Check engine light will not reset

[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/...k+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.