Display group 4 -Basic functions-

Fig 1: Identifying Display Group 4 - Basic Functions

Courtesy of VOLKSWAGEN OF AMERICA, INC.

For Evaluation 1 in Fig 1, see EVALUATING DISPLAY GROUP 1, DISPLAY ZONE 1 - ENGINE SPEED (IDLING SPEED) .
For Evaluation 2 in Fig 1, see EVALUATING DISPLAY GROUP 4, DISPLAY ZONE 2 - CONTROL MODULE VOLTAGE SUPPLY .
For Evaluation 3 in Fig 1, see EVALUATING DISPLAY GROUP 4, DISPLAY ZONE 3 - COOLANT TEMPERATURE .
For Evaluation 4 in Fig 1, see EVALUATING DISPLAY GROUP 4, DISPLAY ZONE 4 - INTAKE AIR TEMPERATURE .

Note on display zone 3:

The engine control module will use the intake air temperature as a replacement value for an engine start (start temperature - replacement value) as soon as there is a malfunction stored in the DTC memory, which affects the coolant temperature sensor (G62). The temperature then rises according to a model stored in the control module. When the engine has reached normal working temperature a fixed replacement value will be displayed after a certain period. This fixed value is also dependent upon the intake air temperature.

Note on display zone 4:

The total temperature range is given as the specification. The displayed value must be above ambient temperature.

EVALUATING DISPLAY GROUP 4, DISPLAY ZONE 2 - CONTROL MODULE VOLTAGE SUPPLY

Indicated on display	Possible cause	Corrective action
Less than 12.0 V	Alternator faulty, battery charge state low	Check alternator and battery voltage, charge battery: See BATTERY, STARTER, GENERATOR, CRUISE CONTROL .
	Battery heavily charged shortly after starting due to high charging current and current consumers	Increase revs slightly for a few minutes and switch off current consumers
	Transfer resistance in the current supply or the engine control module Ground connection	Check engine control module voltage supply. See ENGINE CONTROL MODULE (ECM) VOLTAGE SUPPLY, CHECKING .
	Current draw when ignition is off	Eliminate current draw
More than 14.5 V	Voltage regulator on alternator faulty	Check voltage, replace regulator if necessary See BATTERY, STARTER, GENERATOR, CRUISE CONTROL .
More than 14.5 V	Excess voltage due to jump starting or quick charging unit	Check DTC Memory. See Diagnostic Trouble Code (DTC) memory .

EVALUATING DISPLAY GROUP 4, DISPLAY ZONE 3 - COOLANT TEMPERATURE

Indicated on display	Possible cause	Corrective action
Less than 80° C	Engine too cold	If necessary carry out test drive
Less than 80° C	Coolant temperature sensor or wiring to engine control module	Check coolant temperature sensor. See ENGINE COOLANT TEMPERATURE (ECT) SENSOR -G62-, CHECKING .
Greater than 110° C	Radiator soiled	Clean radiator
	Radiator fan not functioning	Check function
	Thermostat faulty	Check thermostat See COOLING SYSTEM COMPONENTS, ENGINE SIDE .
	Coolant temperature sensor or wiring to engine control module	Check coolant temperature sensor. See ENGINE COOLANT TEMPERATURE (ECT) SENSOR -G62-, CHECKING .

EVALUATING DISPLAY GROUP 4, DISPLAY ZONE 4 - INTAKE AIR TEMPERATURE

Indicated on display	Possible cause	Corrective action
Constant 19.5° C	Malfunction recognized on intake air temperature sensor -G42-	Check intake air temperature sensor. See INTAKE AIR TEMPERATURE (IAT) SENSOR - G42-, CHECKING .
Constant 19.5° C	Intake air temperature sensor -G42-	Check intake air temperature sensor. See INTAKE AIR TEMPERATURE (IAT) SENSOR - G42-, CHECKING .
Constant -46.5° C	Wiring open circuit	Check intake air temperature sensor. See INTAKE AIR TEMPERATURE (IAT) SENSOR - G42-, CHECKING .
141° C (display appears only briefly and then jumps to 19.5° C)	Short circuit between wires 1 and 3	Check intake air temperature sensor. See INTAKE AIR TEMPERATURE (IAT) SENSOR - G42-, CHECKING .