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Wondering if anyone has encountered this. Car sat without battery connected as I was doing some repairs for 3 weeks. Attached is a video. Any ideas?? Thanks!
HP tuners and a generic scanner will not connect. Battery is a year old and always on a tender.
https://youtube.com/shorts/b0uzT_m2mh8?feature=share
Last edited by Nikoslab_Z06; Mar 10, 2023 at 06:16 PM.
If battery is fully charged at 12.66 volts and you still can't connect your scan tool this may be a "communication" issue with the car...if you have at least a DVOM there are a few checks you can do.
If battery is fully charged at 12.66 volts and you still can't connect your scan tool this may be a "communication" issue with the car...if you have at least a DVOM there are a few checks you can do.
I do have a DVOM. Scan tool powers up so I know the DLC on the car does provide voltage at the least
I do have a DVOM. Scan tool powers up so I know the DLC on the car does provide voltage at the least
OK, the first thing is please fill out your profile so we know what model year, mods, tune if any and transmission type and location since someone in the community may be close by to help...if the scan tool powers up that's good but if it can't connect that's another story...first we will check the integrity of the CAN wiring...disconnect the battery negative terminal and with your DVOM set on ohms see if you have around 60 ohms across pins 6 and 14 on the DLC (where you hook up your scan tool)...pic below of the DLC layout...reconnect battery and selects DC volts and see if you have around 2.5 volts at both pins 6 and 14 with ignition ON...you can use pins 4 or 5 for your ground or maybe the door hinge. CAN high CAN low DLC
Take your battery somewhere and have it checked first. Second, check the battery pos+ and ground- connections on both ends of the cables.
This^^^^^^^
Disconnecting and reconnecting the battery may have loosened the cables at their other ends simply because you were moving them, and the connection at the starter solenoid is a known problem area. The connection there may be good enough to power the tool, but not start the car.
And you say you did some work on the car. What did that involve?
Disconnecting and reconnecting the battery may have loosened the cables at their other ends simply because you were moving them, and the connection at the starter solenoid is a known problem area. The connection there may be good enough to power the tool, but not start the car.
And you say you did some work on the car. What did that involve?
Did both slave and master cylinders. Checked grounds and all were attached and none are broken. Checked starter wiring again. Everything looks good. My biggest worry is how the car boots up. It turns on, check engine light is on by itself for 8 seconds or so and the gauges sweep and the car comes to life
OK, the first thing is please fill out your profile so we know what model year, mods, tune if any and transmission type and location since someone in the community may be close by to help...if the scan tool powers up that's good but if it can't connect that's another story...first we will check the integrity of the CAN wiring...disconnect the battery negative terminal and with your DVOM set on ohms see if you have around 60 ohms across pins 6 and 14 on the DLC (where you hook up your scan tool)...pic below of the DLC layout...reconnect battery and selects DC volts and see if you have around 2.5 volts at both pins 6 and 14 with ignition ON...you can use pins 4 or 5 for your ground or maybe the door hinge. CAN high CAN low DLC
Awesome advice! Will be checking them! Updated my profile! However in case I messed up updating it, it’s a 2008 Z06, manual trans. AA kit, built ERL motor and a mantic triple disk. Thank you!
Awesome advice! Will be checking them! Updated my profile! However in case I messed up updating it, it’s a 2008 Z06, manual trans. AA kit, built ERL motor and a mantic triple disk. Thank you!
It's updated so thanks...next time you have an issue all we have to do is look at your profile so we have all your info right there...my break out box is an easy way to check the DLC and has lights that will blink if there is communication on pins 6 and 14...I always keep that thing plugged in between my scan tool and the DLC for any no start issue.
OK, the first thing is please fill out your profile so we know what model year, mods, tune if any and transmission type and location since someone in the community may be close by to help...if the scan tool powers up that's good but if it can't connect that's another story...first we will check the integrity of the CAN wiring...disconnect the battery negative terminal and with your DVOM set on ohms see if you have around 60 ohms across pins 6 and 14 on the DLC (where you hook up your scan tool)...pic below of the DLC layout...reconnect battery and selects DC volts and see if you have around 2.5 volts at both pins 6 and 14 with ignition ON...you can use pins 4 or 5 for your ground or maybe the door hinge. CAN high CAN low DLC
busted out the dvom. 2.3 volts on 14, 2.8 volts on 6. However there is 121 ohms across them with the battery disconnected
busted out the dvom. 2.3 volts on 14, 2.8 volts on 6. However there is 121 ohms across them with the battery disconnected
Ouch !!…well it’s NOT a battery issue !!…normally CAN high and low added together should read about 5 volts so you’re good there but looking at the signals with a scope is the preferred method…seeing 120 ohms is an open in the CAN bus wiring or a bad 120 ohm resistor (these 2 resistors are in the BCM and EMC and are at either end of the CAN network or a module that may have been unplugged and not plugged back in correctly…you said there were repairs done for 3 weeks…were any modules disconnected like ECM,BCM, or any others ???
Ouch !!…well it’s NOT a battery issue !!…normally CAN high and low added together should read about 5 volts so you’re good there…seeing 120 ohms is an open in the CAN bus wiring or a bad 120 ohm resistor (these 2 resistors are in the BCM and EMC and are at either end of the CAN network or a module that may have been unplugged and not plugged back in correctly…you said there were repairs done for 3 weeks…were any modules disconnected like ECM,BCM, or any others ???
found there was some corrosion on the pins to the abs connector at the abs module. Cleaned up, dialectric grease and were back in business. Thank you for all the replies and help. It definitely got me in the right mindset as to what I should be looking for.
found there was some corrosion on the pins to the abs connector at the abs module. Cleaned up, dialectric grease and were back in business. Thank you for all the replies and help. It definitely got me in the right mindset as to what I should be looking for.
Great !!…normally these issues are seen on modules that reside on the outside of the car…it’s a good thing a dealership didn’t look at this…they most likely would have replaced everything in the starting system, battery, EBM and BCM and who knows what else !!…you just have to be careful where you use dielectric grease since it’s an “insulator”…I wouldn’t use it on low current circuits such as the airbag system and on the ECM…there are products that are actually contact enhancers !!
Great !!…normally these issues are seen on modules that reside on the outside of the car…it’s a good thing a dealership didn’t look at this…they most likely would have replaced everything in the starting system, battery, EBM and BCM and who knows what else !!…you just have to be careful where you use dielectric grease since it’s an “insulator”…I wouldn’t use it on low current circuits such as the airbag system and on the ECM…there are products that are actually contact enhancers !!
Great info on the grease. I definitely didn’t go overboard and pack it in. Just a slight touch on the pins. Again thank you for the awesome info!
Having this very same issue. Getting 121 OHMs with battery off. Having a "no comm" issue with every module but bcm. Car was running just a month ago. When i go to BCM X2 connector, i can move the wires around and get very sporadic numbers. Need to re pin a few of them? Unsure of where to go next. Nothing looks out of whack or damaged.
Having this very same issue. Getting 121 OHMs with battery off. Having a "no comm" issue with every module but bcm. Car was running just a month ago. When i go to BCM X2 connector, i can move the wires around and get very sporadic numbers. Need to re pin a few of them? Unsure of where to go next. Nothing looks out of whack or damaged.
If you have communication with just the BCM you have a broken wire between the BCM and the VCIM (Onstar)...we need to know model year and whether you have an auto or manual trans...you need to do a terminal tension or "pin drag" test on the CAN lines at the BCM...you need to check for continuity between the CAN + and - from the BCM to the VCIM if you have it (RPO code UE1)
If you have communication with just the BCM you have a broken wire between the BCM and the VCIM (Onstar)...we need to know model year and whether you have an auto or manual trans...you need to do a terminal tension or "pin drag" test on the CAN lines at the BCM...you need to check for continuity between the CAN + and - from the BCM to the VCIM if you have it (RPO code IE1)
Thanks for the reply. This is a 2013 Z06, 60th anniversary stick car. Thinking maybe the EBCM? I get 120 at the X4 VCIM plug. When BCM plugged in.
But When BCM unplugged, ECM plugged in. The next daisy chain looks like the EBCM, i get 120 ohms to the EBCM connector. Plugged back in - Next i go to the ESC module and have OL. My issue EBCM module?
I don't know what terminals you are checking at the X4 connector...if you checked terminals 2 and 3 which goes out towards the ECM where the other 120 ohm resistor is then the wiring is good out to the ECM...if you have continuity from 8 and 9 going towards the BCM then that wiring is good...remember to jumper 6 and 14 at the DLC to check continuity...if you read 120 on BOTH 8 and 9 and 2 and 3 then it may be the VCIM transceiver in the VCIM module is bad....you can jumper 9 to 3 and 2 to 8 and see if you now have 60 ohms... this is easy to diagnose....below is the correct schematic for your 2013...that is why it is VERY important to let us know the model year and transmission type...the rectangular boxes are the RPO codes...if you see -UE1 that means you DON'T have Onstar...you have the LS7 so just follow that on the other modules....you are a Performance shop in Texas ???
If you are a Tech at this shop you can get some great training by John Thornton at automotive seminars.com on CAN and other types of training....I normally do this training monthly....you DON'T learn this stuff turning wrenches !!!
C6 z06 No start/ delayed boot up on dash
