: Codes 340 and 1016 + Fixed A.I.R. with new coil cartridge?

07-08-09, 09:16 AM
Two items on a '01 DTS with 80,000 miles.

About 6 months ago the code for a bad A.I.R. pump was displayed, 410. Had not gotten around to it when the engine started missing due to a bad coil cartridge on bank #2. After replacing the cartridge I cleared the codes and was puzzled when the 410 did not reappear. I concluded the ECU may have interpreted an intermittent miss from a failing coil as a bad secondary air pump and left it at that. Thoughts?

Secondly, while on a trip last week The check engine light illuminated again and I thought for sure it was 410 again. Nope. It was the following two codes.

P0340 - Camshaft Position (CMP) Sensor Circuit
U1016 - Loss of Communications with PCM

I cleared them and 340 reappeared the next day. I cleared it again and it has not come back since. That was a week ago.

The car runs fine but I wanted to check with the community to see if I may just have a loose connection somewhere with the PCM or if there is something else going on perhaps like a failing cam sensor.

As always, thanks in advance.


07-08-09, 09:26 AM
The CaMshaft Position sensor (CMP) is not a usual failure suspect. Not saying it won't fail, just not common. It's down low on the drive belt face of the rear cam cover, held in by a 10mm bolt into a small flat retainer tab. The location is tight so replacement and connector removal call for magic words. Try cleaning the connector first - if that doesn't take care of the DTC, get a new sensor from www.rockauto.com (http://www.rockauto.com) or call Luke in Parts at Lindsay Cadillac over there >>>>>>> M-F, 9-5 EDT.

If the sensor fails it will default the ignition timing to a set, small advance figure in order to prevent engine damage. Performance and gas mileage will suffer.

07-08-09, 10:01 AM
P0340 - Camshaft Position (CMP) Sensor Circuit

I think "Circuit" usually means a wiring/connector issue. With it being intermittent, it may be hard to find the problem. I would pull the connector, clean with electrical connector cleaner, and make sure the connection was solid when I put it back together. If that doesnt work I would start checking wires.