Techstream help

The mnemonic isn't explained on those two pages. I didn't pore through the manual to see if it is somewhere else.

-Chap

 

That's a good question! It's not something you'll find in the Repair Manual itself, because it's considered basic electrical knowledge you would bring to the table, but of course you do have to pick it up somewhere. The good news is, once you have signed in at techinfo.toyota.com for access to repair manual and the wiring diagrams, you will also have access to the entire technical library there, including the Quick Technical Guides (QTG tab), and the course modules for University of Toyota technician training courses. I'm too rushed at the moment to give you click-by-click for finding them, but they're there, and you will find the modules on electrical diagnosis basics, which is where your question is covered.

-Chap

 

Back in May 2013, I was working on my fuel rail, and had to unplug the cam sensor in order to make room to get a wrench on the last fuel rail bolt. I know I didn't do anything with the inverter to do that.

Or are you saying, unplugging the wires isn't the problem, but the sensor itself is still too inaccessible even after you've unplugged them?

The Repair Manual sometimes says to check continuity (which you can do with an ohmmeter with all ends disconnected), and sometimes it says to check for certain voltages under certain conditions (key ON engine OFF, say, or whatever condition is stated). So you need to pay attention to what it is saying to test, and do that. If it is saying to test for a certain voltage in certain conditions, obviously you can't have the battery disconnected for those, you just have to work carefully and make double-sure you know which pins you're probing. A nice set of thin backprobes for your meter leads can help for when you need to probe into the back of a connector that isn't unplugged.

For the connectors exposed to the elements and built with rubber seals, it helps to know how the seals are constructed, so you poke your backprobes past them rather than through them.

Did you buy the wiring diagram manual also? It's less money than vols 1 and 2. It has more a lot of details that aren't in those volumes, and it has a front section all on testing and repair techniques. It also contains lists of voltages to test for under different conditions, sometimes more of them than you see in volumes 1 and 2. I have also seen some pin numbers in v 1 and 2 be wrong, but right in the wiring diagram. I think some things move around between early drafts and final design, and they make sure to get all the final pin numbers updated in the wiring diagram, but not always elsewhere.

-Chap

 

Asides all this, please can anyone put me through how to graph real-time HV battery block readings? Have tried starting from the DATA LIST section, but it isn't working.

 

For general diagnosis you probably don't need to graph it.
Just watch it live when driving in a safe area.
Or do some power-braking and draining while sitting still and watch things.

 

Yeah, that's what I do all the time.
I just want it graphed. Have done it once, it can't remember the procedures again.
Can you help please?

 

Isn't there an icon toward the bottom of the data list window that looks sort of like a graph?

-Chap

 

Yeah, there is. I'd do a snapshot and post.

 

I suggest that you need to decide if you are determined to fix the car yourself, or not. If you are, then do what is needed to attain access.

The engine coolant sensor and the camshaft position sensor are both hiding on the side of the engine head facing the inverter. I suggest you make sure which sensor you are working with. The camshaft position sensor is held on with one little bolt, while the engine coolant sensor body is threaded and screws into a large threaded hole.

I took a look at my 2007 and at least with 2G, there are at least two bolts holding the inverter coolant reservoir to the side of the inverter. It is possible that you might be able to remove the inverter coolant reservoir to improve your access to the sensors.

If/when you get to the point that you are willing to remove the inverter, you would first disconnect the 12V battery and remove the orange traction interlock on the HV battery, as safety measures.

When you test the integrity of the wiring harness, you would disconnect both ends and use an ohmmeter to test continuity of each wire in question.