Hello I have a 2012 Tahoe hybrid that I just bought from an auction as a non runner. When it was delivered I did make the mistake of trying to jump the 12v battery. Now after looking through these forums I know that was wrong. I did end up putting a new battery in. Everything works in the vehicle as it should but the vehicle does not crank. I used my code reader and pulled codes
p1afe
P0ac4
P0c08
P0521
​​P0521
I've been reading the forums and no that it's bad to jump the battery but did not find anyone that also had these dtcs. Can someone please point me in the right direction? I'm a heavy duty diesel Technician so this hybrid thing is very new to me. Thanks in advance

 

P1AFE = Drive Motor 2 Control Module Shutdown Performance, possibly open or short in one of the 3 power cables going to Drive Motor 2.
P0AC4 = Hybrid Powertrain Control Module Requested MIL Illumination (just saying the HPCM told the ECU to turn on the Check engine light)
P0C08 = Drive Motor 2 Phase U-V-W Circuit, The MCM detects at least one U-V-W phase current sensor is less than 9 amps. (sounds like an open in one of the phases)
P0521 = Engine Oil Pressure Sensor Performance (This seems like it should not prevent the truck from running, troubleshoot the other codes first. Make sure the correct weight engine oil is used (5W-30)).

Make sure you pull out the orange safety plug on the battery before working on any high voltage (300VDC) orange cables. when reinstalling the safety plug, be sure to slide the handle upwards after pushing it in, otherwise you'll get a new code and the truck wont start.
Also, if the truck has been sitting somewhere for months/years, then it's highly likely the hybrid battery is dead. You can try opening it up and charging it (search for forum posts that discuss this). There is also a way of charging the battery by using a built in "Jump Start" mode that is available in the official GM scan tool. I know the 2008's had it, but not sure about 2012. This requires a high current 12V battery charger (60A+).

 

yeah the jump start mode is what's needed to jump it, I've got a bidirectional otc scanner that has the option. if you have a good scanner from work and it covers obd2 cars, it might have the option. the dealer level definitely have it, but it seems some of the other more high end ones do too.

if you do, also check the voltage from the hybrid battery. it would help to know if it's dead, or has enough to start the truck. at the end of the day, there's no starter motor, that front motor in the tranny spins the engine over while cranking. so the code for the motors in the tranny are probably important. also the actual battery voltage, over all and each cell voltage is good info to know

it does seem these trucks hate to be parked a long time.

 

I don't know if this will help or not, but this is what I get for your first code.

 

Hopefully it is just a dead hybrid battery, Any signs of an accident or flood damage? How many miles on this unit?

 

no signs osiaccident or flood damage. 160k miles. I have a scanner coming in at the end of the week going to attempt to enter jump start mode

 

Might turn out to be a good buy if just a dead hybrid battery. I think Greenbean still does the rebuilt hybrid batteries for around 3k

 

Thats the hope. I'm only in it for 4k right now so hopefully I can get the battery to charge but if I can't and have to but a new battery then I'm still not in it for too much money.

 

UPDATE
Truck will crank for about 10 seconds and then stop. and wont let me try to crank again for a little bit. Same codes are active. Trouble shot the p0C08 and p1AFE and troubleshooting wants me to replace the hybrid motor inverter. does this sound right? I wouldn't think it would crank if the inverter were truly out. I have not been able to get it into jumpstart mode but I am reading 290 volt on the battery and .1 amp in each each cell.

 

If it cranks and the ICE does not start I would concentrate on the ICE and verify fuel and spark. If no fuel pressure then reset the fuel pump cut off switch and it should fire right up.
Note: I have gone t the DARK SIDE now just picked up a Toyota 4Runner TRD Off-Road Premium but still enjoy reading these forums when I receive an email notification. Good Luck on the 2012 maybe it is just a small issue with the ICE. Maybe the fuel pump itself is dead?

2023 4Runner replaced the 2009 +266k mile TaHoe beater ride. I call this one BBR the Better Beater Ride LOL