Aux pump and the Starter relay 3 stuck on

[john.malaban]

Hi everyone,


For the past couple of months I’ve been getting recurring errors related to the auxiliary coolant pump on my 2.0 ESS engine. I’ve already swapped in two different pumps, but the problem is still there.


The fault codes are:


• U02A9 – Lost communication with charge air cooler coolant pump “A”
• P023B – Charge air cooler coolant pump “A” control circuit low


Recently I also started getting a warning that the car may stop soon, along with:


• P2AF5 – Starter relay 3 stuck on
• U012D – Lost communication with generator “A” (alternator control module)


So far I’ve replaced:

• both batteries (main and auxiliary)
• N fuse
• Electrical relay 56029766AC
• Battery IBS sensor

Voltage stays constant at around 13.7V, but the errors keep coming back.


Has anyone experienced something similar or have any ideas where else I should look?

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[THAW]

https://www.jlwranglerforums.com/fo...ery-light-and-low-voltage.154795/post-3198084

 

[john.malaban]

Thanks, I’ll check this as well. Since the voltage was constantly around 13.7 V, I assumed it couldn’t be related to the alternator.

 

[john.malaban]

the problem was from the alternator exciter wire connection. It was green.

 

[Hasan mahajna]

the problem was from the alternator exciter wire connection. It was green.

What do you mean ( green )
My jeep through battery light on dashwhen i accelerat. and i replaced the both batteries 6 months ago ,, i think its the ibs sensor and searching for one ( the original not available in my country for now )

 

[john.malaban]

Green Oxidate - corrosion

 

[john.malaban]

also, you can check/debug if you remove the ibs sensor, have the same error. As well the on the alternator, if you remove the can senzor/ exciter connector.

 

[d k]

I am experiencing the same condition at the moment!

Did cleaning the corroded contact fix the issue?

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