ECM - 1 Fuse blowing

[Tony m.]

Hi, My 1999 Tahoe (5.7 ltr.) died without warning on the highway the other day. With no fuel available I initialy suspected the fuel pump. However I came across a blown ECM - 1 FUSE under the hood. I first suspected the ECM which I disconected and tried a new fuse which again blew. I then found a schematic which showed that the circuit feeds the ignition coil, ignition control module, and the crank. pos. sensor. I disconected the coil and ICM and tried the key again and the fuse blew. I then got under and disconected the CKT and turned on the key, the fuse held. I then pluged the CKT back in and the fuse did not blow (I don't know what cleared the short) So I pluged everything back in but the truck will only fire momentarily but not start. Any help would be greatly appreciated. Thanks in advance, Tony

[rhandwor]

Try unplugging separate items use a DVOM and touch one end on a ground and the other end on the wire. If the wire is touching the frame the meter should pick this up.

[ronaldk]

If you pulled crank sensor wires and no more short pull wires again look for wear through which probibly caused short and blowing fuse now looks like sensor cant give info to ecm so it won't run hope thats it should be easy fix. Good Luck let me know how you do.

[j cAT]

Originally Posted by Tony m.

Hi, My 1999 Tahoe (5.7 ltr.) died without warning on the highway the other day. With no fuel available I initialy suspected the fuel pump. However I came across a blown ECM - 1 FUSE under the hood. I first suspected the ECM which I disconected and tried a new fuse which again blew. I then found a schematic which showed that the circuit feeds the ignition coil, ignition control module, and the crank. pos. sensor. I disconected the coil and ICM and tried the key again and the fuse blew. I then got under and disconected the CKT and turned on the key, the fuse held. I then pluged the CKT back in and the fuse did not blow (I don't know what cleared the short) So I pluged everything back in but the truck will only fire momentarily but not start. Any help would be greatly appreciated. Thanks in advance, Tony

I would suspect that the ignition module is bad...