T100 first check engine light in 26 years (1 Viewer)

[rscoleman]

So it finally happened after 26 years and 130K miles my T100 3.4v6 finally through me a check engine light. I hooked up a OBD2 scanner and pulled the following codes. P0450 and candidate P0441. The P0450 is sensor for emissions. It measures vacuum or pressure on vacuum line. Toyota no longer makes the part needed but with some mods a Duralast MAP Sensor SU4197 will work as replacement. The P0441 is Purge Valve also part of emissions package. Toyota does not make this part but Duralast Canister Purge Valve PV421 will work in its place. So next steps is going to be check all vacuum lines and replace any cracked or split lines. I will likely purchase the MAP Sensor and replace it. I will then clear codes and run truck for a while. If I get the check engine light again or candidate code P0441 I will replace the Purge Valve. Guess what I am doing this weekend.

 

[WildernessRimFab]

Id be suspect that two emissions related sensors failed at exactly the same time. I would carefully check all of the lines before replacing sensors.
Good luck.

 

[ERG80]

A few days after kayaking the truck’s check engine light came on and showed a PO450 code. Womp womp. The truck was sluggish and would shake when I applied gas. Not good. What I could find online showed this code was due to the vapor pressure sensor. It’s no longer available from Toyota but Luckily eBay had a used one from a low mileage 98-01 4Runner which plugs right up to the wiring and clips on the same place -p/n 89460-0W070. I installed it and while I was under the hood I installed new plugs and wires. While doing that I noticed a large crack in one of the vacuum hoses. The hose had different id’s at each end so I had to create a new one using two sized hoses and a connector I had in my air compressor hardware stash.
So far so good. No check engine light and the light tune-up seemed to have helped pep up the truck.

View attachment 3359222

I just had this exact issue. I replaced the sensor with the one quoted above. I also fixed a cracked hose. I ordered valve 25860-75100 but didn’t need it. Things are still good after the repair,

 

[rscoleman]

Update so other than I am really slow and really busy. I was finally able to complete my Vacuum sensor replacement and check of all the vacuum hoses. The single MAP Sensor replacement fixed the issue for now. I will wait to call it 100% success till I get few 100 miles on it. I got the part from Auto Zone but had to wait about 3 days for them to get one to store. I had to cut off an alignment protrusion as it did not match up with my plug. After that it plugged in just fine. I had dead battery after letting it sit for 3 plus weeks and had to charge it over night. I just got back from 15 minute test drive. Yea for me.

 

[rscoleman]

I just had this exact issue. I replaced the sensor with the one quoted above. I also fixed a cracked hose. I ordered valve 25860-75100 but didn’t need it. Things are still good after the repair,

I use my T100 to carry my Kayak and Old Towne 106PDL. I also use it to tow my 15foot Wingmaster Sandpiper Skiff. I fish local at Granger Lake for crappie or I run down to Matagorda to go after reds, specs, flounder, drum, sheephead. You have nice day.

 

[rscoleman]

So over weekend I tried the cruise control and it is not working. I know my last long road trip that it worked so either this fix broke it or I have another vacuum leak somewhere. Going to have to pull out Chilton book as I have no check engine lights or codes. Cruise light comes on as normal but set speed is not working. I might get to this in another 2 to 4 weeks. Oh well the fun of owning a 26 year old truck if you want everything to work like it did when it left the factory.

 

[thabruiser]

IIRC, cruise is cable controlled on the 3.4. You may have a bad control switch. If you have any similar vintage Toyotas in your fleet with the same style switch, you could swap it with a known good one, and see if your problem persists. Just an idea. Hope you figure it out!

 

[WildernessRimFab]

So over weekend I tried the cruise control and it is not working.

Do you have any issues with the horn functionality? Airbag light on? The horn/CC controls/airbag run through the clockspring behind the steering wheel.
My T100 has 260K on it and I had to replace my clockspring last year after the horn would intermittently beep on when hitting bumps on rough roads.

Not trying to send you on a wild goose chase, but wanted to point out another possible item to think about.
The clockspring is easy to replace but hard to find, I got one from a local junkyard.

 

[rscoleman]

So update, I can not find time to work on this myself and little bit that I did required 3 trip back and forth to O'Reilly's for parts. I have decided to drop it off at Landcruiser Specialists in North Austin. Aside from figuring out the check engine lights and cruise issue I going to have them replace all the vacuum lines that are 26 years old.

 

[rscoleman]

Got my truck back today. Charcoal canister was root cause of check engine light. It has been replaced. They check all the vacuum lines and said I did not need to replace them. They diagnosed the cruise control issue and I need a new Cruise Servo Actuator. That part is no longer made. They called around and I called around. I did find a remanufactured one on eBay for 100 bucks so I bought it. If it does not work I just out 100 dollars and I will start the salvage yard search. The part when new was like 1400. They also pulled and cleaned my warn hubs on front axles. All in all very happy with LandCruiser Specialist. Now I need to change the oil and rotate the tires. I will hopefully get that done this weekend and my new cruise part should arrive this week and I will install it.

 

[rscoleman]

Update Purge Valve threw code last week so I replaced that part today. I also replaced the cruise control unit with remanufactured unit I purchased off of ebay. Did not get chance to drive the truck only idle in drive way. Some time this week I should get it out on road and check cruise and hopefully no more purge valve codes. The saga of a 26 year old truck with emissions.

 

[rscoleman]

Got a chance to drive have not gone far enough yet to trust the Purge Valve fix. The cruise however is still toast. As cruise throws no codes I not sure were to go with this. My cruise was only made from 96 to 99 for 3.4v6 T100, Pickup/Tacoma, 4Runner. I might find one in junk yard but likely it is 24 years old or older. Called Toyota dealers from East to West Coast and North to South no luck on off the shelf unit. I have Hayes manual so going to read that tonight and see what all if any other things are part of cruise that could cause it to not be working. Light comes on but set speed does not work.

 

[rscoleman]

So 200+ miles and no new check engine light. Purge Valve replace must have been it. Not sure I am going to keep looking at the cruise issue. If it is the clock spring I not sure I can even find one. If it cruise module same issue I wasted 100 dollars on one that did not work so now I have 2. If I have to take it in to Toyota before 2026 timing belt I might have them look at it. Most likely will wait till 2026 timing belt to have Toyota look at it.

 

[rscoleman]

Officially calling check engine solved. Still have not done anything else about cruise control.