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Check Engine Light came on around 1400 miles, while first time driving the vehicle in ICE mode for more than 25 miles. OnStar ran diags and recommended taking into the dealership. Dealership took care of the "00540 - Surge Sensation" update and they talked with GM about the CEL. GM told the tech to clear the codes and okayed safe to drive the vehicle.. Repair invoice lists PP040B and P041B with Progamming Update Pending from GM. i.e. There is no fix for the issue and GM is working on an update. Apparently seems like a calibration or setting issue with a temperature sensor, coolant temperature sensing? I am really concerned of the temp sensor is indeed the coolant temperature sensor and if the sensor failure triggers off other more serious engine issues.

Hopefully an easy fix but makes me quite uneasy that GM was not able to find this issue in their testing or QC.
 

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First, if the code never comes on again, you are golden, but if it does:

Some modern engines use coolant in an heat exchanger to reduce the temp of exhaust gases that are recirculated into the engine. This reduces the NOx emissions.

It is an emissions fault, and they can't "blow it off". Resetting the CEL light is not the solution since it's emissions, and will cause it to fail an emissions test. The first part of a California emissions test is to check the OBDII emissions self-test and codes. A lack of a self test or code can cause it to fail the emissions test, regardless of what the tailpipe sensor says.

Can you drive it safely? Yes.

Since a software issue would affect all cars with that code, I smell BS. Not a Volt mechanic, but I'd think either the EGR valve or the sensor itself is faulty or sticking.

This happened to the initial release of the GM LBZ engines, and it was a batch of EGR valves to blame, hence why it didn't appear on all engines.
 

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This happened to me on my 2016. I took it to Courtesy Chevorlet in San Diego and they diagnosed and fixed the problem. It was a faulty sensor that had to be ordered from Detroit. My car was in the shop for 10 days. I have had no problems since.
 

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I have the same codes on my 2016. Will contact dealership for further details.
 

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I dropped my volt off at the dealership today to take care of the P040B and P041B codes that triggered the check engine light after the first ~350 miles. They said it was a false alarm, reset the code and applied an update.
 
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