Code Help

[jeepboy_90]

Pulled 3 codes from my 1998 Xj today

P0340 - Camshaft Possition Sensor Circuit Malfunction
P0320 - Ignition/Distributor Engine Speed Input Circuit Malfunction
P1391 - Itermittent loss of CMP or CKP

I have checked all the wires everything looks good and clean. Were do I go from here. Any ideas on what it maybe? Are they all related from one problem?

[Runnin'OnEmpty]

The P0340 and P1391 are certainly related, and the P0320 might be.

The cam position sensor is located inside the distributor; I'd take a close look at the wiring going to it; if wiring is OK, then suspect a faulty sensor.

Does it start/run at all? If it runs OK, I'd erase the codes and see if they return.

[jeepboy_90]

I erased the codes and took it for a drive today. The codes that came back up were the P0340 - Camshaft Possition Sensor Circuit Malfunction and P1391 - Itermittent loss of CMP or CKP. Should I just replace the sensor? How much do they run? Any other ideas?

[Runnin'OnEmpty]

Here's some info on them, and pictures.
http://www.rockauto.com/catalog/catalog.php?carcode=1315943&parttype=7176
An AC Delco runs about $43. As to whether to replace it, that's what I'd do. You obviously have a fault (since the codes returned) that's related to the cam sensor. If the wiring looks OK, that only leaves the sensor as being the culprit.

[jeepboy_90]

Well I reset the codes one more time and took the jeep for a spin. Now no P0340 code, but the two others that were there first. Also the p0320 code is written different in both of my repair man's.

P0340 - Camshaft Possition Sensor Circuit Malfunction
P0320 - Ignition/Distributor Engine Speed Input Circuit Malfunction
or
P0320 - No crank Reference Signal at PCM
P1391 - Itermittent loss of CMP or CKP

So right know both P0320 and P1391 are coming up.

Please help me. This driving me crazy.

[djblade311]

replace the sensor as originally advised then try again. If you still get the same codes, replace the Crankshaft Position Sensor too

[jeepboy_90]

Could it be the PCM?

[goodburbon]

if its still running, Its not the pcm


a loose connection or a failing sensor.

[Runnin'OnEmpty]

Jeepboy, I looked in my book, and all those codes point to a faulty camshaft position sensor. I think a new one will eliminate all your codes. When the cam sensor fails, the ECU uses the last known signal from it to keep the engine running, and stores the fault code(s). And it should turn on the CEL/MIL with OBD II. That seems to be what's happening with yours.

It should be accessable without pulling the distributor. You will need to remove the trigger wheel though, and I've found that a small battery terminal puller works good for this.

[jeepboy_90]

Replaced the CMP sensor, but it is still bringing up the P0340 code. Wiring looks good. What else could it be? This really sucks.

[jeepsrock]

I would try the cps next which i beleive works in conjunction with that sensor. Its located on the trannys bellhousing.

pete

[jeepboy_90]

Well after much trouble, found a broken wire in the harness at the back of the motor. It would work sometimes and not at other times. Ran a new wire and we are look'n good. Thanks to those who helped me.