No Start...No Spark???

[GN84Turbo]

My car died on the freeway last night. I was accelerating and all of a sudden the rpms would not climb anymore. the Oil light came on, and then the SES light. The gas pedal does nothing in any gear. So i turn off the car, and try to restart it. Nothing, just the motor tunring over, no start. The electrical turbo guage fluctuates a tiny bit. So I roll off the freeway and have it towed home.

The Turbolink came up with code 41, cam sensor failure. I replaced the cam sensor. Still no start. So i replaced the crank sensor. Still no start. I pulled a spark plug off the # 5 plug and looked to see if there was spark when i cranked the motor over. No spark from the wire.

I checked all the vacuum lines, all good.

Bad module? Bad coil pack? Any ideas would be great, cuz now im without a car!

Someone said that it could be the oil pressure switch..??

 

[Buick From Hell]

Terry, it's possible that it could be the oil pressure switch because without pressure it shuts down the fuel pump. However, I believe that the ECM overrides the oil pressure switch during startup for a short period of time (someone help me here!)...if that's the case, then it should still start IF the shutdown was caused by the oil pressure switch. BTW, the oil light came on BEFORE the SES light? This could be important, cuz the oil light should NEVER come on before the SES light!

Have you checked fuel pressure? Can you hear the pump running when you turn on the key? I know that has nothing to do with no spark, but if the cam sensor went bad while driving, the engine would still run.

Have you checked voltages to/from the cam/crank sensors?

 

[GN84Turbo]

Yes, the fuel pump primes and pressure is high when i turn the key to the on position. I have a caspers fuel pump hotwire. No spark though. Would a bad oil pressure switch cause it to not spark...?

 

[Buick From Hell]

Nope, the oil switch has nothing to do with spark.

EVERYTHING to do directly with spark is:
ECM, ignition module, coilpak, cam and crank sensors.

Since the SES light came on, rule out the ECM fuse and/or the orange battery-to-ECM feed wire...

There's a circuit on these cars, circuit #439, I call it the "pink wire" circuit. (the wiring is actually pink&black) This circuit feeds power to: the ECM, ignition module, canister purge solenoid, wastegate solenoid, EGR solenoid, and the spark control module. Locate it on the above items (especially the ignition module) and check to see if it has 12 volt power with the key on. A short anywhere in this circuit will more than likely cause a no-spark condition! (I had a shorted spark control module give me fits for years)

 

[IRaceAV6]

Ok... If the fuel pressure switch goes bad I assume...

No fuel pressure.... correct?

So... if you have a hot-wired fuel pump then a failed oil pressure switch is irrelevant? I'm trying to diagnose a situation on my car too

"circuit #439, the "pink wire" circuit. (actually pink&black) This circuit feeds power to: the ECM, ignition module, canister purge solenoid, wastegate solenoid, EGR solenoid, and the spark control module"

If you have a known good ignition module, crank sensor, and ECM flashed the promising code "12, 12" 12" we can assume it's something else causing the no start situation? (Spark control module? or would failure of wastegate solenoid /egr solenoid/*canister purge cause a break in the circuit somewhere?)

*I can rule out cannister purge since I didn't have mine connected for over a year.

We really need a "no-start" quick diagnosis chart for these cars with parts numbers for parts replacement. It can be hosted on the "Hot-Air" website for quick access by everyone. Any post will not be retained longer than 60 days on this site - correct? (website may potentially crash - worse case - NOT A FLAME so don't verbally skewwer me)

(A quick note to Terry... my car did the same thing as yours! That's why I'm so interested in the diagnosis of your effort. I'm sure it's the same thing affecting mine. In my case I had a charging problem associated with it - ran a brand new battery to dead status on last outing - Free towing is a great option on car insurance guys! A cell phone is a nice option too)

If it's the Spark Control Module how is that tested? Part #?

 

[Buick From Hell]

hey Terry & Louie,

the key word in the pink wire circuit is "short"...if one of the hot pink & black leads were shorted out in any way, such as melted to a header or accidently pinched and grounded somewhere. However, a direct short SHOULD blow the ECM fuse.

My spark control module problem caused intermittent shutdowns. To this day, I still don't know exactly why the ESC module didn't blow the ECM fuse? I just know that changing the module solved my problem, and the ONLY common connection it has to shutting down the engine is the pink wire circuit! Also, I was getting erroneous trouble codes for the wastegate & EGR solenoids, and the fuel canister would purge while trying to start the car! (That little problem blew the muffler to pieces!)

I'm getting way beyond you guy's possible problem, so first things first: check the cam & crank sensors for proper voltages!

Easiest way to see if the spark control module is to blame, is simply disconnect it! JUST REMEMBER, you'll have NO KNOCK RETARD if you drive the car!

<edit> The MAF sensor is in the pink wire circuit also!
I'm trying to find some info to scan...

 

[Buick From Hell]

Ok, hope this will help you guys! Below are links to repair manual pics to reference from:

ECM Plug
Sensor Plug

You'll need to get at the ECM and the cam & crank sensors to do some voltage tests. If you have a NEEDLE type voltmeter, it may work better for these tests, as it will visibly "swing" when the sensor switches open & close (IF they're working okay!)

Here goes:

First, test your meter and ground! (see ECM Plug) Check connection A-6, "ign, ECM fuse" for 12 volts. (for ALL tests, BE SURE the negative lead of the voltmeter is connected to a GOOD GROUND!)

#1- (see ECM Plug) With the key off, disconnect the ECM A-B connector. With the positive lead of the voltmeter, probe the B-5 connection (highlighted yellow, this is the crank sensor signal) Crank the engine and watch the meter...you should have varying voltage from 1 to 7 volts.
If NOT okay, proceed to #2.
If you ARE seeing correct voltage, your cam & crank sensors are okay, and your coil and/or ignition module may be the problem! You need to loosen the coilpack, and check the BLUE wire for 12 volts, key on. If it DOES have 12 volts, then the problem is likely the ignition module.

#2- now probe the A-11 connection... (highlighted green, this is the cam sensor signal). Crank the engine...you should have varying voltage from 1 to 9 volts.
If it IS okay, THE CAM SENSOR IS FINE, AND YOU ONLY NEED TO TEST THE CRANK SENSOR IN ALL FURTHER TESTS!
If it's NOT okay, there's no cam sensor signal!

Plug the ECM connector back in, and head for the sensors!

#3 (see "Sensor Plug") Unplug the cam sensor plug. Turn the key "ON" ...On the MODULE SIDE of the plug, probe the "A" wire for voltage, after which probe the "B" wire for voltage. You should have between 5 and 11 volts on BOTH wires.
If you ARE seeing correct voltage, THEN: with the negative lead of the voltmeter, probe the "C" wire, and with the positive lead probe the "A" wire. You should have between 5 and 11 volts. Note the results, then REPEAT THIS TEST WITH THE CRANK SENSOR PLUG!

If ANY of the sensor plug tests FAILED, you have a probably ignition module problem...
If ALL the sensor plug tests PASSED, then PLUG IN the sensor plugs, and proceed:

#4. Test the cam sensor: Probe the "B" wire of the cam sensor, then crank the engine and watch the meter. You SHOULD have varying voltage between 1/2 and 9 volts. REPEAT THIS TEST WITH THE CRANK SENSOR!

If either sensor fails this test, then it's possible that sensor is bad! If they PASS this test, it's likely the ignition module, or the connections TO the ignition module are bad)

Hope this makes sense! If not, I'll try to help!