[StartrekMike]

Sister's car was fine. Went to store and came out to no crank, jump started and drove home. Has not cranked since.
New battery, confirmed start circuit OK. Scanner could not communicate with PCM to check brake application and gear selector. Towed to my house. Was able to communicate with PCM but data view is erratic on/off. While checking relays I found that with ignition relay removed, I can communicate with PCM with no erratic readings, confirmed brake application and start button request. While scanning I do not see any BCM data. If Ignition relay is installed I can see ABS and RSS module and shows active loss of communication with PCM/TCM and PCM communication is erratic. Checked PCM and BCM power & grounds good. Any experienced help and input is appreciated.

 

[Mountain Escape]

Sister's car was fine. Went to store and came out to no crank, jump started and drove home. Has not cranked since.
New battery, confirmed start circuit OK. Scanner could not communicate with PCM to check brake application and gear selector. Towed to my house. Was able to communicate with PCM but data view is erratic on/off. While checking relays I found that with ignition relay removed, I can communicate with PCM with no erratic readings, confirmed brake application and start button request. While scanning I do not see any BCM data. If Ignition relay is installed I can see ABS and RSS module and shows active loss of communication with PCM/TCM and PCM communication is erratic. Checked PCM and BCM power & grounds good. Any experienced help and input is appreciated.

Welcome to the city, Mike
here is your red shirt.
You replaced the 12V battery? Did someone else replace the 12 V battery and it won't start, no?
Visually inspect battery terminals, and make sure that all wires have been reconnected, some accessory wires are not part of the main battery terminal clamps. I've seen dumber stuff.
I'm going to suggest that you disconnect your battery, wait for two minutes… Then touch your positive negative cables together, then reconnect to terminals.

When you jumpstarted it, and you drove it home… Were there any fatal messages, or lights on your dash?

when you go to turn your car back on… Engage the ignition without the starter(koeo), wait until you hear no electronic sound from your vehicle before attempting to start… This may be a couple of secs... a full 30 if you want to be sure.

The only other night and day switch like thing I have seen happened like this, is the battery has failed in your key fob. Can you still remotely start/ lock and unlock your doh from inside your house?
you're not Hybrid are you?
Never mind… I don't think the 1.6 was in a hybrid.

 

[dwightbresemann]

Can scan for codes? Run engine-off, key-on self demand test (KOEO). Check all fuses.

 

[StartrekMike]

Welcome to the city, Mike
here is your red shirt.
You replaced the 12V battery? Did someone else replace the 12 V battery and it won't start, no?
Visually inspect battery terminals, and make sure that all wires have been reconnected, some accessory wires are not part of the main battery terminal clamps. I've seen dumber stuff.
I'm going to suggest that you disconnect your battery, wait for two minutes… Then touch your positive negative cables together, then reconnect to terminals.

When you jumpstarted it, and you drove it home… Were there any fatal messages, or lights on your dash?

when you go to turn your car back on… Engage the ignition without the starter(koeo), wait until you hear no electronic sound from your vehicle before attempting to start… This may be a couple of secs... a full 30 if you want to be sure.

The only other night and day switch like thing I have seen happened like this, is the battery has failed in your key fob. Can you still remotely start/ lock and unlock your doh from inside your house?
you're not Hybrid are you?
Never mind… I don't think the 1.6 was in a hybrid.

Dwight...there are assumptions I've had to make. Original battery was dead hence the jumpstart. Battery replaced by sister has not cranked since, all terminals super clean, ALL fuses, relays, etc in multiple junction boxes checked and rechecked. I have yet to reset all modules by your recommendation. Key fob works to lock/unlock and system senses when keyfob is not nearby. Tried the proximity trick to no avail.

 

[dwightbresemann]

You mentioned checking the fuses. All fuses? I think there are 5-6 different fuse blocks. Have you had a chance to scan the vehicle? What is the state of charge for the new battery?

 

[StartrekMike]

Can scan for codes? Run engine-off, key-on self demand test (KOEO). Check all fuses.

This is where is gets head scratch fun. As car sat I could not read PCM. IF I was able to communicate, the codes were apparent due to unplugged sensors, no major U codes. When monitoring any PIDs, the data reads erratic... Ex. brake position applied...shows OFF...N/A...ON...N/A...ON. When monitoring module supply voltage, Ex 12.6V....N/A....12.6V....N/A. just like that. I can watch a graph of this and see the ups and downs with no specific pattern. If I remove the ignition relay. and turn key(button) off/on the readings are steady 12.6V with no drops and the same for all other PIDs. At this time I can only read PCM, ABS and RSG...No BCM communication. I believe this is where my fault lies.

 

[StartrekMike]

You mentioned checking the fuses. All fuses? I think there are 5-6 different fuse blocks. Have you had a chance to scan the vehicle? What is the state of charge for the new battery?

Fuse areas checked = BJB including Maxi fuses (especially the start circuit fuse), BCM and rear panel. State of charge is something I just learned about. I have had to recharge new battery a few times due to long diagnostic time. I was unaware that I had to charge battery on the BMS side and not on the battery direct. I have since reconnected my charger and plan to check battery state of charge the next time I work on this.

 

[dwightbresemann]

Disconnect both battery leads and charge the battery directly until the charger turns off and battery fully charged. Disconnecting the battery leads allows all the capacitors to fully discharge. Once the battery is fully charged, connect leads. Connect multi-meter in the 20V dc range to the battery, so you can view the meter. Turn key on for 3 minutes, but don't crank. Turn key off. Now try to crank and read battery voltage from the meter.

 

[Mountain Escape]

Fuse areas checked = BJB including Maxi fuses (especially the start circuit fuse), BCM and rear panel. State of charge is something I just learned about. I have had to recharge new battery a few times due to long diagnostic time. I was unaware that I had to charge battery on the BMS side and not on the battery direct. I have since reconnected my charger and plan to check battery state of charge the next time I work on this.

It almost sounds like you got a bad battery... I know it was just replaced by your sis

you should not have to recharge your brand new battery after a few minutes of diagnostic time

In this case, I disagree with Dwight
do not charge a brand new battery, return it.
Brand new you should be reading over 13V 13.7 or so
I think if you have had to recharge it several times, it is bad.

you shouldn't have to charge this battery at all, it hasn't done anything. A few minutes with the ignition on, pulling diagnostic codes shouldn't even phase a brand new battery.
even an hour or so

Red shirt test it. Put the old battery back in, jumpstart it and see if it'll start/run again.
I may have missed it, have you tried jumpstarting the new battery?

last thing I could suggest is make sure your terminals aren't reversed… I can't imagine what else would immediately kill a car
I don't think you could pull codes though

 

[StartrekMike]

It almost sounds like you got a bad battery... I know it was just replaced by your sis

you should not have to recharge your brand new battery after a few minutes of diagnostic time

In this case, I disagree with Dwight
do not charge a brand new battery, return it.
Brand new you should be reading over 13V 13.7 or so
I think if you have had to recharge it several times, it is bad.

you shouldn't have to charge this battery at all, it hasn't done anything. A few minutes with the ignition on, pulling diagnostic codes shouldn't even phase a brand new battery.
even an hour or so

Red shirt test it. Put the old battery back in, jumpstart it and see if it'll start/run again.
I may have missed it, have you tried jumpstarting the new battery?

last thing I could suggest is make sure your terminals aren't reversed… I can't imagine what else would immediately kill a car
I don't think you could pull codes though

Thanks Mountain,
The charging has been taking place due to a parasitic draw that I am just now finding is happening. This weekend will see if draw is associated with the BCM issue.

 

[Mountain Escape]

Thanks Mountain,
The charging has been taking place due to a parasitic draw that I am just now finding is happening. This weekend will see if draw is associated with the BCM issue.

I guess the easiest way to determine that would be disconnecting the module? checking voltage night before with full batt charge, and the morning after