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 Cat Man Your Own Question
Cat Man
Cat Man, Caterpillar Engine Expert
Category: Heavy Equipment
Satisfied Customers: 8954
Experience:  23 Years Caterpillar Engine experience.
Type Your Heavy Equipment Question Here...
Cat Man is online now
A new question is answered every 9 seconds up it runs great , full power..light goes..lose power

This answer was rated:

i have a freightliner fl70 2000, when i start it up it runs great , full power, in 10 minutes the check engr light comes on and i loose power, it will not go up hills or any small incline, it i shut the truck off then back on, the light goes off and i get power back, then the light comes back on and i lose power again, what can this be

Hello This issue sounds like you have debri in your fuel tank that is getting caught in/on the stand pipe restricting the fuel flow. I would start with a fuel inlet test to the engine from the tank. Your issue sounds text book because when you shut it off it releases the restriction.

Customer: replied 7 years ago.
i clean out the tanks already,i do not think i have debri in the lines, it has to be something else

Hi. Thanks for using JA! I think I can help you out.

Do you have a Caterpillar 3126 or C7 engine?

Also, if your check engine light is coming on, can you get the flash codes for me?

Here are the procedures for pulling Flash codes from the ECM.


Use the diagnostic Lamp or a Caterpillar electronic service tool to determine the diagnostic flash code.

Use the following procedure to retrieve the flash codes if the engine is equipped with a diagnostic lamp:

  1. Turn the ignition key to the ON position.
  1. Turn the ignition keyswitch to the OFF position.
  1. Turn the cruise control ON/OFF switch to the OFF position.
  1. Move the SET/RESUME switch to either position. Hold that position until the yellow lamp begins to flash.

The yellow lamp will flash in order to indicate a two digit flash code and the SET/RESUME switch may be released. The sequence of flashes represents the system diagnostic message. Count the first sequence of flashes in order to determine the first digit of the flash code. After a two second pause, the second sequence of flashes will identify the second digit of the flash code.

Any additional flash codes will follow after a pause. These codes will be displayed in the same manner. Flash Code 55 indicates that No Detected Faults have occurred since the ignition keyswitch has been turned to the ON position.





Edited by Scott on 4/2/2010 at 4:05 PM EST
Customer: replied 7 years ago.
scott what does this tell me i do not understand, you are telling me how to check codes i am lookin for something to try to fix this, not how to get a code, i am asking you if you ever heard of my problem

Hi. Yes I have heard of your problem. You mentioned that your check engine light came on correct? I was just trying to retrieve the fault codes from the ECM.

Do you have a Caterpillar engine?

If so, the problem I have seen before is with the Injection Actuation PRessure system. WHen the check engine light comes on and the engine looses power, I usually find that the engine has a 164 code. The main thing that causes this issue is the IAPCV. Injection Actuation Pressure Control Valve. The IAPCV failure is very common on Cat 3126 Engines.

Please let me know if you have any more questions.

Customer: replied 7 years ago.

scott you seem to no what you are talking about i will pay you for your time, i did what you said and this is what happen ist i got a code 1 then a pause and then a 5 then a pause then a 3 then pause then 9 then pause then a 4 then pause then 9

i then try again and the same numbers came up then i try a third time same thing what does this mean

i wish i new more about this thanks

Congratulations! You just pulled Flash codes out of the ECM. Thanks for the information. Your engine is showing codes for the Injection Actuation Pressure Sensor (15) and the Injection Actuation Pressure System (39). You also have a code 49 but that is not causing your problem. Since you have a Flash code of 15 I would recommend replacing the Injections Actuation Pressure Sensor. Code 39 can be caused by code 15. I have included a list of the Flash codes for your engine.


Flash Codes for C7 and C9 On-Highway Engines
Diagnostic Flash Code An "X" indicates that the effect on engine performance may occur if the code is active. An "X" indicates the suggested operator action if the code is active.
Misfire Low Power Loss of RPM Shut Down Stop Engine (1) Service Engine (2) Schedule Engine Service (3)
12 Coolant Level Sensor Circuit Fault (4) (5) X
15 An Injection Actuation Pressure Sensor Circuit Fault X X X
17 Injection Actuation Pressure Sensor Out of Range X X X X
18 Driver Fault for the Injection Actuation Pressure Control Valve X X X
21 Sensor Supply Voltage Fault (6) X X
24 Oil Pressure Sensor fault (5) X X
25 An Inlet Air Pressure Sensor Circuit Fault X X
26 Atmospheric Pressure Sensor Fault (5) (6) X
27 Coolant Temperature Sensor Fault (4) (6) X
28 Check Throttle Sensor Adjustment X X
29 Check PTO Throttle Sensor Adjustment (5) X X
31 Loss of Vehicle Speed Signal X X
32 Throttle Position Sensor Fault X X
33 Turbo Wastegate Solenoid Circuit Fault X X X
34 Engine RPM Signal Fault X X X X
35 Engine Overspeed Warning X
36 Vehicle Speed Signal Fault X X
38 An Inlet Air Temperature Sensor Fault (6) X X
39 Injection Actuation Pressure System Fault X X X X
41 Vehicle Overspeed Warning X X
42 Check Timing Sensor Calibrations X X
44 Fuel Level Sensor Circuit Fault (5) X
46 Very Low Oil Pressure (5) X X X X X X
47 Shutdown Occurrence X
49 Inlet Air Heater Circuit Fault X
51 Intermittent Battery Power to ECM X X X X
55 No Detected Faults
56 Check Customer Parameters or System Parameters X X X
57 Transmission Datalink Engine Derate X
58 A Powertrain Data Link Fault X
59 Incorrect Engine Software X
61 High Coolant Temperature Warning X X X X
62 Low Coolant Level Warning X X X X
64 Very High Intake Manifold Air Temperature Warning X X X X
71 Ignition Keyswitch Circuit Fault X X X X
72 Cylinder 1 Fault or Cylinder 2 Fault X X X
73 Cylinder 3 Fault or Cylinder 4 Fault X X X
74 Cylinder 5 Fault or Cylinder 6 Fault X X X
( 1 ) Stop the Engine: Operate the engine cautiously. Get immediate service. Severe engine damage may result.
( 2 ) The operator should go to the nearest location that has a qualified service program.
( 3 ) Schedule Service: The problem should be investigated when the operator has access to a qualified service program.
( 4 ) These Flash Codes reduce the effectiveness of the Engine Monitoring feature when the codes are active.
( 5 ) The code will flash if the sensor is used for this application.
( 6 ) These Flash Codes may affect the system under specific environmental conditions such as engine start-up at cold temperature and cold weather operation at high altitudes.

Edited by Scott on 4/3/2010 at 1:40 AM EST
Cat Man, Caterpillar Engine Expert
Category: Heavy Equipment
Satisfied Customers: 8954
Experience: 23 Years Caterpillar Engine experience.
Cat Man and 2 other Heavy Equipment Specialists are ready to help you