Check engine light will not reset

[BetsyBrown]

86 2wd van

I've fixed the issues that came up, disconnected the battery for at least an hour while installing a new starter.
Light does not reset. Tried pulling the 10A ECU fuse as well and got nothing

Anyone know what else I can do the reset the check engine light?

Thanks!

[BetsyBrown]

Well...i figured out I needed to pull the EFI fuseable link to lear check engibe light, but still no luck getting rid if it so i can test my fixes.

Pulled battery cables off for a whole day as well and still nothing.

Anyone got any ideas?

[AD2101]

Not to be that guy but, you are sure you fixed the problem, right? I can't say I've ever had your specific issue, but whenever I had a check engine light that persisted after disconnecting the battery it was because I hadn't actually got to the root of the problem. What codes was your van showing and what fixes did you do?

[BetsyBrown]

@AD2101
Thanks for the response!

The codes I got were:

Code 4: Water temp signal sensor (REPLACED, working fine)

Code 10: Starter signal (REPLACED, seems to be working well, but having issues with cold starts, looking into cold start injector, fuel pump currently to fix that)

Code 11: Switch signal (could not figure this one out, any ideas?)

Every other vehicle I've own resets the engine light when battery disconnected, so I just assumed it was the same on the van. I suppose that is not the case?

Any thoughts on this greatly appreciated!

[originalkwyjibo]

Code 11 likely is caused by a bad or mis-calibrated throttle position sensor.

[llamavan]

Every other vehicle I've own resets the engine light when battery disconnected, so I just assumed it was the same on the van. I suppose that is not the case?

The Vans' codes DO reset with the battery disconnected (I've heard variably that it needs to be 10 minutes or more; can't remember what the FSM says offhand). If you are still getting codes, you have not found the problem.

Gwen

[AD2101]

There are other possible culprits for your codes, which are all listed in the FSM. Are you saying that, after putting all the new parts in and disconnecting the battery, that none of these error codes went away? 0 out of 3 ain't good, at least on the Meatloaf scale, I would look at the ECU and make sure everything is hooked up snug and there aren't any exposed/damaged wires or burn marks anywhere on the ECU board. It's also the one constant possibility across all your codes so it's worth a looksie.

[BetsyBrown]

Re checked codes and they are all coming up at again
4,10,11

This was after having battery and ecu fuse disconnected all night.

So apparently I didn't fix the coolant sensor and starting issues. Will look into it today.

Started to dig into code 11,
Found good threads but the video where Tim explains how to recalibrate the tps isnt available anymore. Anyone have a copy they can post?

On a positive note me and BetsyBrown just made a 10 hour roadtrip from Portland to lake Tahoe without any issues! Only that it takes me 10 min to cold start her...working on that one.

[AD2101]

This one?


https://www.youtube.com/watch?v=182ZOtfUC_g

[beetleswamp]

Thanks for re posting this video. I saw it a while back and lost track of it as well.

[BetsyBrown]

Thanks for re-posting @AD2101 !

I could only find some sketchy photobucket links ;)

[BetsyBrown]

Made some progress, no more code 10

I changed the starter out bc Ive been having issue with it for a while. But that didn't really help or clear the code.

However, today I was checking connections and noticed a connector on top of the engine block, to the left of the throttle body, was partially melted and loose. I cleaned it up got it re connected and code cleared...and my cold start issue seemed to have gotten better...

Still trying to figure out which cable it is. Can't get a picture uploaded for some reason

EDIT it is the connection to the cold start valve, it was loose and damaged

[BetsyBrown]

Regarding code 4, I am getting a normal temp reading on dash gague and sensor is new and has good resistance...no breaks in the wiring.

I am assuming my ecu is good bc I was able to clear another code

Any thoughts on code 4 and clearing it?

[AD2101]

Yea I was going to say I wouldn't worry about the ECU anymore if you were able to clear at least one of the codes.

[originalkwyjibo]

RE: code 4. Which sensor did you replace? The gauge and the computer use different sensors. The gauge uses a single wire sensor threaded into the cylinder head just above the distributor. The computer uses one threaded into the upper water outlet. Here's an image from another thread to help with the location. It's the one marked "temperature switch".
6414

[BetsyBrown]

Replaced the temperature switch, I'm assuming there's something up with the wiring I'm not finding...

On another note, the idle up switch in this picture is not wired up at all in my van. Just a nub...guess I'll be looking into this too. I don't even see a loose connection just the sensor with an open end staring up at me.

[originalkwyjibo]

Try searching these terms. These are all common problems discussed many times before. Temp sensors, wiring, and plugs get brittle causing them to break or creating bad connections. I've had to replace the temp sensor connector on one of my vans and probably should in the other. Part numbers are given in other threads for the sensors/switches as well as replacement connectors. Idle up switches are no longer available so when broken or non functional the wire is attached to ground.

[BetsyBrown]

Ive been searching and reading up on these issues for a few days now, apologies if i am repeating things but just not finding the answers myself.

Found the idle temp switch here i think...based on a part number i got in another post
https://www.toyotapartsdeal.com/oem/toyota~switch~temperature~89428-20050.html

What does this switch do? Should I be concerned about replacing it and running a new wire to it? Could this be the cause of my code 4?

[timsrv]

Ive been searching and reading up on these issues for a few days now, apoppogies if i am repeating things but just not finding the answers myself.

Found the idle temp switch here i think...based on a part number i got in another post
https://www.toyotapartsdeal.com/oem/toyota~switch~temperature~89428-20050.html

What does this switch do? Should I be concerned about replacing it and running a new wire to it? Could this be the cause of my code 4?

Don't waste your money on that one as it won't change anything (especially this time of year). Here's a post I made on that previously:


That switch (Pressure-up Temperature Switch) is worthless anyhow. There was a service campaign back in the day that replaced that switch with a lower temperature one. Very few vans had that service campaign completed, and now the new switch is NLA. You're better off to just cut the old connector off, then put an eye terminal on that wire and ground it out. I usually extend the wire and put in on the front stud of the intake plenum along with all the other grounds. Doing so will activate your "pressure-up" system for 2 minutes after every start. This will help combat the Heat Soak (http://www.toyotavantech.com/forum/content.php?218-The-infamous-hot-soak) issue. Tim

Here's a thread that further explains the "pressure-up" system of the van: http://www.toyotavantech.com/forum/showthread.php?1582-What-does-a-particular-VSV-do-See-excellent-attached-diagram&highlight=pressure-up

[BetsyBrown]

Thanks for the info Tim!

So on another note all the codes cleared today after I cleaned all the connections, and gave the tps a couple light knocks with a hammer. It's a Christmas miracle :)

I'm sure it's a temporary, lucky fix, so ill be changing the tps out soon to be sure.

Thanks for the input everyone!

[scotty]

I’m getting a code 10 on my ‘87 van. It was running and some dash lights came on. It starts and runs fine. Any ideas where to start troubleshooting this? Thanks

[JDM VANMAN]

I tried searching “check engine reset” and came up a a few threads, I think this thread may be close to what your looking for-

https://www.toyotavantech.com/forum/showthread.php?3039-quot-Check-Engine-quot-staying-on-most-of-the-time-now&highlight=Check+engine+reset

read thru it and see if this will answer your issue? :?:

Good Luck

JDM

[scotty]

Thanks for the link.

I started digging in and it seems that the starter relay is bad. The switch still clicks when you apply voltage, but it failed the continuity test. It shows 64ohm resistance between terminal 1 and 3 on e relay. I got a used one and it measures the same. It's strange, because the van still starts. I think it has multiple start signals to or from the ECU maybe, and the relay just gives you extra juice at start up? (4wd has a starter relay).

I checked the fusible links and got a new battery and alternator ( not sure if it's related, but they both went bad pretty much at the same time). I cleared the code and it successfully clears, but comes right back. I changed the ECU to see if it made any difference, but it did not. I'm worried that I could be damaging the alternator, starter or battery by driving it with this code. Any idea what the continuity or ohm reading is supposed to be on a starter relay and could I just wire in a different one to see if it will make this code disappear, before I keep buying used ones for over $100.

[originalkwyjibo]

The wiring schematic I have doesn't show a starter relay for autos. Where is the relay located on yours?

[scotty]

It’s right behind the air filter to the left. It’s only in the manual transmission vans.

[originalkwyjibo]

I was reading too many threads and got yours mixed up with someone else's that's an auto. The relay seems to be there instead of having a second clutch switch to kill the cruise control when the clutch is depressed. The starter is not "signaled" through the computer rather a signal is also sent to the computer when the ignition switch is turned to start. In theory, if the starter cranks then the computer should be getting a signal. The service manual has a diagnostic flow chart and wiring schematic specific to this circuit on page FI-33.

[originalkwyjibo]

You won't damage the starter or alternator and as far as the relay test, continuity and ultimately function is more important than resistance. If the starter cranks, the relay is working. 1 and 3 show resistance because that is the electromagnet side of the relay. It has resistance by design.