lt1 throwing codes and runs bad [Archive]

zlow6869

05-20-2013, 09:26 AM

over the winter I changed out the opti -rich porter brand, new water pump, timing chain, plugs wires and so on.Wen I bought the car I kept getting codes 36-42-43 so I changed all of the parts listed above and now im showing codes 16and 43 my battery went bad earlier this week so that may be causing code 16 but for code 43 knock sensor circuit im lost any ideas?

Injuneer

05-21-2013, 04:31 PM

DTC 16 is for the low reolution pulse signal from the cam position sensor in the Opti. I don't see that as tied to the bad battery. Clear the codes and see how fast that one comes back. If the engine is running, it's a stored code. If it's active, the PCM shuts down the fuel system - engine stops. It isn't unusual to see it pop up once in a while. I think sometimes the PCM sets it on the first couple cranks of the starter when it can't find the signal. Clear it, see how fast it comes back. Anything other than a GM or MSD Opti is risky - anything else seems to run the risk of a high failure rate.

DTC 43 is telling you the voltage is wrong on the knock sensor. First, make sure the single wire is connected to the pin on the knock sensor. If it's there, pull it off and measure the resistance between the single pin on the knock sensor and the block. Should be close to 4,500 ohms. Then with the harness connector still off, measure the voltage between the single pin in the harness connector and the block. Should be 5V. Put the connector on the knock sensor. Measure the voltage between the single pin and the block. Should be in the range of 1.5 - 3.5V. If any of those aren't met, it will set the code. This code hurts, because when it sets, the PCM starts calculating an amount of knock retard based on engine operating conditions, so you'll pulling anywhere from 1 - 15-deg of timing all the time.

DTC 42 is the most difficult code to solve. The best thing to do is get the logic tree from the shop manual for sorting through the problem step by step.