Quick answer. This 2003 Cadillac CTS had a stuck throttle actuator. The scan tool showed four stored codes. Our tech traced the fault to the gas pedal and wrote it up as a new pedal plus a pedal relearn. The visit was one hour of diagnosis, $150.
Key Points
- The car had 217,919 miles on it.
- Four codes were stored: P0700, P2176, P0123 and P0223.
- Our tech found the throttle actuator stuck.
- The fix on the ticket: a new accelerator pedal, then a pedal relearn.
- The charge on record is one hour of diagnosis, $150.
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What Our Tech Found
The throttle actuator was stuck. That is the part that opens and closes the throttle on this car. There is no cable from the pedal to the engine. A computer reads the pedal and moves the throttle with a motor.
So when that system goes bad, the engine does not get the gas you ask for. Our tech did not stop at the throttle. The fault on the ticket is the pedal. The pedal needs to be replaced, and then the car has to relearn it.
The Four Codes on the Screen
The scan tool showed four stored codes. Here is what each one means in general.
P2176 means the idle position of the throttle was never learned. A code guide says the computer can limit the throttle and put the car in a fail safe or limp mode when it sets, and that symptoms can include little or no throttle response and a transmission that will not shift (obd-codes.com, P2176).
P0123 and P0223 are both "circuit high" codes for the throttle or pedal sensors, A and B. The computer saw a voltage above its normal limit. One guide notes P0223 is only used on drive by wire cars, where the computer runs the throttle off one or more pedal sensors (obd-codes.com, P0223). The same site says these sensors usually get a 5 volt feed and send back a signal that rises as the throttle opens (obd-codes.com, P0123).
P0700 is a transmission code, and it scares people. It should not, on its own. It only says the transmission computer has a code stored and asked for the light (obd-codes.com, P0700). It does not name a broken part.
2003 Cadillac CTS, October 8, 2026
Came in with: 217,919 miles and four stored codes.
Our tech found: the throttle actuator stuck.
What it needs: a new accelerator pedal and a pedal relearn.
Cost on record: one hour of diagnosis, $150.
Why the Relearn Matters
A new pedal is not plug and play on a car like this. The computer has to learn where the pedal and throttle sit at rest. That is what P2176 is about. Skip the relearn and the car can keep throwing codes and keep acting up, even with good parts in it.
That is why our tech wrote both steps on the ticket. The part and the relearn are one job.
Why We Did Not Guess
Four codes look like four problems. A parts counter would sell you a throttle body, two sensors and maybe a trip to a transmission shop. Our tech read them together and found one fault behind the throttle codes.
That is the whole point of paying for one hour first. You get a finding before anyone buys a part. We log every finding in Shop Desk, the software our San Jacinto shop built, and any mechanic can use it free.
The record does not show whether the pedal was replaced after this visit. So we will not tell you it was.
A Recall Worth Checking on This Car
This has nothing to do with the throttle, but every 2003 CTS owner should know it. In 2014 GM recalled 554,328 Cadillac CTS cars from model years 2003 to 2014 (NHTSA recall 14V394). The weight on the key ring or a hard bump can turn the key out of the run position. The engine shuts off, and the air bags may not deploy in a crash. Until it is fixed, NHTSA says to keep only the ignition key on the ring (NHTSA, 2003 Cadillac CTS).
The recall applies to certain vehicles. Our job record does not show whether it was done on this car. You can check yours by VIN on the NHTSA site for free.
Frequently Asked Questions
What does a stuck throttle actuator do?
The engine may not get the gas you ask for. Many cars go into a limp mode with weak throttle response until the fault is fixed.
Does code P0700 mean my transmission is bad?
Not by itself. It only says the transmission computer has a code stored. Read that code before you buy anything.
Why would a bad pedal set throttle codes?
On a drive by wire car the pedal is a sensor. If its signal is wrong, the computer cannot move the throttle the right way and sets codes.
Do I need a relearn after a new pedal?
On this car our tech called for one. The computer has to learn the new pedal and the closed throttle position.
How much was the diagnosis?
One hour, $150, which is the only charge on this job record.
What We Read
- NHTSA, Recall 14V394, Cadillac CTS Ignition Key
- NHTSA, 2003 Cadillac CTS
- obd-codes.com, P2176 Throttle Actuator Idle Position Not Learned
- obd-codes.com, P0123 Throttle Position Sensor A Circuit High
- obd-codes.com, P0223 Throttle or Pedal Position Sensor B Circuit High
- obd-codes.com, P0700 Transmission Control System
Supercanic tip: Car feels like it will not take gas, or the scan shows a stack of throttle codes? Call us at (951) 904-2477 and we will find the fault before anybody sells you a part.
Throttle Acting Up?
Call us. We test first, then we quote the fix, and you say yes before the work starts.
