Need some help with this. I Don’t want to bypass the security system. My daughter has a 1999 Chevy express van with a 5.7l. About a month ago it died on her, no spark or fuel and could not communicate with the ecm. Since it was in warranty we sent it back and they said it was bad, that it got too much volts. Found the problem, it was a shorted wire on the #6 injector that was blowing the ecm 1 fuse. Fixed that, tried to do the relearn but would not work. Van would now start and die. I also have a P1626 code, theft deterrent fuel enable signal not received. Since the passlock module was also in warranty we sent it back and they said it was locked up and sent another one. I tried the relearn several times but would not work. It starts and dies, same code, P 1626. I disconnected the battery for 2 hours charged the battery,to drain it but still won’t work. When I crank it the security light blinks. I checked at the 3 wires at the ignition switch, I have 12v at white, ground at black, and 4.9v at yellow and when you turn the key on it drops to 1.9v just like it suppose to if the sensor is good. That is as far as I know to go. Again I do not want to bypass the security system. Thanks in advance for your help.

 

i recall reading somewhere on this chevy forum that any aftermarket modification or add on to the OEM security system can cause such a problem as you're now having . there might be a TSB on this issue . do you have the haynes and chilton manuals on yr van ?

if you and bypass the security system then clear the codes w your OBDII, does it start ?

 

@MitchM
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