: P1376, P0340, I'm desperate...



Hooshee
06-09-10, 01:27 PM
Hi guys...

I have a 96 Eldorado TC (export version). I had an overhaul lately, because my Northstar ate a lots of oil, and it turned out one of my pistons were broken. Problem solved, engine assembed, everything seems to be O.K, unless there is a code, I can't get rid off. It is the P0340, Camshaft Position Sensor circuit. And sometimes I see P1376, which is ignition ground, but it's always history, and oes not come back right after start.

We tried to figure out with the diag charts of the shop manual, found nothing. Wires good, measured reistances and voltages are good, we tried to measure things with an oscilloscope, everything seems to be ok. The last step is to replace the PCM, but accourding to several sources, it's not as easy as it seems, because I should flash the eprom, which I cannot do here in Hungary without the proper tools. I have a friend with similar PCM, but it's a Deville, and the Vin Y version, so the EPROM is definitely not the same, and I can't take the risk to ruin his car also.

We replaced the Camshaft Position Sensor, we tried in another ICM, all the same (my ICM in another car is working perfectly without any codes set).

I'm really getting desparate with this thing, do anyone have an idea what to try, or what else can cause this? The engine runs perfectly of course, I just don't like the SES, and the service ignition messages...

Hooshee
06-09-10, 04:12 PM
New info, I was driving home, rolling down a slope, and suddenly the car stalled. P1599 was written, no any other codes. Is it possible, that the problem is not the Camshaft Sensor but the Crankshaft? It has no codes, but the devil never sleeps....

Submariner409
06-09-10, 04:54 PM
P1599 is fairly common in the post-2000 CKP failures because they occur most often during slow coastdown or stop: the engine acts exactly as if you had turned the key OFF - and it will restart immediately when the stick is placed in N or P.

I believe that both your CKP sensors are identical - look at www.rockauto.com or E-mail Luke in Parts at Lindsay Cadillac over there >>>> M-F EDT (GMT +4) 0900-1700.

Hooshee
06-09-10, 05:12 PM
O.K, I'll replace both, but can they cause the original problem, P0340? Because it's related to the Camshaft, but who knows... This whole sensor-ICM-PCM mess is black magic...

Forgot to mention, I live in Hungary, and noone is familiar with these vehicles of course, so I'm pretty much on my own with the shop manual :)

Submariner409
06-09-10, 07:50 PM
The CMP (CaMshaft Position sensor) is on the front face of the rear cam cover - right at where you would imagine the rear exhaust cam drive sprocket to be.

Your code calls for a circuit problem, so I would start with cleaning the connector (horrible location) and (extremely difficult) checking the wiring harness for opens or chafing.

Hooshee
06-10-10, 03:45 AM
The CMP (CaMshaft Position sensor) is on the front face of the rear cam cover - right at where you would imagine the rear exhaust cam drive sprocket to be.

Your code calls for a circuit problem, so I would start with cleaning the connector (horrible location) and (extremely difficult) checking the wiring harness for opens or chafing.

We did that. Every connector between the ICM and the Sensor, and ICM and the PCM is clean, the wires are good, voltages, resistances absolutely right.

However, we replaced the Cam Position Sensor just in case (no effect), and I have a friend with a 95 eldorado which has the same ICM, so we changed it for a test, did not solve the problem (my ICM in his car works perfectly).

So it must be something else...

porkfarm
06-10-10, 08:09 AM
I had P0340 errors that every time I cleared, they would come back. Replaced O2 sensor, problem fixed. Thing was before that, I had CPS codes and even after replacing that, I could still get an error every now and then if I ran cheap gas.

Your 02 wires might also be twisted up a bit if work was done in that area.

Hooshee
06-10-10, 08:46 AM
I had P0340 errors that every time I cleared, they would come back. Replaced O2 sensor, problem fixed. Thing was before that, I had CPS codes and even after replacing that, I could still get an error every now and then if I ran cheap gas.

Your 02 wires might also be twisted up a bit if work was done in that area.

Which of the three O2 sensor did you replace? All of them?

Hooshee
06-12-10, 03:36 PM
Well, the P1376 did not come back since we soldered the gound point, but P0340 is still on...