No Start
- Thread starter dice64
- Start date
bmackinnon
Active Member
- Joined
- Feb 24, 2005
Code 12 is simply the ecm 'handshake' and verification that it is functioning correctly in self diagnostic mode. It is set when the key is on, the aldl is grounded, and no dist. pulses are sensed (ie. key on/engine off). If you had NO code 12, it would indicate a problem with the ecm. In your case, if you are getting nothing other than code 12, then whatever problem you are having has not set a code. Here's a reference for the codes..... and hang on, I'll get you the no-start diagnostic tree.....
Malfunction Codes Reference (courtesy of Turbo Regal Web Site)
Malfunction Codes Reference (courtesy of Turbo Regal Web Site)
MeanBuicks
Scaring the neighbors!
- Joined
- May 24, 2001
Code 12 is normal & doesn't indicate any problems. Check the CCCI fuse first along with the FP/INJ fuse. Then, be sure you have fuel pressure. If not, check pump, wiring, relays, etc.
Make sure the crankshaft sensor is tight and adjusted properly with about .025" clearance with the interrupter ring. If it's damaged or has been dragging, replace it.
Next, place test light terminals across the two terminals in any injector connector and see if it blinks. If not, you've got wiring, ECM or cam sensor issues. If so, good; continue on.
Check for spark on wires 1, 3, & 5. If you have spark on all, check for fuel wet plugs. If you don't have any spark, there may be a bad ignition module connection or bad module. If you have spark on just one or two of the wires, the coil pack is most likely toast.
To verify, remove the six coil pack screws and tilt it back. Connect a test light between the common blue wire and each control wire separately. If the light fails to blink on any one of the control wires, the module is probably bad.
Good luck with it. With a bit of persistence, you'll lick it.
Make sure the crankshaft sensor is tight and adjusted properly with about .025" clearance with the interrupter ring. If it's damaged or has been dragging, replace it.
Next, place test light terminals across the two terminals in any injector connector and see if it blinks. If not, you've got wiring, ECM or cam sensor issues. If so, good; continue on.
Check for spark on wires 1, 3, & 5. If you have spark on all, check for fuel wet plugs. If you don't have any spark, there may be a bad ignition module connection or bad module. If you have spark on just one or two of the wires, the coil pack is most likely toast.
To verify, remove the six coil pack screws and tilt it back. Connect a test light between the common blue wire and each control wire separately. If the light fails to blink on any one of the control wires, the module is probably bad.
Good luck with it. With a bit of persistence, you'll lick it.
bmackinnon
Active Member
- Joined
- Feb 24, 2005
No Start Diagnosis - Page 1
From the factory service manual. Methodically follow the steps of the 3 pages linked above to identify the no-start problem. Need to verify the simple stuff first. Fuel pump priming at key on? Fuel pressure at rail? Any blown fuses? Injector pulse? Spark?.... some tests may be obvious.... the link above will cover all the bases...
HTH
From the factory service manual. Methodically follow the steps of the 3 pages linked above to identify the no-start problem. Need to verify the simple stuff first. Fuel pump priming at key on? Fuel pressure at rail? Any blown fuses? Injector pulse? Spark?.... some tests may be obvious.... the link above will cover all the bases...
HTH
MeanBuicks
Scaring the neighbors!
- Joined
- May 24, 2001
Oh yeah...you reminded me that I've got that up on my own site.
Here's a link: Engine Cranks But Won't Run - '86/'87 3.8L Turbo That old page displays best in Internet Explorer.
MeanBuicks
Scaring the neighbors!
- Joined
- May 24, 2001
Don't count that old module out just yet until you do more diagnosis. I just went through this very thing on a buddy's GN this morning and he's still got his original module. Turns out the coil went bad and the CCCI fuse popped. Replaced the fuse and the car started but missed horribly. Replaced the coil pack and it's fine now.
