HT4100 4.1, 4.5, 4.9 Discussion, 93 Seville 4.9 rough idle, slow response, P041 code in Cadillac Engine Technical Discussion; Hey guys,
I just wanted to pick some brains. I've been working on my brothers 93 Seville with the 4.9. ...
I just wanted to pick some brains. I've been working on my brothers 93 Seville with the 4.9. We have been getting a P041 code which is "No cam reference signal from Ignition Control Module" and it has been on most of the time. It has shut off on its own, and when it does the idle smooths right out and it runs beautifully. Then it goes right back into the same problem. Sometimes it will go into violent surges and even stall out.
We took a look under cap and rotor and found that the "hall effect switch" was a bit loose, and the wires were just all over the place and in a few places worn right through the insulation. I went through and checked continuity and fixed all worn areas. Still same problem.
We have replaced cap, rotor, plugs, wires, cleaned throttle body, replaced air and fuel filter. Still no success. Ignition module was replaced not too long ago as well as "hall effect switch" within last year. Also all the plastic ends on all the wires inside the distributor have completely disintegrated and thus the problem of wires going anywhere the wanted. I also found a piece of metal inside dist. cup that seems to be the same size as the one I believe trips the hall effect switch to send cam position to pcm.
Any suggestions would be greatly appreciated.