'92 Calif version Code 71 (1 Viewer)

[Scota4570]

I get a code 71 after several trips. I have gone through the ERG systems and repaired/replaced several parts. All of the EGR parts check OK. In the factory manual I noticed second trip logic between the EGR gas temp sensor and the coolant temp must be in certain parameters or the 71 code will trip.

"A" I bought a coolant temp sensor. I checked it against the old and the behavior was the same for resistance and temperature. That one is "A" in photo checks OK Part # 89422-2210

"B" in the photo is a single lead sensor on the bottom half of the thermostat housing, it seem to work
What is the part and number? Might as well replace.

"C" in the photo is another single lead sensor on the top half of the thermostat housing, it is open and does nothing. What is this part and the number? Might as well replace

"D" in the photo is the cold start coolant temp sensor. It appears to be dead. It give 82 Ohms regardless of the temp. part # 89462-20040 I suspect this is the problem, replace.

 

[Scota4570]

I found a nice picture. Hopefully it helps. I intend to replace items C and D.

 

[Scota4570]

Item D costs $306 at the dealer,
Item C is no longer made,
Anyone know the testing procedure on these?

 

[jonheld]

www.partsouq.com
enter your VIN and all part numbers are available to you. You can order directly from them if you wish.

A non-OEM water Temp Switch is available at Rock Auto:

More Information for STANDARD MOTOR PRODUCTS TS213

The water temp SENDER is for the dash gauge.
The water temp SENSOR is for the ECU.
The BVSV valve is part of the emission control system.
The CSI time switch is a bi-metal switch that fires the cold start injector under certain conditions.
The water temp switch is for fuel pressure control.

All this info is in the Toyota FSM and EWD.

 

[Scota4570]

The book I am calling the FSM is green and black, Pub# RM258U. It appears to be from Toyota Motor Corporation. At any rate I look through it for quite a while and did not find what I needed. I do not understand why an index is not included. IT seems like a major oversight. I am dyslexic and find the hidden gem in the word jumble is not easy for me.

I replaced the two apparently bad sensors. I found a broken wire that was supposed to go the the water temp sender. Poorly repaired wiring was replaced. All the associated hoses were replaced. The rear passenger location thermostat housing bolt was broken off before I got in there. I though I smelled coolant. I welded a nut on it. Heated it red several times, and snapped it off flush on about the 10th try. I then made a drill bit bushing to fit the housing, drilled the bolt out and re-tapped the threads. That was a lot of work because the last guy did not use anti-seize. At any rate it is now running as smoothly as it has since I got it. Hopefully code 71 is gone for good.

 

[jonheld]

I do not understand why an index is not included.

All of the original hardcopy FSMs have an index page. All of the digital FSMs are bookmarked according to the hardcopy indices. The advantage of the digital ones is that you can search on a keyword within Acrobat.

 

[Scota4570]

That is the index page for what I have.

So, with the electronic version you can search a key word? Cool, exactly like the index in the back of most paper technical books.