crank no start
Thread Starter
Teching In
Joined: Oct 2019
Posts: 17
Likes: 2
From: Ct
crank no start posted this before in a different section and didn't get a lot of responses so here goes nothing:
*CAR USED TO RUN - car started and ran without issue until I moved it from one house to another, drove on the trailer and drove off, has not wanted to start since*
Engine – 5.3l v8 gen 3-cam,pistons,intake,headers,11:1 compression
Trans – t56
Car – 97 bmw 3 series
Ecm – 411
Cable throttle, truck harness unpinned for unneeded stuff ie: no egr, no rear o2, no auto trans stuff
Issue – crank no start – no rpm signal – crankshaft sensor not getting 12v reference
Diagnostics done so far - fuel pressure is 58psi and pump primes > no pulse from fuel injectors>reference power is good to all 8 injectors>trouble codes - code for throttle position, egr(not there, wideband signal wired through here) > no rpm signal - not on dash, not in tech 2, not in hptuners > continuity from pcm to crank sensor is good>replaced crank sensor> not getting reference power out of pcm to crank sensor> verified all power and ground into pcm is good > disconnect reference wire pin 2 at ecm and manually apply 12v to crank sensor and car will start/run/drive
Basic checks – per my wiring diagrams:
Blue 20 and 57 B+ hot at all times – confirmed
Blue 19 and 75 B+ ignition run/start – confirmed
Blue 1 and 40 ground – confirmed
Red 1 and 40 ground – confirmed
All 3 wires to crankshaft sensor ohm out fine
new crank sensor
I do not get 12v at blue pin 2 in run or start (crank sensor 12v reference)
I’ve double and triple checks these readings with an assistant to turn to crank to verify I’m not dropping voltage while cranking.
If I disconnect blue pin 2 at the pcm (still connected to crank sensor) and manually apply 12v to it the car will start and run.
Tune was write entire after Vats disable – since the car will sit and idle with the above test I think that shows proof that vats is not enabled.
Tried another pcm – no change
I used a snapon multimeter to perform the electrical checks, I was a tech for 10 years I know my way around electrical issues but I’m at a loss here. I feel like I may be overlooking something or could be an issue in programming.
I tried to include as much info as possible, thanks for any insight into this , hopefully something stupid that Im just over looking
*CAR USED TO RUN - car started and ran without issue until I moved it from one house to another, drove on the trailer and drove off, has not wanted to start since*
Engine – 5.3l v8 gen 3-cam,pistons,intake,headers,11:1 compression
Trans – t56
Car – 97 bmw 3 series
Ecm – 411
Cable throttle, truck harness unpinned for unneeded stuff ie: no egr, no rear o2, no auto trans stuff
Issue – crank no start – no rpm signal – crankshaft sensor not getting 12v reference
Diagnostics done so far - fuel pressure is 58psi and pump primes > no pulse from fuel injectors>reference power is good to all 8 injectors>trouble codes - code for throttle position, egr(not there, wideband signal wired through here) > no rpm signal - not on dash, not in tech 2, not in hptuners > continuity from pcm to crank sensor is good>replaced crank sensor> not getting reference power out of pcm to crank sensor> verified all power and ground into pcm is good > disconnect reference wire pin 2 at ecm and manually apply 12v to crank sensor and car will start/run/drive
Basic checks – per my wiring diagrams:
Blue 20 and 57 B+ hot at all times – confirmed
Blue 19 and 75 B+ ignition run/start – confirmed
Blue 1 and 40 ground – confirmed
Red 1 and 40 ground – confirmed
All 3 wires to crankshaft sensor ohm out fine
new crank sensor
I do not get 12v at blue pin 2 in run or start (crank sensor 12v reference)
I’ve double and triple checks these readings with an assistant to turn to crank to verify I’m not dropping voltage while cranking.
If I disconnect blue pin 2 at the pcm (still connected to crank sensor) and manually apply 12v to it the car will start and run.
Tune was write entire after Vats disable – since the car will sit and idle with the above test I think that shows proof that vats is not enabled.
Tried another pcm – no change
I used a snapon multimeter to perform the electrical checks, I was a tech for 10 years I know my way around electrical issues but I’m at a loss here. I feel like I may be overlooking something or could be an issue in programming.
I tried to include as much info as possible, thanks for any insight into this , hopefully something stupid that Im just over looking
