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2002 double cab mini
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Discussion Starter · #1 ·
So I’ll make this short and sweet. I had a 2002 3.4 auto 4x4 truck. I technically turned it into a pre runner, so the same 3.4 with an auto 2x4 trans. I keep having a problem where once I drive it,it won’t start back up. It’s throwing p1135 code which is the bank 1 sensor 1 a/f sensor. That and the sensor two are both brand new in the truck. I can’t for the life of me figure out what’s going on.
I’m wondering if I need to swap to a 2x4 ecm? Thanks in advance for any tips
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97 2.4l extra cab manual trans #🌮⏳
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It's a b1s1 heater circuit code if im not mistaken? May have wiring issue
 

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Mambeau / Admin
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I agree with pimpRunner that it's probably a wiring issue.

Here (attached) is the 2002 5VZ V6 engine control wiring diagram. There are some things that are different among various 4WD and / or auto models, but I don't understand why any of them should be throwing a P1135. None of them seem to have anything to do with the heated O2 heater circuit.

An ECM fault is listed as a possible cause for a P1135, but I have no idea what / where this fault may be.

NOTE: When you check your wiring, make a point to trace the wiring leading to your EFI Main Relay. A problem with the relay is listed from 2003 onward as a possible cause for heated O2 heater circuit codes. Beyond that - any fault with the EFI Main Relay would result in a no-start condition. This may be a big clue ...

NOTE: The diagnostic codes changed betweeen 2002 and 2003. P1135 is the old single code. As of 2003 it was changed to a set of 4 codes (B1S1 = P0031 & P0032) to conform to some OBDII standard. I don't see any changes in the relevant wiring between '02 and '03, so I'm fairly confident an EFI Relay fault would have been a problem in '02 as well.

Hope this helps ...
 

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2002 double cab mini
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Discussion Starter · #4 ·
👍I appreciate the help I’ll look into the the relay and trace it back. As you stated it did show that it could be the ecm, I saw that same thing and that’s why I asked maybe I need to change it to a 2x4.
 

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Discussion Starter · #5 ·
👍I appreciate the help I’ll look into the the relay and trace it back. As you stated it did show that it could be the ecm, I saw that same thing and that’s why I asked maybe I need to change it to a 2x4.
 

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Mambeau / Admin
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As far as I can tell there's no clear reason to swap ECMs unless it can be proven the ECM you're using is somehow defective or broken.

I don't think a missing 4WD engagement signal would trigger a no-start condition.

Seems to me either a wiring fault or relay problem is much more likely.

If you swapped transmissions I suppose there's a chance something's not right with the gear selector wiring (making the ECM think it's not in Park when starting), but I don't think that should trigger a P1135.

The EFI Relay is the power source for the heater O2 heater circuit, so that explains how a relay fault could trigger a P1135 (voltage on the heater circuit out of spec range high or low).
 
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