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Test Procedure

-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK .

Start diagnosis

Checking heater resistance

-- Disconnect the Heated Oxygen Sensor (HO2S) -G39- / Oxygen Sensor Heater -Z19- electrical harness connector -3-.

Fig 1: Exploded View Of Exhaust Temperature Control Components
GWWN26-10829Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Using a multimeter, measure the resistance of the heater from terminal 3 to terminal 4 of the Heated Oxygen Sensor (HO2S) -G39- / Oxygen Sensor Heater -Z19- connector.

Specified value: 2 - 4 Ω with the exhaust system at room temperature

If the specified value was Not obtained:

-- Replace the Heated Oxygen Sensor (HO2S) -G39- / Oxygen Sensor Heater -Z19-. Refer to the Repair Information.

If the specified value was obtained:

-- Switch ignition on.

-- Using a multimeter, measure the voltage from terminal 4 of the Heated Oxygen Sensor (HO2S) -G39- / Oxygen Sensor Heater -Z19- harness connector to ground.

Specification: About Battery voltage

-- Switch ignition off.

If specified value is Not obtained:

-- Check the wiring connection for an open or short circuit.

-- Check the wiring connection for damage, corrosion, loose or broken terminals.

-- If necessary, repair the faulty wiring connection and replace any open fuses

-- Go to Final Procedures 

If the specified value was obtained:

-- Connect scan tool.

-- Start the engine and let idle.

-- Perform the function test located in diagnostic mode 06. Refer to DIAGNOSTIC MODE 06 - READ TEST RESULTS FOR SPECIFIC DIAGNOSTIC FUNCTIONS .

If specified values are obtained:

-- Fault may be intermittent.

-- Check for loose or corroded connections and any leaks in the exhaust.

-- Check Freeze Frame data for conditions when the DTC set.

-- Go to Final Procedures 

If the specified values are not obtained:

-- Using a Multimeter, Check the Heated Oxygen Sensor (HO2S) -G39- / Oxygen Sensor Heater -Z19- electrical harness connector terminals 2 to 6 for voltage.

Specified value: 0.400 to 0.500 Volts

-- Switch the ignition Off.

If the specified value was obtained:

-- Replace Heated Oxygen Sensor (HO2S) -G39- / Oxygen Sensor Heater -Z19-. Refer to Repair Information.

If the specified value was not obtained:

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