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Jerry Newton
Jerry Newton, Cadillac Technician
Category: Cadillac
Satisfied Customers: 4830
Experience:  ASE Master Technician, L1, Master GM Technician. Over 20 years of bumper to bumper GM experience.
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94 cadillac seville sls: the service vehicle soon message is coming

Customer Question

i have a 94 cadillac seville sls and the service vehicle soon message is coming on what do that mean
Submitted: 6 years ago.
Category: Cadillac
Expert:  Jerry Newton replied 6 years ago.
A tuneup won't fix it. You'll need to retrieve the code that's making the light come on, and diagnose it from there.

Are you familiar with how to pull the codes from your car? I can walk you through it, if you'd like.
Customer: replied 6 years ago.
no i dont know how to do that
Expert:  Jerry Newton replied 6 years ago.
Follow this procedure, write down the codes, and let me know what they are. We'll get this figured out.

To enter diagnostic mode, proceed as follows:

  1. Turn ignition "ON."
  2. Depress the "OFF" and "WARMER" buttons on the Climate Control Center (CCC) simultaneously and hold until the segment check appears on the Instrument Panel Cluster (IPC) .

After entering On-Board Diagnostics, a segment check is automatically performed and then any trouble code stored in computer memory will be displayed. Codes may be stored for the Powertrain Control Module (PCM) , Instrument Panel Cluster (IPC) , Air Conditioning Programer (ACP) , Supplemental Inflatable Restraint (SIR) Traction Control System (TCS) or Road Sensing Suspension (RSS) systems.

Each trouble code consists of the system abbreviation: (E: Engine, PCM), (I: IPC), (A: ACP), (R: SIR), (T: TCS), (S: RSS), a three digit code identifier, and the letter C or H. All codes for each system are displayed together, in the order of their three digit number (lowest first). The final digit of the code, a "C" or "H" is used to indicate whether the code is Current or History. A "C" means the fault was still present the last time the diagnostic test was run, while "H" means the failure was not present the last time the code was tested for.

If no codes are present for a system, a "NO X CODE" message (with "X" being the system i.e. E, I, A, R, T or S) will be displayed. If the communication line to a component is not operating, a "NO X DATA" message will be displayed, indicating that the IPC could not communicate with that system.

After trouble codes have been displayed, a specific vehicle system PCM, IPC, ACP, SIR, TCS, RSS may be selected for testing.

The first available system will be automatically displayed (i.e. PCM?). While selecting the system to test, any of the following actions may be taken:

  1. Depressing the "HI" button on the CCC will select the displayed system for testing.
  2. Depressing the "LO" button on the CCC will display the next available system selection. This allows the display to be stepped through all system choices. This list of systems can be repeated following the end of the system list.
  3. Depressing the "OFF" button the CCC will stop the system selection process and return the display to the beginning of the trouble code sequence.

Having selected a system, the first available test type will be displayed (i.e. PCM DATA?, PCM CLEAR CODES?). While selecting a specific test type, any of the following actions may be taken:

  1. Depressing the "HI" button on the CCC will select the displayed test type. At this point the first of several specific tests will appear.
  2. Depressing the "LO" button on the CCC will display the next available test type for the selected system. This allows the display to be stepped through all available test type choices. This list of test types can be repeated following the display of the last test type.
  3. Depressing the "OFF" button on the CCC will stop the test type selection process and return the display to the next available system selection.
Selection of "CLEAR CODES?" test will result in the message "CODES CLEARED" being displayed along with the selected systems name. This message will appear for 3 seconds and then return to the next available test type.

To get out of the diagnostic mode anytime during the test, depress the "AUTO" or "DEFOG" button, or turn the ignition switch "OFF." Trouble codes are not erased if this is done prior to selecting "CODES CLEARED."
Customer: replied 6 years ago.
i search my code history and i have 5 codes in my history they are only one current p105
Expert:  Jerry Newton replied 6 years ago.
P105 is for low brake booster vacuum. Kind of a peculiar code, it will keep the service vehicle soon light on.

What were the other codes in history?

There is a little vacuum sensor attached to the brake booster that monitors the brake booster vacuum. I can probably provide you with some diagnostic chart or schematic if you're inclined to try to diagnose this yourself.
Customer: replied 6 years ago.
P071 p032 p103 a037 pass codes no ipc no sir no tcs history
Expert:  Jerry Newton replied 6 years ago.
Two of those are MAP sensor codes, you replaced that already, so I assume those codes are no longer valid.

The other two are for your brake booster vacuum, one for low vacuum and one for an open sensor. I think I'd be looking at that sensor pretty closely.
Customer: replied 6 years ago.
You I put a new map on the car so that why in getting the low booster code what sensor I need to look at
Expert:  Jerry Newton replied 6 years ago.
There is a sensor attached directly to the booster, on the driver's side of the booster next to or below the master cylinder. It looks like a MAP sensor; that's all it really is, it measures vacuum. I'd start with a visual on that, make sure it's attached, plugged in, etc.

Beyond that, I can probably find some information that you can use through the onboard diagnostics to see what the reading is, and go from there. Let me know how it looks when you get a chance to look at it.
Customer: replied 6 years ago.
That what I replaced it hook to the booster by a hose so that's not the map sensor
Expert:  Jerry Newton replied 6 years ago.
Ah, here we go. No, that's not the MAP sensor, although it looks just like one. That's the brake booster vacuum sensor.

The MAP sensor lives under the cover of the intake manifold. You have to take all of the bolts out of the upper cover and take it off, then you'll see the sensor on the left side. This may be why you're setting brake booster vacuum codes, it's got the wrong sensor on it. Put the old one back on the booster and that problem should go away.

Customer: replied 6 years ago.
It plug in the same way and the hose is in the same way so the map sensor is under the intake and I don't have the old one I got no reading with the old one with the new one I get a reading but not enough
Expert:  Jerry Newton replied 6 years ago.
Well, here's my thinking: you didn't have brake booster vacuum codes until you replaced that sensor. They are calibrated differently, not all MAP sensors are the same.

The MAP sensor under the intake looks differently, as I recall. I don't think it's the same shape as your brake booster vacuum sensor, but my recollection could be wrong on that. I don't have any pictures to tell me, I'm playing from memory here.

Nonetheless, it seems like you built the brake booster code problem by replacing that sensor, so I would make that go away and put the right one back on. The MAP sensor that's inside the intake is a fairly common problem: they get oil soaked, you'll see when you pull that cover off that there's a lot of oil in there. They only put them in there for a couple of years, then they redesigned the intake in 1995 and the MAP was external.
Customer: replied 6 years ago.
I guess ill go to a Cadillac dealer I got the codes cleared and now service vehicle soon is on and service ride control
Expert:  Jerry Newton replied 6 years ago.
The service ride control is usually due to faulty struts. They don't make those electric struts anymore, the fix is to disable the system and replace all four struts. You might as well know what they're going to try to sell you before you get there.

Good luck with it. Please click ACCEPT if you're satisfied with the advice I've given you, it's how we get compensated for our time. Thank you!

Customer: replied 6 years ago.
K thank jerry one more question where's the best place to get the strut at at good price and are you sure the map sensor is in the intake on a 94 Cadillac Seville sls
Expert:  Jerry Newton replied 6 years ago.
If it's a 94, then yes, it's inside the intake. 95 and up, they are external.

Strutmasters . com is a good place to get struts by mail, and pretty affordable. They'll give you directions on disabling the ride control system on your car, too.
Jerry Newton and 4 other Cadillac Specialists are ready to help you
Customer: replied 6 years ago.
Thank you jerry
Customer: replied 6 years ago.
Where do get a diagram of a 4.6 32v v8
Expert:  Jerry Newton replied 6 years ago.
You want the wiring diagram for the MAP, or what would you like? Let me know what you're after, and I'll try to track it down for you.
Customer: replied 6 years ago.
I can't find the map sensor so I need the diagram of my motor my car is cutting off now while driving

Expert:  Jerry Newton replied 6 years ago.

This shows how the cover comes off the intake, and you can see the fuel injectors and the MAP sensor under that cover.
Customer: replied 6 years ago.
Will the map sensor make the car cut off where can I find the connector that fits in the map sensor
Expert:  Jerry Newton replied 6 years ago.
The electrical connector is under that cover as well. If your connector is messed up/needs to be replaced, you'll have to see the dealer, they'll look it up for you and get you the right one. Connectors are about $50, though, not cheap.

MAP sensors did cause some pretty bad problems back in those days, that's why GM redesigned the intake and took the MAP out of that nasty environment and made it externally mounted starting in 1995. Not unusual to have a car that barely runs due to a faulty MAP sensor.