Threw a lot of codess (1 Viewer)

[mtlandcruiser]

Good afternoon,
Just threw 5 codes
21
26
83
84
85
Can someone point me in the right direction where 2 start.
It does have an egr valve kit from huddexpo.com installed
No loss of power.

 

[ZackR]

Guessing you have a 93 or 94.

I'd recommend clearing the codes and see which ones come back. The 83/84/85 codes point to an issue with the ECU.

 

[Malleus]

It would be helpful if you stated the year and mileage, and any work you've done recently, and what you were doing when the check engine light (MIL) came on.

These are unrelated faults, except in that they all have ECM communication in common.

 

[mtlandcruiser]

It would be helpful if you stated the year and mileage, and any work you've done recently, and what you were doing when the check engine light (MIL) came on.

These are unrelated faults, except in that they all have ECM communication in common.

1993
244k
Normal driving

 

[Malleus]

So, no recent repair or work of any kind?

 

[mtlandcruiser]

So, no recent repair or work of any kind?

None

 

[Malleus]

OK, the fault codes, taken together, make me think there is a loose connection at the ECM and the engine harness.
Code 21 typically indicates the front O2 sensor or circuit has a fault.
Code 26 typically is the output from the O2 sensor indicating fuel management problem(s).
Codes 83, 84, and 85 are related to the Electronic Spark Advance program in the ECM (it's actully in the TCM, but ignore that for now).

Only if I saw any of these alone would I start at the book diagnosis. This is one of the rare cases where you actually have to know something in order to work on this truck (usually, you can cookbook your way through a problem and its solution).

There are no troubleshooting procedures for the ESA circuits. This is probably because almost all the work happens in the ICs and the related wiring, on and off the board. I would first pull the rightmost cable from the TCM (it's under the glovebox, and you'll have to remove that to get at it). Make sure you DO NOT pull on the wires to remove the connector. There's a tab you have to depress to disengage the connector housing. Look for it.

Don't worry about checking the circuit at this point, all you're trying to do is ensure the cable is connected properly.

Look at the harness end connector housing and make sure the wires are all seated in the connector, as best you can. Also, check to make sure there is no corrosion in there. Assuming the terminals are all seated well, and they are not corroded, reconnect the cable and clear the codes.

The easiest way to clear the codes is to pull the EFI Main fuse in the engine compartment fuse block. Pull the fuse, count to 15 and put it back in. Now reset your clock.

You shouldn't have to drive anywhere to see if you've solved the problem; idling in the driveway should be enough. If the light doesn't come back on, have a beer.

You can download the Toyota service manual (FSM) and the electrical wiring diagram (EWD) from the Resources section, for free. Thre is also a wiring harness repair manual in there; I'd recommend you get that, too - lot's of good information in there.

 

[mtlandcruiser]

OK, the fault codes, taken together, make me think there is a loose connection at the ECM and the engine harness.
Code 21 typically indicates the front O2 sensor or circuit has a fault.
Code 26 typically is the output from the O2 sensor indicating fuel management problem(s).
Codes 83, 84, and 85 are related to the Electronic Spark Advance program in the ECM (it's actully in the TCM, but ignore that for now).

Only if I saw any of these alone would I start at the book diagnosis. This is one of the rare cases where you actually have to know something in order to work on this truck (usually, you can cookbook your way through a problem and its solution).

There are no troubleshooting procedures for the ESA circuits. This is probably because almost all the work happens in the ICs and the related wiring, on and off the board. I would first pull the rightmost cable from the TCM (it's under the glovebox, and you'll have to remove that to get at it). Make sure you DO NOT pull on the wires to remove the connector. There's a tab you have to depress to disengage the connector housing. Look for it.
View attachment 3742932
Don't worry about checking the circuit at this point, all you're trying to do is ensure the cable is connected properly.

Look at the harness end connector housing and make sure the wires are all seated in the connector, as best you can. Also, check to make sure there is no corrosion in there. Assuming the terminals are all seated well, and they are not corroded, reconnect the cable and clear the codes.

The easiest way to clear the codes is to pull the EFI Main fuse in the engine compartment fuse block. Pull the fuse, count to 15 and put it back in. Now reset your clock.
View attachment 3742941

You shouldn't have to drive anywhere to see if you've solved the problem; idling in the driveway should be enough. If the light doesn't come back on, have a beer.

You can download the Toyota service manual (FSM) and the electrical wiring diagram (EWD) from the Resources section, for free. Thre is also a wiring harness repair manual in there; I'd recommend you get that, too - lot's of good information in there.

Watching the Mets then I will try
Thanks

 

[mtlandcruiser]

Can't seem to clear codes even after I pulled Ithe EFI fuse out. No moisture anywhere.
Connections are good.

 

[Malleus]

Can't seem to clear codes even after I pulled Ithe EFI fuse out. No moisture anywhere.
Connections are good.

That's a problem, because pulling the EFI main will clear the codes. There should be at least some time before they return. They should not be persistent and should not return immediately, unless there's a fault in the circuit you unplugged.

 

[ajax1]

What ecu part number do you have? Early 93s I believe we’re known for this and you need to find used newer ecu, sorry do t remember part numbers, but search this site bunch of threads on it.