Hey all! I'm new to the site, but I've gotten endless amounts of priceless info from this site over the years owning my trailblazer. Yesterday I headed to the grocery store. Everything was fine! Full tank of gas, running smooth. When I get in the car to go home, starts and drives just fine. I'm heading up a small hill and it just stalls. I get to a safe spot and start cranking thinking it was a fluke... no luck, no start. This thing has been running like a top for some time so I figured it must be something I could narrow down. I called a tow truck to tow me 5 mins home. At home, I got the code reader out and saw p1515 and p1516. The reduced engine power light is on sometimes, off sometimes. That's with the key in and the car not running. I have no other vehicle at the moment and time is always of the essence with our vehicles obviously. I rattled the connections and got no different results. I can crank away, just never starts up. Obviously to me, it was not getting gas. The fuel pump was replaced a year ago, so I hope that isnt my problem. The car had a tune up a few months ago and all seemed well. Literally no problems, until this stall and no restart situation I'm in now. Where do I begin? Should I just order a throttle body with the sensor and replace mine ASAP? Could it be my fuel pump? Possibly fuel filter? I have to get a ride to the auto parts store, so I dont have the luxury of just going back and forth for more parts to try this or that. What would you guys do? What would you do FIRST? I can provide any additional info I may have forgotten. And any help is much appreciated. I'd love to get this narrowed down and have an idea of what I need to buy today to get her up and running. Thanks in advance!
SOLVED! Randomly stalled and wont restart. P1515 p1516 codes.
- Thread starter BonezCustoms
- Start date
P1516 Chevrolet: Code Meaning, Causes, Symptoms, & Tech Notes (With Video)
The Engine Control Module (ECM) determines the driver's intent based on input from the accelerator pedal position sensors, then calculates the appropriate
www.engine-codes.com
Watch the video. It may help you.
Thanks STSCowboy! I've given the "wiggle test" to the harness just to see if I could get her to fire up, but never gave the "tug test" to each individual wire. I'd love to find this is the problem! Out to check some wires now, I'll be sure to post if I find anything interesting! I just feel the fact my car stalled, and now WILL NOT re start should be telling me something. It stalled out so fast and unexpected, it could definitely have been a loose wire disconnecting etc. Thanks again
Eric04
Member
Thread is a few years old but fairly close to your situation save for intermittence.
gmtnation.com
Sudden p1515 and p1516 codes with stalling
I drove ~800 miles in the last few days, no problems at all. Was getting 19 mpg at 85 which I'm quite happy with. Got home went to bed. Took care of some errands today and the truck quit. I was ae to restart it after several attempts and get it running. Or so it seems, I'm not home yet, was on...
gmtnation.com
I was reading that thread before I decided to post my own Eric04. I thought maybe somebody has found something new that hadnt been posted. Seems to be a problem that is not unheard of. Could the TPS or one of the other sensors related to the throttle body cause a car to stall and not restart with no signs or symptoms beforehand? If that's feasible, I'm gonna say I need to replace the throttle body and any attached sensors ASAP. Even the tow truck driver who is also a mechanic told me it's probably a dang sensor on the ride home. If it's reasonable that one of my sensors or the throttle body itself has failed and that this would cause my stall and no restart situation. I'd suspect that's gonna be my problem... just doesnt seem right to me. I'm NO mechanic though, lol! I just checked the wires to the sensors etc and all seems as it should. No loose or dirty/wet connections etc. Still scratching my head.
Eric04
Member
It's possible, definitely. If the TPS flakes out, the PCM can no longer verify between the pedal position sensor and the TPS just what the hell is exactly going on and will shut the engine down for safety purposes(think runaway vehicle).
I threw the link up as food for thought even though there wasn't definitive conclusion. It would *appear* that those involved settled on throttle body replacement but worth digging for any test procedures you can find. I've no firsthand experience with this issue, it's not a common failure, so hopefully someone else who has will chime in yet. I'd say swap with one from a junkyard but I know lack of transportation has you in a bind.
I threw the link up as food for thought even though there wasn't definitive conclusion. It would *appear* that those involved settled on throttle body replacement but worth digging for any test procedures you can find. I've no firsthand experience with this issue, it's not a common failure, so hopefully someone else who has will chime in yet. I'd say swap with one from a junkyard but I know lack of transportation has you in a bind.
I appreciate the info man for sure! That was my "go to" thread before I bbn posted this one, though the answer is probably the same. I ordered a new throttle body assembly for $148 + $8 for expedited shipping, since time is of the essence. No local parts stores had one in stock so I'm waiting on shipment either way. The cheapest was at O'Reilly's and was a Remanufactured Cardone branded model for about $255. Shipped in just a few days, but $90 extra and still gotta wait for shipping, get a ride to the store etc. Hopefully this comes in the mail quick, I'll swap it out and then I guess my problem should be cured correct? I'll be sure to post my results for any future searchers. If I'm understanding correctly, the sensors I am getting codes for are built into the throttle body correct? Or are there other sensors I should maybe order etc? I just need this thing back how it was yesterday... no concerns about anything, no knocks, no weird sounds or idling, no stalling. It just blew my mind when it stalled and then again when it never started back up. These dang computer controlled cars though, one sensor is sending the wrong message and the engine is NOT starting. I guess I'll be on to fuel if this doesnt work? I hear the fuel pump on start up though, and it's only 1 year old. We will see! I appreciate the replies, and hope for anybody else to step forward with info.
Just some info and background that may be helpful... I live in a county in NC that only requires the safety inspection. No emissions test etc. So I'm always less worried about clearing the codes than I am just getting the truck running again. Though, I imagine the CEL will go out if the new throttle body fixes the problem anyway... 2 birds with 1 stone lol. Also, this car has been a member of the family, and has therefore been somewhat of a money pit. The engine was replaced with a crate engine at about 190,000 miles. Then the transmission was rebuilt less than a year ago. It has a new fuel pump. We haven't hesitated to fix this car as we dont have the heart to give up on it. It's a well cared for and maintained old car. 245,000 miles now and this baby runs smooth! The engine etc... the car itself is old and needs new front struts etc lol. I either diagnose and fix or take the car to the shop anytime I have ANY suspicions or problems. Honestly since the engine swap I haven't had much beside the fuel pump situation. I just want to stress this car is old, but most of the major things have been replaced etc. Its a well cared for car and not your average 2002 with the engine and tranny we have put in it. Now I just get smaller goofy things going wrong here and there, mostly things I can take care of. Lately, nothing until this situation. I am still in the process of charging the battery (brand new replaced Oct. 2019) as no i hope the new throttle body assembly will have her purring like a kitten again! Like I said, I'm welcome to any other suggestions, things to check etc. I will also be SURE to post back once I complete the swap to say one way or the other if it was the fix or not. Just wish me luck at this point, on the diagnosis and the shipping speed Haha! Thanks for all the help!
The new throttle body came in the mail this afternoon. I have tried wiggling, tapping, messing with EVERYTHING over the past few days. Couldnt get even a single start out of her. I recharged the battery after so many attempts and decided to wait for the part to come. I took off the required parts, installed the new throttle body, reconnected and checked everything... and when I tried to start it, it fired right up! I drove around the neighborhood, everything was back to perfect! I drove around even more just now and this baby runs even smoother than before, and she was running great before the stall! My gas mileage wasnt all it could be before the stall, maybe I can get a few extra mpg out of her now too! I hope this will help somebody out in the future. A $150 part, 2 screws, 4 bolts, 4 clips and literally 15-20 mins and I was done. The shop would have wanted $400-500+ depending on which part I wanted to use. I haven't driven long term yet, but after having just fixed it, I'd say my problem is resolved. Thanks for all the help and I hope I can return the favor someday myself!
JEREMY HALLETT
Member
I realize this thread is older, but this is exactly what's going on with my 03 Envoy. I'm getting both P1515 and P1516. Has this fix kept you going or have you had any more issues since?