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DR.Cummins
DR.Cummins, FIELD SERVICE TECHNICIAN
Category: Heavy Equipment
Satisfied Customers: 3539
Experience:  16 Years working on Cummins Diesel engines,
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I have a 1997 cummins M11 and it has problem with the throttle,

Customer Question

I have a 1997 cummins M11 and it has problem with the throttle, it is very sensitive as soon as I step on it the rpm jumps to 1500 and back down again so the drive is very jerky.  So I decided to change the tps and as soon as I start it,  it jump to 1500 rpm and no movement on the throttle.  I have calibrated and no codes on the ESM.  Please help.  

Should I try to run new set of wires directly from sensor to the ESM.
Submitted: 5 years ago.
Category: Heavy Equipment
Expert:  DR.Cummins replied 5 years ago.
Hello and welcome to Just Answer! I would be more than happy to assist you today. What is the engine serial number
Customer: replied 5 years ago.
2HSFMAR5VC027919
Expert:  DR.Cummins replied 5 years ago.
May I have just the engine serial number from the data tag on the engine located on the rocker box
Expert:  DR.Cummins replied 5 years ago.

You can try to replace the wires, i'd check out the circut first make sure it is not an ecm issue, Also sometimes the whole pedal assy must nbe replaced(not always the case)

The accelerator position sensor is attached to the accelerator pedal. The accelerator position sensor sends a signal to the Electronic Control Module (ECM).The accelerator position circuit contains three wires: +5 VDC supply (wire 18), return (wire 19), and signal (wire 11).see pic below

If all wiring and sensors check good, replace the APS circuit wires between the accelerator pedal and ECM with new wires. Run them through, or around, the bulkhead without using the bulkhead connector. The ECM and accelerator pedal must be calibrated to each other for proper engine response. This is required when a new accelerator pedal is installed, replaced, an ECM is replaced, a new calibration is downloaded to the ECM, or the accelerator pedal wiring is disconnected while keyswitch "ON". With keyswitch "ON" slowly push the accelerator to the floor and release, do this three times. This recalibrates the ECM and accelerator pedal.

The three wires in the accelerator position sensor circuit must be twisted together.

 

Measure the resistance between the +5 VDC supply and the accelerator position sensor return on the sensor side of the accelerator position sensor when the accelerator pedal is released and when it is depressed must be

2000 to 3000 ohms. if not it is bad Recheck even know it is "new"

 

Measure the resistance from the +5 VDC supply to the signal wire on the sensor side of the accelerator position sensor connector must be

Released: 1500 to 3000 ohms; Depressed: 200 to 1500 ohms

 

Check for continuity from ECM to accelerator position sensor.

  • Measure the resistance from pin 18 of the ECM OEM harness connector to the +5 VDC supply pin of the accelerator position sensor.
  • Measure the resistance from pin 11 of the ECM OEM harness connector to the signal pin of the accelerator position sensor.
  • Measure the resistance from pin 19 of the ECM OEM harness connector to the return pin of the accelerator position sensor.
  • must be less than 10 ohms. if more wireing is bad

Check the accelerator position supply for proper voltage.

  • Measure the voltage from pin 18 to pin 19 in the OEM port at the ECM.must be

    4.75 to 5.25 VDC if not replace theECM

 

Check signal pin resistance at the ECM.

  • Measure the resistance from pin 11 of the ECM OEM port to pin 19 in the ECM OEM port, must be Less than 100k ohms, again ecm is bed if not in spec

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Customer: replied 5 years ago.
Engine serial # 34840275. ECM was replaced and no codes. If there derated power anywhere it would have triggered a faulty code as it the old ECM. I will run some test of what you have recommend and I did calibrate the peddle with ECM prior to requesting an answer. Let know soon.
Expert:  DR.Cummins replied 5 years ago.
Try these tests, as i described. it may be a wiring or entire pedal issue.

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