Alex Caoile

1995 Cadillac sts rough start idle

8 posts in this topic

hello i have a 1995 Cadillac seville sts and the other day i started my car and it had a rough idle for just over a minute after start lots of vibration it would not happen if i turned car off and restart but if sat for about 2 hours or longer it would happen again. does anybody know whats wrong? any help is appreciated

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It sounds like a leaking FPR to me but first we should look at the OBD codes. To get the codes on the message panel under the speedometer, turn the key on, then on the A/C buttons, press <Off> and <Pass Warmer> together for a few seconds until all the dash lights come on like you just turned on the key, then release them both. The car's computers will then read out their codes one module at a time, ending with a prompt "PCM?" at which time you can press <Off> to repeat the process or <Auto> or <Information reset> to take the car's computes out of the diagnostic mode. Write down the codes and post them here.


CTS-V_Dashboard.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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code I027-PRND321 switch failure, code T027-LF wheel speed sensor continuity fault and code T073-PCM EBTCH/EBCM pulse width modulation signal fault. i think its the T073 code plus do you know where i could get the parts to fix the PRND321switch and speed sensor. Thank you

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i was also wondering would any of these codes make ABS light and traction control disabled come on and make the car start out in second gear

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Either one of the codes, T027 or T073... will disable Traction Control, turn on the ABS light and make it start in 2nd gear.


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thanks Jim do you know where i could get the parts to fix

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My first call for parts is Rock Auto, with GM Parts Direct, New Cadillac Parts, GM Motors, and Rippy Automotive as well. Rock Auto has nearly everything and ships quickly, and the dealer-based outfits usually offer a VIN check to make sure that the part will fit.

All three of your codes look more like electrical problems than parts failures. I would look at the connector and wiring to the LF wheel speed sensor to address T027, the connector at the EBTCM to address T073, and the adjustment of the PRNDL switch to address I027.


CTS-V_Dashboard.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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