mikerayvt

It makes a sense! Yes, I used that info sheet. You're awesome! You answered to my question. I reviewed my test results and did one more test after the transmission temperature was lowered to 80 deg F. With a new wire connection to the temp sensor outside, I measured voltage between two wires with my little voltmeter. The temp sensor resistance is 1500 ohms, the voltage read 1.2 volts when the volt range is 9V. When I switched range to 1.5V on my voltmeter, it read .15 volts. Something wrong. The volts were supposed to be about same in two different ranges. I tested a 1.5 volt battery with my voltmeter and the reading was same in the both range. I suspect current is weak? I swapped TCM and the result was the same. If you read my replies/answers in justanswer.com, it's same result. (9/6/09 7:38pm) An expert asked me to measure voltages that were inputs to TCM and they seem ok. I think the connector to TCM is bad or maybe both TCM's bad. I could take the cover off and measure some points inside to test the terminal connection. Is it required that the TCM box is grounded all times? Is there any variable or control to vary the voltage to the temp sensor? Tomorrow is my appointment with Subaru service for my car. Maybe I leave it to them.

The temp sensor is inside but it is off since another temp sensor is temporarily mounted on the surface outside and it's active. I added it to isolate a root-cause problem. When a problem is found, it will be removed. A pair off wires are also added between TCM and the outside/temporary temp sensor. The wires to the inside temp sensor is cut off. If I reconnect the inside temp sensor, it would flash "Oil Temp High". It seems confusing. Does it? I briefly tested circuit between the connector outside the transmission and the temp sensor connector inside and they were ok. I didn't test wires to ground (make sure they are not short to ground). They were not at operational temperature and I didn't move wires around to see if circuit becomed open or short to ground. I didn't expect it until I realized that this section is the only remain to test??? It could be somewhere else. If the wire inside the transmission is causing the problem, would wire replacment be easy without having the transmission taken out? Is there anybody who knows about voltage spec for TCM and temp sensor?

Its 2-wire. I have put a ground wire between the transmission and the firewall before and it didn't help. Normal wires route from TCM connector B55 to transmission connector and from transmission connector going into transmission to temp sensor connector. I tried new wires. I cut wires just after TCM connector and cut wires just out of tranmission and connected new wires between them and it didn't help. Only a temp sensor temporarily mounted on transmission with new wires straight to TCM connector works. No Oil Temp High and no harsh shift. The problem according to the diagnosis instruction is that voltage across the temp sensor is too low but my car works fine. (I measured temperature with an IR gun on the transmission surface and resistance across the temp sensor and they are good (about 180 deg and about 300 ohms). Voltage across the other temp sensor inside is same (too low). The voltage with a different TCM is too low too. It's from 2005 Mitchell Repair Information Co. If the voltage is normal, then wires inside transmission are bad but I am not sure about the instruction. I tested voltages like 10 times spring and summer.

Hi, My Subaru Outback 1999 experienced a very little but noticable harsh shift at 25mph in cold mornings after the rebuilt transmission replaced. The service couldn't find a problem and thought it was ok as long as it's warmed up first. Oil Temp High came on a couple of times in the past year and went away when stopped and restarted. Now it came on all time and gears shifted too harsh at 40 or 45 mph. With a given instruction for P0710, I was able to locate a problem with voltage input to the temp sensor. According to the paper, voltage should be 2.9 - 4.0 volts but I got 1.6 volts even the sensor resistance was within spec. TCM replaced didn't fix and got the same result. Temp Sensor replaced didn't fix. Wires replaced between TCM and AT didn't fix. Added a Temp Sensor to the exterior surface (deep concave) of Transmission with new wires to TCM (cut wires to Temp Sensor that was inside AT) solved the problem and driving good for a couple of months. Now weather is turning to cold soon and need to fix it permanently. I want to know about voltage input to Temp Sensor from TCM. Is the instruction wrong? or Is a new TCM bad? Does the wire assembly inside the transmission need a replacement? Thanks!