Check engine and brake lights stuck on (while key is on)

Hello,

This sounds like the TIPM is going out which is common in these cars. Here is a test guide and the location of the TIPM and how to replace it below with diagrams showing the location and the brake light wiring diagrams so you can see how the system works:

Perform Body Verification Test
Disconnect all jumper wires and reconnect all previously disconnected components and connectors. Make sure all accessories are turned off. Make sure the battery is fully charged.

Turn the ignition on.
With the scan tool, record and erase Diagnostic Trouble Codes (DTC)s from all modules.
If an electronic control module was replaced, select the applicable module from the scan tool. If the module has programmable features, program as necessary.
(Export only) If the Intrusion Transceiver Module (ITM) and/or Siren was replaced, select the ITM from the scan tool and perform the applicable replacement procedure.
Turn the ignition off, wait 10 seconds, and then turn the ignition on.
Operate all functions of the system that caused the original concern. If a repair or module replacement was done to the power windows, operate the motor fully down and then to the full up position and stall it for two seconds. With the scan tool, view all the modules and check for DTCs.

Are DTCs present in any of the modules or is the original condition still present?

You can see the brake light signal is supplied by the TIPM. When replacing this unit it must be programmed at the shop which should run about $130.00.

Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.

Cheers, Ken