C5 z06 wont start!
07-31-2018, 08:38 PM
#1
C5 z06 wont start!
I have a EB 2002 C5 Z06 that will not start. It will turn over. Battery has a full charge and was bought new 6 months ago. The car has 32,000 miles on it.
With the ignition on the cooling fan relay 42 is buzzing. I replaced it with a new one and still buzzing.
No fuel pressure. It does not seem to be getting power to the fuel pump from what I have tested (I was able to test it within the 2 second window) but it does have continuity from the under hood relay. The fuses are ok.
I checked for spark by inserting a wire into the boot. The wire was sparking with just the ignition on!
Any help or direction would be greatly appreciated.
Thank you.
With the ignition on the cooling fan relay 42 is buzzing. I replaced it with a new one and still buzzing.
No fuel pressure. It does not seem to be getting power to the fuel pump from what I have tested (I was able to test it within the 2 second window) but it does have continuity from the under hood relay. The fuses are ok.
I checked for spark by inserting a wire into the boot. The wire was sparking with just the ignition on!
Any help or direction would be greatly appreciated.
Thank you.
08-01-2018, 09:30 AM
#2
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Hello my friend !!...so we have a cranking no start ??...I'm ASSUMING you have spark while cranking but humor me and let's do the next step...how did you verify that the pump was not getting power??...what test was performed ??...the FIRST thing I'd do is spray a good shot of Brake Kleen into the brake booster hose and reconnect it and see if the car at least tries to start or runs for a few seconds...if so we have a fuel delivery issue...we have some direction...so do you have a test light and and are confident in its use ??...I'd check the F/P relay control and feed side...I'm not sure if you looked at that ???
Last edited by C5 Diag; 08-01-2018 at 09:57 AM.
08-01-2018, 10:02 AM
#3
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08-01-2018, 11:47 AM
#4
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CI 6,7,8,9,11 Vet
St. Jude Donor '08
Time to break out a Multimeter and take some voltage measurements. Start at the fuel pump FUSES. There are two test points on top of each fuse. Measure those test points to a good chassis ground and see if you really have voltage at that fuse. All of the fuses that are supplied by the IGNITION SWITCH are suspect. The ignition switch can and will fail to output proper voltage due to wear and tear.
Eliminate that as a suspect. Its easy.
Check Fuses: Under Hood Fuse Box, Mini Fuse #13 (20 amp) fuse test points to ground when the ignition switch is ON. Should be full battery voltage with key ON.
Bill
Eliminate that as a suspect. Its easy.
Check Fuses: Under Hood Fuse Box, Mini Fuse #13 (20 amp) fuse test points to ground when the ignition switch is ON. Should be full battery voltage with key ON.
Bill
08-03-2018, 02:23 PM
#6
Hello my friend !!...so we have a cranking no start ??...I'm ASSUMING you have spark while cranking but humor me and let's do the next step...how did you verify that the pump was not getting power??...what test was performed ??...the FIRST thing I'd do is spray a good shot of Brake Kleen into the brake booster hose and reconnect it and see if the car at least tries to start or runs for a few seconds...if so we have a fuel delivery issue...we have some direction...so do you have a test light and and are confident in its use ??...I'd check the F/P relay control and feed side...I'm not sure if you looked at that ???
Yes we are cranking but not starting. Strange thing is spark is with key in and turned to the ignition Before cranking! Strange. Didn’t test if it was sparking while cranking. I saw the sparks with the ignition and stopped.
I checked thr 4 prong connector at the fuel pump to see if it was getting power. It was not getting power. And I was able to test it quickly as I know it will time out.
I have not sprayed anything to see if that will get it going.
And yea the fuel relay feed side is not getting or sending power.
08-03-2018, 02:25 PM
#7
Time to break out a Multimeter and take some voltage measurements. Start at the fuel pump FUSES. There are two test points on top of each fuse. Measure those test points to a good chassis ground and see if you really have voltage at that fuse. All of the fuses that are supplied by the IGNITION SWITCH are suspect. The ignition switch can and will fail to output proper voltage due to wear and tear.
Eliminate that as a suspect. Its easy.
Check Fuses: Under Hood Fuse Box, Mini Fuse #13 (20 amp) fuse test points to ground when the ignition switch is ON. Should be full battery voltage with key ON.
Bill
Eliminate that as a suspect. Its easy.
Check Fuses: Under Hood Fuse Box, Mini Fuse #13 (20 amp) fuse test points to ground when the ignition switch is ON. Should be full battery voltage with key ON.
Bill
08-03-2018, 02:29 PM
#8
Still seems Ems strange that I have spark coming with only the ignition on not while cranking (didn’t test while cranking stopped when sparks came with ignition) any ideas why the cooling relay would be buzzing? Battery is new and has a full charge.
08-03-2018, 03:41 PM
#9
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Hello !!
First thing is that you said... "And yea the fuel relay feed side is not getting or sending power"....the relay has a "control" and a "load" side feed...which one ??...to jump the relay to power the F/P directly its pin 30 to 87.....DO NOT...and I repeat DO NOT DO NOT DO NOT...jump the wrong pins (85 to 86) or you will FRY your PCM !!...the control side of the F/P relay is "power side switched" from the PCM so if you touch those 2 wires by mistake you will basically short that wire directly from the PCM to ground. Now about the ignition can you take a video of what your doing ??...so you are removing the spark plug wire and sticking a wire inside the plug wire and grounding it ??...and the coil is firing with the key on ??...NEVER seen that before...has anyone else here ??...the only way that plug could possibly fire is if the feed wire to the primary side of the coil has a constant 12 volts going to it ( shorted to a hot wire) with the key on....get a multi meter out !!...and it's doing that on all plug wires ??....each of the 2 banks has a separate feed and I believe it's also a feed for the injectors too... a video would be great to see !!...and the relay buzzing happens if the relay is receiving to much or not enough voltage but right now that's the least of your worries !!
First thing is that you said... "And yea the fuel relay feed side is not getting or sending power"....the relay has a "control" and a "load" side feed...which one ??...to jump the relay to power the F/P directly its pin 30 to 87.....DO NOT...and I repeat DO NOT DO NOT DO NOT...jump the wrong pins (85 to 86) or you will FRY your PCM !!...the control side of the F/P relay is "power side switched" from the PCM so if you touch those 2 wires by mistake you will basically short that wire directly from the PCM to ground. Now about the ignition can you take a video of what your doing ??...so you are removing the spark plug wire and sticking a wire inside the plug wire and grounding it ??...and the coil is firing with the key on ??...NEVER seen that before...has anyone else here ??...the only way that plug could possibly fire is if the feed wire to the primary side of the coil has a constant 12 volts going to it ( shorted to a hot wire) with the key on....get a multi meter out !!...and it's doing that on all plug wires ??....each of the 2 banks has a separate feed and I believe it's also a feed for the injectors too... a video would be great to see !!...and the relay buzzing happens if the relay is receiving to much or not enough voltage but right now that's the least of your worries !!
Last edited by C5 Diag; 08-03-2018 at 04:29 PM.
08-03-2018, 05:38 PM
#10
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I'm looking through the power distribution wiring for your '02 and seeing if that cooling fan relay and the power feed for the coils are tied in somewhere...we might have a relay stuck somewhere...as Arnold said...I'll be back !!
08-03-2018, 05:55 PM
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08-03-2018, 06:04 PM
#12
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If you meant Ignition relay 42 was buzzing and the load side of the relay were stuck closed it would power the Injector 1 (fuse 22 )...how about pulling that relay and see if the coil stops firing....the only thing is that that relay is hot all the time...I understood you said the coil was firing with KOEO !!
Last edited by C5 Diag; 08-03-2018 at 06:05 PM.
08-03-2018, 06:05 PM
#13
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CI 6,7,8,9,11 Vet
St. Jude Donor '08
My guess is that you have a bad ignition switch! If its fan relay 43 or 44 that is buzzing, the ignition switch is powering the coils on those relays as well as the fuel pump. READ the fuse test points on top of the fuse to ground to see if you have FULL BATTERY VOLTAGE on those test points.
BC
BC
Last edited by Bill Curlee; 08-03-2018 at 06:07 PM.
08-03-2018, 06:59 PM
#14
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CI 6,7,8,9,11 Vet
St. Jude Donor '08
Find your COOLFAN #3 fuse. In my schematic its Fuse # 14. Read the test points on top of that fuse with the ignition switch ON to ground. You should see FULL BATTERY VOLTAGE at that fuse. Compare that reading with a volt meter reading directly at the battery terminals. Should be the same voltage.
08-03-2018, 08:16 PM
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I'm SOOO DOPID...IT'S been a LONG week !!...the ignition coil / module needs a "control" signal from the PCM to fire the plugs from signals received from the CKP/CMP sensors...you'll have voltage "standing by " at the PINK wires with the IGN relay closed in ON or START... I don't know which coil is firing in your case but I would check for voltage at the "control" feed wire at the coil...(and I'm not 100% sure of that coil /module "internals) ..."they are purple (1&8) light blue (3&6) , dark green (4&5) and red (2&7)...with ignition switch ON those feed wires shouldn't be powered...if they are things could get interesting...maybe one of those PINK wires is shorted to the control wire...but this doesn't address why the F/P isn't being powered we're assuming !!...TEST DON'T GUESS !!
Last edited by C5 Diag; 08-03-2018 at 08:38 PM.
08-04-2018, 01:06 AM
#16
Find your COOLFAN #3 fuse. In my schematic its Fuse # 14. Read the test points on top of that fuse with the ignition switch ON to ground. You should see FULL BATTERY VOLTAGE at that fuse. Compare that reading with a volt meter reading directly at the battery terminals. Should be the same voltage.
08-04-2018, 03:30 AM
#17
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Sir, you state that the fuel pump fuses are OK...are you referencing Fuse 13 (F/PMP) which feeds pin 87 of the Fuel Pump Relay (35) ????? ...if fuse 14 is no good as you stated fuse 13 should not be powered either !!
08-04-2018, 02:06 PM
#18
I have not had a chance to test fuse 13 with the ignition on. I tested the fuse (13) by itself and it was ok. The fuse has not been blown. 14 is the only one I was able to test so far with the ignition on and there was no power to it.
08-04-2018, 02:10 PM
#19
My guess is that you have a bad ignition switch! If its fan relay 43 or 44 that is buzzing, the ignition switch is powering the coils on those relays as well as the fuel pump. READ the fuse test points on top of the fuse to ground to see if you have FULL BATTERY VOLTAGE on those test points.
BC
BC
08-05-2018, 06:20 AM
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Last edited by C5 Diag; 08-05-2018 at 06:22 AM.