Cadillac Seville - Recent Questions, Troubleshooting & Support

Question edited for clarity. Question moved to model category. Bridging with a resister is an 'old wives tale' according to Jeff Armer our full time electronics technician. He wrote this on GM Passlock and the Ford system is the same. https://www.fixya.com/cars/r29887709-gm_passlock_security_system ..

Climate control needs to be looked at, or replaced.

bad transmission, no miles 1992 SEville reclic. DRIVE fails does reverse? ever see is shift right before?, or last decade?most are not running now. find it in a barn dead? like all bad automatic transmissions, IS IT. the endless posted here standard list of all on car tests to find the cause here we go 100time

1. all fuses good. FUSE d1 TRANNY FUSE BLOWN? 10-AMP
2. dip stick check, levels hot engine near center of stick hot, idle in park.
3. dip stick end smells burnt or atf looks like TAR.
4. shift linkage checked and not failing and adjusted by the book.
5. main tranny test, at PUMP test ports fail> , yes bad tranny
6. 4t60e box? GM box , and uses ECM to shift. ON SOME,.
7. bad speed sensors or 2 shift solenoids
8. OR ALL THE SEALS LEAK INSIDE AND ADD UP TO PUMP-OVERLOAD-SEE WHY STEP 6 FAILS, THIS IS IT OR THE PUMP IS BAD. AND SO BE THE TRANNY

Just look at the rear of the engine...this is what they look like

If I am not mistaken, it is under the rear seat bottom cushion.

Cadillac recommends using a 5w-30 oil. My 2000 STS has 125k and I use Castrol full synthetic 5w-30 oil with no problems. I'm also from the old school regarding oil and filter changes. For me it's still every 3000 miles.

Short in opener circuitry or bad switch

Take it to auto zone and have them run the free diagnostic and reset the codes. that should help.

I will paste instructions from autozone.com below, but recommend you also read thru my post at http://www.fixya.com/cars/r5973094-starter_replace and let me know if you have questions.

4.5L and 4.9L Engines

1. Disconnect the negative battery cable.
2. Raise and safely support the vehicle securely on jackstands.
3. Remove the starter motor shield.
4. Remove the exhaust front and rear pipe assembly.
5. Remove the flexplate inspection cover.
6. Disconnect the solenoid 'S' terminal nut and battery cable nut.
7. Unbolt the starter motor mounting bolts, and remove the starter motor.

Fig. Later model starter location and mounting on the 4.9L engine


To install:

1. Install the starter motor, and tighten to 32 ft. lbs. (43 Nm).
2. Install the solenoid 'S' terminal nut. Tighten the nut to 35 inch lbs. (4 Nm).
3. Install the battery cable nut and tighten to 12 ft. lbs. (15 Nm).
4. Install the flexplate inspection cover, the front and rear exhaust pipe assembly and the starter motor shield.
5. Lower the vehicle.
6. Connect the negative battery cable.

Hello. It seems your Cadillac is getting too much air into its engine; causing it to 'surge'. This could be due to a malfunctioning/defective vacuum brake booster. If your Cadillac's catalytic converter is 'clogging'; this will cause the engine to 'surge' too. Good luck and keep me informed; if you want to.

4.5 And 4.9L Engines

1. Remove the air cleaner.
2. Remove the TP sensor connector.
3. Unscrew the 2 TP sensor attaching screws and retainers, and remove the TP sensor.

To install:

1. With the throttle valve in the normal closed idle position, install the TP sensor on the throttle body assembly.
2. Install 2 TP sensor attaching screws with retainers. Do not tighten the screw until the TP sensor is adjusted.
3. Install the TP Sensor connector. Adjust the TP Sensor and perform the idle learn procedure.
4. To Perform the TP sensor adjustment.
   1. Disable the generator by grounding the green harness connector plug adjacent to the generator.
   2. Start the engine, enter diagnostics, and select PCM override PS103 'ISC Actuator'
   3. Press the 'COOLER' button on the CCP to retract the ISC Actuator. This action will disengage the A/C compressor and command the EGR 'OFF'. The Climate control center display will change from '50 to 00'. The ISC Actuator will slowly retract (about 20 seconds) to a fully retracted position. Verify that the throttle lever is resting on the minimum idle speed screw. With the ISC Actuator plunger fully retracted, disconnect the ISC harness.
   4. Select the PCM data PD01, 'TP Sensor', while still in PCM override PS03. Note the throttle position (in degrees) displayed on PCM parameter PD01.
   5. (-0.5° TO + 0.5°) No TP sensor adjustment required. Reattach the ISC Actuator harness and disconnect the grounding wire at the generator.
   6. TP Sensor (-10.0° TO -0.6°) or TP Sensor (+ 0.6° TO + 90.0°) TP Sensor adjustment required.
5. With the engine 'OFF' and the ignition 'ON', reenter diagnostics and select PCM override PS03 'ISC Actuator'. Press the 'COOLER' button to retract the ISC Actuator the minimum air setting.
   1. Loosen the TP sensor screws just enough to permit the sensor to be rotated. Open the throttle slightly and allow the throttle lever to snap shut against the minimum air screw. Adjust the TP sensor so the parameter display is 0°. Tighten the TP sensor mounting screws with the sensor in the adjusted position. Recheck the parameter to be sure the TP sensor parameter is (-0.5° to + 0.5).
   Install the air cleaner.

on brake pedal bracket under dash disconnect wiring remove switch -replace

their is none

your damper control has a problem

Videos and text based articles. They are nearly always to the left and right of the centre console under the dash. https://www.google.com/search?q=1994+cadillac+seville+sts+replace+blend+door+actuator ..

Could be the interlock brake switch . don't guess an just replace parts . You don't know how to test , take it to someone who can .

Lets start by checking your brake light switch. Your car has a switch on the brake pedal that not only makes the brake lights come on, but also tells the transmission it can shift out of park. This really may be 2 separate switches, but should be under the dashboard and both should "open" when you push the brake pedal down. Take a good flashlight and look. The switches are small, about the size of your thumb, and both should have 2 wires attached to them. Be blessed.

E13-Oxygen sensor voltage stays between 0.307 and 0.609 volts for 64 seconds. Engine was at normal operating temperature at a speed over 800 RPM.
E44-Right oxygen sensor was lean for more than 50 seconds when engine was warm and at 800 RPM or greater.
E52-PCM has lost primary battery power.
E58-Pass Key fuel enable was not correct.
F47-PCM has received bad data from IPC for 3 seconds while engine speed was 500 RPM or more for 3 seconds.
F48-EGR open command was given during off idle operation. EGR opening should cause the mixture to be slightly richer because of the low oxygen content of exhaust gas. Vehicle speed was over 35 MPH and engine was warm.
Good luck and hope this helps, keep me posted be glad to answer any questions you may have. 

If it's not running rich it may need a new cat

The Haynes repair manuals are very good about showing the wiring diagrams for all wired connections. You can go to or contact the dealership and ask if they have one for free. Most wiring diagrams are going to cost if you have lost your owners manual.