1993 ECU Pin Out Diagram

[Fzj80 1997]

I have a 93 fzj80 that has an uneven idle and stalling issue when idling. I think that it is an ecu issue because I went through all the usual suspects, fuel pump relay, intake tube, TPS, Fuel pump resistor, IAC and it is still having this issue.

I think it might be an ecu wiring problem because I swapped a known good ecu off the shelf into the truck and it idled perfectly for a good while until I buttoned it up (replacement was just hanging while original ecu was still installed in the original location). Once I put the replacement ecu back into its original position, the truck started acting up again in the same way, dying at idle. The issue I have right now is that one of the connectors going into the ECU has an extra brown and black wire in position e11 on my factory harness. I have a 94 harness sitting on the shelf and was comparing them and the 94 harness is missing a wire going into position e11. The manuaI I have is for a 94 and there is no pin out, only a diagram showing the connectors and labels, but no explanation of what each wire is for. The 94 Electrical wiring diagram also does not mention terminal e11.

My question is what is e11 for? And why does my 93 have it while 94’s do not?

 

[OfficialGamings]

E11 Looks to be a Ground terminal.

 

[OfficialGamings]

E11 Looks to be a Ground terminal.
View attachment 3648366

Note that that is for the 1995-1997
1993-1994 doesnt seem to have a E11 pin in my book

 

[Fzj80 1997]

My buddy with a 93 confirmed that his truck does have a brown and black ground wire and it is listed in the 93 wiring diagram he has but not the 94 that I have. I depinned it to see if it made a difference and it did not. I wonder why 93’s have this extra ground.

I should mention that I unplugged the o2 sensors and the truck started running perfectly so I no longer think it’s an ecu or wiring issue. I think when I plugged in the new ecu the first time the car was thrown into a certain setting which made it run rich. After finding an obd1 scanner, it was reading lean with the o2 sensors plugged in with no change when pushing on the accelerator which is making me think these denso obd2 fzj80 o2 sensors might be the culprit by giving an inaccurate reading to the ecu. I was told Denso 234-4153 would work if the alignment stub was shaved off to fit the 93 connector housing. I’m thinking this could be my issue.

 

[efjayatee]

You forgot the ICM that controls the fuel system. Igniter control module (ICM).
Not to often the ECU fails. Get a toyota ICM and not the Napa/Orileys/AutoZone crap.

 

[Fzj80 1997]

You forgot the ICM that controls the fuel system. Igniter control module (ICM).
Not to often the ECU fails. Get a toyota ICM and not the Napa/Orileys/AutoZone crap.

What makes you think that it’s the igniter?

 

[efjayatee]

What makes you think that it’s the igniter?

Idling issue and erratic RPM could also be a vacuum leak. Check your MAF as well.
After I replaced $$ of parts, mine was the ICM. I had stumbling at idle. Replaced fuel oump, fuel filter, TPS, knock sensors, dizzy.....

 

[OfficialGamings]

You forgot the ICM that controls the fuel system. Igniter control module (ICM).
Not to often the ECU fails. Get a toyota ICM and not the Napa/Orileys/AutoZone crap.

Thought ICM received data from the ECU for ignition timing.

How could this cause a Rich/Lean condition?

Based on the fact he has a obd1 scanner and it is reading lean. Wouldnt you start with O2 Sensors.

My thought is that since O2 Sensors are reading a lean condition, ECU would be trying to feed more fuel when it may not be needed.

 

[OfficialGamings]

My buddy with a 93 confirmed that his truck does have a brown and black ground wire and it is listed in the 93 wiring diagram he has but not the 94 that I have. I depinned it to see if it made a difference and it did not. I wonder why 93’s have this extra ground.

I should mention that I unplugged the o2 sensors and the truck started running perfectly so I no longer think it’s an ecu or wiring issue. I think when I plugged in the new ecu the first time the car was thrown into a certain setting which made it run rich. After finding an obd1 scanner, it was reading lean with the o2 sensors plugged in with no change when pushing on the accelerator which is making me think these denso obd2 fzj80 o2 sensors might be the culprit by giving an inaccurate reading to the ecu. I was told Denso 234-4153 would work if the alignment stub was shaved off to fit the 93 connector housing. I’m thinking this could be my issue.

I wonder if those Densos are meant for 95 onwards which use Upstream and Downstream O2 Sensors instead of Left and Right which I think the 93-94 use.

I believe i have seen a post about needing to just swap two pins. You would have to search for it but could be worth a shot…..

 

[efjayatee]

Thought ICM received data from the ECU for ignition timing.

How could this cause a Rich/Lean condition?

Based on the fact he has a obd1 scanner and it is reading lean. Wouldnt you start with O2 Sensors.

My thought is that since O2 Sensors are reading a lean condition, ECU would be trying to feed more fuel when it may not be needed.

As mentioned, after replacing my fuel system including ignition coil and other sensors the ICM fixed my 93 issue.

Goggle:
The Ignition Control Module controls the firing of the ignition coil/s so it can create the voltage the spark plugs need to ignite the air/fuel mixture in the engine cylinder.