Well Crap

TylerM

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So this happened on the way to work.

p0135
p0325
p0330
p0690

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stkjock

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are you looking for tech insights or just complaining?
 

TylerM

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Solidarity. I'm pretty sure the motor is gone. Both knock sensors, o2 sensor.

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Juice

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P0690 = pcm supply voltage issue.
I would test alternator and battery before yanking the engine.
 

Dino Dino Bambino

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p0135: Heated Oxygen Sensor → Sensor Heater Circuit Malfunction → Bank 1, Sensor 1

p0325: Knock Sensor “Bank 1” – Circuit Malfunction

p0330: Knock Sensor ” Bank 2″ – Circuit Malfunction


p0690: ECM/PCM Power Relay Sense Circuit Voltage High

There's probably one common cause for all of those codes, and my prime suspect is a faulty alternator diode causing a small AC current to leak into the main engine wiring harness.
 
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TylerM

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I recently replaced the relay switch. The knock sensors and o2 sensor are what is throwing me through a loop.

I've already checked all the wiring from the last time I had the p0690 code. It was not the 0690 code that was causing the no start the last go round. It was really fouled spark plugs.

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Pentalab

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Put a DVM across the battery terminals...and put the DVM on AC volts. If you read anything more than a few Mv (millivolts)... you got 1 or more shorted diodes inside the alternator. With 1 or more shorted diodes, you will be pumping raw AC into the battery. Raw AC will fuck up a battery very quickly. The (esp) pcm..and everything else wants to see pure DC. Simple test, that can be done in the driveway, with eng idling.
 

TylerM

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Put a DVM across the battery terminals...and put the DVM on AC volts. If you read anything more than a few Mv (millivolts)... you got 1 or more shorted diodes inside the alternator. With 1 or more shorted diodes, you will be pumping raw AC into the battery. Raw AC will fuck up a battery very quickly. The (esp) pcm..and everything else wants to see pure DC. Simple test, that can be done in the driveway, with eng idling.
Car is in a no start state. I was shifting gears getting on the highway, heard a pop and engine immediately cut out. No fluids leaking anywhere.

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TylerM

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p0135: Heated Oxygen Sensor → Sensor Heater Circuit Malfunction → Bank 1, Sensor 1

p0325: Knock Sensor “Bank 1” – Circuit Malfunction

p0330: Knock Sensor ” Bank 2″ – Circuit Malfunction


p0690: ECM/PCM Power Relay Sense Circuit Voltage High

There's probably one common cause for all of those codes, and my prime suspect is a faulty alternator diode causing a small AC current to leak into the main engine wiring harness.
I'll go through all of the fuses and relays later and test them. Since almost all are a circuit failure.

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TylerM

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I found that the pcm power relay #1 supplies power directly to the heated oxygen sensors, so I'll be testing that relay probably this weekend.

I'll pull the alternator as well to inspect it.

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TylerM

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Got the car to start and run. Idled for about 10 minutes and dies. Codes for pcm power relay sense high and o2 sensor bank 1 sensor 1. Have new relays on the way.

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TylerM

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Put in a brand new relay. Car started and idled without issue. Sounded great. Took it out and two blocks from the house it died on me. Same exact codes as original. I think it may be the o2 sensor as one source of the issue. I'm beginning to think the pats transceiver may be the other.

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RavenGT

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It's not an O2 sensor (HO2S). I highly doubt it has anything to do with PATS as well.
 

TylerM

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It's not an O2 sensor (HO2S). I highly doubt it has anything to do with PATS as well.
I let the car sit for a week because of work and classes after the last incident and it fired right up today.

I have an lc-2 from innovate wired to feed a narrow band signal to the pcm return for the bank 1 sensor 1 location. If it's not an issue with that, could you offer up a suggestion. I've been over the wiring harness three times already from the pcm to the bec. The issue isn't there. I've done the checks according to the ford manuals. I cannot replicate the trigger either.

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RavenGT

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How long does the car have to sit before it will start again?
 

TylerM

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About a week.

Atleast I only have the weekends to really touch the car so.

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Pentalab

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See post #8. That will explain exactly how to test the Alternator.... ( the next time you can start it).
But you require a digital voltmeter... that will read AC voltage down to the millivolt range. The DVM also has to have block caps inside it, so when trying to measure AC ripple voltage, the block caps will block the 14.75 DCV from the battery. All Fluke dvms have block caps ( when using the ACV function).... but some DVM's don't have dc blocking caps...like my older B+K brand DVM. ( if block caps are not inside the DVM, when DVM placed in 'ACV' function..and test leads put across battery terminals...the DVM will indicate...14.75 vdc). Ideally the dvm should read...'zero volts AC'. IF it instead read several hundred Mv of acv, you got 1 or more shorted diodes.
lf 1 or more diodes fails..open, you got more problems.

It will take you all of 5 x secs to do the simple test...and while you are at it, measure the exact DC voltage on the battery terminals...another 5 secs.

BTW, what year is your car, and is it a manual or auto? What mods if any?
How old is the alternator ?

IF one or more the 6 x diodes inside the alternator has failed shorted, you will then be pumping RAW AC from the 3 phase alternator....directly into the battery...and also the ECU..and those 2 x items (+ a bunch more... but excluding stuff like headlights and horn etc) don't want to see anything but clean DC....IE: NO AC ripple.
 
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TylerM

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See post #8. That will explain exactly how to test the Alternator.... ( the next time you can start it).
But you require a digital voltmeter... that will read AC voltage down to the millivolt range. The DVM also has to have block caps inside it, so when trying to measure AC ripple voltage, the block caps will block the 14.75 DCV from the battery. All Fluke dvms have block caps ( when using the ACV function).... but some DVM's don't have dc blocking caps...like my older B+K brand DVM.

It will take you all of 5 x secs to do the simple test...and while you are at it, measure the exact DC voltage on the battery terminals.
I'll have to borrow a fluke from work since my dvm is real basic.

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