F0: Data List - Test Step No.39 O2 Integrator Opel Frontera A

F0: DATA LIST

Engine running at idle speed, operating temperature

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 115 and 02 BLM IDLE THR. less than 50:

System gets leaner, mixture too rich.

· 02 INTEGRATOR less than 115 and 02 BLM PART THR. less than 118:

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.

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

· Check fuel pump pressure (observe safety regulations)

· Install pressure gauge in feed

· Pressure regulator defective

· Disconnect vacuum hose from fuel pressure regulator

Feed pressure above 3 bar:

· Return line blocked or kinked

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

· Leaky injectors

· Coolant temperature sensor P12 defective (see test step 06)

· Oxygen sensor P32 defective (see test step 36, 37)

· Motronic control unit K61 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

· Fuel pump defective

· Splash baffle in tank loose

· Fuel filter dirty

· Disconnect vacuum hose from fuel pressure regulator

· Fuel injection unit relay K68 defective (see test step 19)

· Fuel pump M21 defective

· Injector defective or dirty

· Poor fuel quality

· Exhaust system leaky (in front of oxygen sensor P32)

· Intake system leaky (air leak)

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

· apour lock in fuel feed or return line

· Coolant temperature sensor P12 defective

· Oxygen sensor P32 defective