C-15 MXS Intake Valve System Starting

[jackalfa]

Hi members,

I have a problem with a C-15 MXS. The ECM throw codes (can't remember now) but it was something with a open actuator harness inside the cover. A test with ET (Intake Valve Actuator Solenoid Test) showed that there was a problem with the harness so both harnesses inside cover where replaced.
The actuator solenoid test now pass all solenoids connections, all OK.

After assembled everything and run the engine, it started for a few seconds then stopped and it doesn't starts anymore just cranks.

The ECM is not displaying any codes, just a status flag that is displayed in ET that says "Intake Valve System Starting".

Has anyone else encountered this problem?
Any ideas what's triggering this status flag?
Any help or suggestions would be greatly appreciated,

Thanks...

[jackalfa]

Please, cat gurus...

[eric486]

Sounds to me like you lost fuel prime. Do you have a hand priming pump? Or gently run it off of brake cleaner and see if it picks up on it's own.

[drizzt4321]

Its not throwing a code, because it isn't registering anything to throw a code.

CAT Guide for No Start:
Engine Cranks but Will Not Start

SMCS - 1000-035

Probable Causes



Theft deterrent
Diagnostic codes
ECM flash file
Air inlet shutoff (if equipped)
Engine speed/timing signal
Keyswitch
Communications between the Engine Control Module (ECM) and the Caterpillar Electronic Technician (ET)
Aftermarket engine protection devices
Power to ECM
Electrical connections to the electronic unit injectors
Fuel supply
Combustion problem
Cold weather and problems with the starting aids

Recommended Actions


Theft Deterrent


If the display screen on Messenger indicates that the theft deterrent is enabled, the theft deterrent passwords must be entered before the engine will start. Ensure that the theft deterrent (if equipped) is not active. Turn the keyswitch to the ON position. Observe the display screen on Messenger.
Diagnostic Codes


Check for active diagnostic codes.

Connect Caterpillar Electronic Technician (ET) to the data link connector.

Check for active diagnostic codes. Certain diagnostic codes will prevent the engine from starting.

Troubleshoot any diagnostic codes that are present.

Flash File for the Engine Control Module (ECM)


Check that the latest version of the ECM flash file has been installed. Verify that the flash file that is installed matches the application. A new ECM is not programmed at the factory. The engine will not start until the ECM flash file is installed for the specific application. Also, the ECM will not communicate until the flash file has been installed. Use "WinFlash" to program a new ECM.
Air Inlet Shutoff (If Equipped)


Check the air inlet shutoff system. If the engine was shut down due to the air inlet shutoff system, the air inlet shutoff needs to be manually reset.
Engine Speed/timing Signal


Check the engine speed/timing signal. Observe the engine rpm on Cat ET while the engine is being cranked. This may require Cat ET to be powered directly by the vehicle batteries or this may require Cat ET to be powered directly by a separate power source. Use the 167-9225 Harness (SERVICE TOOL ADAPTER).
If Cat ET displays 0 rpm and the engine is being cranked, there is a problem in the circuit for the primary engine speed/timing sensor or in the circuit for the secondary engine speed/timing sensor. Refer to Troubleshooting, "Engine Speed/Timing Sensor Circuit - Test".
If an engine rpm is present, check the sensor installation. If the sensor is not properly installed, the sensor may read engine speed but the sensor may not be able to sense the tooth pattern. The ability to detect the tooth pattern is necessary to determine the cylinder position. Engine rpm is present when the engine rpm is 50 rpm or more.
Keyswitch


Use Cat ET to check the status of the keyswitch.
Access the status for "Ignition Key Switch" in Cat ET.

Slowly cycle the keyswitch on and off while the status of the keyswitch is being monitored. The status should indicate the state of the switch.
If the ECM will not communicate and the keyswitch is in the ON position, refer to "Aftermarket Engine Protection Devices". Note: If the engine shutdown output is used, the status for the keyswitch may indicate that the switch is on even though the keyswitch is in the OFF position.


Communications Between the ECM and Cat ET


Check the communications between the ECM and Cat ET.
Ensure that the keyswitch is in the ON position. Attempt to access one of the status screens on Cat ET. If Cat ET indicates that the ECM will not communicate go to "Aftermarket Engine Protection Devices". If the ECM communicates go to "Power to the ECM".


Aftermarket Engine Protection Devices


Check aftermarket engine protection devices. These devices usually interrupt power to the ECM. This will prevent communications between the ECM and Cat ET.
Check for the correct installation of the aftermarket engine protection device.

Check for the correct operation of the aftermarket engine protection device.

Verify that the ECM is receiving the correct battery voltage.


Power to the ECM


Check the power supply connections for the ECM and the ground connections for the ECM.

Verify that the ECM is receiving battery voltage with the keyswitch in the ON position. Refer to Troubleshooting, "Ignition Key Switch Circuit and Battery Supply Circuit - Test".

Check for proper operation of the ECM.
Before replacing the ECM, try to install a new flash file into the existing ECM. Refer to Troubleshooting, "Flash Programming". If the ECM is suspected of being the problem, temporarily connect a test ECM. This will prove whether the problem is with the suspect ECM.

Electrical Connections to the Electronic Unit Injectors


Check the electrical connections to the electronic unit injectors. Ensure that the valve cover connectors are fully connected. Ensure that the valve cover connectors are free of corrosion and of moisture.
Fuel Supply


Check the fuel supply.
Monitor the exhaust for smoke while the engine is being cranked. If no smoke is present, there may be a problem with the fuel quality or with the fuel supply.

Check the fuel quality. Refer to Systems Operation/Testing and Adjusting, "Fuel Quality - Test". Also refer to Truck Application and Installation Guide, LEBT5109.

Check the operation of the low pressure fuel system. Refer to Systems Operation/Testing and Adjusting, "Fuel System Pressure - Test".

Ensure that the fuel system has been primed. Refer to Systems Operation/Testing and Adjusting, "Fuel System - Prime".

Check for a restriction in the fuel supply lines.

Check the fuel filters.

If the temperature is below 0 ?C (32 ?F), check for solidified fuel (wax).


Combustion Problem


Check for mechanical problems that may affect combustion of the fuel.
Cold Weather and Problems with the Starting Aids


The engine may have an air inlet heater and a starting aid (ether) may also be utilized. If the "Starting Aid Output" is programmed to "Automatic" and if the conditions are correct, the ECM will enable the output for a maximum of 30 seconds. The air inlet heater will not turn on until five seconds after completion of the ether injection.
If there is a problem with the ether injection system, excessive cranking and/or failure to start could result. For example, if the ether canister is empty, the ECM might activate the starting aid output for 30 seconds. Another five seconds would elapse before the air inlet heater is turned on. Make sure that the starting aid system is OK. For engines that do not use the starting aid output, the air inlet heater is designed to help with starting in cold weather. Make sure that the circuit for the air inlet heater is OK.

[saican]

Please, cat gurus...
Please check ECM power harness some time this harness cut and would not allow engine to start.

[jackalfa]

Tomorrow I'm going to connect a ECM from a another truck, thanks for taking the time to help me...

[eric486]

Please check ECM power harness some time this harness cut and would not allow engine to start.

If he lost ecm power there would be no communication with ET.

[eric486]

If the only thing you did was replace the actuator harness' I don't see the need to swap ecm's off the bat. Disable the inlet heater if it is equipped with one and run it off of ether or brake cleaner. That will narrow it down to if it is a fuel problem or not. Or take the fuel filters off and make sure that they aren't plugged and have fuel in them. If the filters are dry you are sucking air in from somewhere. Have you checked fuel pressure?

[Far_Call]

Simply go to the ET Status screen and look at Fuel Position.

Without cranking it should read 0... whilst cranking it should move from 0 upwards>>> 2>> 3 etc and this means the ECM is happy with the wiring and faults and is asking for Fuel.

If the fuel position is above 0 and the engine doesn't fire you have a Fuel problem so leave the electronics alone and look for Fuel.

If whilst Cranking the fuel position doesn't move from 0 position you have electronic faults and these need to be fixed.

DONT keep cranking if you have 0 fuel position as it will never start and only flatten your batteries.

[Gear head]

Intake valve actuator starting is normal. The vva harness is also the inj. Harness make sure all inj. Wires are going to right injectors?

[jackalfa]

Thanks a lot guys for all the help.
After several tests, follow your suggestions and looking closer to the harness, I found out what I always suspect: the shop manager order the wrong harness and one mechanic helper installed it, they don't checked or compared the old and new one, and the senior mechanic never compared the wires position or colors in the harness when installed. I ask them several times if was correctly installed and ordered the correct one.
I just the "computer guy" not the mechanic, so they call me when they don't know what what's wrong or when they have a problem with diagnostics or ECMs and they don't know what to do. (I don't know what to do sometimes, but DK is my secret) :)
I feel embarrassment about these gentlemen, and for my self too for not checking the obvious right away, but honestly sometimes, one wants to believe the persons and take their words for good...
I learned a lot on this one, thanks again DK members, best regards.

[eric486]

Just out of curiosity did they put the back one in the front and vice versa?