saturn L300 trouble codes P0700 & P0727

[kssbss]

I pulled these codes with my scanner P0700 & P0727 If anyone has any info on these codes it would be appreciated symtoms are trans will slam when shifting and illuminate light on dash and intermittent no start

[fdryer]

DTC P0700 Transmission Control System Malfunction

DTC P0727 Engine Speed Circuit No Signal

From our How-to library on page 5 titled OBD II Powertrain codes.

If you ignore the first error code for the second one, you see that the speed circuit signal loss is the crank position sensor (CPS) failure, the intermittent no-start problem. Replace the cps, located next to the oil filter. Buy it from any store stocking it. No cps = no EFI system, a dead engine. An intermittent cps is worse than an outright cps failure because you'll never know when it will fail as you're driving along one moment and suddenly the engine dies. Dying at random doesn't give you a sense of vehicle reliability, leaving you stranded at the most inconvenient moment.

[jason25]

Originally Posted by fdryer

DTC P0700 Transmission Control System Malfunction

DTC P0727 Engine Speed Circuit No Signal

From our How-to library on page 5 titled OBD II Powertrain codes.

If you ignore the first error code for the second one, you see that the speed circuit signal loss is the crank position sensor (CPS) failure, the intermittent no-start problem. Replace the cps, located next to the oil filter. Buy it from any store stocking it. No cps = no EFI system, a dead engine. An intermittent cps is worse than an outright cps failure because you'll never know when it will fail as you're driving along one moment and suddenly the engine dies. Dying at random doesn't give you a sense of vehicle reliability, leaving you stranded at the most inconvenient moment.

I too had both of these codes along with P1810 and P0128 which I would appreciate knowing. My car doesn't have the slam while shifting as the OP but it does have the intermittent no-start. I would start fine in the morning and would stall only when I was stopped...until today when it stalled about 3 miles from home and I didn't have my cell phone on me. If I let it sit for a short period it wouldn't start, but if I let it sit for 45-60 minutes, it starts everytime. I was thinking it was the fuel filter, but I am a no mechanic. A fuel filter is cheaper than the CPS so I will try that first. Even if that isn't the culprit, it should probably be replaced anyway.

[fdryer]

Originally Posted by jason25

I too had both of these codes along with P1810 and P0128 which I would appreciate knowing. My car doesn't have the slam while shifting as the OP but it does have the intermittent no-start. I would start fine in the morning and would stall only when I was stopped...until today when it stalled about 3 miles from home and I didn't have my cell phone on me. If I let it sit for a short period it wouldn't start, but if I let it sit for 45-60 minutes, it starts everytime. I was thinking it was the fuel filter, but I am a no mechanic. A fuel filter is cheaper than the CPS so I will try that first. Even if that isn't the culprit, it should probably be replaced anyway.

Replace the crank position sensor. The bolded text is the giveaway to an intermittent cps failure. It will occur at random and eventually fail altogether where you'll be able to sit all day and crank to your hearts content but the engine will never fire up anymore, possibly stranding you in the most inconvenient place. Search the threads about failing cps'. The cps acting intermittently may be causing the other issues as they're not crucial to EFI operation; if the cps dies at any time there won't be any fuel pump running, no ignition for spark, and no injector pulses, a dead engine. Replace the cps and then reset the codes.

DTC P0128 Coolant Thermostat - If your temperature gauge needle is below the 1/4 mark, repalce the thermostat.

The PO1810 code is a trans code. The Automatic Transmission Fluid Pressure Manual Valve Position switch (TFP Val. Position Sw.) consists of five normally open switches. Ignition voltage is applied to each of the switches. By grounding one or more of these switches with fluid pressure from the manual valve, the Powertrain Control Module (PCM) can detect which gear range is selected.

If the PCM detects an invalid combination of the TFP Val. Position Sw., then DTC P1810 sets. DTC P1810 is a Type B DTC.

[jason25]

thanks, replaced the cps this evening. I am going to drive it around tomorrow and see what happens. How do I reset the codes?

[fdryer]

Disconnect the battery for a few minutes and the codes will reset.

[jason25]

Originally Posted by fdryer

Disconnect the battery for a few minutes and the codes will reset.

Wow, that's it? Thanks, easy enough. Reseting the oil light is harder then that was.

[quickskill]

I just wanted to throw in my two cents since I appear to have had the exact same problem as jason25.

Started with intermittent starting problems. I typically only had issues shortly after I turned off the car after the engine had drive a significant distance/heated up, ie. running into a grocery store on the way home for work. Once it sat for an hour or two at home, it would start fine again.

In a week's time, it failed to start one morning. Thankfully I got it started up about 10 min later, but this time with a check engine light, later determined to be the aforementioned P0700 and P0727 codes. The car shifted gears noticeably jerky, which I imagine is the 'slamming' mentioned by the original poster.

After that one day, the jerkiness disappeared and the car continued working intermittently as described earlier. The Check Engine light eventually disappeared a few days later. Unfortunately, the car failed entirely a day or two after that.

Luckily, the crankshaft position sensor I ordered online for $40 after shipping had come in. After sitting over the weekend and still failing to start, I replaced the CPS and it started right up. I did still have the Check Engine light and the jerkiness during shifting on the drive home. The next time I drove my car, the jerkiness had disappeared.

As a side note, I tried disconnecting the battery for 5-10 minutes to clear the Check Engine lights (as advised by fdryer), but that did not appear to work for me for whatever reason. I plan to just wait it out until it disappears and not worry about it assuming the jerkiness when shifting does not return.

Just wanted to share my similarities and slight differences in case future Google searchers stumble across this post looking for answers.

[lschlenger]

Just wanted to post a quick thanks to fdryer. Our 2003 L300 (6 cyl) threw these codes (P0700 and P0727) and had the intermittent non-starting issues a few months ago. We began to consider trading in the car and finding something else since we had just been through a $1500 exploratory research project by our local chevy dealer till he found the cause of the previous set of weird behavior (that time with the electical system). But I found this and a few other threads about P0700 and P0727 pointing to the CPS. I bought a CPS ($80) at a local auto parts place, had a local mechanic (who works on my buicks) install it for me ($90). The guy thought I was nuts installing a CPS if the codes were transmission related but I made clear I wanted to try this first before him going off and hunting out the issue. Lo and behold the issue had resolved itself with the new CPS.
So I am hereby confirming yet another case of these symptoms being the CPS at fault and thanking fdryer and everyone else who has contributed to these threads on here and the managers of this site & forum for making such useful information available.

[kinless]

This just started happening to my 2005 L300 after 113K miles. The new CPS will be delivered today, and my dad and I will attempt to replace this thing ourselves (well mostly me, he'll just supervise haha).

I'm assuming crank position sensor and crankshaft position sensor (as stated in the repair manual and product catalogs) are the same thing.

I've also been searching around trying to find pictures/videos of the CPS location on L300s for some reference but seem to be coming up short. (Anything looking promising has been removed or has bad links.) I know it's next to the oil filter but I was hoping for an actual visual to save myself from fumbling around. Would anyone happen to have a fresh source? It's been a while since either of us were on the underside of a vehicle.

[fdryer]

You don't need pictures or drawings to find the crank sensor. It's still next to the oil filter housing, mounted with one torx bolt (the only sensor next to the oil filter housing. You'll waste more time attempting to search for drawings or pictures of its location than it will take you to crawl under the engine and find it. The long wire harness may be covered in a heat shield (resusable), connected above the engine towards the front on a bracket. Disconnecting it may be troublesome.

[kinless]

Thanks fdryer. When you mentioned the housing I realized I could just do a search for that (duh), lo and behold I found this older thread with pictures that Wolfc70 took, and of course right there in the front is the CPS.

You're right, you can't miss it once you get under there. Just hoping it's not too big a pain to remove like you mentioned. Dad still has many tools from his service station days so I'm sure we'll figure it out. Will let you know how it goes.

[kinless]

Easy peasy! Installation took about 20 minutes and the car now idles properly and starts up every time.

Only bummer is when I reset the codes with my scanner I didn't realize it also resets the smog readiness monitors (which I purposefully avoided disconnecting the battery for that reason). Now I just have to go through that highly annoying process of driving the specific parameters to get it "ready" again. Smog is due in a few weeks... of course.

[fdryer]

Resetting the ecm by battery or reader does the same to reset volatile memory. You did fine as anticipating state inspection ahead of time allows you to simply drive your car without performing the painstaking 'drive'cycle' that's more about technical knowledge than just getting into our cars and driving them. Whether you know it or not, every time the engine is started and car driven, the emissions self tests are performed continuously. The moment the car left the assembly line, emissions self tests are performed and with zero monitors, driving simply allows the emissions programs monitor and stores parameters into memory. As long as emissions meets programmed EPA guidelines already stored in permanent memory, the car simply checks each parameter against stored values and if within range, goes from a not ready to ready status in as little as one 50 mile 'drive cycle' or over a few days of regular driving. No one needs to perform a drive cycle when regular driving does the same. A reader can tell you if your OBD II system is not ready or ready. Ready means the car already passes federal emissions requirements and will pass state emissions inspection. While the check engine light may be off with no indication of ready status, a reader is the only way to see this status, the same way every emissions inspection station does when plugging in their state computer into the same OBD II port. They see nothing more than any reader.

[kinless]

Haha yep, I learned all that the hard way a few years back after getting 100K service/repairs done and thinking I could just mosey on over to the smog station right after that. That's when I picked up an AutoLink AL519 scanner that checks both OBDII and smog monitor ready codes, to avoid wasting time/money on future tests.

I remember one of the more stubborn monitor parameters absolutely would not turn "Ready" until executing the 55MPH-for-5-minutes-then-slow-to-stop-without-braking routine. Luckily there's a stretch of freeway close by for that, but in busy SoCal it's best performed at night. I only drive this car 100 miles a week so it may need to be driven with a few requirements from the drive cycle in order to make the deadline.