crank n cam sensor no power, no 5volt ref; IAt sensor reads 4.5 volts;tps 2.5 v.

No start; ecm shut down the crank and cam sensors after replacing fuel pump. New fuel pump read 50 lbs then I snapped open throttle it shorted. Fuel pump wiring all good test directly to battery, pump works. Their is no pwer to the fuel pump wire color blue blk stripes.

no coil spark either; there power going to the coils; I don't understand yet how to do power to ground testing;

voltage dropped test was done to fuel ground it dropped from 12 volts to 9 volts.

All fuses and relays checked including EFI and open circuit fuel relay all good.

I get lost reading wire diagrams blending and confusing afraid to touch the computer.

It would seem the computer is the source?

Help and guide, thank you. I have spent a week attempting to troubleshoot no success yet.

Respectfully,
Alexander Gonzalez.

Is this the 4 Speed Automatic OR 3 Speed Automatic / Manual ?

The cam and crank sensor are both Variable Reluctance Sensor and makes its own voltage. I'm not sure how you have high voltage from iat and tps, if you say you have no 5 volt ref.

Did you check the C/OPN (circuit opening) relay in the driver side R/B (relay box?). That relay will feed power to the BLU/BLK wire to the fuel pump which you say is missing. While cranking you should have two power feeds at the relay. One load side power and one control side power.

Hello Leeeroy,

Thanks for your response. The toyota corolla 2000 4 CYL, is an automatic tranny.

I have check resistance with load on all relays they click and are working: EFI RELAY; STARTER RELAY; ENGINE RELAY ; OPEN RELAY UNDER THE DASH BOARD ALL GOOD.

DISCONECTED INTAKE AIR SENSOR VOLTAGE 4.5 IS MY REFERENCE VOLTAGE FROM ECU COMPUTER.
DISCONECTED CAM AND CRANK SENSOR ZERO VOLTAGE DEAD NO POWER. THESE ARE MY INPUTS FOR THE COMPUTER TO GIVE ME RPM SIGNAL FOR IT TO WAKE UP.
DISCONNECTED THROTTLE SENSOR VOLTAGE 0.2
DISCONECTED MASS AIR FLOW SENSOR DON'T REMEMBER VOLTAGE LOW.

THE COILS HAVE POWER NO SPARK. BACK PROBE 4 WIRES ON COIL POS N GRD THEN TWO SIGNAL WIRE ALL SHOWED A VOLTAGE READING.

DON'T HAVE SCOPE; DO HAVE TEST LIGHT AND MULTI METER WITH AMP RANGE.

i DON'T KNOW WHAT TO DO AT THIS POINT?

ANDRAMEDA271

Check your reference wire at the pcm..and chase it out to the first splice,check there..most likely loosing the 5 volts somewhere..is there more then one ref wire?

This is image from 4 speed automatic transmission, I hope this is right.

I would try to find out why you're not getting power on the blue/black pump power feed. Follow highlight and backtrack to find where you're losing the power.

i.imgur.com/P9PyDVB.jpg

Hello Goodfellow,

Discovered 3 fuses, 10 amps, without power feed, they are not blown! Very Interstin! Two fuses in engine compartment; one under-dash, no power; what is this related to? ig or anti theft ystem I never knew about; fuses are classified as *1 all three, what does this mean ?

Crank sensor has 0.01 volt ref; cam sensor has 2.0 volt ref. Ohm both sensors, crank reads 1700 ohms; cam reads lower than 1700;

I can't find wire diagram for this car and I am not skilled to read it?

ignition key switch, is good; all relays good;

I want to thank you for your response:
Respectfully,
AG

Hello Goodfellow,

Discovered 3 fuses, 10 amps, without power feed, they are not blown! Very Interstin! Two fuses in engine compartment; one under-dash, no power; what is this related to? ig or anti theft ystem I never knew about; fuses are classified as *1 all three, what does this mean ?

Crank sensor has 0.01 volt ref; cam sensor has 2.0 volt ref. Ohm both sensors, crank reads 1700 ohms; cam reads lower than 1700;

I can't find wire diagram for this car and I am not skilled to read it?

ignition key switch, is good; all relays good;

I want to thank you for your response:
Respectfully,
AG

Hello Noah,
Hello Tech Whisper,
Thank you for your response, I have been working on the car steady away from the website applying what Paul is teaching on videos and revisiting the patient making notes of unusual discoveries and behaviors. Able to attach pics

Yes, the mind is in a confused state because its learning in puts are greater then or equal to the thousand questions during the learning process, synthesizing and distilling the complex engineering techniques of integrated circuitry and their main principals which often comes with governing principals to maintain balance, amplitude, frequency and vibrational pulses in synchronization to mechanical motion orchestrating the functions of sensors, transistors, fuses, relays, and modules controlled by computer, it amazing however grueling because i did not have a head start in learning and the car suddenly has more then one problem so it is not fun at all the pressure is on to perform emergency CPR.

Fuel pump was weak pulling up a false code P0171 lean condition.

Fuel regulator was mentioned because I put a vacuum to the fuel regulator it did not hold vacuum it leaked down. I purchased a defective part it would seem however the original regulator under vacuum held never leaking? So is this normal or is it defective in a stuck state? This fuel regulator issue came up earlier, while reassembling the fuel sending unit one month ago, when I had joined 9/22/18; and did not get a response to help me discern fuel regulator in a return-less system so the new possibly defective fuel regulator is installed assuming that the old one was stuck. It is now installed into the tank with new fuel pump. Fuel pump was tested directly with battery power it works good no reverse polarity wiring its sweet it was not the cause of the no start; no injector;no spark something else was the cause.

Test & discoveries:

What shut down the car's computer was not the fuel pump, it was reading 50 lbs while cranking.

It was an after market alarm and remote system, I never new existed. My foot hit a toggle switch on the foot panel and some how it was activated, even though found 2 wires cut off; however the power pak and my foot trips the after market module's logic circuits into anti-theft mode shutting the cars fuel pump; no spark and no injectors.

All relays working, ohmed and tested under load.

All fuses good not blown, except for 3 10amps fuses; 1 fuse inside the dash ; 2- 10 amp fuses inside engine fuse box; there is no power going through these three fuses, the filaments are fine not blown. Paul, says in video, that these unblown fuses are not getting the power feed from the ground side of the computer implying no return power on ground side, of fuses?

No power, from the load side of fuses terminal, on battery side, the ground terminal of fuse does not light up when test light to bat neg so ground side is good; to confirm this test light to battery pos+ it lights up on the ground side terminal of fuses.

Crank sensor: ohm is 2000; cam ohm is 1045 ; on connector side; no power from battery on both sensors; this is a new symptom after cutting after market devise, from under dash board; no injectors; no coils; no spark; no fuel pump action either, just crank. coils still show power to connectors.

reconnected both sensors; back probed signal wire; crank reads 2 voltage ref; cam reads 000, in reverse polarity, on the meter no reference voltage it pulls down to 000.

Bypass taps, on both crank and cam signal wires simultaneously; no meter reading; while cranking the reluctance gears, no RPMs readings, while bumping ignition key no average volts.

resources n deficit in skills:

Haynes wiring diagrams is all I got.

Don't know how to check for ECU powers n grounds yet?

Don't know how to follow wire maps to find spliced circuits?

don't know how to find connector pins on computer?

Voltmeter, has an amp setting, for current flow under load.

No scope; no wave form readings!

Is voltage regulator in computer damaged?

Is transistor switches unable to reverse pulse, through ground side of computer, back to battery?

Is my cam sensor dead?

If I need a new computer, how will I be able to program it, without a scope?

Battery has clean terminals n cables; battery cells read 2.0 volts each; charge is 12.76 drops to 12.45 after 3 hours of cranking, lowest was 11 .43 it never dropped below 10.

Removed after market devise and re-spliced original wires and sealed open insulation. New symptom no power to crank n cam sensor; crank does read 2 ref volts; cam reads 000 on signal n power wires with reverse polarity indicator on meter?

Its been intense learning; thank you for any or all support and recognition and considerations! Its a joy to plug into your world!

The car sits in drive way, with a beaten down diagnostic student, staring into space!

Respectfully,
Alexander Gonzalez.

[attachment=after market relay spliced was removed not certain if it belonged/attachment] [attachment=aftermarket alarm removed/attachment] [attachment=computer home[/attachment] [attachment=passenger side modul.JPG[/ dash yelow wire spliced between 2 red wires where a relay was found it was removed[/attachment]

AG,

Trust me I know how you feel. I have a similar issue but have all necessary voltage refs needed in wiring so my hands are up in the air. What it sounds like is a open or short circuit. Have you tried testing your cam sensor for short? It’s definitely sounds like it could be a ground short in harness. I would run your short test on the cam sensor plug to verify a short. You can find how to do this in the shop manual.


Sent from my iPhone using Tapatalk

Hello MB Mazda,

Thanks for acknowledgement Mr. Mazda.

I will have to do more reading on shorts to ground; perhaps start from beginning of book sections.

Appreciate, courtesy and communing into space, thanks for fellowship good fellow.

Respectfully,
Ag