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Paul M ASE Master
Paul M ASE Master, ASE Master Tech
Category: Car
Satisfied Customers: 4684
Experience:  Ase Master 20+ Years Experience Foreign and Domestic
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2000 malibu 3.1, p0134, not reading 02 sensors

Customer Question

2000 malibu 3.1, p0134, not reading 02 sensors
Submitted: 4 years ago.
Category: Car
Expert:  Paul M ASE Master replied 4 years ago.

Hello and thank you for using Just Answer

I'm Paul and I will help you with your Question

 

you need to check the wiring to the PCM

 

I am attaching test information

click here to view

Remember to rate my answer positive so I get credit for my help.

 

If you need more help just log in to the site and reply the question will remain for follow up.

 

 

Paul
Customer: replied 4 years ago.

in tan wire there is no difference if grounded or not scanner reads 450mv, I already checked resistence of those 2 wires to pcm. no open or shorted to ground


 


both o2 sensors are new, map, ect and iat too.

Expert:  Paul M ASE Master replied 4 years ago.

if there is no Change and the wires test good the PCM is bad.

are you looking at these values on a scan tool?

 

I would make sure it acts the same after at operating temperature I have seen some PCM's show a set value until the engine is warm

 

if it is stuck even after a full warm up and while running the above testing and the wires test good the PCM is bad

Paul

Customer: replied 4 years ago.

yes, mt2500 It does it even warm up, no change.


 


and that set value, is there any chance that the pcm show it if any other sensor is bad?,


 


also i think for the same reason its not going into closed loop even when temperature 225 F it show 'OPEN FTL"


 

Expert:  Paul M ASE Master replied 4 years ago.

if the coolant temp is reading ok and there are no other codes

 

I would suspect there is no reason it wouldn't go into closed loop

 

I am attaching the testing procedures in a couple different formats to see if they might help.

I would be suspecting a bad PCM if wiring tested good and values of Coolant temp looks ok.

click here for troublshooting p0134

 

click here for another troubleshooter p0134


Paul

Expert:  Paul M ASE Master replied 4 years ago.
Hi Jose

I'm just following up with you to see how everything worked out?


Please remember to rate my answer positive so I get credit for my help

Paul
Customer: replied 4 years ago.

sorry, I still waiting for ecm to arrive, anytime during this week.

Customer: replied 4 years ago.

i replaced the pcm and now the car doesn't start, its programmed already,


 


antitheft light keeps flashing, already tried leaving key on for 10 mins until light turns off after trying to start.

Expert:  Paul M ASE Master replied 4 years ago.

You have to do the 10-12 minute procedure

 

3 times and then try to start.

once the antitheft light goes out turn key off and repeat 2 more times after the 3rd time the light goes out attempt to start

Keep a charges on the battery when doing this

Paul

Customer: replied 4 years ago.

after the ligh goes out the first time, the second time stays on the whole time i have been there for 20 min and does not go out.i even tried to do the whole thing with the door open or closed and even removing the key each time and the same.

Expert:  Paul M ASE Master replied 4 years ago.

the doors should be closed

after it goes out the first time you should be turning off the key for a couple seconds

 

then when attempting the second time you need to hold the key to the crank position for a second and release to run position.

it should be going out 3 times to complete the relearn

let me know if these steps help

 

Paul

Customer: replied 4 years ago.

it did start like u guided me.


 


now its still in open loop the whole time and its not reading 02'sensor even warmed up

Expert:  Paul M ASE Master replied 4 years ago.

Jose

 

did you get it figured out?

it's possible you are getting a bad reading from the scan tool are there fault codes setting now?

did you run through the testing again?

Paul

Customer: replied 4 years ago.

there are no codes, runs good 700 rpm,


 


the tp sensor its a .60 mv, and temp sensor reading 210, map 40,


 


no resistance in ect sensor from ecm, and since they share ground from ecm with map its good with them disconnected, I am about to replace tp from a junkyard and see if it changes anything since its supposed to read .40mv and maybe after closed loop reads o2 sensors,


 

Expert:  Paul M ASE Master replied 4 years ago.

I have seen situations where scan tools were giving bad readings also

 

is it showing the open loop status?

the TP reading .6 should not be a problem

 

Paul

Customer: replied 4 years ago.
I have tried two diferent ones, and keep reading the same