Nissan Altima Hybrid 2009 Cannot Start

Naabil Technician Ghana Posted   Latest   Edited  
2009 Nissan Altima Hybrid 2.5L (QR25DE) (RE0F01H) — 1N4CL21E19C113287
P0AFA — Hybrid/EV Battery System Voltage Low
P0AC4 — Hybrid/EV Powertrain Control Module Requested MIL Illumination
Crank / No Start

The vehicle went for service and they worked on the roof and also did some welding works on the frame because water was leaking in, the car did parked for long. after all the works the car cannot starts, the car was towed in and after hooking up the scanner all this codes came up I did try to erase but it still comes back and I change the 12V battery with new one still the car could not start this my first time working on Nissan Altima hybrid any advice on how I should start my troubleshooting will be welcome

Bill Owner
Bill Default

Check the diagnostic port for the HV battery. It can become disconnected.

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Eric Instructor
Eric Default

I think Bill may mean the HV battery disconnect device. Its in the trunk, on the right, forward as you are looking in to the trunk. behind a grey trim door. Its orange and may have been removed before any welding.

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Naabil Technician
Naabil Default

Got on the car this morning and it started so I drove around but it got stuck twice on the road i and all I have to isolate 12V Battery negative terminal and wait for 5mins before I got to workshop. it seems the fault has been found using the scanner on live data on the hv battery I found out block v17&16 voltages drops to zero while the remaining blocks voltages are constant. The attached…

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Matt Technician
Matt Default

I would remove the HV battery and check the sense wire connections for corrosion at the HV battery and also at the module. These are the small wires that connect to the copper bus bars of the pack and measure the voltage. The V-blocks intermittently dropping to 0 volts is strange. Typically the voltage modules (cells) develop high resistance internally and either remain low or drop down when…

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