SHavis

A little background. I've had a bad cam sensor for a while. No drivability issues, so it's not been addressed. A few weeks ago, the AC pulley bearing disintegrated. I replaced the AC compressor, the belt and tensioner. All was well for about 40 miles, then the PS pump started leaking profusely. Seems that some of the old belt had remained around the PS pump shaft and ate the seal. This being a little more involved, I decided to address the cam sensors at the same time. The new PS pump, and both cam sensors were replaced. The removal and replacement went without any other issues. When everything was back together, she would crank, but not start.

I connected the Durametric and found codes P0335 Crankshaft Sensor open circuit. Ok, I think, parts fail when they fail; weird coincidence. So I replaced the crank sensor.
She still won't start. Every few times, she would start and immediately die.
Connected to the computer again and now I have P0335 still with the addition of P0341, and P0346 Camshaft Sensors signal implausible. I check connections, test the wiring between the controller DME and the sensor, look for output(about 7vac while cranking) on the crank sensor (can't get to the cam position sensors). All seems normal.

I open the Durametric and observe the engine speed cranking and there is signal, and rpm is displayed, so I'm assuming the crank sensor is sending a readable signal to the ECU.

I can reset the faults. Every time the engine cranks, fault P0335 shows up. About half the time, the cam sensor faults appear.

I've gone through the t-shooting steps in the service manual. The only thing I haven't been able to do is measure the 5v signal to and from the cam sensors.

I'm suspecting the ECU now due to the RPM reading on the Durametric.

Anyone run into something like this? It's got me completely baffled. What is common between these 3 sensors?

Thanks!!

J'sWorld

They are all hall effect sensors. A bad crank sensor can give a cam sensor code. Try unplugging the cam sensor on the bank that originally gave you the code for cam sensor. It may start. I may be wrong but I thought Durametric could give actual values? That way you could see the action of the cam sensors as the ECU does.

hopsis

At that point I'd suspect the new cam sensors. I know it is a pita to get at them but put the old original sensors in and try it. Ecu fault is very unlikely.

SHavis

After my first post, I back probed the B connector on the ECU and found 5.011vdc out to the cam sensors and the proper pulse width modulation signal back. All sensors are getting and returning signal to the ECU. My hunch is one of the new cam sensors is interfering with the others through the ground loop. That's the only thing external to the ECU that links them. I agree that it's highly improbable that the ECU is at fault. I'm going to unplug the sensors one at a time today and see if there is a change. I think I can get to the connectors by removing the air pumps. I sure hope this is it! Have a Merry Christmas!!

MKITGO2

Curious if you ever found a root cause on your problem?

I have a similar situation brewing... I have had a P0293 for 'Bank 2 Camshaft signal communication'.. Didn't have any driveability issues, maybe a bit poorer gas mileage. Changed the oil, reset and it came back in short order, so i moved on to replace the Hall Sensor.

Now immediately after the install of the new camshaft sensor (hall sensor) I am getting 3 codes (usually I like a 3 for 1 deal, but not like this)

P0346 - Camshaft sensor 2, Implausible signal
P0018 - Crankshaft position in relation to bank 2 intake camshaft, below lower limit exceeded
P2093 - Intake camshaft position actuator circuit bank 2, no signal/communication

Would there be a 'learning curve' with the new sensor or a calibration to perform?

If anyone has thoughts I would appreciate it... not really keen on the idea of taking it to the mechanic to chase gremlins. I'm decent mechanically, not great electrically and don't really have the tools/knowledge to track wires and signals.

Cheers,
MK

SHavis

This did kick my butt. Ended up that the cam was out of time. I retimed the cams and the CEL and all diagnostic codes went away. Resetting the timing was relatively easy. Along the way, I did get codes relating to bad cam AND crank sensors and the engine would not start. Replaced each sensor one by one, no luck. Swapped the cam sensors and plugs and the codes stayed on the same bank telling me the trigger for the sensor is off.

The cams are held in place by a friction washer. No key. Just loosen a bit, set the position, and lock it down. The torque is very specific. It's a torque plus so many degrees, I'd have to look that up.

I ended up getting the manuals from a list member that were a tremendous help, very much worth the cost. If you are interested I can PM you his email.

Cheers!

MKITGO2

Thanks for replying.

Uggg... That's not what I was hoping to hear... I don't think of going out of time as just a random happening, makes me think it means chains have stretched or a tensioner is/has failed or something.. But it sounds like it solved your problem.

The old sensor I pulled out looked fine but had a moderate medium brown color coating of oil. I am going to clean it up and put it back in to see where that gets me. Then may do the same and swap sensors around to see if the code moves or not.

Maybe a stupid question... would a timing light be of any use to tell us if we are out of time on these engines?

MKITGO2

Reviving this old one in the case that someone else is looking at it... so I continued to live with my engine light until this past summer (July '22) after receiving nothing but death sentences from every shop I talked to or who 'looked' at the problem. In July I took it to a shop recommended by a good friend, they took a proper look and in fairly short order diagnosed the Hydraulic Cam Actuator as having died.. .confirmed by directly connecting to it and not getting response.

Now after that replace, no more engine light, and it is running even smoother than before - my previous opinion was the condition was not affecting how it ran, and I was wrong.

Only downside is the part was $700 CDN. The labour was only a couple hours.

MK

Kevin M.

Any DIY on how to replace this, i believe i have the same issue?

Mr 4x4

I experienced this same problem after fitting new camshaft sensor. With a diagnostic device plugged in i had the same camshaft sensor codes. I cleared the codes and the car started and runs brilliantly. From what i know the sensors are plug and play no calibration or anything else the car should crank and start after fitting. Have I discovered that the bad crankshaft codes need clearing.