CEL and ABS + PO125 code Fix (1 Viewer)

[achileocruiser]

Good morning everyone,
Just joined the forum after recently purchasing my 1996 FZJ80 non-triple locking cruiser with 297,000+ miles on it. Loved the car so much after test driving it and just had to complete the purchase. Finding out there are some leaks that need to be tended to!

The check engine light is on and the ABS light is on. It shows a P0125 code and also says the O2 sensors need to be replaced. The engine gauge never says it’s overheating but sometimes takes a bit to warm up after driving a mile or 2. I’ve taken photos of the leaks, that I can see underneath and around the engine. The trans pan definitely could be replaced and resealed (photo not included). If you guys could help point me in the right direction as to where these other leaks are, based on the photos, that would be very helpful as my terminology is very low with this. I can also take more photos, but these are the ones I have so far!

 

[Malleus]

Photo #1 is likely the oil cooler seal
Photos #2/#4 are either the power steering pump rear seal or high pressure line, or both
Photo #3 is either the rear main crankshaft seal or the ever present pan seal leak between the upper and lower pans.

Keep an eye (or ear) on the power steering; if it starts to groan, top it up with ATF.

Nothing looks dire; clean it well and drive it.

What makes you think you need a new transmission pan?

Download a copy of the Toyota service manual (FSM) and Electrical Wiring Diagram (EWD). They are both in the Resources section. Also, get a copy of the Wiring Harness Repair Manual (in the 80 section). Even if you do not plan to do any work on the wiring harness, there is very valuable information in there.

Welcome and congratulations.

 

[Malleus]

I'd check the ABS error code(s) first, before I did anything else. The procedure is on page DI-190 to DI-197 (the code definitions are on ppg DI-196- to DI-197)

This is the diagnostic connector on the engine side of the firewall, below and to the left of the wiper motor. Use a paperclip to connect the two terminals, but make sure the metal terminals contact the jumper wire.

 

[Malleus]

Not knowing the vehicle history, I'd try to clear the code, after recording it, and watching to see if it returns:

If it were me, I'd just pull the fuse, wait a minute and put it back in.

 

[Malleus]

Your P0125 fault may or may not be the O2 sensor. Here's the Reader's Digest version:

 

[Malleus]

You will need a multimeter to check the O2 circuit. It doesn't need to be a multi-million dollar unit, get a $20 meter, if you don't already have one. After you use it for a while, and decide you need a better one, give it to your kids. They'll have fun tripping all the circuit breakers in the house.

This looks daunting, if you don't have any electrical/electronic background, but think of it like you would if you were trying to find a plumbing leak. Except you can't see the leak, even if you find it.

To find the correct terminal to measure, use the Alphanumeric code to identify the correct terminal block (top image) and then find the numbered terminal within that block. For example, OX1-E1 connects the #24 terminal of block E4 to the #5 terminal of block E5. You need to make these measurements with cables connected, through the back of the cable connector housings. Use a paperclip to extend the terminals out of the connector housings, if necessary.

You can ignore the "pulse generation" signal values (unless you have an oscilloscope, and even then, ignore them); as long as the voltage changes constantly, you're OK.

Wiring colors are always in the format [main color]-[stripe or tracer]:

Do this, before you buy new O2 sensors.

 

[achileocruiser]

You will need a multimeter to check the O2 circuit. It doesn't need to be a multi-million dollar unit, get a $20 meter, if you don't already have one. After you use it for a while, and decide you need a better one, give it to your kids. They'll have fun tripping all the circuit breakers in the house.

This looks daunting, if you don't have any electrical/electronic background, but think of it like you would if you were trying to find a plumbing leak. Except you can't see the leak, even if you find it.

View attachment 3740903
View attachment 3740904
To find the correct terminal to measure, use the Alphanumeric code to identify the correct terminal block (top image) and then find the numbered terminal within that block. For example, OX1-E1 connects the #24 terminal of block E4 to the #5 terminal of block E5. You need to make these measurements with cables connected, through the back of the cable connector housings. Use a paperclip to extend the terminals out of the connector housings, if necessary.

You can ignore the "pulse generation" signal values (unless you have an oscilloscope, and even then, ignore them); as long as the voltage changes constantly, you're OK.

Wiring colors are always in the format [main color]-[stripe or tracer]:
View attachment 3740914

Do this, before you buy new O2 sensors.

Just ordered a multi meter off Amazon. Is there a good cheap OBD II scanner you’d recommend as well? I took a look at the 02 sensors and everything seems intact except for the downstream denso which is held in by clamps. I have feeling that might need to be fixed!

Going to turn my Saturday into a good ol’ morning project and take a wack at this.

 

[achileocruiser]

Photo #1 is likely the oil cooler seal
Photos #2/#4 are either the power steering pump rear seal or high pressure line, or both
Photo #3 is either the rear main crankshaft seal or the ever present pan seal leak between the upper and lower pans.

Keep an eye (or ear) on the power steering; if it starts to groan, top it up with ATF.

Nothing looks dire; clean it well and drive it.

What makes you think you need a new transmission pan?

Download a copy of the Toyota service manual (FSM) and Electrical Wiring Diagram (EWD). They are both in the Resources section. Also, get a copy of the Wiring Harness Repair Manual (in the 80 section). Even if you do not plan to do any work on the wiring harness, there is very valuable information in there.

Welcome and congratulations.

Thank you for the insight on this. It’s good to hear this from people who know Landcruiser well. Every shop I’ve taken her to turns me away immediately because they are afraid of the work and also just don’t know how the 89 series are made.

The trans pan has a pool of fluid/oil underneath slowly dripping. One mechanic told me I need to get it replaced. I’m going to clean everything underneath and start checking to see where some of the leaks are. I can definitely smell burning oil throughout the duration of my drives. Nothing sound bad on the engine though.

 

[achileocruiser]

Your P0125 fault may or may not be the O2 sensor. Here's the Reader's Digest version:
View attachment 3740899
View attachment 3740900

So I’ve also noticed that my coolant in the overflow reservoir is practically empty and brown looking. I want to do a coolant flush this weekend and have all the necessary tools. One mechanic told me the head valve cover gasket needs to be replaced and that there might be coolant leaking into the engine oil.

I’m not quite sure what that intels or means, but i figured a coolant flush might be needed soon with the coolant so low and looking black. Also the when I start the car it takes about 2 miles for the engine temp monitor to move to the middle. Not sure if that’s normal or not.

 

[achileocruiser]

Thank you for the insight on this. It’s good to hear this from people who know Landcruiser well. Every shop I’ve taken her to turns me away immediately because they are afraid of the work and also just don’t know how the 89 series are made.

The trans pan has a pool of fluid/oil underneath slowly dripping. One mechanic told me I need to get it replaced. I’m going to clean everything underneath and start checking to see where some of the leaks are. I can definitely smell burning oil throughout the duration of my drives. Nothing sound bad on the engine though.

*80 series

 

[Malleus]

Just ordered a multi meter off Amazon. Is there a good cheap OBD II scanner you’d recommend as well? I took a look at the 02 sensors and everything seems intact except for the downstream denso which is held in by clamps. I have feeling that might need to be fixed!

Going to turn my Saturday into a good ol’ morning project and take a wack at this.

I use a BAFX OBDII Bluetooth plug-in, but it appears to be MIA. I really don't think the scanner matters, what does matter is the app it relays to.

I use Torque Pro, and it's just OK, but it only works reliably with an Android phone. And you have to buy it (the pro version) in order to get past the ads. Not a lot of money, and I've been using it for years without any problems, but there may be newer, better, cheaper, etc. options.

You can buy a handheld, similar to the Toyota Intelligent Tester the dealerships have, but a) they're very expensive for what you get, and b) if I was going to spend that kind of money on a tool, I'd get the Toyota tool which has far more capability. If you find one, let me know. I'll buy it and let you borrow it.

The one thing that isn't on any OBDII scanner or app is transmission oil temperature, because it's not exposed by the Toyota protocol. That's really unfortunate, because there is a transmission temperature sensor in the cooler line. You can write your own PID to expose it, presumably, but I haven;t gotten around to it yet.

 

[Malleus]

Thank you for the insight on this. It’s good to hear this from people who know Landcruiser well. Every shop I’ve taken her to turns me away immediately because they are afraid of the work and also just don’t know how the 89 series are made.

The trans pan has a pool of fluid/oil underneath slowly dripping. One mechanic told me I need to get it replaced. I’m going to clean everything underneath and start checking to see where some of the leaks are. I can definitely smell burning oil throughout the duration of my drives. Nothing sound bad on the engine though.

Before you replace it, find out exactly where it's leaking from.

Burning oil smells are likely due to oil spraying on the exhaust. Not a good thing. If that much oil is spraying, you've really got a leak you need to fix.

Get a five gallon container of purple power and a venturi hose sprayer. I have a GuardAir sprayer and I think it's the best money I've spent on a tool in a long time. You do have to have a compressor to use it, but a really small one will work fine. It gives you the ability to get a low volume, low pressure pressure wash that really cleans, especially the engine compartment and underbody where oil and gunk accumulates. The long wand and small nozzle lets you get anywhere you need to be to clean.

Once you get the surfaces clean, you can clean a month's worth of grime in short order, using only water. I use mine every time I open the hood to do any work. It takes five minutes and I don't have to work on in a dirty engine compartment. The low volume means it's effective without making a swimming pool under the truck. I can't recommend this tool enough. If you're taking care of your own maintenance, you need one.

IMO, it works as well as a professional hot wash, without the cost and without making a mess as it cleans:

It works on the siphon principle, so you put pickup in a gallon container and spray away. Great for mixing exactly what chemicals and ratios you need for any use. The Chinese copies are much cheaper, and probably work just as well, I'm just not buying anything from them if I don't have to.

 

[Malleus]

So I’ve also noticed that my coolant in the overflow reservoir is practically empty and brown looking. I want to do a coolant flush this weekend and have all the necessary tools. One mechanic told me the head valve cover gasket needs to be replaced and that there might be coolant leaking into the engine oil.

I’m not quite sure what that intels or means, but i figured a coolant flush might be needed soon with the coolant so low and looking black. Also the when I start the car it takes about 2 miles for the engine temp monitor to move to the middle. Not sure if that’s normal or not.

First, stay away from that guy. You may need a new valve cover gasket, but there's no way that would cause coolant in your oil. Unless you have a blown head gasket, there's very little chance he could tell there's oil in your coolant without a chemical analysis. If you're concerned about that at all, send samples of the oil and coolant to Blackstone. The service is cheap, quick, and you'll know exactly what is going on inside your engine.

Second, the warm up temperature rise is controlled by the thermostat. It stays closed to force the engine to use only the coolant inside the block immediately after startup. Once the engine coolant temperature reaches about 176°F to 183°F, the thermostat begins to open so that the cold coolant in the radiator can go to work keeping the engine at a constant temperature. 2 miles doesn't sound unreasonable, but a better measure is how much time, not how many miles, and whether the engine is idling or running at 1200rpm.

You can clean the overflow tank and pretty much restore it to like new appearance with a sulphamic acid mixture; it's sold in the pool cleaning section in powder form.

There's no way to tell where all the crap in your overflow tank came from, and you're better off starting with a clean tank so you can gauge the condition of the radiator's interior.
I like Thermocure for radiator cleaning, because it cleans the block at the same time.

I'd recommend draining the radiator and refilling with Thermocure as directed. Once you get it clean, pull the block drain (it's on the driver's side, you have to reach around the wheel to get to it) and flush the entire cooling system with clean water until it flows clean from the block. Then refill it with distilled water and the coolant of your choice ( I use the Toyota stuff, but that's just me), not purified water, which is tap water.

Lastly, I replaced my block drains with the 100 series engine block drains, 90910-09095, which have a 90° drain tube on them, so you can attach a drain hose and drain the block into a bucket, instead of washing the entire driver's side of the engine compartment in engine coolant. Well worth the investment, IMO.

 

[Malleus]

Thank you for the insight on this. It’s good to hear this from people who know Landcruiser well. Every shop I’ve taken her to turns me away immediately because they are afraid of the work and also just don’t know how the 89 series are made.

The trans pan has a pool of fluid/oil underneath slowly dripping. One mechanic told me I need to get it replaced. I’m going to clean everything underneath and start checking to see where some of the leaks are. I can definitely smell burning oil throughout the duration of my drives. Nothing sound bad on the engine though.

Last point, just for consideration, since you're nearby, if you really need a shop to work on the truck, take it to OTRAMM. Also the best source for Land Cruiser repair videos, if you need one. Check them out.

 

[achileocruiser]

Before you replace it, find out exactly where it's leaking from.

Burning oil smells are likely due to oil spraying on the exhaust. Not a good thing. If that much oil is spraying, you've really got a leak you need to fix.

Get a five gallon container of purple power and a venturi hose sprayer. I have a GuardAir sprayer and I think it's the best money I've spent on a tool in a long time. You do have to have a compressor to use it, but a really small one will work fine. It gives you the ability to get a low volume, low pressure pressure wash that really cleans, especially the engine compartment and underbody where oil and gunk accumulates. The long wand and small nozzle lets you get anywhere you need to be to clean.

Once you get the surfaces clean, you can clean a month's worth of grime in short order, using only water. I use mine every time I open the hood to do any work. It takes five minutes and I don't have to work on in a dirty engine compartment. The low volume means it's effective without making a swimming pool under the truck. I can't recommend this tool enough. If you're taking care of your own maintenance, you need one.

IMO, it works as well as a professional hot wash, without the cost and without making a mess as it cleans:
View attachment 3741726
It works on the siphon principle, so you put pickup in a gallon container and spray away. Great for mixing exactly what chemicals and ratios you need for any use. The Chinese copies are much cheaper, and probably work just as well, I'm just not buying anything from them if I don't have to.
View attachment 3741728

So I can spray this directly on the engine and anywhere around it? Confirming before I accidentally screw up wiring or anything of that matter.

 

[achileocruiser]

Last point, just for consideration, since you're nearby, if you really need a shop to work on the truck, take it to OTRAMM. Also the best source for Land Cruiser repair videos, if you need one. Check them out.

I have watched their videos and heard they are the best around. It’s about an hour away from me so finding time to get their around work has been difficult.

 

[achileocruiser]

First, stay away from that guy. You may need a new valve cover gasket, but there's no way that would cause coolant in your oil. Unless you have a blown head gasket, there's very little chance he could tell there's oil in your coolant without a chemical analysis. If you're concerned about that at all, send samples of the oil and coolant to Blackstone. The service is cheap, quick, and you'll know exactly what is going on inside your engine.

Second, the warm up temperature rise is controlled by the thermostat. It stays closed to force the engine to use only the coolant inside the block immediately after startup. Once the engine coolant temperature reaches about 176°F to 183°F, the thermostat begins to open so that the cold coolant in the radiator can go to work keeping the engine at a constant temperature. 2 miles doesn't sound unreasonable, but a better measure is how much time, not how many miles, and whether the engine is idling or running at 1200rpm.

You can clean the overflow tank and pretty much restore it to like new appearance with a sulphamic acid mixture; it's sold in the pool cleaning section in powder form.View attachment 3741739
There's no way to tell where all the crap in your overflow tank came from, and you're better off starting with a clean tank so you can gauge the condition of the radiator's interior.
I like Thermocure for radiator cleaning, because it cleans the block at the same time.
View attachment 3741740

I'd recommend draining the radiator and refilling with Thermocure as directed. Once you get it clean, pull the block drain (it's on the driver's side, you have to reach around the wheel to get to it) and flush the entire cooling system with clean water until it flows clean from the block. Then refill it with distilled water and the coolant of your choice ( I use the Toyota stuff, but that's just me), not purified water, which is tap water.

Lastly, I replaced my block drains with the 100 series engine block drains, 90910-09095, which have a 90° drain tube on them, so you can attach a drain hose and drain the block into a bucket, instead of washing the entire driver's side of the engine compartment in engine coolant. Well worth the investment, IMO.
View attachment 3741750

Thank you for this! I’ve heard this drain works great and in most of the videos I’ve watched it is highly recommended. Should I drain the radiator and engine block before putting in the thermocure and then drain again before putting water and distilled water in?

 

[Malleus]

So I can spray this directly on the engine and anywhere around it? Confirming before I accidentally screw up wiring or anything of that matter.

Yes. It is an alkaline solution, so don't let it sit undiluted on aluminum, or it will mar the surface appearance. Dilute with as little as 50% water, it'll be fine to allow it to soak for 30 minutes. Full strength it'll dry your skin (because it's alkaline and dissolves proteins, which is what oil is), so wear gloves. I've never had any problems using it.

The wiring Toyota installed under the hood is waterproof. Make sure the engine is running when you clean it for the first time. That way, if you get anything wet that doesn't want to be wet, the engine heat will dry it off. If the engine stumbles while you're cleaning it, stop spraying that area; the engine idle should return pretty quickly. This will show you any vacuum leaks, too. The air intake is inside the right front fender, so you shouldn't be able to get water into the engine.

I use it full strength on fan blades and brush it after five minutes, rinse with clean water. You'll be happy with the result.

Spray liberally around and under the battery. It'll neutralize any overflow acid that may be there.

You may need to spray it full strength on frame, axle housing, suspension parts and oil pans, and let it sit for an hour, if the oil/grime is not something that'll wipe off.

It cleans concrete, too.

 

[Malleus]

Thank you for this! I’ve heard this drain works great and in most of the videos I’ve watched it is highly recommended. Should I drain the radiator and engine block before putting in the thermocure and then drain again before putting water and distilled water in?

I wouldn't bother with that. Follow the directions on the container and you'll be fine. If your radiator is full of really dirty coolant, drain that, but only because it'll give you more concentrated solution to clean the block with.

 

[achileocruiser]

Yes. It is an alkaline solution, so don't let it sit undiluted on aluminum, or it will mar the surface appearance. Dilute with as little as 50% water, it'll be fine to allow it to soak for 30 minutes. Full strength it'll dry your skin (because it's alkaline and dissolves proteins, which is what oil is), so wear gloves. I've never had any problems using it.

The wiring Toyota installed under the hood is waterproof. Make sure the engine is running when you clean it for the first time. That way, if you get anything wet that doesn't want to be wet, the engine heat will dry it off. If the engine stumbles while you're cleaning it, stop spraying that area; the engine idle should return pretty quickly. This will show you any vacuum leaks, too. The air intake is inside the right front fender, so you shouldn't be able to get water into the engine.

I use it full strength on fan blades and brush it after five minutes, rinse with clean water. You'll be happy with the result.

Spray liberally around and under the battery. It'll neutralize any overflow acid that may be there.

You may need to spray it full strength on frame, axle housing, suspension parts and oil pans, and let it sit for an hour, if the oil/grime is not something that'll wipe off.

It cleans concrete, to

You will need a multimeter to check the O2 circuit. It doesn't need to be a multi-million dollar unit, get a $20 meter, if you don't already have one. After you use it for a while, and decide you need a better one, give it to your kids. They'll have fun tripping all the circuit breakers in the house.

This looks daunting, if you don't have any electrical/electronic background, but think of it like you would if you were trying to find a plumbing leak. Except you can't see the leak, even if you find it.

View attachment 3740903
View attachment 3740904
To find the correct terminal to measure, use the Alphanumeric code to identify the correct terminal block (top image) and then find the numbered terminal within that block. For example, OX1-E1 connects the #24 terminal of block E4 to the #5 terminal of block E5. You need to make these measurements with cables connected, through the back of the cable connector housings. Use a paperclip to extend the terminals out of the connector housings, if necessary.

You can ignore the "pulse generation" signal values (unless you have an oscilloscope, and even then, ignore them); as long as the voltage changes constantly, you're OK.

Wiring colors are always in the format [main color]-[stripe or tracer]:
View attachment 3740914

Do this, before you buy new O2 sensors.

Here is a photo of the 02 sensor. Might be having an effect since the previous owner used two clamps to hold it in place.