tymeboy

I have a p0115 engine temp circuit code and the vsc/ vsc off lights are on and no separate code for those lights. the p0115 threw the CEL light. I just had the valve cover gaskets replaced and now these are on. I replaced the engine temp sensor but still no change. I searched the forum and didn't see any info on the p0115 light. Thanks!

sbagdon

Well, found this thread...

The post says "valve cover gaskets", so presume you have a GS4.

Any engine or ABS code will trip the VSV. If you check the VSV codes, it would probably report "engine code, disabling system".

P0115 Engine Coolant Temperature Circuit Malfunction

Ground the coolant sensor, and does the coolant gauge move? If it does, you might have a bad replacement sensor.

Quick google says to check the primary O2 sensor plugs. There's (4) O2 sensors on the GS4... one "upstream" on the primary cats, and one "downstream" on the flex pipe (for each bank)... our left downstream was throwing a code, and we couldn't get the downstream O2 sensors out of the Y-pipe (rusted in), so we just replaced both, with the Y-pipe. The plugs for the downstream are inside the car in the seat area (had to replace those when we replaced the Y-pipe), not sure where the upstream plugs are... guessing they might be in the engine bay. They might have been disturbed while they were working on the gaskets.

tymeboy

Nad1370

Can you access current data list with your scanner, check what the coolant temp is reading?
I'd like to see if its an open or short in the wiring since you said you replaced the sensor already.

Thanks.

tymeboy

So I figured out that the car has two temp sensors. One behind the thermostat ( pictured) and one in the radiator at the bottom driver side. The one I replaced was the radiator sensor. No change. I replaced the sensor behind the thermostat and the CEL and the vsc lights went out. However, I am still not getting a reading on the temp gauge and the car is idling at about 2400 rpm. What gives? Thanks guys!

tymeboy

Nad1370, Here is a screen shot of my scanner screen. It is reading the engine temp.

Nad1370

Thanks.
Glad you figured it out.
Temp sensor in the radiator is for the AC temp switch.

The one by the t-stat is output signal going to the ECU
The ECU then transmits the signal to the temp gauge receiver in the combo meter.

If you can see engine temp (im assuming this is engine coolant temp) on your scanner and not on the combo, you possibly have a bad temp gauge in the combo meter.

Did your temp gauge work prior to the work that was done?

tymeboy

yep. Temp gauge worked prior to repair.

sbagdon

Ground the temp sensor, see if the temp gauge moves.Very old-school, yet effective.

tymeboy

how do I ground it? I will let you know what I find.

Nad1370

tymeboy

no the motor was hot and the fans kept coming on when it reached about 90. Is it possibly a thermostat issue?

Nad1370

Does the hose coming off the T-stat get HOT?
It should be just as hot as the top radiator hose when the T-stat opens.

Fans should kick ON once they see temps go around 195+ degrees F
Not at 90 degrees.

tymeboy

sbagdon

For all the temp-sensors I've ever worked on (that I can remember!), whether coolant, oil, trans, diff, etc, it was 1-wire... just jumper-ing the single lead to engine-ground (block, battery, ground-wire, etc) would drive the sensor to max-temp (infinite resistance?). On most of our Toyotas, the needle will jump to the max, when the single-wire sensor is jumper'ed to ground.