2004 Cadillac CTS Problems

What owners report

Owners of the 2004 CTS most often describe brake behavior at low speed — pedal feel, assist loss and long stopping distance — along with rear-end and differential noise and leaks, and a cluster of electrical complains such as keys that will not release from the ignition. Many of these complaints were filed in the vehicle's first few years at low mileage, while brake and electrical reports tend to arrive later in life; several owners note their car was not covered by recalls issued for later model years.

1. 1
   Transmission and drivetrain

   Rear differential noise, whine or leak

   • 39 complaints (17%)
   • median 19,000 mi at 2.5 yrs old (33 state mileage)
   • 2 mention a crash, fire or injury
   • filed 2004–2020

   Owners describe a whine, moan, growl or grinding from the rear of the car that builds with speed and can be heard most clearly while accelerating. Several report the differential was replaced, sometimes more than once, and in some cases the noise returned or a new unit leaked. Others mention fluid weeping from the rear axle seals, and a few say the dealer called the sound normal. Reported from as low as about 1,000 miles up to roughly 160,000 miles, with many complaints filed under 40,000 miles.

   3 related service bulletins

   What to check: Listen for whine or howl from the rear axle on a test drive at highway speed, and check the differential and axle seal areas for oily residue or fresh fluid.

   2 excerpts from owner complaints in NHTSA records

   “Rear pinion seal failed and rear axle locked up. Lost control and was involved in accident. Shocked to find out there is a recall for 2005 and newer CTS (NHTSA campaign number: 07v589000, GM recall no. 07204) but not my 2004 which has an identical rear main seal. The part number used in the recall is the same to repair my 2004.”

   NHTSA complaint #10714151, filed 2015-05, 153,000 miles

   “2004 Cadillac CTS. The car has made a loud noise in the differential since purchased. The differential was replaced however, the noise and jerking of rear wheels continues. I have returned to the dealer several times only to be told there is nothing wrong with the vehicle. I have replaced the tires three times because the dealer said they were the source of the noise and jerking, but the condition still exists. …”

   NHTSA complaint #10245255, filed 2008-10, 1,000 miles
2. 2
   Brakes

   Low-speed brake assist loss and long stops

   • 34 complaints (15%)
   • median 75,500 mi at 8.1 yrs old (30 state mileage)
   • 5 mention a crash, fire or injury
   • filed 2003–2018

   Complaints describe the pedal going soft or to the floor, a service brake assist message appearing, and the car taking much longer to stop, often while turning at low speed such as entering a parking space. Some owners report ABS or traction control lights at the same time, and dealers variously pointed to sensors, the power assist unit or the master cylinder. Mostly reported between roughly 21,000 and 140,000 miles, commonly during low-speed maneuvering and turns.

   What to check: Test the brakes while turning slowly in a parking lot and ask whether the power assist unit or master cylinder has ever been replaced; a soft pedal or warning message is worth investigating before purchase.

   2 excerpts from owner complaints in NHTSA records

   “Brake failure in Cadillac CTS I have a large amount of information in a pdf that explains our experience as well as documents multiple similar experiences from other individuals. How do I send it to you? The brakes are intermittently completely failing at slow speeds and significant injury to a pedestrian seems inevitable. Please help!!!”

   NHTSA complaint #10352482, filed 2010-08, 75,000 miles

   “My Cadillac '04 CTS has a brake issue. When turning sharp at low speeds the brakes disengage and I lose complete control of the car. It is intermittent and I can't duplicate it at will. It just happens. I have filed a case with GM customer service and am taking to the dealer tomorrow.”

   NHTSA complaint #10361668, filed 2010-10, 76,000 miles
3. 3
   Electrical system

   Ignition key will not release or car will not restart

   • 18 complaints (8%)
   • median 92,876 mi at 11.0 yrs old (15 state mileage)
   • filed 2006–2022

   Complaints describe the key sticking in the ignition when turned off, so the car cannot be shut down normally, and in other cases a no-start condition after parking. Some owners also report the engine cutting out with an anti-theft message on the display, or the security system locking doors and windows while driving. According to complaints, diagnoses ranged from battery and alternator to an unspecified electrical fault. Reported from about 31,000 to 129,000 miles, without a clear weather or seasonal pattern.

   Recall 14V3940002 related service bulletins

   What to check: Check whether the ignition recall was performed on this VIN, and try shutting the car off and removing the key several times during a test drive.

   2 excerpts from owner complaints in NHTSA records

   “My Cadillac CTS 2004 key is stuck in the ignition and will not release. The car was towed to two different dealerships one said it was a battery. I purchased a new one that wasn't the problem and one thought it was the alternator and that wasn't the problem. I did have a recall on the key ring and got that taken care of, but honestly the same recall that is dealing with the camaros and the cobalts need to be enforced with the cadillacs. Gm new there was something faulty about the keys getting stuck in the cadillacs. …”

   NHTSA complaint #10652380, filed 2014-11, 90,000 miles

   “This incident occurred twice. The first time (april 29th 2013), the car was at a stop light. The engine turned off by itself and the message: anti-theft was displayed on the car sat-nav screen. Key was removed from ignition and reinserted. After turning the key, the engine restarted. The second time (may 3rd 2013), the car was in motion in a parking lot. While pulling into a parking spot the engine turned off again. The message: anti-theft* was displayed on the car sat-nav display. …”

   NHTSA complaint #10510790, filed 2013-05, 94,000 miles
4. 4
   Brakes

   Corroded brake lines and hoses leaking fluid

   • 14 complaints (6%)
   • median 84,747 mi at 10.9 yrs old (12 state mileage)
   • filed 2010–2018

   Owners describe brake fluid puddles near a front wheel, a corroded hard line or a ruptured flexible hose at the caliper, and in some cases a sudden loss of braking with warning messages on the display. Several complaints note the car was outside the regional scope of a brake line recall that covered certain states, or that the trim level was not included. Reported from about 55,000 to 115,000 miles, generally on older vehicles in salt-belt use.

   Recall 10V105000

   What to check: Have the hard brake lines and flexible hoses inspected for rust and wet spots, especially on a car that lived in a road-salt state, and ask whether the brake line recall was completed.

   2 excerpts from owner complaints in NHTSA records

   “I observed a large puddle of brake fluid around the front left tire. Upon removal of the wheel, I discovered a large brake fluid leak at the interface between the hard brake line going to caliper and the flexible line that goes to the body of the car. During removal, the interface completely failed. …”

   NHTSA complaint #10644215, filed 2014-10, 112,000 miles

   “Shortly after a routine oil change, I was driving at highway speed in suburban minneapolis. When applying the brake to exit the interstate, there was little change in speed and the driver information center displayed braking and stability system errors. I was able to slowly drive back to the dealership I purchased the vehicle at where it was determined the passenger side front brake hose had corroded and ruptured, resulting in the braking failure. …”

   NHTSA complaint #10661026, filed 2014-11, 90,000 miles

Buying note. On a 2004 CTS, plan on a brake inspection and a rear-axle listen on the test drive, and ask for the recall status by VIN, since some owners report symptoms that recalls covered on other model years or in other states. Service records showing past differential, brake line or ignition work are useful to review.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.