Seems this last week new problems started. I lost my alternator and had to replace it. The battery was disconnected about 24 hours while I installed the new alternator. My HHR is a 2008 with 2.4.
All seems ok other than the ambient air reading on the dash is not right at all. The first day or two it was real crazy going from 120 to 133. Now it is closer to actual but still off. We are very hot here in TX. When it is now 100 the reading on the dash is 110 to 115 and often floating back and forth.
Is there a way to calibrate or do I have to replace the sensor. Can someone tell me where the sensor is for sure and is it just a plug in mounted somewhere.
THANKS
AL

 

2008s cannot deal with extended lack of battery. There is a TSB about it, you may need to have the firmware reloaded.

There is no calibration for the sensor.

I know that somewhere in the 81 results I got for "ambient air" there are pictures of the location, I only had a few minutes to look. If you got time give the search tool a shot.

 

Certain year/models, the sensor is hidden deep under the bumper like the picture below.(yellow circle shows location )
I believe the other location is easy to find just in front of the radiator.

 

I think this is the tsb that was mentioned.

#08-03-16-001B: Key Fobs Inoperative, TPM System Not Reading Correctly - Dashes on Al Four Tire Readings, DTCs C0775, C0569, B3105 Set, Unable to Program TPM Sensors (Reprogram RCDLR) - (Jul 31, 2008)


Subject: Key Fobs Inoperative, TPM System Not Reading Correctly - Dashes On All Four Tire Readings, DTCs C0775, C0569, B3105 Set, Unable to Program TPM Sensors (Reprogram RCDLR)


Models: 2008 Chevrolet Cobalt, HHR, Malibu

2008 Pontiac G5, G6, Solstice

2008 Saturn AURA, SKY

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This bulletin is being revised to update the Important statement to reflect the new direction to no longer contact TCSC. Please discard Corporate Bulletin Number 08-03-16-001A (Section 03 - Suspension).


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Condition
Some customers may comment that the key fobs are inoperative or that the TPM system is showing dashes as the reading for all four tires.

Technicians may find DTCs C0775, C0569 and B3105 set simultaneously in the RCDLR module.

In addition, the technicians may find Tire Pressure Monitoring sensors are unable to be programmed to the vehicle by adding or releasing pressure to the tire while the vehicles in the TPM learn mode.

Cause
These conditions may be caused by the following:

• The RCDLR may lose its transmitter and tire pressure monitoring data from its memory if a low voltage condition occurs on the vehicle.

• The ability for TPM learning by adding or releasing pressure to the tire has been disabled in the RCDLR.

Correction
Reprogram the RCDLR with an updated software calibration to address both issues listed above. This new service calibration is available on TIS2WEB using Service Programming System (SPS). As always, make sure your Tech 2® is updated with the latest software.

Important: If the Tech 2® could not establish communication with the RCDLR AND the programming event ended with error, attempt to reprogram in Service Programming System (SPS) by selecting "Remote Control Door Lock Receiver (TSB 08-03-16-001) with E4399 error -- Pass Thru Only".

Once the RCDLR module has been reflashed with the latest software and calibrations, the following may also be necessary:

• Relearn all keyless entry transmitters.

• Reconfigure the tire pressure placards and the tire type.

• Relearn the tire pressure sensors.