTEGRATOR and thus injection period is increased in steps (system becomes richer).

To be able to evaluate a deviation of the 02 INTEGRATOR value, the value of the 02 BLM IDLE THR. correction and 02 BLM PART THR.  correction must also be evaluated.

Possible interrelationships if nominal values are not attained:

·   02 INTEGRATOR less than 1 1 5 and 02 BLM IDLE THR. less than 50:            System gets leaner, mixture too rich.

·   02 INTEGRATOR less than 1 1 5 and 02 BLM PART THR.  less than 1 1 8:      System gets leaner, mixture too rich.

·   02 INTEGRATOR greater than 141 and 02 BLM IDLE THR. greater than 200:  System gets richer, mixture too lean.

·   02 INTEGRATOR greater than 141 and 02 BLM PART THR.  greater than 138:  System gets richer, mixture too lean.

Notes on Trouble - shooting:

Nominal Value:

Cause of Fault:

Measured value lower than 115 steps (system becomes leaner, mixture too rich):

·   Check fuel pump pressure

     (observe safety regulations)

·   Install pressure gauge in feed

·   Engine running at idle speed

Feed pressure: 1.7 to 2.2 bar

·   Fuel pressure too high

·   Pressure regulator defective

·   Splash baffle in fuel tank blocked

·   Disconnect vacuum hose from fuel pressure regulator Close off vacuum hose

Feed pressure: 2.5 to 3.0 bar

·   Vacuum hose to pressure regulator leaky

     Feed pressure above 3 bar:

·   Return line blocked or kinked 

·   Tank vent valve constantly open (activated carbon canister full)

·   Leaky injectors

·   Temperature sensor P 12 defective (see test step 06)

·   Oxygen sensor P 32 defective (see test step 36, 37)

·   Control unit K 61 defective

Measured value greater than 141 steps (system becomes richer, mixture too lean):

·   Check fuel pump pressure (observe safety regulations)

·   Install pressure gauge in feed

·   Engine running at idle speed

Feed pressure: 1.7 to 2.2 bar

·   Fuel pressure too low

·   Fuel pump defective

·   Splash baffle in tank loose

·   Fuel filter dirty

·   Prefilter dirty

·   Disconnect vacuum hose from fuel pressure regulator Close off vacuum hose

Feed pressure: 2.5 to 3.0 bar

·   Check fuel pump supply quantity (see Technical Data)

·   Fuel pump relay K 44 defective (see test step 19)

·   Fuel pump defective

·   Injector defective or dirty

·   Poor fuel quality

·   Exhaust system leaky (in front of oxygen sensor)

·   Intake system leaky (air leak)

·   Tank vent valve constantly open (activated carbon canister empty)

·   Vapour lock in fuel feed or return line

·   Coolant temperature sensor P 12 defective

·   Oxygen sensor defective

·   Control unit K 61 defective