2000 Deville backup mode? (car performance)

[TROYBLISS]

I gotta get my crankshaft sensors replaced. In the meantime, ive driven the car a couple times and it seems like the car is operating in some kind of backup mode because of the sensors. Is this what happens when the sensors are going bad? I noticed the steering is a little harder, breaking etc. as if the car is running off some kind of backup system.

[BodybyFisher]

I doubt it, but check and post your codes so we can look them over.

Steering a little harder, check your serp belt for slipping, cracking, and missing sections

What is your RPM at idle? If your RPM is low it could cause hard steering.

Braking being hard, were your brakes done recently? I put ceramic pads on and until they are warmed up, they don't grab well at all.

The crankshaft sensors cause stalling when they are bad as far as I know. What was your symptom again?

KEEP your threads together, there are a lot of questions here that are answered in your other threads. Ill merge this with your crank sensor thread.

[TROYBLISS]

I doubt it, but check and post your codes so we can look them over.

Steering a little harder, check your serp belt for slipping, cracking, and missing sections

What is your RPM at idle? If your RPM is low it could cause hard steering.

Braking being hard, were your brakes done recently? I put ceramic pads on and until they are warmed up, they don't grab well at all.

The crankshaft sensors cause stalling when they are bad as far as I know. What was your symptom again?

KEEP your threads together, there are a lot of questions here that are answered in your other threads. Ill merge this with your crank sensor thread.

u r right, i apologize for starting numerous threads about the same problem. you can merge this. my symptons are stalling at red lights and when making turns into parking lots. the new symptons are the sluggish performance, which i thought may be attributed to the crankshaft sensors causing the car to run into some type of backup mode. i read on another forum that they could do that. anyway, my idle is 650 rpm and the codes are: ipm bo 429 current, pcm po 0741 current, rim co625 current, rim u1000 current, irc u1016 history, pcm po335 history, pcm po385 history, rim co625 history.

[BodybyFisher]

B0429 - Temperature Control #3 Rear Circuit Range/Performance

P0741 - TCC System Stuck Off, this is stopping your torque converter from locking up and dropping your RPMs down, your engine will run at a higher RPM as a result at highway speeds and you will lose about 2 miles per gallon or so in fuel efficiency. In my state you would not pass inspection with this. If you are lucky its just the TCC solenoid in your side pan. I replaced my TCC solenoid, pressure solenoid and ISS sensor last year they are all in the side pan. There is also a condition in the torque convertor that can cause this problem that is more involved to repair and more $$.

P0385 - Crankshaft Position (CKP) Sensor B Circuit It is possible that this puts you into a default timing that is not advancing and causing your performance to feel like a pig, ill check the manual.

Check to make sure that you don't have the traction control OFF, you will start in second gear and it will feel sluggish.

P0335 - CKP Sensor A Circuit Performance same comments as your P0385, here, ill check the manual

C0625 - Left Rear Position Sensor Malfunction check the connections at the drivers rear level sensor and check the rod that connects it to the control arm.

Mike

[Carvone]

I just went through this last month on my 2000 Eldo, the system actually does go into a back up mode. Here is how the manual explains it...

The PCM uses two basic methods of decoding the engine position: Angle Based, and Time Based (using either CKP A or CKP B sensor input). During normal operation, the PCM uses the angle based method. In order to operate in this mode, the PCM must receive signal pulses from both CKP sensors. The PCM uses the signal pulses to determine an initial crankshaft position, and to generate MEDRES (24X reference) and LORES (4X reference) signals. Once the initial crank position is determined, the PCM continuously monitors both sensors for valid signal inputs. As long as both signal inputs remain, the PCM will continue to use the angle based mode.

When either CKP signal is lost, the PCM will compare the MEDRES signal to the camshaft Position (CMP) sensor signal. If the PCM detects a valid CMP signal, and the MEDRES to CMP signal correlation is correct, the PCM determines that CKP sensor A is at fault. However, if the MEDRES to CMP correlation is incorrect, the PCM determines that CKP sensor B is at fault.

If the PCM detects a loss of signal for CKP sensor A, DTC P0335 will set. The PCM will switch from angle based mode to Time Based mode B using CKP sensor B signal input. If the PCM detects a loss of signal for CKP sensor B, DTC P0385 will set. The PCM will switch from angle based mode to Time Based mode A using CKP sensor B signal input. A noisy signal input from either CKP sensor will cause the ignition system to re-sync. If the number of ignition system re-sync is greater than a calibrated amount, DTC P1372 will set

With the two codes showing both of your sensors are bad it could make it run rough.

I still drove for about a month with my "A" sensor bad until I got around to fixing it, it still ran OK but was not 100% like it is now. You don't need to do the relearn procedure either if everything seems fine when your done. Good Luck.

[BodybyFisher]

Thanks for that detail on the failure mode Carvone, I figured it did something like that.

The transmission has a backup for the Input Speed Sensor (ISS) when it goes bad. The ISS goes bad, the PCM relies upon the Vehicle Speed Sensor (VSS) for speed info and line pressure goes into default mode, causing harsh shifting.

You gotta love the Northstar Platform.. Thanks

[TROYBLISS]

I just went through this last month on my 2000 Eldo, the system actually does go into a back up mode. Here is how the manual explains it...

The PCM uses two basic methods of decoding the engine position: Angle Based, and Time Based (using either CKP A or CKP B sensor input). During normal operation, the PCM uses the angle based method. In order to operate in this mode, the PCM must receive signal pulses from both CKP sensors. The PCM uses the signal pulses to determine an initial crankshaft position, and to generate MEDRES (24X reference) and LORES (4X reference) signals. Once the initial crank position is determined, the PCM continuously monitors both sensors for valid signal inputs. As long as both signal inputs remain, the PCM will continue to use the angle based mode.

When either CKP signal is lost, the PCM will compare the MEDRES signal to the camshaft Position (CMP) sensor signal. If the PCM detects a valid CMP signal, and the MEDRES to CMP signal correlation is correct, the PCM determines that CKP sensor A is at fault. However, if the MEDRES to CMP correlation is incorrect, the PCM determines that CKP sensor B is at fault.

If the PCM detects a loss of signal for CKP sensor A, DTC P0335 will set. The PCM will switch from angle based mode to Time Based mode B using CKP sensor B signal input. If the PCM detects a loss of signal for CKP sensor B, DTC P0385 will set. The PCM will switch from angle based mode to Time Based mode A using CKP sensor B signal input. A noisy signal input from either CKP sensor will cause the ignition system to re-sync. If the number of ignition system re-sync is greater than a calibrated amount, DTC P1372 will set

With the two codes showing both of your sensors are bad it could make it run rough.

I still drove for about a month with my "A" sensor bad until I got around to fixing it, it still ran OK but was not 100% like it is now. You don't need to do the relearn procedure either if everything seems fine when your done. Good Luck.

so, would cleaning the throttle body cure this problem because i AM getting the sensor codes for the crankshaft. i called the dealer and they said a dirty throttle body wouldnt cause the stalling, but they may be just trying to get my money. the rpms are 650 when parked in idle.

[Ranger]

A very dirty TB could affect idle if the IAC circuit was clogged with carbon, but would not set the P0335 & P0385 codes. If the TB was never cleaned it is overdue, but not the cause of you stalling.

[BodybyFisher]

You need to replace the crank sensors immediately. Check to see if there is a maxi fuse for the sensors first, I am not sure if there is one but since BOTH of your sensors are out its worth looking into. I am not near my service manual or I would check

I have not had the privledge of having the crank sensor problem yet, so my experience is based on what I have read here.

A dirty TB would only cause this stalling if the IAC runs out of compensation room. Typically a dirty TB causes a high idle and racing engine.

You will notice with me, that I tend to start at the bottom of the food chain of the problem and creep up. I NEVER hit the panic button FIRST. That is why I ask leading questions WITHOUT drawing a conclusion at first. In another thread, a member was using oil, now one could immediately conclude that its leaking or it needs the WOT procedure. My first question was, is it leaking. These engines can leak in many places, cooler lines, oil filter adapter, oil filter, oil pressure switch, oil level sensor, pan gasket, drain plug, cam covers, and lastly and the most expensive case half seals. To conclude case half seals on the members first post is to respond with the worst and I never do that. That is why I have to laugh when service writers immediately conclude without the vehicle being inspected. Once the member said, its NOT leaking, we can move on to the WOT procedure... the dealer of course at this point would suggest a decarbonization procedure or new pistons, I have seen that.

The way I try to think is as an INVERTED CONE, where at the beginning of the problem there are a LOT of possibilities and you eliminate them one by one to get to the POINT at the bottom of the cone. Its not necessarily the fastest way to think but it works for me. Its like the tortoise and the hare analogy. When I have a problem I look at the simple things first to eliminate them.

Those Crank Senfor codes you are getting are not a good sign and you need to get rid of those codes especially given that the NS goes into a limp mode.

[TROYBLISS]

You need to replace the crank sensors immediately. Check to see if there is a maxi fuse for the sensors first, I am not sure if there is one but since BOTH of your sensors are out its worth looking into. I am not near my service manual or I would check

I have not had the privledge of having the crank sensor problem yet, so my experience is based on what I have read here.

A dirty TB would only cause this stalling if the IAC runs out of compensation room. Typically a dirty TB causes a high idle and racing engine.

You will notice with me, that I tend to start at the bottom of the food chain of the problem and creep up. I NEVER hit the panic button FIRST. That is why I ask leading questions WITHOUT drawing a conclusion at first. In another thread, a member was using oil, now one could immediately conclude that its leaking or it needs the WOT procedure. My first question was, is it leaking. These engines can leak in many places, cooler lines, oil filter adapter, oil filter, oil pressure switch, oil level sensor, pan gasket, drain plug, cam covers, and lastly and the most expensive case half seals. To conclude case half seals on the members first post is to respond with the worst and I never do that. That is why I have to laugh when service writers immediately conclude without the vehicle being inspected. Once the member said, its NOT leaking, we can move on to the WOT procedure... the dealer of course at this point would suggest a decarbonization procedure or new pistons, I have seen that.

The way I try to think is as an INVERTED CONE, where at the beginning of the problem there are a LOT of possibilities and you eliminate them one by one to get to the POINT at the bottom of the cone. Its not necessarily the fastest way to think but it works for me. Its like the tortoise and the hare analogy. When I have a problem I look at the simple things first to eliminate them.

Those Crank Senfor codes you are getting are not a good sign and you need to get rid of those codes especially given that the NS goes into a limp mode.

in this picture, can you mark the location of where the valve cover gasket would be and the head gasket or half seal, etc.

[BodybyFisher]

Look at the CAM covers, there is a seal there, in this photo the cam covers are not on

The engine is split horizonally at the centerling of the crankshaft, you can see it in this photo, look at the centerline of the crank shaft that is where the upper and lower halfs of the engine come together.

If you look at the oil filter, the oil filter is attached to the oil filter adapter, there are two orings behind it that can leak.

To the left of the oil filter screwed into the pan is the oil level sensor.

You can not see the oil pressure switch in this photo