Display group 32 -Oxygen sensor control- Oxygen sensor learned values

WARNING: This page is about a different car, the 2002 Volkswagen Cabrio, 2001 Volkswagen Cabrio, and 2000 Volkswagen Cabrio. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Display Group 32 - Oxygen Sensor Control (Oxygen Sensor Learned Values)

Courtesy of VOLKSWAGEN OF AMERICA, INC.

Display Group 32 - Oxygen Sensor Control (Oxygen Sensor Learned Values)

For Evaluation 1 in Fig 1, see EVALUATING DISPLAY ZONE 32, DISPLAY ZONES 1 AND 2 - OXYGEN SENSOR LEARNED VALUES (LOW OXYGEN SENSOR LEARNED VALUES) .
For Evaluation 2 in Fig 1, see EVALUATING DISPLAY ZONE 32, DISPLAY ZONES 1 AND 2 - OXYGEN SENSOR LEARNED VALUES (LOW OXYGEN SENSOR LEARNED VALUES) .

Notes on display zones 1 and 2:

Low values indicate that the engine is running too rich and therefore the Oxygen sensor control is leaning the mixture.
High values indicate that the engine is running too lean and therefore the Oxygen sensor control enriches the mixture.
If there is no voltage supply to the control module all the values learned will be cancelled.
add = additive - The effects of the malfunction (e.g. unmetered air) will reduce as the engine speed increases. The injection period will be modified by a fixed amount for additive learned values. This amount is not dependent upon the basic injection period.
mul = multiplicative - The effects of the malfunction (e.g. malfunctioning injector) will increase as the engine speed increases. A multiplicative learned value is a proportional change to the injection period. This change is dependent on the basic injection period.

EVALUATING DISPLAY ZONE 32, DISPLAY ZONES 1 AND 2 - OXYGEN SENSOR LEARNED VALUES (LOW OXYGEN SENSOR LEARNED VALUES)

Indicated on display	Possible cause	Corrective action
Low Oxygen sensor learned values	Low learned values at idling but with normal learned values at part throttle: possible oil dilution (high level of fuel in oil)	Disappears after motorway drive or oil change
	Injector leaking	Check injectors. See FUEL INJECTORS, CHECKING .
	Fuel pressure too high	Check fuel pressure regulator and holding pressure. See FUEL PRESSURE REGULATOR AND HOLDING PRESSURE, CHECKING .
	EVAP canister purge regulator valve permanently open	Check EVAP canister purge regulator valve. See OUTPUT DIAGNOSTIC TEST MODE (DTM) (SCAN TOOL FUNCTION 03)
	Mass air flow sensor faulty	Check mass air flow sensor. See MASS AIR FLOW (MAF) SENSOR, CHECKING .
	Oxygen sensor heating faulty or Oxygen sensor soiled	Check Oxygen sensor heating before catalytic converter. See OXYGEN SENSOR AND OXYGEN SENSOR CONTROL BEFORE THREE WAY CATALYTIC (TWC) CONVERTER, CHECKING .

EVALUATING DISPLAY ZONE 32, DISPLAY ZONES 1 AND 2 - OXYGEN SENSOR LEARNED VALUES (HIGH OXYGEN SENSOR LEARNED VALUES)

Indicated on display	Possible cause	Corrective action
High Oxygen sensor learned values	High learned values at idling speed, not so high learned values at part throttle: possible unmetered air in area of intake manifold	Check intake air system for leaks. See INTAKE AIR SYSTEM, CHECKING FOR LEAKS (UNMETERED AIR) .
	Unmetered air between mass air flow sensor and throttle valve	Rectify cause
	Injector blocked	Check quantity injected rate. See FUEL INJECTORS, CHECKING .
	Display zones 1 and 2 high: Mass air flow sensor faulty	Check mass air flow sensor. See MASS AIR FLOW (MAF) SENSOR, CHECKING .
	Fuel pressure too low	Check fuel pressure regulator and holding pressure. See FUEL PRESSURE REGULATOR AND HOLDING PRESSURE, CHECKING .
	Unmetered air at exhaust manifold gasket
	Oxygen sensor heating faulty or Oxygen sensor soiled	Check Oxygen sensor heating before catalytic converter. See OXYGEN SENSOR AND OXYGEN SENSOR CONTROL BEFORE THREE WAY CATALYTIC (TWC) CONVERTER, CHECKING .