Coolant Temperature Gauge
- Disconnect 4-wire electronic thermoswitch harness connector, located on coolant pipe behind right cylinder head. Connect Digital Volt Ohm Meter (DVOM) between ground and terminal "T" at electronic thermoswitch harness connector. See Fig 1. Turn ignition on. Voltage should be 9.8-10.3 volts. Turn ignition off. If voltage is not as specified, check for open circuit to coolant temperature gauge sending unit. See WIRING DIAGRAMS . If wiring is okay, check voltage stabilizer. See VOLTAGE STABILIZER . If voltage is as specified, go to next step.
- Connect Gauge Tester (VW 1301) between ground and terminal "T" at electronic thermoswitch harness connector. See Fig 1. Set gauge tester dial to 560. Turn ignition on. Note 2 dots, one on each side of cold mark on gauge. If coolant temperature gauge needle falls within these 2 dots, go to next step. If coolant temperature gauge needle does not fall within these 2 dots, go to step 4).
- Set gauge tester dial to 58. Note 2 dots, one on each side of mark that is just past halfway mark on gauge. If coolant temperature gauge needle does not fall within these 2 dots, go to next step. If coolant temperature gauge needle falls within these 2 dots, gauge is okay.
- If voltage tests were okay and gauge test were incorrect, replace coolant temperature gauge. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION.
Courtesy of AUDI OF AMERICA, INC.