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.?

 

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.

 

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

 

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.

 

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

 

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.

 

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.

 

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.

 

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.

 

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.