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Cat Man
Cat Man, Caterpillar Engine Expert
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Century: freightliner..throttle..acceleration..gas pedal..mi scanner

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i have a 2004 freightliner century class heavy duty truck with no throttle acceleration. starts but gas pedal does not do any thing. i scanned with mi scanner and it is showing 2 hard codes. #1 TROUBLE CODE IS SENSOR SUPPLY VOLTAGE SID 232 FMI FLASH CODE 46. SECOND CODE IS ACTIVE THROTTLE SENSOR PID 91 FM4 FLASH CODE 22.

HiCustomer Thanks for using JA!

Here are the descriptions of your Flash codes.

Section 49.2
Troubleshooting Flash Code 46, PID 168/FMI 1

The power wiring supplies 12 or 24 volts to the ECM/ECU. The system must be sourced directly from the battery. ?

Note: Connection to reverse polarity will damage the system if not properly fused.

Flash Code 46 p 168/1 indicates that the main battery supply voltage to the ECM/ECU has dropped below the recommended operating range.?

The DDEC V system will operate on 12 or 24 volts. ?

  • Normal operating voltage of the DDEC system is 11 to 32 volts DC, measured at the ECM/ECU.
  • Operating the ECM/ECU between 6 and 11 volts may result in degraded engine operation. (Transient operation in this range during engine starting is considered normal for 12-volt systems.)
  • Operating the ECM/ECU over 32 volts will cause damage.
  • Reversing polarity will cause damage to the ECM/ECU if the power harness is not properly fused.

Troubleshooting Flash Code 22, PID 91/FMI 4

This diagnostic condition is typically:?

  • Open sensor signal circuit
  • Open sensor +5 volt supply circuit
  • Sensor signal is shorted to sensor return circuit or to ground

Refer to "28.2.1 General Throttle Information (Automotive Limiting Speed Governor)" for general throttle information, refer to "28.2.2 Multiple Code Check" to begin troubleshooting Flash Code 22. ?

Section 28.2.1
General Throttle Information (Automotive Limiting Speed Governor)

The correct TPS/AP Sensor counts for DDEC engines at idle should be 64 - 205 counts.?

  • Typical DDEC V foot pedals today, at idle, provide 90-175 counts.
  • The DDEC system will log a TPS/AP Sensor low volt code (PID 91, FMI 4, Flash Code 22) if the TPS/AP Sensor counts go below 48.
  • The DDEC system will log a TPS/AP Sensor high volt code (PID 91, FMI 3, Flash Code 21) if the TPS/AP Sensor counts go above 968 counts.
  • In order to go from 0% to 100% throttle, the counts have to increase 546 above the idle count, or 100 counts, whichever is greater.
  • If an idle validation switch (IVS) is configured, to go from 0% to 100% throttle, the counts have to increase 546 above the counts at which the IVS opens or 100 counts, whichever is greater.
  • If 0% throttle is attained with the foot off the pedal, and if 100% throttle is attained with the pedal to the floor, then the pedal should not be considered a factor for low power complaints.

If you have no voltage to the TPS, you may have a wiring problem from the ECU or you have a possible ECU problem.

 

Please let me know if you have any more questions!

Customer: replied 7 years ago.
MY PRO LINK IQ SCANNER INDICATED THE READING OF SENSOR SUPPLY VOLTAGE OF 0.88 VOLTS. WHAT DO YOU THINK? THANKS JUAN V.
That is not enough of a voltage supply voltage.
Customer: replied 7 years ago.
SO I GUESS MY PROBLEM IS MORE THAN JUST THE THROTTLE POSITION SENSOR? SHOULD LOOK AT THE WIRING ? THANKS
Yes. I think you have a wiring problem.
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