1999 Taurus SE Warning Lights

Need some help and advice. 1999 Taurus SE. Dash warning lights show Service Engine, Theft flashing and Brakes warning lights on constantly. Have had the error messages cleared from the computer but after a month or so, all indicators return. Do I need to replace the computer?
Thanks ahead of time!!!

Welcome to the forum!

Before clearing the codes I hope you had them read out. What were they? We need exact code numbers, not someone's interpretation of what they mean.

As for the theft light, is that flashing even when the car is running?

Do you have the Brake warning indicator (red) on or the ABS (yellow/amber) showing?

Other than clearing the engine codes, have you done anything to attempt to fix them?

-Rod

Thanks Rod, it's my Mom's car. It was just given to her by my sister-in-law. It was recently serviced before giving to her. I was over at her place today since it would not start for her. After connecting a battery charger for a few minutes, the car started.
After it started, I noticed all those indicators I mentioned. She passed along what my sister-in-law had told her about the indicators. She had it checked, mechanic reset them but they come back. She was told not to worry about them.
I don't agree with that assessment. I say the indicators are there for a reason and told her I'd do some research. I will get a code reader and check it out. I'll post the exact error codes. As for the warning lights, the brake indicator is red. Theft indicator was amber flashing with the car running.
Thanks for the help and I'll get back to you with the exact codes. It will be a couple of days though.

Many of the chain auto parts stores will read the OBD-II diagnostic codes at no charge. You'll want to get the exact code number though rather than their interpretation of the code.

The brake light may be on either because the parking brake lever switch is sensing that the parking brake is not fully released or because the fluid level in the master cylinder is low. If the fluid level is low, don't just top it off. It's low for a reason, either due to a leak or because the brake friction surfaces are worn significantly.

The flashing Theft light would often prevent a start because the system is detecting a key that has not been properly programmed. Since the car has started, the source of that code may be the system detecting a fault in the system, such as a broken PATS key antenna, etc. I'm still surprised it will start even with the flashing indicator. You will need access to a professional scan tool that can access the Ford PATS system to read out the codes from that system. Some shops may have such a tool (like an OTC Genisys) or you can visit a Ford dealer.

-Rod

Thanks Rod,
I had her take the car to AutoZone and let them run their tester. I have not seen the printout myself yet but I had her read it to me. This is what she read to me.
BBFuel Trim Bank 1 Condition
BBFuel Trim Bank 2 Condition
BB The ECM has detected a rich or lean air fuel ratio

She also says the Theft light has gone out.
According to the AZ tech, she needs an oxygen sensor and a mass flow sensor to the tune of about $150 for both. As far as the brake light, I'll have to check that out but suspect a leak, as you said. I told her this and she pass along that the previous owner (my sister-in-law) told her it had a leak of some kind but did not know what it was. I'll just have to make time to get over there to check it out.
Do you concur with the sensor replacement? Car does run well, which I would think unusual if these sensors are bad. Thanks again for your help and advice!!!

I would not suspect an oxygen sensor, especially since both banks are reporting an issue. There would be a separate oxygen sensor for each of the banks, you might get both O2 sensors for $150, but I don't think you'd get two sensors and a MAF sensor for $150. All too often the parts sales folks (not usually techs) will equate "lean condition on bank 1" to mean "needs a bank 1 oxygen sensor." Often it's quite the opposite, the properly functioning oxygen sensor is correctly detecting a lean condition, but rarely is the oxygen sensor the cause of the lean condition. You could replace "lean" with "rich" if you preferred. I think you're on the right track with looking for air leaks. Vacuum leaks or the intake air tube after the MAF sensor would be where I'd start my search. If the intake air tubing is loose or not installed properly it could cause issues, or it might have cracks in it where it flexes. The age of the vehicle is such that it wouldn't be surprising if the now brittle vacuum hoses have split, cracked, or no longer make a tight seal.

The code definitions mentioned by your wife over the phone are partial and do not include the code identifier which should be in the form "P0123" where '0123' would be numbers identifying the particular powertrain code.

-Rod

The code definitions mentioned by your wife over the phone are partial and do not include the code identifier which should be in the form "P0123" where '0123' would be numbers identifying the particular powertrain code.

-Rod

It's my Mom...LOL
Thanks for the speedy replies too. Just finding the time to get over there to troubleshoot is a biggie for me. Your hints and tips will help me better utilize what little daylight I have when I can get over there. She parks on a slab so that should help in finding a fluid leak.
I'll start in the MAF sensor area and look for vacuum line deterioration. When I can make it over there I'll get the printout myself and see if and what codes it actually shows.
MANY thanks again Rob. I have a good starting point anyway.
:)

Vaccuum leak would be the prime suspect if i were trying to chase this down