Check Engine light. Codes 4 and 11.

Today my check engine light came on in my 86 toyota van while driving but then it went away. Later on I noticed that It came on again while I was driving when I hit the gas while running and got no power but then eventually the power caught up and resulted in a power surge. The van is running kinda roughy. Not too bad but the check engine light comes and goes. Where should I start? I checked the codes and got codes 4 and 11. I find the owners manual so I hope someone can look that up for me and give me some decent advice on what to do.

Here ya go :)

Code 4 / Water temp sensor / may be the coolant temperature sensor circuit OR the sensor itself.

Code 11 / Switch / air conditioner switch, TPS circuit, TPS, or neutral start switch.

(I'll wager your TPS is faulty for code 11.)


Here is the .PDF file for your codes -- Print it out and keep it in your van :D

Where is the coolant temperature sensor circuit located? Or the TPS circuit? Thanks for the help.

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Originally Posted by mahleek87

Where is the coolant temperature sensor circuit located? Or the TPS circuit? Thanks for the help.

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The circuit is the electrical connection between the sensors and ECU. Anywhere along that circuit could be an electrical short (chaffed/melted wires, loose connections etc.) I'd start investigating by checking the sensors themselves. The actual location of the Coolant Temperature Sensor is on the radiator fill neck. (I'll take a picture of it tomorrow to show you.)

The TPS (Throttle Position Sensor) is a black plastic box located on the rear side of the throttle body manifold. Removal of the throttle body is required to gain access to that sensor. You will also need a new throttle body gasket to replace the old one. Tim has posted a video on how to calibrate a TPS properly here.

That would be a good starting point -- I wouldn't be surprised if new sensors were all your van needed.

http://i8.photobucket.com/albums/a23...tempsensor.jpg

As promised, here is the picture showing the location of the coolant temp sensor. I believe it takes a 19mm deep socket or wrench to remove.

JRSJ

(ps. mods, if there is any issue with putting TVT on images I contribute with, please PM me. Just trying to give back to the community.)

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Originally Posted by JRSJ

(ps. mods, if there is any issue with putting TVT on images I contribute with, please PM me. Just trying to give back to the community.)

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As far as I'm concerned it's awesome. Thanks for your great responses (makes my job easier). I also like the way JRSJ Photos display in the forum. Nice website by the way. Tim

I'm good with it, too. Various people "lift" photos and post them elsewhere on the internet for all kinds of reasons; having ToyotaVanTech (or better still, ToyotaVanTech.com) on the photos gives people a way to find to this site, and by definition, if they are looking at a van-specific photo, they probably can benefit from locating us. So, THANKS! :thmbup:

Gwen

Cheers guys, I'll make sure it says ToyotaVanTech.com in all future posts. :)

I'd like to add one more point to the original thread topic. Its worth noting that the Coolant Temperature Sensor (CTS) has nothing to do with the temperature gauge in your dash cluster. That sensor is located on the passenger side of the cylinder head, beside the distributor cap. The CTS is connected to your vans ECU, and helps it make decisions when the engine is cold. It relays information to the ECU, then from the ECU to the cold start injector. I believe it also has a play in air-to-fuel ratio when cold starting.)

Keep us updated with your findings and any hiccups along the way, mahleek87. :D

JRSJ

Hey guys,
I am not fond of getting parts from Toyota that I can get elsewhere, I am just unsure as to what these models are finicky about.
I know that most Toyota's dislike non OEM Manufactured parts. Toyota wants $90 for the TPS and the best part I can find otherwise is BECK ARNLEY.
What to do Toyota or Beck Arnley. difference is like $40 so not the end of the world. I am opposed to Wells like AutoZone has all around.
Lifetime warranty means piece of crap we have to warranty !!!!

I've used Beck Arnley TPS units a couple of times on vans. I popped the cover off one once and had a look at the internals. It was stamped "made in Italy" but appeared to be of a quality construction. I guess time will tell if it lasts as long as Toyota. Tim

I'm using a Beck Arnley TPS as well. All is well for my van.

Thanks guys,
I appreciate your input!!
Price difference of $30-40.... I have new O2 sensors that are denso so no question about those!!!
Thank Ebay for competition!!!

Ok so I was just looking at this new beck arnley TPS I got from Rockauto and it looks nothing like the one in the video!!
It as well does not seem adjustable, for that matter it looks nothing like the picture I saw on their website???

really it is a little 90 degree looking thing made of plastic WTF.

do your guys both look like they do in the video? if I have to send it back I will just go to toyota!

It should look like this:


http://info.rockauto.com/getimage/ge...tex/5S5171.jpg

Yep, the one JRSJ posted is it. Of course the one in my video was attached to the throttle body (removed from the van). After installing and adjusting to the throttle body the entire assembly gets mounted back on the van. Tim

Yeah that is not at all what they sent me!! this is the unfortunate part of ordering online!!
And this part looks nothing like it.
Can someone list a part # on the correct one?

TPS= Toyota #89452-14020 or Beck Arnley #158-0503

Hello everyone, Newbie here, but been owner of for 80's vans... but finally stumped....

Got a code 4, replaced sensor, checked wiring to ecu, checked ecu voltages... checked output from tps,
now here are my clues.


For a year or more, i have round the cts thru a switch i flick when i step on the gas and flick again when idling. by taking the cts in and out of operation I am able to go.... so, I always figured it was the cts, and replaced, fully expecting repair fix, reset code. But code comes right back and did not repair. This lead to checking tps, which i took apart, contacts good, checked voltage on terms, ok.

Then i peeked into the ecu, looking for fried caps, etc., looking good there, plus the readings were ok.

My dearly beloved, which i did a total engine overhaul over 5 years as i became sober. Toyo and zen thing... so, my patience is being tested once again...

my hunch is that still must be wiring for the code to show up right away....

any suggestions or clues?

That sensor is just a thermistor that changes resistance with temperature (the colder it is the more resistance). It has a range of 100 ohms (at around 250 deg F) to 20,000 ohms (at around 0 deg F). The resistance changes are fairly linear throughout the temp range, so if you have any doubts about it just disconnect and test resistance between the 2 terminals. If the sensor is not installed, then then you should see around 2,000 ohms at room temp. If the sensor is installed, use a thermometer in the filler neck and calculate the resistance based on coolant temp. To check the wires, go to the ECU and pull the connectors off. Set your meter to sound a tone when continuity is detected, then touch one lead to the brown sensor wire and the other lead to the brown wire in the E2 position of the ECU harness. if the circuit is complete the meter will sound a tone. Repeat the these steps for the green sensor wire and the THW position of the ECU harness. If you don't have a manual let me know and I'll post some pics. Tim

Thanks, I will do that check tomorrow....but earlier, I found a puzzling thing that sure threw me... One of the wires to sensor goes to the thw of ecu and the other splices, the brown one, into other brown ones that are grounded. This makes no sense to me.... Am I correct that this brown one should not be grounded? Maybe it has been wrong for eons... It's a 4ye engine in an '84 model with a 3ye ecu. maybe somehow the wiring went wrong. I have always had crappy gas mileage. Further puzzled what else has happened that made the problem so bad that is undriveable. I will post back my wiring findings tomorrow. I have a schematic and see that the brwn ties into the Air Flow meter and E2. Geezus what has been going on?

By the way, I bought all new connectors for the fi, cts, tps, cold start, .... I am committed! Going all the way now...