Need help with a mystery wire - 1988 FJ62 (1 Viewer)

[BobbyKnobby]

Hello! I just bought my first Landcruiser - a 1988 FJ62. It was about 200+ miles away, and I bonded with it on the long drive home!

A couple issues I could use y’all’s expertise on:

1: Check engine light came on after 4 hours on the freeway. After leaning how to read the codes on this forum, I got diagnostic code 25 and 26. “When air-fuel ratio feed-back compensation value or adaptive control value feedback frequency is abnormally high during feedback condition. I searched up some old posts on the forums, but curious if other FJ62 owners have solved this issue.

2. The mystery wire! I’m my exploration checking connection on the various enmissions tubing, I discovered a disconnected, single, dangling wire coming from the wire harness behind the air filter on the passer side engine component. I do not know what it is suppose to be connected to! I’ve poured over the wiring diagrams, but I’m a noob. The wire is black and yellow. I have attached pictures.

If a kind FJ62 (might be the same on a FJ60?) owner would be willing to trace this wire to whatever sensor, component, or whatever it should be attached to I would be very grateful!!

Please see pics…

 

[BobbyKnobby]

Hello! I just bought my first Landcruiser - a 1988 FJ62. It was about 200+ miles away, and I bonded with it on the long drive home!

A couple issues I could use y’all’s expertise on:

1: Check engine light came on after 4 hours on the freeway. After leaning how to read the codes on this forum, I got diagnostic code 25 and 26. “When air-fuel ratio feed-back compensation value or adaptive control value feedback frequency is abnormally high during feedback condition. I searched up some old posts on the forums, but curious if other FJ62 owners have solved this issue.

2. The mystery wire! I’m my exploration checking connection on the various enmissions tubing, I discovered a disconnected, single, dangling wire coming from the wire harness behind the air filter on the passer side engine component. I do not know what it is suppose to be connected to! I’ve poured over the wiring diagrams, but I’m a noob. The wire is black and yellow. I have attached pictures.

If a kind FJ62 (might be the same on a FJ60?) owner would be willing to trace this wire to whatever sensor, component, or whatever it should be attached to I would be very grateful!!

Please see pics…

View attachment 3352174

View attachment 3352175

View attachment 3352176

UPDATE:
Thanks to the forums, I found someone else coming at this problem from the opposite direction…needed to connect the oil pressure sender gauge, but unable to find the right wire - a black and yellow wire!

I located my oil pressure sender gauge, and sure enough, it was disconnected! Gotta love all the knowledge documented in these posts! Hopefully this will help others in the future!

 

[BobbyKnobby]

Vendor - Oil Pressure Sender switch Wire Harness Connector Repair Kit w/ Ground Tab Wire Also FJ40 FJ60 FJ62

__ Oil Pressure Sender switch Wire Harness Connector Repair Kit FJ40 FJ60 FJ62 Oil Pressure Sending Unit sensor switch Wire Harness & Connector Repair Kit FJ40 FJ60 F & 2F engines 3FE This Kit includes : - 36" inches of Yellow w/...

forum.ih8mud.com

Another post from a few years back. This fella made some clips / wiring setups and sold them to the community.

Question: the oil pressure sender gauge in my FJ62 has two contacts.

1: in the center of the oil pressure sender, there is a little ‘button’ with the remains of a ‘clip’ that assume was were the black/yellow wire should be re-attached. Can I just pull/pop the old clip off and re-attach the wire. (Not sure what this clip is called)

2: next to the center ‘button’ with clip, is a prong still connection…nothing is on this. I’m reading it might be for a ground, but mine has nothing connected, and it looks like nothing was ever plugged on it. Can I leave this prong as-is, or do I need to create a ground wire connector?

I see some oil pressure senders with two contacts and some with just the center button. Pictures attached.

 

[kirvesmies]

welcome aboard mud. i think if you were to reach out to @ToyotaMatt , you might be able source what you need wiring wise for that. he seems to have a myriad of electrical stuff crawling out of the skunkworks

 

[BobbyKnobby]

100%! I’m going to snag a wiring kit from @ToyotaMatt - loving all the solutions kicking around here!

 

[BobbyKnobby]

Call back to issue #1 (which turned into the discovery of the loose mystery wire / disconnected oil pressure sender gauge and fruitful goose-chase above)

Error codes 25 and 26 consecutively. The forum hive-mind of several years ago seems to think this is solved by replacing the O2 sensors …or…the FPR (fuel pressure regulator) …or both.

Anyone else deal with check engine light and error codes 25 + 26? The CEL tripped after driving 200+ freeway miles, which is a lot for my old girl!

I’m new to working on cars, but I’m committed to my newly acquired FJ62. My son and I want to learn how to fix it up. Is changing O2 sensors and/or FPR doable for a noob?

 

[SteveH]

@BobbyKnobby

1: in the center of the oil pressure sender, there is a little ‘button’ with the remains of a ‘clip’ that assume was were the black/yellow wire should be re-attached. Can I just pull/pop the old clip off and re-attach the wire. (Not sure what this clip is called)

2: next to the center ‘button’ with clip, is a prong still connection…nothing is on this. I’m reading it might be for a ground, but mine has nothing connected, and it looks like nothing was ever plugged on it. Can I leave this prong as-is, or do I need to create a ground wire connector?

Earlier sending units grounded through the screw threads, later ones had a separate ground tab (as you noted). Be VERY CAREFUL not to ground the sending unit wire, as you will fry the dash gauge. If your gauge works well, you can skip grounding the 'can' of the sending unit.

 

[BobbyKnobby]

Thanks - I have a sending unit with center ‘button’ and the grounding ‘tab’…but it appears that the previous owner had it setup with just the center button attached. I think I’ll start there - wiring the center button up with everything off / battery disconnected.

Do you know the name of the connector type that slides over that button? I need to buy one to re-attach my wire…but not sure what it’s called and how to search for it! Or, I can buy a clip + wire kit from @ToyotaMatt for $20…

 

[John McVicker]

I suggest buy what you need…the yellow wire and the clip from @ToyotaMatt . Great vendor and you will get what you exactly need.

 

[ToyotaMatt]

Hello! I just bought my first Landcruiser - a 1988 FJ62. It was about 200+ miles away, and I bonded with it on the long drive home!

A couple issues I could use y’all’s expertise on:

1: Check engine light came on after 4 hours on the freeway. After leaning how to read the codes on this forum, I got diagnostic code 25 and 26. “When air-fuel ratio feed-back compensation value or adaptive control value feedback frequency is abnormally high during feedback condition. I searched up some old posts on the forums, but curious if other FJ62 owners have solved this issue.

2. The mystery wire! I’m my exploration checking connection on the various enmissions tubing, I discovered a disconnected, single, dangling wire coming from the wire harness behind the air filter on the passer side engine component. I do not know what it is suppose to be connected to! I’ve poured over the wiring diagrams, but I’m a noob. The wire is black and yellow. I have attached pictures.

If a kind FJ62 (might be the same on a FJ60?) owner would be willing to trace this wire to whatever sensor, component, or whatever it should be attached to I would be very grateful!!

Please see pics…

View attachment 3352174

View attachment 3352175

View attachment 3352176

-TOYOTA has NOW updated and upgraded across the LAND CRUISER board anyway 1962-1990 ALL the various OIL PRESSURE Sending units for a mechanical in-dash gauge , PETROL & DIESEL Alike with the additional male ground tab feature ,,,,,


- this ensures a smooth SOLID and reliable pulsing beating heart signal pattern to the gauge pod ......oil gauge

- i give high marks , like 5 F'ing 's in-fact to TOYOTA japan engineers for remembering who we are and what we all still drive as both a need and now more then ever before , myself included one hell of a must have want ! ....


- my only begging question , that is now there annoying as S#IT norm ? is why no tiny leaflett micro-fsm mini-meme is including explaining the change to this 2nd male spade tab also a SCARY warning to make sure NOT to intall the button connector tab connector to the male ground spade by mistake ,,,,,?

because in say 21+ metic seconds or LESS , your gauge sender and also guage pod oil gauge , and just like me , my BLUE PRINTED circuit board on GHOST got fried too on back of FJ60 / FJ62 , hell ....55 and 40 will suffer same fate if u space on this connection step by step .....

this ain't a JOKE here , its dead serious , so knows this now and know it well ,,,please

 

[BobbyKnobby]

Hey Matt - thanks for the PM - I’m looking forward to getting that ‘double’ wire installed and (hopefully) seeing my sweet, sweet oil pressure gauge rise up!

Yea, the whole ‘wire it wrong, and you’ll destroy your gauge’ has me a little spooked. My broken, loose, oil pressure sender wire was rattling around my engine for a while before I noticed it. Hoping it did not ‘touch’ something causing a ground, killing my dash gauge!