2003 grand am ,start/passlock problem?

[daved2010]

2003 grand am 3.4 140km ,wont start rolls strong wont engage,towed home ,did the 25 mn reset ,started up let idle in park for 15mn .tried to rev up,stumbled wants to stall no power.checked dtc po101 mass volume air flow[circuit range performance] cleared code .shut car off .previously stumbled,lost power at stop sign about 1 week ago and 3months ago.also had security light no start issue twice in past yearso i thought i would clip yellow data wire/ install switch bared black and yellow wire prior to cuttingi thought i would get resistance values with key in on position must have gone into tamperproof mode or something else cause now i turn ign sw to on position dash lights up but starter wont engage,no sound anywhere.probably shold have cut wire first then diagnosed other problems,[fuel pump intermittent?filter ] hope i didnt damage anything bcm/ etc ... any way to reset system so car will start

[thephantom1492]

Originally Posted by daved2010

2003 grand am 3.4 140km ,wont start rolls strong wont engage,towed home ,did the 25 mn reset ,started up let idle in park for 15mn .tried to rev up,stumbled wants to stall no power.checked dtc po101 mass volume air flow[circuit range performance] cleared code .shut car off .previously stumbled,lost power at stop sign about 1 week ago and 3months ago.also had security light no start issue twice in past yearso i thought i would clip yellow data wire/ install switch bared black and yellow wire prior to cuttingi thought i would get resistance values with key in on position must have gone into tamperproof mode or something else cause now i turn ign sw to on position dash lights up but starter wont engage,no sound anywhere.probably shold have cut wire first then diagnosed other problems,[fuel pump intermittent?filter ] hope i didnt damage anything bcm/ etc ... any way to reset system so car will start

I can not claim to be an expert, I am not.
But the starter is connected to absolutelly no electronics, unless you have some third party alarm or alike.

Check your fuses and your battery charge state, maybe you drained it so much that there is simply not enought power left to crank...

The starter solenoid is fused somewhere, my guess is the ignition fuse. Might have a dedicated fuse for it too, but I'm not sure...

You said you cut the yellow and black wire, was the wire as big as the red wire? Or was it small? The yellow and black wire should be with a white wire too, all of the same size.

If you cut the big yellow wire, you cut the starter wire!


The normal path for the starter is like this: battery -> fuse -> ignition key (big yellow wire) -> transmission safety switch (as in "don't start while engaged") -> solenoid (coil side) and battery -> solenoid (switch side) -> starter

The passlock2 will not prevent you from cranking, it shut off the fuel injectors, so you would just crank... and crank... and crank... until you get bored or the battery get drained.

As for the passlock bypass, I suggest to use a resistor (anything from 470 to 10k) instead of a switch, solder it! This way the security light will stay off, and no issue if you disconnect the battery (or drain it completly)

[daved2010]

2003 gr am, [3]20 ga wires bl,y,&wh didnt cut wires just bared enough for probe.key on dvom set to ohms?mla?does it have to be in start pos to read r values.would wrong dvom setting cause bcm to enter tamperproof mode& shut off power to starter.battey close to fully charged ,disconnected battery &charged for rest of day reconnected.starter engages rolls over wont start.same as original symptoms..key on didnt hear fuel pump whirr tapped gas tank with mallet ,checked fuel rail shraeder valve just afew dribbles.did 15mn reset still wont start.could it still be in security mode?would a system relearn help 3/15mn clycles.checked prices for fuel pump cant purchase seperately sending unit asm $245to $399,mass air flow $285,passlock ign 295,bcm 360,fuel filter80?/20? fuel pump relay 20 /30? expensive guesses so i would like a good idea of problem before i start throwing money at it,have to tow to get it scanned,will scanner reset system or dealer only.any way to isolate problem ..[key on i get oil,battery,security, ses, sbelt,lights on in dash ,no dtc,s ]

[thephantom1492]

Originally Posted by daved2010

2003 gr am, [3]20 ga wires bl,y,&wh didnt cut wires just bared enough for probe.key on dvom set to ohms?mla?does it have to be in start pos to read r values.would wrong dvom setting cause bcm to enter tamperproof mode& shut off power to starter.battey close to fully charged ,disconnected battery &charged for rest of day reconnected.starter engages rolls over wont start.same as original symptoms..key on didnt hear fuel pump whirr tapped gas tank with mallet ,checked fuel rail shraeder valve just afew dribbles.did 15mn reset still wont start.could it still be in security mode?would a system relearn help 3/15mn clycles.checked prices for fuel pump cant purchase seperately sending unit asm $245to $399,mass air flow $285,passlock ign 295,bcm 360,fuel filter80?/20? fuel pump relay 20 /30? expensive guesses so i would like a good idea of problem before i start throwing money at it,have to tow to get it scanned,will scanner reset system or dealer only.any way to isolate problem ..[key on i get oil,battery,security, ses, sbelt,lights on in dash ,no dtc,s ]

Connecting an ohmsmeter on the passlock wire WILL cause the bcm to fall in tamper mode ! Technically it could even kill it, but that I hightly doubt it.
Ohmsmeter send a voltage on the probes.

Are your security light blinking? if so it IS in tamper. Do a relearn procedure (put key in, turn to run, wait 10 minutes until security stop blinking, turn to off, wait a few seconds, start the car)... However, if you have other problem preventing the car from starting... I don't know if the relearn procedure will complete. (as does the procedure end after the 10 minutes? or after a successfull start?)

So, To be clear, you put your key in, turn to run, the security light flash?
turn to start, the starter turn, the engine crank, but no start?

[daved2010]

key in run pos. security&other 3 lights solid[bat,oil,ses.],turn to start just rolls over.trying 15 mn reset now.is there a proper way to test & determine resistor value so i can solder it inline and eliminate security shutdowns.if i pick up various resistors trail &error it would be atleast 15 combinations and wait times for system reset

[thephantom1492]

Originally Posted by daved2010

key in run pos. security&other 3 lights solid[bat,oil,ses.],turn to start just rolls over.trying 15 mn reset now.is there a proper way to test & determine resistor value so i can solder it inline and eliminate security shutdowns.if i pick up various resistors trail &error it would be atleast 15 combinations and wait times for system reset

The resistor bypass can be anything between 470 and 10k. You will have to do a relearn procedure.

If the security light is not blinking, then your car is NOT in lockdown.

Check your fuses, all of them, you might have a fuse that is burned out...

But chance is that you have a problem with one of the sensors, so have your car code scanned.

[daved2010]

1-checked all fuses/relays in engine area bec/fusebox all good, pulled out each one and checked for continuity, corrosion /reinserted........... 2-checked for dtc"s with code reader nothing appears. So i thought because i dont hear any activity from fuel pump and at 140km its probably close to fuel pump replacement anyway.so i changed pump and filter. No change at all.Doesnt seem to have power at pump ,though without schematics im not sure of values at pump/harness plugs they say the pump operates at reduced voltage to prolong their lifespan. .........Would a temporary jumper line from fuel pump relay to fuel pump fill the gas lines and allow engine to start ,just to see if im headed in right direction or if for some reason its in lockdown would injectors work.Then again you said security light has to flash to indicate security issue.Im also reluctant to try this or anything that might magnify my problem or create additional expenses............... Any further advice or info is greatly appreciated.

[skeeter123]

If you don't hear the fuel pump run for a second or two when turning key-on, that's your first problem. Forget about security/other things until you get a fuel pressure gauge to show at least 47psi fuel pressure.
How did you check the fuel pump relay? try swapping it with one of the other relays (same p/n) and see if you hear the pump run.
I recently got a fuel pressure gauge at HarborFreight for $12; or some of the autozone's will loan you one (or sell it to you and buy it back when you return it) Make sure it will work with a "schrader valve"
Hope this helps.

[daved2010]

swapped relays as well ,prior to fuel pump change...originally i thought i would just check for power at gas tank /fuel pump harness as starting point...guages work but pump doesnt activate....was also going to do pump pressure test prior to current start problems because of a couple of lost power while driving episodes, but now i have this situation

[thephantom1492]

you have 4 pins of interrest at the fuel pump relay
the 2 coils pins
the 2 contact pins

check if you get any power on the coils pins.
You might get power only for 1-2 seconds when you turn the key.
If you get no power there, it mean the relay can't turn on due to... not having power to turn it on.

The contact pins, shorting them should make the fuel pump run all the time when the ignition key is on. Normally, you should mesure ground on one side and 12V on the other side.

I forgot if there is a pressure switch that turn off the pump...
I already bypassed the relay on my bro's geo metro 93 minutes before he trashed it... His tank was almost full, disconnected the gas line going to the injector put in a tank, key to on... normally I got gas for 1-2 second then it stopped, shorting the pins allowed me to drain the full tank... you would be surprised to see how fast it flow

So to sum it up, check for 12V at the coil side, check for 12V at the contact side, if any is missing then trace where the problem is.