Oxygen sensor code 21, 28 HELP! (1 Viewer)

[Vasiliy]

HI there! sorry for my bad English I have trouble with my TLC 80 94.

Diagnostic cel code 21-28 mean "bad oxygen heater" ok, i buy two 89465-69085 for 260$

my old oxygen sensors were not identified ( i think its OEM parts)
old oxygen wiring color > gray, brown, white, blue,

new oxygen wirig color > black, black, white, blue,
plug in the new sensor is different from the old men just replaced plug

i found this thread https://forum.ih8mud.com/80-series-tech/118555-o2-sensor-replacement-1994-fzj80.html

O2 wire Color Code Mr. T - OE
Blue = Signal wire
White = Heater wire 1 (non polarity)
Brown = Heater wire 2 (non polarity)
Grey = Aux Ground

O2 wire Color Codes: Bosch 4 wire sensors use the following code:
Black = signal wire
White = heater wire (non polarity)
White = heater wire 2 (non polarity)
Grey = Aux Ground

Ok, the obvious (T = toyota B = Bosch):
T - Blue > B - Black (MOST IMPORTANT)
T - White > B - White
T - Brown > B - White
T - Grey > B - Grey

O2 wire Color Codes: Denso 4 wire sensors use the following code:
Blue = signal wire
Black = heater wire (non polarity)
Black = heater wire 2 (non polarity)
White = Aux Ground

(T = Toyota D = Denso):
T - Blue > D - Blue
T - White > D - Black
T - Brown > D - Black
T - Grey > D - White

is that correct?

 

[half k cruiser]

Did you buy factory replacement sensors, or did you get aftermarket ? The diagram you made looks correct. Also, sometimes moisture can get into those plugs and cause it to send a 21 - 28 code.

 

[Vasiliy]

new sensor from toyota shop (non used) with different plug (see photo) was replaced for old sensor plug. sensors were replaced on truck service so I don't know correct sensor wires diagram

on photo my old o2 sensor

 

[Vasiliy]

The diagram you made looks correct.

so you say this diagram the right and i can use it without "fear" of burn my ECU?:whoops:

here photo 2o sensor plug

 

[Offroads4x4]

FYI
Always use dielectric grease on connections it will help improve the continuity and keep water out.

 

[half k cruiser]

You will not burn up your ECU. Before you re-install look at your new sensors and see if they have a Denso part number stamped on them somewhere. They should be numbered 234-4520 on both. If not then you have been sold the incorrect sensors.

 

[Vasiliy]

Oxygen sensor error 21-28 is gone!

I have driven on car quite a bit, CEL is not showing any error codes

i will continue testing tomorrow, thanks for your help!