With Manufacturer's Scan Tool
Oxygen Sensor (O2S) heater behind TWC, checking
NOTE:
- Connector for Oxygen Sensor (O2S) heater (behind TWC) -Z29- (bank 1, sensor 2): 4-pin, green.
- Connector for Oxygen Sensor (O2S) 2 heater (behind TWC) -Z30- (bank 2, sensor 2): 4-pin, brown.
Required special tools and test equipment
- VAG 1551 or VAG 1552 Scan Tool (ST) with VAG 1551/3 adapter cable
- VAG 1598/22 test box
- Multimeter US 1119 (Fluke 83 or equivalent)
- VW 1594 connector test kit
- Wiring diagram
Test requirements
- Fuse for Oxygen Sensor (O2S) heater OK
- Engine Coolant Temperature (ECT) at least 80° C (176 °F)
Checking
- Connect VAG 1551 or VAG 1552 scan tool and press buttons -0- and -1- to insert "Engine Electronics" address word 01 (with engine running at idle).Refer to "Scan tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG 1551/VAG 1552 Scan Tool" [1][2]Scan Tool Connecting and Initial Checks
Indicated on display
Rapid data transfer HELP
Select function XX
- Press buttons -0- and -8- to select "Read Measuring Value Block" function 08, and press -Q- button to confirm input.
Indicated on display
Read Measuring Value block HELP
Input display group number XXX
- Press buttons -0-, -4- and -0- to input display group number 40 (040), and press -Q- button to confirm input.
Indicated on display (1-4 = display fields)
Read Measuring Value Block 40 ->
1 2 3 4
- Compare display and specified values (display fields 3 and 4):
Display Group 40:
If displayed values are OK (as specified):
- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06, and press -Q- button to confirm input.
- Switch ignition off.
Continuation
- Disconnect 4-pin connector for respective Oxygen Sensor (O2S) behind Three Way Catalytic Converter (TWC).
- Connect multimeter US 1119 (Fluke 83 or equivalent) between O2S connector terminals 1 and 2, using VW 1594 connector test kit.
- Measure resistance.
Specified value: 0.00-19.9 Ohms
If resistance is NOT OK:
- Replace respective Oxygen Sensor (O2S) behind TWC.
If resistance is OK:
- Switch multimeter to 20 VDC measuring range.
- Connect multimeter between harness connector terminals 1 and 2 (to ECM), using VW 1594 connector test kit.
- Measure voltage supply and check display in display group 40, display field 4.
If display = Htg.aC.ON:
- Specified value: 11.0-14.5 volts
If display is switching between "Htg.aC.ON" and "Htg.aC.OFF":
- Specified value: 0.0-12.0 volts (oscillating)
If there is no voltage:
- Connect multimeter between harness connector terminal 1 (to ECM) and vehicle Ground, using VW 1594 connector test kit.
Specified value: 11.0-14.5 volts
If there is still no voltage:
- Check wiring between terminal 1 and relay panel using appropriate wiring diagram.
If there is voltage:
- Connect multimeter between harness connector terminal 2 (to ECM) and Battery Positive Voltage (B+), using VW 1594 connector test kit.
- Measure voltage supply and check display in display group 40, display field 4.
If display = Htg.aC.ON:
- Specified value: 11.0-14.5 volts
If display switches between "Htg.aC.ON" and "Htg.aC.OFF":
- Specified value: 0.0-12.0 volts (oscillating)
- Switch ignition off.
If specified value is not attained:
- Connect VAG 1598/22 test box to ECM harness connector.Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG 1598/22 Test Box" [1][2]Scan Tool Connecting and Initial Checks
- Check wiring for open circuit between ECM/test box and 4-pin O2S harness connector (to ECM).
- Connector terminal 2 to ECM/test box socket 28
- Specified value: max. 1.5 Ohms
If wiring is OK:
- Replace ECM -J220-
- Carry out adaptation of throttle valve control module to ECM.
- Check readiness code.If Diagnostic Trouble Code (DTC) memory has been erased, or ECM was disconnected, generate new readiness code. Audi Drive Cycle/Readiness Code