I have, The lights are bright Everything works fine.. Even put the battery in a different car to make sure it wasn't the battery. It cranked right up in a different car. I'm at a loss and out so much money in parts already. Thanks for your suggestion, anything else I can try?
2010 Chevrolet impala LT flex fuel 3.5l v6
I have a 2010 Chevrolet impala lt flex fuel 3.5 v6. I have been without a car since October. First my car started going into limp mode, it would stay running but when I hit the gas nothing happened. I took it to 2 parts houses and they both told me something different. I borrowed a obd2 scanner and every time it would give me a code and I would change said part, another code would come up days later and it still drove the same (limp mode) or rpms higher than normal. Since October, I have changed Map sensor, MAF sensor, camshaft sensor, wiring harness for the camshaft sensor, oil pressure sensor, VVT solenoid, changed the oil and filter, ect. It has always cranked and ran fine until recently and it wouldn't start, even though it has good power. Now its giving me a code (U0100) Lost communication with ecm/pcm "A" ..
I'm not sure what the A is but I did have a code that came back camshaft position sensor open circuit "A" which I changed the sensor and harness. I dont know if I need a Ecm/pcm or a TCU since they both run hand in hand. I truly appreciate any advice or recommendations you can give me. I have done all the work myself with the help of a obd2 scanner and Google. I'm out of options here. Does anyone have a wiring diagram for circuit "A" please.
I'm not sure what the A is but I did have a code that came back camshaft position sensor open circuit "A" which I changed the sensor and harness. I dont know if I need a Ecm/pcm or a TCU since they both run hand in hand. I truly appreciate any advice or recommendations you can give me. I have done all the work myself with the help of a obd2 scanner and Google. I'm out of options here. Does anyone have a wiring diagram for circuit "A" please.
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Thank u so much,At your DLC on pins 6 and 14 you should have a reading of 60 ohms for normal
If you get 120 ohms you have an open in the wiring
If you get 0 you have a short in the wiring
Did you by chance unplug the EBCM (abs brake module) of you did make sure the connector is seated properly...They can be tough to get right...lf it's not connected right it will cause some weird electrical problems...head scratchers lol
Oh yea DLC pins
Looking at connector top row three pins in from right is pin 6 and pin 14 is just below pin 6
Do I get a regular electrical checker, or do I need a specific one. This is exactly the info I needed I just didnt know what pins to check and what goes to everything. I'll get a checker today or tomorrow and will let u know .
Ok I just left advance auto and they only has the meeter with very short ends , I figured I needed ones that had the long pins . But I'll go back tomorrow and get one. I truly appreciate all the help, I'm a female btw and have done all this myself, this car is the only one I have so its really frustrating that I cant fix it no matter how much I change parts. Now it wont turn over or crank. I cant give up because I just spent $600 on parts. So, I'm truly grateful for your advice and time. Thank youJust a regular multimeter.
Your library or auto zone web site has wiring diagrams
Ok so I borrowed a meter, here is what I got
Ohms:
6&14 was 62.0
4&5 was 1.2
1&16 was 150/160 bouncing
Volts:
1&16 was 19v
16&4 was 25.1
16&5 was 25.1
16&6 was 21.6
Hope this helps tell u anything..
If I put those at the bottom on ohms, it would make the screen on the meeter go blank. It is a $5 POS meter from harbor freight so, it may be that too.
Ohms:
6&14 was 62.0
4&5 was 1.2
1&16 was 150/160 bouncing
Volts:
1&16 was 19v
16&4 was 25.1
16&5 was 25.1
16&6 was 21.6
Hope this helps tell u anything..
If I put those at the bottom on ohms, it would make the screen on the meeter go blank. It is a $5 POS meter from harbor freight so, it may be that too.
Ok so I borrowed a meter, here is what I got
Ohms:
6&14 was 62.0
4&5 was 1.2
1&16 was 150/160 bouncing
Watts:
1&16 was 19v
16&4 was 25.1
16&5 was 25.1
16&6 was 21.6
Hope this helps tell u anything..
Ok I'm gonna go check the pins it says. I'll be back with that data in a little bit. Thank u so very much! I truly appreciate your help.Read this and start the tests as stated in this article
Your numbers are strange
Gears Magazine - Can We Talk? Diagnosing a Lack of Scan Tool Communication
There are many different types of communication protocols in today’s vehicles, depending on the manufacturer and system. These include CAN, Flex CAN, UART, Keyword 2000, MOST, BEAN, LIN, LAN, CCD, UDS, Byteflight, Flexray, and PCI to name a few. If you want to repair today’s vehicles, your...gearsmagazine.com
I unplug the ecm just a few mins ago and made sure it had a good connection and didn't see any wires or anything exposed. No mess under the airbox, everything looks good. Someone told me my ecm/pcm was bad but I know it's at least getting power to it because on my obd2 meeter it says I'm getting 11.xx volts to it. So that's why I'm trying to figure out why it wont crank now out of nowhere. And since I have got the U0100 "A" code, even my obd2 meeter wont give me but 4 or 5 options to look at, when before i had maybe 50. There is a bad connection or wire somewhere i cant see. That's what I'm trying to find now.The ECM & TCM are in the air filter box on the dirty side of the air filter.
Mice sometimes chew on the wiring and make nests in the airbox on the W body GM cars. Pull out the air filter and take a look. If it's full of mouse nest put on some gloves and cover your face before evicting them.
Mice carry Hanta virus. It'll be in the dust and urine found in their nests. Don't touch your face before you wash your hands and arms up to your elbows and don't breathe the dust. Be careful and aware.
I'd get the bulk out and in a trash bag then make sure the filter is firmly in place on your shop vac, face the exhaust away from you, and vacuum the rest of the airbox out. If the mouse urine is obvious on the airbox and wiring clean it up with bleach and water before proceeding.
If they've chewed the wiring it's a tedious job to repair but not impossible.
OkRead this and start the tests as stated in this article
Your numbers are strange
Gears Magazine - Can We Talk? Diagnosing a Lack of Scan Tool Communication
There are many different types of communication protocols in today’s vehicles, depending on the manufacturer and system. These include CAN, Flex CAN, UART, Keyword 2000, MOST, BEAN, LIN, LAN, CCD, UDS, Byteflight, Flexray, and PCI to name a few. If you want to repair today’s vehicles, your...gearsmagazine.com
6 to 14 I got 62.0 ohms and .03v
6 to 16 It either went blank on the meeter or 1 time I got it to read 88 to 103 ohms jumping back and fourth, and 11.36 volts
6 to 16 was. 33 ohms and 0.02 volts
6 to grond was 1.00 volts
14 to ground was 1.00 volts
I'm hoping Chevrolet or gm will email me back with that information. I have tried to find a mechanic around me, I thought I found 1 and he said since I didnt have a code visible that he couldn't do the computer part of the car and just told me what the outside needed, and still charges me $100. I deleted the camshaft sensor code after I replaced it and the harness, hoping that was gonna fix it. So since he didng see that code then, he said he couldn't pull codes with his computer. Hopefully I'll get this diagram soon and go from there. Or find someone that knows what there doing that can come to my house.You need a wiring diagram. You need to make sure you have all the power and grounds to your ECM. Also, in order to check the data lines, CAN bus, you need a lab scope. This is where you need to find a technician, not a parts changer, that understands how the data flows in these new systems. Only when you see what the data lines look like, can you go forward to determine which module is causing the problem. You could also have a shorted sensor pulling the data lines down as well. This is where a scope is invaluable in troubleshooting communication issues today.
Here is my email if some way u can find it again please send it. I have been through all fuses but not eith the key on, I'll do that tomorrow. Thanks so much for your help! My email is [email protected]You have a short on the Can high side.. Get a wiring diagram for Can bus high side
Check all fuses ....turn key to on not start and check all fuses under hood and inside car fuse box.
I had a wiring diagram for your car but it magically disappeared when l tired to upload... Send it back google lol
Lol, I been at this with no car since October, 10 miles of spaghetti dont sound that bad right now, especially if I can find this dang short and fix it. 🤦♀️🤣You could go old school with a clamp type meter
At the computer seperate all the wires and turn the key on not start and measure the amps of every wire ...one by one..The one wire with the highest amps is the circuit that has the short... Takes time but no fancy equipment needed.. Then trace that circuit for the short... 10 miles of spaghetti lol
I have the wiring diagrams and will be tracing wires tomorrow! I'm so grateful for everyone's help and advice on this. I cant give up now, and with this information i hope to solve this issue soon! Have a great night everyone. Hopefully I'll have a good update soon! 🤞🤞
Noted! And will do that this evening. I'm actually sitting in a emergency room right now, and it rained today so I didnt get a chance to look at it. But I'll definitely post on there website and get back to working on it tomorrow. Thank you so much for the info. It might have took me 5 months but if it's the last thing I do I'm gonna figure this car situation out! LolThere are stored codes that a good quality scope can pull up providing they haven't been erased previously. A savvy technician should know that. I would reach out to the Scanner Danner website. You can join and present your issues on the website. There are some really good technicians that prescribe to the website that can help guide you along. Sounds like you either have a module that is dead or a sensor shorting the data line. CAN buss. You can take a multimeter and check the 5 vdc at all the sensor connectors. They should all have a 5 vdc. If not, the sensor is shorted. Disconnect the connector. If the 5 vdc returns, you have identified the problem sensor. Another way is to disconnect every sensor and see if the problem disappears. That will tell you if you have a bad sensor. Thats a lot of work but may be the best route. If all the sensors are good, then its either a bad module or a shorted wire somewhere. Also, as has been mentioned, be sure every connector to all the modules, especially the ABS/Antilock brake module is completely connected. That connector has to be completely seated. If it isn't, it can cause some weird issues.
Thanks again I truly appreciate the info!
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