Bank A misfires, codes: P0345,300,302,304,306

Tiny
AVOTOS
  • MEMBER
  • 2003 TOYOTA AVALON
  • 3.0L
  • V6
  • 133,939 MILES
Symptoms: Rough idle, engine light-solid on from start then blinks after a few minutes. VSC light on, Trac Off Light on, occasional Oil Light upon pressing accelerator with little power and or slight decrease in RPMs(Oil Level is okay). A whiny sound is present at first but then fades as the computer tries to correct the timing/misfire issues. Codes: P0345,300,302,304,306 found. No O2 codes but car has not moved for a few months (no money to fix the car at the time) but was started frequently. The car initially stalled on the highway and had a rough Idle that day.

Cam sensor bank A is okay, but replaced anyway. Spark plugs have been replaced with OEM plugs.
PCV was replaced seven months ago. Bank A VVT has been inspected and cleaned but knowing solenoids, there should be more of a snap sound. Bank A O2 coil checked and found to be okay although if it was not the code would have flagged right away.

Not sure where to look next or what could be causing the problem on just one side of the engine…

Your help is appreciated.


Just tested the voltage that should be at the connector to the Cam Position Sensor and there is no voltage of any kind when the ignition is on or even started. I assumed there should be some kind of voltage at the connector (guessing maximum 12 volts). Plugging the sensor in while the engine was on had no affect on the engine in any way. I assume there should have been a change in engine operation.

It is only a two wire connector: Blue wire and a black wire with a white stripe. Doing a continuity test determined that the blue wire is ground and the black wire with white stripe is the signal wire. It is obvious that the blue wire through the connector has continuity to battery ground. There is 24K across the two connector pins which suggests the signal wire is connected to something.

Should there be a voltage at the connector to the Cam Position Sensor?
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Saturday, May 4th, 2019 AT 12:19 PM

7 Replies

Tiny
KEN
  • ADMIN
Hello,

It sounds like you have a wiring issue or the PCM has gone out be to be sure we will need to do some testing here is the engine wiring diagrams and guide to go over them with the location of the PCM which I would check for water damage.

https://www.2carpros.com/articles/how-to-check-wiring

Check out the diagrams (Below). Please let us know what you find. We are interested to see what it is.
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Monday, May 6th, 2019 AT 3:21 PM
Tiny
AVOTOS
  • MEMBER
I appreciate the reply and thank you for the Diagram/Schematics as it is not easy to find them online. I will most certainly let you know what I can find I suspect the ECU if that is what you meant by PCM. Upon further testing yesterday(Sunday) it seems that both Cam/VVT sensors along with Crank Sensor are directly connected to the ECU without any breaks prior to ECU. There is a junction somewhere for the ground connections but grounds look solid based on various continuity checks.
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Monday, May 6th, 2019 AT 3:51 PM
Tiny
KEN
  • ADMIN
Please let me know, yes the PCM and the ECU, check for water damage. We are interested to see what it is.
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Tuesday, May 7th, 2019 AT 11:28 AM
Tiny
AVOTOS
  • MEMBER
Apologies for the delay.
I have performed many continuity checks between both cam sensors and the crank shaft sensor. The diagram attached shows where there is no signal. There seems to be no shorts or breaks with all three sensors and no visible water damage of any kind.

First I need to say that I had found a workshop manual for a 2001 Avalon online( have to sift through it a page at a time no link able index) which gives a few more details as to the resistances (hot and cold) that should appear at all three sensors and what the signal/voltage range is with all sensors.

It turns out that the cam sensors sold to me by O'Reily auto parts do not meet the resistance ranges that are mentioned in the manual(around 1,000 cold) and have the resistance range of the crankshaft sensor(around 2,000 cold). However I have one of the original cam sensors and its resistance range is in the 1,000 range. The workshop manual states to replace the sensors if the ranges are not within the appropriate values..I will need to get Denso replacements.

As stated, I have performed many continuity checks with the determination that there is no signal at e4 pin 22 of the ECU since there is a 24,000 resistance value from pin 22 of connector e4 and pin 25 of connector e5, it has been determined that the connection is solid through to the ECU board itself(internally, there is a 24,000 resistor that is across the two connections. I have traced the circuit for both sensors to an IC that has no distinguishable number).

There is signal at the other two sensors (cam and crank sensor) the ne- at pin 25 is labeled as e2 ground in the service manual-not case ground. There is a 100ohms between e2 and case/body ground so there is some form of power inversion within the ecu to create AC based frequency signals.

I am still looking for any parts(resistors/capacitors etc) that may be blown within the ecu but so far all resistors that I can trace test okay. Caps are a little harder to check when in circuit. The board itself is multilayered(more than two layers of pathways) which makes things difficult to reverse engineer without a schematic of the ECU itself.

Is there any other area that may have influence on whether the sensor in question actually has signal?

If the ECU is bad where can I get another cheaply because Toyota wants way too much money for a replacement?

If the ECU needs replacement, what are the instructions to reset the keys? I have heard of shorting 2 pins on the scanner port.
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Friday, May 31st, 2019 AT 2:29 PM
Tiny
KEN
  • ADMIN
Yes, I would get the Denso sensors and if that does not work get a rebuilt ECU. They will ask for your VIN which will be programmed into the unit so your keys will work. Try here:

www. Carcomputerexchange. Com

Please let us know what happens.
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Saturday, June 1st, 2019 AT 2:27 PM
Tiny
AVOTOS
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The site mentioned above does not have computers for a 2003 Toyota Avalon.
Do you know of any other reputable places?
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Tuesday, June 4th, 2019 AT 8:10 AM
Tiny
KEN
  • ADMIN
Try one of these:

https://www.ebay.com/b/Engine-Computers-for-2003-Toyota-Avalon/33596/bn_7065230714

let me know.
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Tuesday, June 4th, 2019 AT 11:41 AM

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