ECM PROBLEMS

[aznturboz]

I currently experience the check engine light problem, my mechanic say that I need to replace the ECM due to the voltage is between 9to 14, which he indicate that its both 12.19 volts for my ECM. But the odd thing about this is that when im driving with the check lights on. At times, it would turn off by itself until maybe days to weeks later it turns on. My theory is that it might be the O2 sensor behind the engine, because i recently got a new o2 sensor in front of the engine where the header for a perivous check engine problem. Which it a same trouble as is, because after i change the first o2 sensor the lights have turn on for months. So could i be right that it the 2nd o2 sensor that cause the check light problem, since once and awhile it turn off by itself and turn on again and so on. so is there anyone could help, the ECM is not cheap and i really dont have much money to get it replace. any suggestion on my theory?

[SC V6]

what error code did they pull? Did they have an actual error code or just shooting in the dark?

[aznturboz]

p1135,p1155,P0125 those are the code errors appear on the scanner at my mechanic.......

[Turbosolara]

I think the idiot is measure the voltage from the power line, so it is 12v.


i looked up on line and found those code for matrix is
P1135 and P1155 A/F sensor heater circuit malfunction. ---> Check for the fuse or wires. They are the two black wires that connect ot your A/F sensor.

P0125 insufficient coolant temperature.

they might not identical to solara (but i think they are since they are toyotas with OBDII).

My diagonosis is that you have some electrical problem. it might be one code triggered other code. sometimes you light are on and off, that are two reasons.
1. It was not major and consistent, so the ecu turn it of by itself
2. somewhere has broken wires and they had contact sometimes. when they contacted, it triggers your light. when they apart, the light is off

good luck

[aznturboz]

so you guys are sure that it a electric problem? Because I have check the fuses and they seem to be fine. Also the wiring looks ok from last time i check. maybe i should check again. so your for sure that there's no problem with the ECM? anyways i wanna double check the fuse again, so can anyone tell which fuses to check and where the A/F sensor is at?

[SC V6]

I would say to also check O2 sensors... I wouldn't go and replace the ECU because of the mechanic... because the Ecu has very low voltage running to it from the sensors... and if he was reading somewhere around 12 then he was reading the wrong thing and probably shouldn't be working on cars... I'll check my Chiltons when I get home and check for sure what the problems are... definitally don' t but a whole new ECU...

[JAYDEE23]

nouns, pronouns, verbs, adjectives, etc...

tough reading