Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

hello, i rebuild wrecked cars, and this my first hybrid.
I bought a silverado 6.0L hybrid 2009 that doesnt start, i will have the silverado
with me in 2 weeks or so. The silverado has a hit on the back left corner, just on the left corner light.
been reading and came acrross that instruction shown in the picture.
I believe the HVCID crash sensor was activated and car wont start.

Need to replace the HVCID sensor and reset codes.
My question is where can i buy this sensor ?
and also will i need a GM tech 2 scanner or can i use a cheap OBD2 code to clear the code on the or Hybrid power train control module.?

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

A sensor crash detect "latches". Yes you need a Tech 2 or other Dealer service tool to re-set. Also you need to reset in 2 computers. I think hybrid and SDGM.

Parts will be dealer only right now.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

ok, So i will need tech 2 to reset codes.
Is there any ECM or repair manual you could share?
thanks.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

No manual I can share, I have on-line subscriptions through work.

The main thing to know about GM hybrids is... The engine is NOT the lead dog pulling the sled anymore. The hybrid computer is in charge.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

Dear, I have rebuild chevy tahoe hybrid too. it does not start. do find solution.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

What I found is this.

These vehicles contain a high voltage circuit impact detection(HVCID) sensor in addition to the supplemental inflatable restraint(SIR) impact sensors. The SIR sensors are designed to identify the severity of a collision and from what direction a collision has occurred. The SIR sensors typically detect collision conditions for occupant impact-protection reasons. The HVCID sensor is located in the front of the vehicle and is designed to detect an offset collision that may have damaged the high voltage system. The drive motor generator control module, also called the hybrid powertrain control module(HPCM), will open the high voltage contactor relays and disable the vehicle whenever an SIR deployment occurs or the HVCID sensor detects a collision event. The HVCID sensor detection of a vehicle impact does not cause SIR deployment.
The serial data gateway module(SDGM) monitors the HVCID sensor for collision/impact detection and operational status. The SDGM transmits a GMLAN message to the HPCM whenever an HVCID impact event or sensor fault is detected.
A complete inspection of the high voltage(HV) system and components must be performed if the vehicle has been involved in a collision. The HVCID sensor and/or SIR Deployed vehicle-disable condition will remain active until cleared by the HPCM output control function of the scan tool.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

If you have a no start, there can be a myriad of reasons. You need a sophisticated scan tool for these.

A collision detected has to be cleared in HPCM and SDGM.

If air bags deployed there may be another.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

HVCID and/or SIR Deployed Vehicle Disable Condition Clearing Procedure

1.Perform the Inspection Procedure if the vehicle has been involved in a collision.
2.Ignition ON, clear the SDGM vehicle disable condition with a scan tool.
•If the SDGM had a HVCID sensor fault DTC, repair the condition and clear SDGM DTC Information.
•If the SDGM had an HVCID collision detection condition, perform the SDGM Crash Sensor Reset special function.
3.Ignition OFF, wait 2minutes.
4.Ignition ON, clear the HPCM vehicle disable condition with the scan tool HPCM Clear 300V Impact Detection Status special function.
5.Ignition OFF, wait 2minutes.
6.Perform the HV Enable Procedure. Refer to High Voltage Enabling.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

I bought salvage Tahoe hybrid to built hybrid offroad truck.

I installed 7.5" lift kit, big tire, G80 diff and hitch tire carrier. Now ready but engine does not work. It is gonna be first lifted hybrid for off-road.

Air bags were deployed. I removed all side airbags because I don't need them for off-road. New airbag for driver.

Engine does not start and has Service hybrid system message. Scangauge II gives code.
P0AC4 -????
C1233 ABC SYSTEM
U1888 HCM LOST COMMO WITH ESCM

I stuck. don't know what i do. :)

Advice please.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

P0AC4 means that the Hybrid told the Engine to turn on the Check Engine Light.

Now you need to figure out why the hybrid is mad. Are both high speed CAN busses intact?

The hybrid, brakes, power inverter, DC to DC converter APM, SDGM, and an inertia sensor under passenger seat are ALL on the second CAN bus.

Like a string of Christmas lights... pull one out... and... nothing.

That vehicle has 2 ( 2-wire ) data busses and the single wire common to non hybrids.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

Dears,

I found GM AIRBAG MODULE RESET / REPAIR SERVICE. Do you think it will work for me?

http://karmanauto.com/product/gm-air...repair-service

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

The SDGM holds the latch. If the air bag module keeps sending errors then yes.

The interdependancy of all these systems makes the hybrid much more difficult.

Have you aquired a Tech 2 or equivalent yet?

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

tech 2 is too expensive. there is clone one but i am not sure they works

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

Your earlier post says you installed a G80 "locking" diff. What happened to the locker that came with the hybrid.

Based on pictures it is the same Eaton unit.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

i was about to the a clone of the tech2 from china.
But they hold because they didnt know if it would work with the Silverado hybrid.

My truck has airbags intact.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

Hillbily Hybrid
do you have access to the silverado hybrid 2009
HVCID sensors locations and DTC related to it?
I would donate from paypal if you could help.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

If air bags did NOT deploy, there should be NO air bag fault. A collision detected sets faults in CGM and Hybrid controllers.

The only way to clear them both is with Tech 2. Changing a sensor may only complicate things.

The collision sensor High Voltage Circuit Impact Detection Sensor is under the radiator about center of vehicle. I think a single bolt holds it on.

You can set a crash detected by hitting a large deer.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

I will check the truck on sunday, weird thing is that,
The crash was on the rear, im starting to believe its the
POC76, code when they tried to jump start the car with a dead battery.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

There is a seervice bulletin about 2 Mode No Crank After Discharged Or Dead 12v Battery setting that code.

Still need Tech 2 and still need to reset 2 controllers using Special Functions.

No parts needed. NO shortcuts allowed.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

I changed impact sensor, sent air bag module to reset.

Then I got my Tahoe hybrid to dealer. No success. :(

Dealer will change 2 high voltage contactor/relays in HV battery. this is only chance now. Both sounds like stuck open.

There are 2 relays in positive and negative line. Each costs almost 100$ and total 200$.

Dealer said that 3rd relay can be changed and it costs 200$. So we will try not to change it.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

What makes them think the contactor relays are bad?

You can simply power them with 12V to test them. You can do that without taking them out of the pack.

NEVER heard of one going bad. Same parts as Prius.

Third relay is Pre-Charge. If it's bad you won't go either.

These guys are going fishing on your dime.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

You are right. I called dealer told them to chack it with 12V. They are very upset.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

918$ for reset, what a rob

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

Did they make it run for that?

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

That won't be the first dealer service department that took ME off the Christmasl List.:shade:

Where is this at? What dealer?

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

Did you ever fixed Code U1888?

Engine does not start and has Service hybrid system message. Scangauge II gives code.
P0AC4 -????
C1233 ABC SYSTEM
U1888 HCM LOST COMMO WITH ESCM

I stuck. don't know what i do. :)

Advice please.[/QUOTE]

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

PoAC4 = Check Engine Light. So now you need to find out what has the hybrid computer mad.

U1888 can be a bad wire or connection somewhere in the Controller Area Network CAN communication wires. Are there some unplugged wires anywhere? Something that got moved and maybe chaffed a wire?

Still under warranty? There is a very long GM service bulletin on that code.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

Havent checked that well, the pickup is in a parking lot.
i just had time to pull the codfes, and i got U1888 and P0AC4
This CAN wires go beneath the Chassis? or below the car carpet?

U1888 can be a bad wire or connection somewhere in the Controller Area Network CAN communication wires. Are there some unplugged wires anywhere? Something that got moved and maybe chaffed a wire?

Still under warranty? There is a very long GM service bulletin on that code.[/QUOTE]

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

Could code U1888 be triggered by a dead 12v battery?

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

Dead 12V usually causes a multitude of codes. Several of the same code number from multiple computers all complaining about low system voltage. AND MORE "U" codes... lots of them.

The U1888 is related to the main High Speed communication bus wires.

These main communication wires are tan in color and twisted. One is tan with a black stripe.

The GM dealers have a hard time figuring these out with their specialized scan tools.

However with a good quality ohm meter there is a test you can do.

At the OBD diagnostic connector, the black trapezoid that Scan Gage and others use, pins #6 and #14 are that main communication pair of wires.

If you removed or altered any seemingly unnecessary modules that had tan twisted wires to them... that could be a problem.

With the 12V battery disconnected so ALL the computers are OFF, there should be anywhere from 59 to 62 OHMs across them.

All the computers have to be asleep to do this basic test.

Have you cleared codes and seen what comes back? You have to clear Engine, Brakes, Hybrid, HV Battery, and the Transmission to get a clean sheet. The engine computer is just a SLAVE in a 2 Mode. It is n ot in charge, the Hybrid is.

I can't reinforce that enough. So if you have done any body/structure repairs near a pair of twisted TAN wires... one with a black stripe... start there. These are NOT dome light wires.

Have you removed any seemingly unnecessary modules? Have you had to do body/structure repairs? A slightly imperfect connection on one of those tan wires can cause this. A tiny single strand of copper from a chaffed tan wire touching ground for 0.040 seconds can do it.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

I have a PoC76 in my 2009 Yukon hybrid the definition is high voltage detected what would the cause of this be

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

That code sets if the high voltage does not ramp down fast enough. Was something being worked on? Some major computer or component un-plugged before the truck was properly shut off?


You need dealer scan tool to re-set it.

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

I have a 2010 gmc sierra that the battery died i was able to jump it once after i killed it would not start at all not even by jumping it i bought a new battery and all this has been about 4 months it has been sitting in my drive way i take the battery to get it charged every few weeks or so just so it wont be without power finally have alittle money to maybe have it taken in if i have to i have checked fuses grounds had a mobile mechanic come try to diagnose the problem with no luck only code that comes up is service hybrid system anybody have any ideas or help they may be able to offer

Re: Hybrid silverado 2009 wont start after collision, HVCID crash sensor code?
 

You need to plug in a scanner into the OBD2 port and read the codes to even begin to troubleshoot. Tell us what codes you get.