By ALLDATA Tech-Assist Team
Here are some of the “Tech Tips” ALLDATA has compiled as its Tech-Assist Team helps technicians tackle vehicle issues. More detail on these tips — including marked-up schematics, images and recommendations — are searchable in the “ALLDATA Community.”
Audi A3 MIL on, ECT gauge pegged hot
Problem: The owner of an Audi A3 Quattro sedan (8VS, L4-2.0L Turbo, automatically shifted manual transmission/transaxle) with 122,366 miles dropped it off at the shop because the malfunction indicator light (MIL) was on, and the engine was running extremely hot, according to the coolant temperature gauge.
Details: The technician connected a scanner and retrieved diagnostic trouble code (DTC) P0116 – Engine Coolant Temperature (ECT) Sensor 1 Circuit Range/Performance. The owner said that the thermostat, water pump, and coolant temp sensor (at radiator outlet) had already been replaced at another shop. After those repairs, the gauge still showed hot. The scan tool data confirmed that the system was reporting 248 degrees Fahrenheit (120 degrees Celsius).
The technician noticed that the upper radiator hose was not getting hot. He put a call into ALLDATA Tech-Assist to discuss the problem. The Tech-Assist consultant advised that this vehicle had two ECT sensors — one in the radiator outlet and another on the engine block. The DTC referred to the latter sensor (G62). He suggested checking the resistance of that sensor. It should be 2,250 +/- 750 Ohms. He also suggested making sure all the air was purged from the cooling system, because that may be causing the cold upper radiator hose issue.
The technician followed that advice and found the …
