P0135 & P0155 codes
#16
05-22-2013, 07:40 PM
Join Date: Oct 2012
Location: New Maryland
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I think your missing an important point on this.
The problem is not a short but an 'open'.
If it was a short, you would have blown fuse 23 and had all kinds of codes from it.
All you needed to do was test the sensors with a low cost meter for being open and verify the missing voltage and you would have found them good for their heater continuity and not have the change them until later, if you still wanted to after finding the open fault.
Never test the 'sensor' leads with even an ohm meter, only the heater leads.
Of course the PCM will see the open right away because it looks at the current draw.
These sensors are part of the system at all times.
The fact that both are open tells me the harness is cut or worn open at some common point between the fire wall, down the pass side of the motor back to the sensors.
In this harness is the transmission control, the EVAP and neutral control leads.
Where the leads break out of the harness separate; from that point on is likely to be the trouble area.
Check for voltage to the rear sensors and see if it's there.
That will further narrow the area down.
Was there any other work done under the truck?
Good luck.
The problem is not a short but an 'open'.
If it was a short, you would have blown fuse 23 and had all kinds of codes from it.
All you needed to do was test the sensors with a low cost meter for being open and verify the missing voltage and you would have found them good for their heater continuity and not have the change them until later, if you still wanted to after finding the open fault.
Never test the 'sensor' leads with even an ohm meter, only the heater leads.
Of course the PCM will see the open right away because it looks at the current draw.
These sensors are part of the system at all times.
The fact that both are open tells me the harness is cut or worn open at some common point between the fire wall, down the pass side of the motor back to the sensors.
In this harness is the transmission control, the EVAP and neutral control leads.
Where the leads break out of the harness separate; from that point on is likely to be the trouble area.
Check for voltage to the rear sensors and see if it's there.
That will further narrow the area down.
Was there any other work done under the truck?
Good luck.
The only think I got done was both exhaust manifolds, but can't remember if it was before or after the codes.
#17
05-22-2013, 09:37 PM
, - the heaters are the two white wires at each sensor and throughout that harness. That harness gets pinched, shorted or cut in two on top of the bell housing. Both sides are tied together there, so a harness problem, short open or whatever most likely will be right on top, -where the trans bolts to the engine. That's where they usually go to hell unless the harness became un-pinned from the block, then sunk down on top of the exhaust... Seen that as well.Since you have a PO403, - sounds like you have a few things melted together. Pull the air intake and inspect the engine compartment/ drivers side. They can get REAL HOT there, -specially if the cats halfway stopped up.
That should give yuh a few things to look at. Personally, I'd just disconnect the sensors and check the harness first. - With given history in mind. Unless you feel like pulling the intakes ? Do real good visual check eng comp drivers side like I said. If it got hot there you'll know it. Do that before you crawl under lol.
#19
05-23-2013, 07:15 PM
If I were you, I'd ask more questions here. Like what do you need explained further, to determine were the problem is?
I have to say, every time I've dealt with O2 DTC'S 135/155, it has either been the sensor itself or the connector. What happens allot, if you disconnect the connector, then plug it back in without cleaning them up first, you can throw numerous O2 DTC's. O2 connectors/plugs are extremely deliquite and finicky. More than any other on the vehicle. You have your two heaters, one signal wire and one PCM ground (direct). They all need a solid connection for that part to work properly.
You may get lucky at the dealer and the tech will know exactly what to do. Even still, IF your harness at the top rear of the motor is damaged, that's going to be a 4-6 hour labor charge to fix.
So depending upon the time you have to put into this, you COULD save yourself a lot of cash. Just ask for further explanation with what you don't quite understand. Everyone that's trying to help you here is damn good at that stuff.
Last edited by jbrew; 05-23-2013 at 07:19 PM.
#20
05-23-2013, 09:03 PM
Join Date: Oct 2012
Location: New Maryland
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Keep in mind, that may be VERY expensive. Specially if the tech working on this isn't that experienced in this area.
If I were you, I'd ask more questions here. Like what do you need explained further, to determine were the problem is?
I have to say, every time I've dealt with O2 DTC'S 135/155, it has either been the sensor itself or the connector. What happens allot, if you disconnect the connector, then plug it back in without cleaning them up first, you can throw numerous O2 DTC's. O2 connectors/plugs are extremely deliquite and finicky. More than any other on the vehicle. You have your two heaters, one signal wire and one PCM ground (direct). They all need a solid connection for that part to work properly.
You may get lucky at the dealer and the tech will know exactly what to do. Even still, IF your harness at the top rear of the motor is damaged, that's going to be a 4-6 hour labor charge to fix.
So depending upon the time you have to put into this, you COULD save yourself a lot of cash. Just ask for further explanation with what you don't quite understand. Everyone that's trying to help you here is damn good at that stuff.
If I were you, I'd ask more questions here. Like what do you need explained further, to determine were the problem is?
I have to say, every time I've dealt with O2 DTC'S 135/155, it has either been the sensor itself or the connector. What happens allot, if you disconnect the connector, then plug it back in without cleaning them up first, you can throw numerous O2 DTC's. O2 connectors/plugs are extremely deliquite and finicky. More than any other on the vehicle. You have your two heaters, one signal wire and one PCM ground (direct). They all need a solid connection for that part to work properly.
You may get lucky at the dealer and the tech will know exactly what to do. Even still, IF your harness at the top rear of the motor is damaged, that's going to be a 4-6 hour labor charge to fix.
So depending upon the time you have to put into this, you COULD save yourself a lot of cash. Just ask for further explanation with what you don't quite understand. Everyone that's trying to help you here is damn good at that stuff.
It sucks when you don't have access to a lift and laying on a gravel driveway
Guess I'll start with checking the connections. Maybe I'll find my 10mm socket I dropped when taking off the plastic top cover.
