0411 PCM swap on 99 tahoe no start. Ideas?
02-09-2014, 07:40 PM
#1
0411 PCM swap on 99 tahoe no start. Ideas? I have a 99 tahoe 4WD that I had several mods on and wanted to add efans (Mark VIII) so I decided to do the 0411 swap, per this article:
http://www.gmtruckcentral.com/articles/12200411.html
I obtained the swap excel spreadsheet from the guy who has led the way on this swap, and I was very careful to move one pin at a time to my new 0411 PCM, but it doesn't start. I have double checked all the wires and pin locations. I have tried two PCMs (one from the recognized expert on the swap) such that I don't think I have a PCM problem. Yet when I tried to start it it cranks for ever; scan tool shows no RPM, and I get the Po335 DTC. Scan tool also shows it in 3rd gear for some reason (as part of the swap I did splice into the trans signal in the gauge cluster per the article link above, but I verified continuity for each of those wires).
I did a test of the CKP sensor per this article with my DMM and the output went from 0V to 5V as I rotated the crankshaft. So if this technique is correct, my sensor works, as well as the ground and the power to the sensor:
http://troubleshootmyvehicle.com/gm/...crank-sensor-2
So to check spark, I took an old spark plug, I pulled one boot and rested it on the metal bolt of the AC compressor while cranking and I am not getting a spark.
So my question is if the crankshaft position sensor is both receiving ground & power correctly, and sending the correct signal back to the PCM, what in the 0411 logic would prevent it from starting? I'm pretty sure there is only one small problem, but I need to find the needle in the haystack.
So thoughts on my next steps?
http://www.gmtruckcentral.com/articles/12200411.html
I obtained the swap excel spreadsheet from the guy who has led the way on this swap, and I was very careful to move one pin at a time to my new 0411 PCM, but it doesn't start. I have double checked all the wires and pin locations. I have tried two PCMs (one from the recognized expert on the swap) such that I don't think I have a PCM problem. Yet when I tried to start it it cranks for ever; scan tool shows no RPM, and I get the Po335 DTC. Scan tool also shows it in 3rd gear for some reason (as part of the swap I did splice into the trans signal in the gauge cluster per the article link above, but I verified continuity for each of those wires).
I did a test of the CKP sensor per this article with my DMM and the output went from 0V to 5V as I rotated the crankshaft. So if this technique is correct, my sensor works, as well as the ground and the power to the sensor:
http://troubleshootmyvehicle.com/gm/...crank-sensor-2
So to check spark, I took an old spark plug, I pulled one boot and rested it on the metal bolt of the AC compressor while cranking and I am not getting a spark.
So my question is if the crankshaft position sensor is both receiving ground & power correctly, and sending the correct signal back to the PCM, what in the 0411 logic would prevent it from starting? I'm pretty sure there is only one small problem, but I need to find the needle in the haystack.
So thoughts on my next steps?
