Engine Coolant Temperature (ECT) Gauge -G3-, Checking
If the engine coolant temperature gauge in the instrument cluster does not indicate a reading, first check whether the signal is received by the instrument cluster.
- Connect VAG1551/VAG1552 Scan Tool (ST) and press buttons -1- and -7- to insert "Instrument Cluster" address word 17 (with ignition switched on).
Indicated on display
Rapid data transfer Q
17 - Instrument Cluster
- Press -Q- button to confirm input.
Indicated on display (after approximately 5 seconds)
460919930B C5-KOMBIINSTR. UN4D13->
Coding 07262 WSC 06812
- Press button.
Indicated on display
Rapid data transfer HELP
Select function XX
- Press buttons -0- and -8- to select "Read Measuring Value Block" function 08.
Indicated on display
Rapid data transfer Q
08 - Read Measuring Value Block
- Press -Q- button to confirm input.
Indicated on display
Read Measuring Value Block HELP
Input display group number XXX
- Press buttons -0-, -0- and -3- to input display group number 003, and press -Q- button to confirm input.
Indicated on display (1-4 = display fields)
Read Measuring Value Block 3 ->
1 2 3 4
If the engine coolant temperature is displayed in display field 1 on the scan tool, the instrument cluster is faulty and must be replaced. Removing instrument cluster.
If the engine coolant temperature is not displayed in display field 1 on the scan tool:
- Check the signal to the multi-pin connector for the instrument cluster.
- Press button.
Indicated on display
Rapid data transfer HELP
Select function XX
- Press buttons -0- and -6- to select "End Output" function 06.
Indicated on display
Rapid data transfer Q
06 - End Output
- Press -Q- button to confirm input.
- Connect VAG1598 test box to blue 32-pin connector using adapter VAG1598/25.
- Using multimeter US1119 (Fluke 83 or equivalent), measure resistance between terminals 8 and 7, (signal Ground).
Specifications:
- Engine coolant temperature 60 °C (140 °F): approx. 259 Ohm
- Engine coolant temperature 90 °C (194 °F): approx. 107 Ohm
- Engine coolant temperature 120 °C (248 °F): approx. 40 Ohm
If values are not as specified:
- Checking wiring.
If wiring is OK:
- Replace sensor.