Need help with code 12 (88/89)

[Jlhollowx13]

So today when I started the van it sort of stumbled and threw a check engine light. The light went out shortly after and it seemed to run fine. I checked the codes and got one blink and 2 blinks. According to the FSM it's air flow meter. What is this?

Also, when I went to clear codes and check again to make sure codes cleared it just blinks repetitively and fast, what is this?

One thing I'll note is when I was doing some other maintenance the other day I noticed the wires from the air filter area to the lower green connector on the front of the distributor were frayed and cut. I cut out the bad parts and spliced in some new wire. I also noticed a clicking sound coming from the air filter area when the car is off. Not sure if these are related but worth a shot.

Thanks for any insight!

[Jlhollowx13]

Ok, I had a chance to do some diagnostics as per the manual in the included photos. My readings are this:

ECU
VC-E2 is 7.94 so within range
VS-E2 is 1.91 within range
VS-E2 at idle 5.92 within range

I couldn't check ground from ecu at terminal E1 or E2 because I'm not sure where they go to so I couldn't find its end point. I'm assuming it's good from the other tests.

ECU seems good.

Air flow meter
E2-VS is 120 within range
E2-VC is 115 within range
E2-VB is 180 out of range
E2-THA not getting anything
E1-FC not getting anything, guess that's infinity and good?

Seems like my air flow meter is bad? Any other ways to test them or is this definitely the bad part? Any input is appreciated, can't afford to start throwing parts at it right now.

[Jlhollowx13]

Does anyone know why my check engine light just blinks repetitively when I try to check codes now? It's not doing it in the interval that the manual says is normal for no codes, I think 1 blink every 4.5 seconds, this is blinking much faster.

[Jlhollowx13]

Ok so now I'm really confused. Yesterday I didn't have my volt meter with me so I borrowed one. I wanted to make sure it was right as I didn't trust it so I test everything again with my volt meter I trust. This time everything came back within spec!

Was this a fluke? And why is my engine light still blinking like crazy when I try to check codes? I'm hoping this issue doesn't arise somewhere bad and leave me stranded!

[djshimon]

Mine blinks pretty slow-like yours-when there's no codes.
Also, I thought my air meter was bad so I got a j/y one and they both work great and are not within spec-I don't know why but I don't think anyone's air meter is.
Maybe this is a bigger problem with the Universe?

[llamavan]

The Air Flow Meter is a super-easy fix (well, it was easy on an '85, which has none of the 2nd gen igniter "bonus parts" on top of the air filter box ... ). I harvested one from a long-dead parts van, used a new gasket per the manual, and all has remained well with that van. If you're not flush with cash, it would definitely be worth trying an AFM from a junkyard van (and if it was me, I'd pull more than one if possible ... just because ... )

Now, the blink speed(s) — They're different for 84-87 and 88-89 vans!

1984-87 vans have single digit trouble codes.

Quote from the 1985 Factory Service Manual:

(a) Normal System Operation (no malfunction)

The light will blink once every three seconds.

When displaying a trouble code:

• The ON interval is 1/3 second and the OFF interval is 2/3 second
• Each code is separated by three seconds, whether repeating a single trouble code or separating a series of multiple codes.

1988-89 vans have two-digit trouble codes, so the display intervals are different.

Quote from the 1989 Factory Service Manual:

(a) Normal System Operation (no malfunction)

• The light will alternately blink ON and OFF for 2 times per second.

To put that another way, according to the manual, the proper blink speed with no codes is 0.5 ON, 0.5 seconds OFF.

When showing codes, the ON interval remains 0.5 seconds, and the OFF interval is what varies:

• 4.0 seconds before the first "ON" interval
• 0.5 seconds OFF between each 0.5 seconds ON to display a code digit
• 1.5 seconds OFF between the first and second digits of each code
• 2.5 seconds OFF separate codes (for example, between the end of the second digit of the first code and the first flash for the first digit of the second code)
• 4.5 seconds OFF before repeating the full sequence of stored codes.

Hopefully this helps clarify.

Gwen

PS — I wasn't ignoring you up until now, honest ... nor am I some kind of Van minutia trivia geek. Full disclosure — I just got Skyler (1989) running again this afternoon and cleared codes and got the "fast blinking light" and about flipped out for the same reasons you were concerned — all my other vans all do the "slow blink" and I didn't realize there was any difference ... until today.

[Jlhollowx13]

Thanks for the reply. I did realize 84-87 where different than 88-89. I was told my van is an 88, I think the title may even say that, but it's a build date of December 87. I thought maybe I have a newer ecu, and thus is giving new style codes. According to my Vin my ecu should be the older style but I also diagnosed and tested it as if it was a new code of 12, this gave me rpm signal and when I tested it it came back fine. Not too sure what the deal is now, air meter checks out, ecu checks out. Maybe my air meter is going out? I'll just keep monitoring it and see if I get another code. As of now I'm not seeing any signs of problems (other than issues I've already had), van runs well, starts normally, etc.

Unfortunately the nearest junk yard the latest MIGHT have a van is about 200 miles away, so I've been looking around online for a used one. Only problem is I can't test a used air meter from ebay like I can in a junk yard before I buy.

[llamavan]

Build date of December 1987 would be the 1988 model year (Sept 1987 thru Aug 1988).

Gwen

[Jlhollowx13]

Thanks, so I was assuming the wrong code. Instead of the air flow meter it's rpm signal. Still, I thought I might have been wrong and tested both aspects. It came out fine but I tested it based on the FSM for the 87 model year I found online. Is that still the same procedure? Would the new rpm signal code have something to do with the wires I had to splice? Haven't gotten anymore codes since.

[llamavan]

The procedure for pulling codes is the same for all years. It's just the results that are different for different model years.

Makes sense to me that it's not the AFM — those don't act up intermittently. When they go south, they stay that way.

Your van's code could quite possibly be the result of the wire that needed splicing. As long as the code doesn't come back, drive on!

Gwen

[Jlhollowx13]

Thanks. I actually meant are the procedures outlined in the 87 FSM to diagnose the sensors, such as the procedure to diagnose faulty rpm signal, the same throughout the years. Just want to make sure I did diagnose correctly and the fact that I'm coming up good is accurate. I'm assuming they are the same but you never know if they changed how something is connected. So far so good though so I'll keep my fingers crossed that all is good.

[Kauco]

Hey guys so I bought an 89 wagon and since I've had it I've done a ton of work to it lots of the basic pm stuff spark plugs drained coolant new thermostat new plug wires igniter and completely converted the thing into a camper van. I'm super stoked on it and invested a lot of time and money but I've got an issue that's really annoying me. First issue is code 12. I've replaced the igniter with 2 from a pick and pull and tried to clear codes and the engine light stays on with code 12. I changed the ecu with a used one from a pick and pull place thinking that would solve the issue since as soon as I start the van the engine light stays on. I've tried clearing the codes but they don't clear. The idle in park sits at 1300 rpm and the exhaust is pretty nasty and smelly at first but goes back to normal after abit of time along with the idle. Other than that the van is mint and I wanna figure this out it's driving me crazy. Any pros on here with some suggestions would be greatly appreciated!

[blakebecker37130]

Kauco,

Welcome to the best Toyota Van Wagon site on the internet. Here you can search and find most of the answers to problems you might be having with your van. I had a similar issue with my 87 2wd. Here is how I resolved it. I inspected all of the vacuum lines and switching valves. I found vacuum lines with cracks and switching valves with broken connections. Please see the posts attached below for more info about the vacuum switching valves and their functions.I did a semi-complete tune up, including new wires, rotor, rotor cap, belts, airfilter, oil filter, new oil, new PCV valve and PCV valve hose, new thermostat, coolant flush and a few other things as well. I reset the timing, it had been advanced by a previous tech/owner and was causing the rpms to stay up. I had to adjust the screw on the throttle body, recheck the timing,readjust the screw, and readjust the timing, until I got it dialed in at factory spec. I utilized an Actron Cp-7677 meter and a timing light to complete this activity. The Actron has a neat function. It is able to measure RPMS. I plugged it into the service connector on the distributer and was able to set correct timing and RPMS. The van smoothed right out and has stayed dialed for months now. One thing to note about my 87 is that it only utilizes (1) 02 sensor. The van has an automatic high idle until it reaches operating temp, then it settlesdown into factory idle spec. Please see the links below. Hope this information helps. No check engine lights on mine now except one related to the A/C not working.




http://www.toyotavantech.com/forum/showthread.php?1582-What-does-a-particular-VSV-do-See-excellent-attached-diagram&highlight=bvsv
http://www.toyotavantech.com/forum/showthread.php?704-Idle-adjustment-question&highlight=idle+screw
http://www.toyotavantech.com/forum/showthread.php?4468-Factory-Manual-Confusing-Instruction-on-Ignition-timing&highlight=timing

Best regards,
Blake