How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Tim's Auto Repair Your Own Question

Tim's Auto Repair
Tim's Auto Repair, mechanic
Category: Chevy
Satisfied Customers: 13070
Experience:  Have owned a repair shop for 25 yrs.
14541291
Type Your Chevy Question Here...
Tim's Auto Repair is online now
A new question is answered every 9 seconds

2003 chevy suburban dtc p1125

Resolved Question:

2003 chevy suburban dtc p1125
Submitted: 4 years ago.
Category: Chevy
Expert:  Tim's Auto Repair replied 4 years ago.

hi

hi

the problem may be the throttle acuator on the throttle body...this can also cause this code to show up

thanks

please ACCEPT my answer so I can get credit for my work.i don't receive commission unless you do ..i'm not always going to be giving you good news,so please dont let this stand in the way of you accepting my answer.it does not cost you more money.we will still be able to communicate.. Bonuses and positive feedback are appreciated!if you are not satisfied with my answer,please do not leave bad feed back,i will gladly opt out and let another expert handle the question.PLEASE ASK IF YOU NEED MORE HELP

Description and Operation

THROTTLE BODY ASSEMBLY

Throttle Body Assembly
The throttle body for the TAC system is similar to a conventional throttle body with a couple of exceptions. One exception being the use of a motor to control the throttle position instead of a mechanical cable.

The other exception is the new design Throttle Position (TP) sensor. The TP sensor mounts on the side of the throttle body opposite the throttle actuator motor. The TP sensor is actually 2 individual TP sensors within one housing. Separate signal, low reference, and 5.0-volt reference circuits are used to connect the

TP sensors and the TAC module. The TP sensor 1 signal voltage increases as the throttle opens, from around 1.0 volt at 0 percent throttle to above 3.5 volts at 100 percent throttle. TP sensor 2 signal voltage decreases as the throttle is opened, from around 3.8 volts at 0 percent throttle to below 1.0 volt at 100 percent throttle.

P1125

CIRCUIT DESCRIPTION
The Accelerator Pedal Position (APP) sensor is mounted on the accelerator pedal assembly. The sensor is actually three individual APP sensors within one housing. Three separate signal, low reference, and 5-volt reference circuits are used in order to connect the accelerator pedal sensor assembly and the Throttle Actuator Control (TAC) module. If only one APP sensor DTC is set, the redundant APP systems allow the TAC system to continue operating normally. This DTC sets if the Powertrain Control Module (PCM) detects a condition with more than one APP sensor. One APP sensor DTC will not cause the Reduced Engine Power message to be displayed. Two APP sensor DTCs for the same sensor also will not cause the Reduced Engine Power message to be displayed. However, if two or more DTCs are set involving more than one APP sensor, this DTC will set and the Reduced Engine Power message is displayed.

CONDITIONS FOR RUNNING THE DTC

  • DTCs P1517 or P1518 are not set.
  • The ignition switch is in the crank or run position.
  • The ignition voltage is greater than 5.23 volts .

CONDITIONS FOR SETTING THE DTC

  • Two or more APP sensors are out of range or all three APP sensors disagree or one APP sensor is out of range and the other two APP sensors disagree.
  • All of the above conditions exist for less than 1 second .

ACTION TAKEN WHEN THE DTC SETS

  • The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
  • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.
  • The control module commands one of the following Reduced Engine Power modes:
  • The APP indicated angle is limited to a predetermined value to limit the amount of throttle control.

OR

  • The APP indicated angle is limited to 0 percent . The control module only allows the engine to idle.

OR

  • Under certain conditions the control module commands the engine OFF.
  • The message center displays Reduced Engine Power.

CONDITIONS FOR CLEARING THE MIL/DTC

  • The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  • Use a scan tool in order to clear the MIL and the DTC.

DIAGNOSTIC AIDS

  • Inspect the TAC module connectors for signs of water intrusion. When this occurs, multiple DTCs could be set with no circuit or component conditions found during diagnostic testing.
  • The APP sensor 1 and the TP sensor 1 5-volt reference circuits are internally connected within the TAC module.
  • The APP sensor 2 and the TP sensor 2 5-volt reference circuits are internally connected within the TAC module.
  • When the TAC module detects a condition within the TAC system more than 1 TAC system-related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Keep this in mind when reviewing captured DTC info.

TEST DESCRIPTION

Steps 1-2
The number below refers to the step number on the diagnostic table.

 

  1. When the problems are corrected which are causing the APP sensor DTCs to set, the status of this DTC will change to History.
Service and Repair

REMOVAL PROCEDURE

NOTE: Handle the electronic throttle control components carefully. Use cleanliness in order to prevent damage. Do not drop the electronic throttle control components. Do not roughly handle the electronic throttle control components. Do not immerse the electronic throttle control components in cleaning solvents of any type.


 

  1. An 8 digit part identification number is XXXXX on the throttle body casting. Refer to this number if servicing, or part replacement is required.
  2. Remove the air induction assembly. IMPORTANT: Cover or plug any openings when servicing the throttle body in order to prevent possible contamination.
  3. Disconnect the throttle actuator motor harness connector.
  4. Disconnect the throttle position (TP) sensor harness connector.
  5. Remove the throttle body attaching nuts. IMPORTANT: Do not reuse the throttle body gasket. Install a new gasket during assembly.
  6. Remove the throttle body and the gasket.
  7. Discard the throttle body gasket.

INSTALLATION PROCEDURE


 

  1. Install a new throttle body gasket.
  2. Install the throttle body assembly. IMPORTANT: Always use a torque wrench in order to obtain the proper torque.
  3. Install the throttle body attaching nuts.
Tighten
Tighten the throttle body nuts to 10 N.m (89 lb in) .

IMPORTANT: Ensure that the electrical connector to throttle body motor and the connector seal are properly installed and not damaged.

  1. Connect the TP sensor harness connector.
  2. Connect the throttle actuator motor harness connector.
  3. Install the air induction assembly.
  4. With the vehicle not in reduced engine power, turn ON the ignition with the engine OFF. Inspect for complete throttle opening and closing positions. Use a scan tool to monitor the throttle angles while operating the accelerator pedal to open and close the throttle. The accelerator pedal should operate freely without binding between full closed throttle and wide open throttle.
  5. Start the engine.
Tim's Auto Repair, mechanic
Category: Chevy
Satisfied Customers: 13070
Experience: Have owned a repair shop for 25 yrs.
Tim's Auto Repair and 8 other Chevy Specialists are ready to help you

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money. Todd L Rochester NY
< Last | Next >
  • I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money. Todd L Rochester NY
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
 
 
 

Meet The Experts:

 
 
 
  • Tim's Auto Repair

    mechanic

    Satisfied Customers:

    7641
    Have owned a repair shop for 25 yrs.
< Last | Next >
  • http://ww2.justanswer.com/uploads/TI/tim37857/2011-10-28_23053_S6301814.64x64.JPG Tim's Auto Repair's Avatar

    Tim's Auto Repair

    mechanic

    Satisfied Customers:

    7641
    Have owned a repair shop for 25 yrs.
  • http://ww2.justanswer.com/uploads/DT/dt69nova/2012-6-15_234154_pic1.64x64.jpg Dave Nova's Avatar

    Dave Nova

    Chevrolet Technician

    Satisfied Customers:

    6870
    ASE Master Certification. GM World Class Certification
  • http://ww2.justanswer.com/uploads/ggrote1/2009-06-27_031011_me.jpg Gary's Avatar

    Gary

    Chevy Technician

    Satisfied Customers:

    5404
    15 years GM master tech
  • http://ww2.justanswer.com/uploads/testedtuff/2009-09-26_170108_pictures.jpg John's Avatar

    John

    Master A.S.E Automotive technician

    Satisfied Customers:

    4071
    A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician
  • http://ww2.justanswer.com/uploads/RO/rodcuda/2011-7-25_224114_Donhoff1.64x64.JPG Neal's Avatar

    Neal

    Chevy Mechanic

    Satisfied Customers:

    2306
    Shop Owner and Mechanic on multiple makes.
  • http://ww2.justanswer.com/uploads/goodwrench9124/2008-11-09_220838_dscf0007.jpg goodwrench9124's Avatar

    goodwrench9124

    ASE Certified Technician

    Satisfied Customers:

    2041
    Ase Master Certified, GM Master Certified Tech. Awarded GM Top performer, Hybrid certified
  • http://ww2.justanswer.com/uploads/DR/drivefast1971/2012-1-12_172422_0009051tQKh.64x64.jpg Ron Z.'s Avatar

    Ron Z.

    - Chevy Tech -

    Satisfied Customers:

    1912
    18+yrs experience. State Inspector and Chevy Diagnostics