Technical Check engine warning - alternator issue?

[dank]

A week ago, the engine check light displayed on my Grande Punto (06). Despite no noticeable power loss, I took it to a local garage to do a diagnostic check. They said they found an error code indicating it was an alternator issue.

After replacing the alternator and driving only 10 miles, the engine check light reappeared. Now, with the garage closed for the weekend, I'm left wondering about the underlying cause. If the initial error code pointed to the alternator, and it has since been replaced, what else could be triggering the warning light?

 

[dank]

Since posting the above, I managed to get my hands on an OBD2 scanner (ELM327 + Torque Pro app) and the fault displayed is O2 Sensor Circuit (Bank 1 Sensor 1).

Is it possible the mechanic may have accidentally done something to the sensor when changing the alternator, or am I just unfortunate that another issue has arisen in the space of one week?

 

[Greasytrucker]

I very much doubt the check engine light in the first case was for the alternator, the engine light would have been for the lambda the first time, the alternator is the coincidence and just it’s time to fail I’d have thought

 

[Greasytrucker]

Did you have a battery light as well as the check engine light the first time?

 

[dank]

No. No battery light. Just the yellow check engine light.

 

[Greasytrucker]

I could be wrong then and others may disagree but sounds to me like you may have payed for an unnecessary alternator. Was it going flat or noticeably turning over slower than normal before the alternator was changed?

 

[dank]

I could be wrong then and others may disagree but sounds to me like you may have payed for an unnecessary alternator. Was it going flat or noticeably turning over slower than normal before the alternator was changed?

I had no noticeable problems with the car before the light came on. Granted, I hardly use it and it sits on the road for six days a week, and does 20-30 miles max. I had the alternator changed 10 years ago before this.

 

[Greasytrucker]

I had no noticeable problems with the car before the light came on. Granted, I hardly use it and it sits on the road for six days a week, and does 20-30 miles max. I had the alternator changed 10 years ago before this.

Think i’d be questioning the garage that fitted the Alternator. See what others think

 

[varesecrazy]

I could be wrong then and others may disagree but sounds to me like you may have payed for an unnecessary alternator. Was it going flat or noticeably turning over slower than normal before the alternator was changed?

Grande of that age had a design flaw where rainwater was ducted over the Alternator.. A modified hose was used on later Grande, Evo and 2012 models of the 199 body

So alternator failure is not uncommon..
But any failure would normally be found through charging issues, warning light and flat battrries

 

[dank]

Grande of that age had a design flaw where rainwater was ducted over the Alternator.. A modified hose was used on later Grande, Evo and 2012 models of the 199 body

So alternator failure is not uncommon..
But any failure would normally be found through charging issues, warning light and flat battrries

I bought that accessory shortly after replacing the alternator, as that's what caused it to malfunction the first time around.

 

[Greasytrucker]

What accessory did you buy?

 

[dank]

One of these. To divert the rain water away from the alternator.

 

[Greasytrucker]

One of these. To divert the rain water away from the alternator.

Sorry yes i get what you’re saying. Even less reason for it to fail again then

 

[dank]

Is there any chance that, while replacing the alternator, they may have accidentally done something to the sensor? They took longer than expected while changing the alternator as the mechanic found it difficult to get to.

 

[Greasytrucker]

Doubt you’d damage the sensor TBH, more likely the wires going to the sensor if anything, but if that was the case you’d be able to see it and rejoin any broken wires

 

[dank]

Thanks for your help so far. Not looking forward to the conversation I'll be having with them on Monday morning about all this!

 

[Greasytrucker]

I think you’ll have to take the hit on the alternator as it’s your word against there’s although you could ask them if it was the alternator at fault why was the battery light not illuminated? Hopefully they realize they’ve misdiagnosed it and don’t charge you much for the O2 sensor