Need help with a used 2004 Cadillac CTS 3.6l ECU

[DOC]

Anyone out there with a scanner that can help me find out why my new car is having issues. I can't get it to pass the internal smog test to get it ready for Emissions test.
I was hoping someone has access to advance scanner like a Tech 2 or similar that can help me find out if the computer is bad.
The car's temp and gas gauge don't work. The gear shifter light doesn't light up and the reverse lights don't work either. I think they are all related to the ECU since I reset it and all those things worked for a little while. I was hoping to get it reflashed if it was done wrong the last time. The former owner changed the ECU and I'm not sure it was done right.
Thanks in advance. Of course I will pay. I'm just hoping to avoid the dealership fees for a car of this age. And I want to get someone that cares a little more than a run of the mill garage that will take your money but might not earn it.

[Great-Kazoo]

What does the smog place says is the reason you failed?

[DFBrews]

Anyone out there with a scanner that can help me find out why my new car is having issues. I can't get it to pass the internal smog test to get it ready for Emissions test.
I was hoping someone has access to advance scanner like a Tech 2 or similar that can help me find out if the computer is bad.
The car's temp and gas gauge don't work. The gear shifter light doesn't light up and the reverse lights don't work either. I think they are all related to the ECU since I reset it and all those things worked for a little while. I was hoping to get it reflashed if it was done wrong the last time. The former owner changed the ECU and I'm not sure it was done right.
Thanks in advance. Of course I will pay. I'm just hoping to avoid the dealership fees for a car of this age. And I want to get someone that cares a little more than a run of the mill garage that will take your money but might not earn it.

What does the smog place says is the reason you failed?

they can fail based on emissions related OBD systems not being online or not having run their internal diagnostics

[SouthPaw]

Did you just recently buy this car?

[ChickNorris]

Not necessarily helpful to your query but by Colorado law, a new emissions test is required prior to the sale on vehicles over 7 years for private transaction even if the vehicle has a current tag. Dealers may provide vouchers if a test isn't requested at point of sale.

[matttahoe53]

Has your battery died recently or been disconnected for a long time? If that is the case you will need to drive the car some distance so all the emissions equipment has had a chance to cycle a couple times, then the scan tool will then be able to retrieve the data on the equipment.

[Great-Kazoo]

they can fail based on emissions related OBD systems not being online or not having run their internal diagnostics

Right. However until one knows why it failed, guessing is just that. Did it fail for something simple, or will the new car repairs cost more than the OP wants to invest.

[DOC]

What does the smog place says is the reason you failed?

They said the onboard smog test stuff hasn't passed the tests yet. The cat, evap, O2 and O2 heater tests had not run yet and they kicked it out without further tests. I think I can have one not run yet. But I had 3 not run. There might be more issues going on to get it back to stock.
The brake lights were out and it was a bad soldier joint and that fixed it when I re soldiered the joints in a computer. A common problem with GMs.

Did you just recently buy this car?

Yeah. A month ago. I got it from my neighbor that had to get rid of it. His wife told him its cursed and needs to get rid of it. They are moving too and have to unload some of their stuff.

Has your battery died recently or been disconnected for a long time? If that is the case you will need to drive the car some distance so all the emissions equipment has had a chance to cycle a couple times, then the scan tool will then be able to retrieve the data on the equipment.

It has sat for a year and the battery was changed before I got it. I recently put in a good battery that I know was new. Optima Redtop 1000 ca 800 cca.
I think that is what I needed. I hate throwing parts at stuff though without knowing that is what is wrong. But some of the gauges are not working and even though the emissions stuff still works. The evap test won't run, because it has to see the gas tank between 1/4 and 3/4 full and it doesn't show anything. The temp gauge doesn't show anything either. I think they are run by the ECU so its not sending any info to the gauges.
The emissions test looked for the internal smog test to run and the catalyst test, evap, O2 sensor and O2 heater test need to run and those take time. During the last month I have gotten all to pass except the EVAP test to run. I think I can run the emissions test with one not run yet. Now the temp tag is expired. I ordered another one over the phone and it was a 10 day tag. It started the day I ordered it and it showed up on day 8. SMH.
I think I need it reflashed with a stock program. I have seen mechanics updating the firmware like they were updating their phone or something.

[Great-Kazoo]

They said the onboard smog test stuff hasn't passed the tests yet. The cat, evap, O2 and O2 heater tests had not run yet and they kicked it out without further tests. I think I can have one not run yet. But I had 3 not run. There might be more issues going on to get it back to stock.
The brake lights were out and it was a bad soldier joint and that fixed it when I re soldiered the joints in a computer. A common problem with GMs.


Yeah. A month ago. I got it from my neighbor that had to get rid of it. His wife told him its cursed and needs to get rid of it. They are moving too and have to unload some of their stuff.

It has sat for a year and the battery was changed before I got it. I recently put in a good battery that I know was new. Optima Redtop 1000 ca 800 cca.
I think that is what I needed. I hate throwing parts at stuff though without knowing that is what is wrong. But some of the gauges are not working and even though the emissions stuff still works. The evap test won't run, because it has to see the gas tank between 1/4 and 3/4 full and it doesn't show anything. The temp gauge doesn't show anything either. I think they are run by the ECU so its not sending any info to the gauges.
The emissions test looked for the internal smog test to run and the catalyst test, evap, O2 sensor and O2 heater test need to run and those take time. During the last month I have gotten all to pass except the EVAP test to run. I think I can run the emissions test with one not run yet. Now the temp tag is expired. I ordered another one over the phone and it was a 10 day tag. It started the day I ordered it and it showed up on day 8. SMH.
I think I need it reflashed with a stock program. I have seen mechanics updating the firmware like they were updating their phone or something.

Don't forget to put a new gas cap on before the test. It's the weakest link and most overlooked in the system.

[BushMasterBoy]

I have an Optima Red top that lasted two years. It is still sitting on the kitchen floor. It was a problem with my 07 Silverado radio drawing it down. Dealer had to reprogram a "body control module/ radio".
My suggestion is charge the battery fully. Check the voltage, should be above 13 volts fully charged. You will need a cheap digital multimeter for this. The Optima battery manufacturer has had serious quality control declines according to some truck forum members.
Another suggestion is to get a Blue Driver OBD reader that Bluetooth connects to your smart phone. The app is a free download. The Blue Driver is a $100 new on ebay. I have seen used go for $80. An OBD reader is indispensable these days and will pay for itself in short time. There are other OBD readers that are cheaper. I hope this information helps.

https://www.bluedriver.com/

Or a cheaper version...
https://www.amazon.com/Vgate-Bluetoo.../dp/B019SURWYO