P0A9B OBD Error Code: Problem & Solutions

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The trouble code P0A9B can be elucidated as Hybrid Battery Temperature Sensor "A" Circuit. The temperature of each and every battery cell is monitored with the help of multiple sensors of the hybrid battery pack. The error code P0A9B will be set if an unbelievable temperature is reported by at least one of the battery temperature sensors. The failure in multiple sensors will likely disable the high voltage system.

The battery temperature sensor is present in 3 positions of the HV battery. If the HV battery temperature changes, then the thermistor’s resistance that is inbuilt in every battery temperature sensor will also keep on changing. If the thermistor resistance is high then the battery temperature will be low and similarly if the temperature is high, then the resistance will be low. The HV battery temperature is identified by the battery smart unit with the help of battery temperature sensors and this identified value is further sent to the power management control ECU. If the HV battery temperature rises above a fixed level, then the blower fan will start functioning.

What causes this problem with the Hybrid Battery Temperature Sensor "A" Circuit?

• Malfunctioning HV battery assembly
• HV battery assembly harness might be unlocked
• HV battery assembly circuit might have bad electrical connection
• Unusable battery smart unit

1. Engine Control Module - Dead cells in batteries can cause a failure in the engine control module. Many times, a battery is left in the rig long after a cell has died. This would affect the grounding in the car battery.
2. Powertrain Control Module - If there are some faults in the PCM, then it may throw off the timing and fuel settings of the engine, which can negatively affect the performance. A flawed PCM may cause the vehicle to experience a reduction in fuel efficiency, power as well as acceleration. Buy high grade PCM online from us.
3. Electronic Control Unit - Do you know that the poor performance or unexplained drops in fuel economy or efficiency are often associated to onboard car computer problems, or defective ECU issues? It's better to replace it with a brand new one.
4. Hybrid Battery - Whenever the hybrid battery fails, one is likely to experience a fall in the MPG. Apart from this, a failure in the hybrid battery is likely to trigger symptoms that may lead to an unusual MPG. in addition to these the driver is likely to observe a high mileage. So, in order to prevent expensive repairs, we recommend you to change the hybrid battery right away from Parts Avatar.
5. Battery Coolant Pump - Even if the temperature sensor is working properly, the battery coolant pump can be at fault and may need replacement. If the pump is not responding to the PCM requests, then the malfunctioned pump can cause overheating of the battery which in turn can affect the vehicle performance.
6. Coolant Hoses/Pipes - Damaged hoses and pipes can cause leakages and thus reduce the effectiveness of the cooling system. Thus, cracked and damaged pipes must be replaced immediately.
7. Cooling System - There can be many components in the cooling system that can be faulty, causing battery overheating and underperforming. So, replace the faulty components immediately.
8. Battery Temperature Sensor - If the temperature sensor is faulty, the ECU will not be able to calculate the battery temperatures and the battery can overheat or run cold. Thus, it is important that the temperature sensors work properly so that the ECU can control the blower fan to manage the temperatures. Buy new battery temperature sensors form us.

You might be thinking that how would you diagnose these problems? We at Parts Avatar Canada would help you diagnose the major symptoms easily.

Common Symptoms

• Visibility in the check engine light

Looking out for some ways with the help of which you can correct this fault code? Then you have arrived at the correct place. We are here to help you out, so you must check out the steps mentioned below as follows:

• You must fix the defective HV battery assembly
• Rehabilitate the defaults in the HV battery assembly harness
• The malfunctioning HV battery assembly circuit should be repaired or replaced as per the need
• Recondition the non-functioning battery smart unit

There is no need to get strained if your OBD Code is still flashing up as we are here at your service. Have a look at our superior variety of HV battery temperature sensor, HV battery assembly, battery smart unit, HV battery assembly harness, hv battery, pcm, ecm, ecu, pcm module, ecm module and many more. Now all your problems would vanish within no time.

Here are some steps which you should follow in order to diagnose this fault code:

• This is a general type of error code which is diagnosed with the help of a scanner.
• The mechanic will insert a scanner to diagnostic port of the vehicle and recover the codes and freeze frame data.
• If he happens to find any additional error codes, he has to address them as well.
• Once it is done, he has to reset the vehicle, and then test drive to see if the error code appears.
• If the error code does not return, then there can be an erratic condition.
• Then the mechanic has to check the wires, connectors and other electrical components and quickly replace them if he finds them to be damaged or defective.
• Check for the damaged hybrid battery temperature sensor "A" circuit and its components for error. It the mechanic finds the fault in the connectors in relation to the hybrid battery temperature sensor "A" circuit, replace it immediately.
• Also check for the particular battery cells emitting high voltages and thus might need battery replacement as well.
• Parts or components should not be replaced with reference to only a P0A9B DTC. The vehicle service manual should be consulted for more information on possible causes of the fault, along with required testing.
• If all the components seem to work perfectly, inspect the PCM for faults and replacement along with reprogramming.

Common Mistakes When Diagnosing The P0A9B Code

• High voltage battery assembly might start failing
• Flaws in the high voltage battery interface control module
• Issues with the car wiring