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iGUARD Troubleshooting
Electronic Engines
- Will not allow a manual start
- "ECU not responding" message
- Engine will not crank (WTS lamp?)
- Engine cranks but won't start
- Engine cranks, starts and then stops almost immediately
- Engine cranks starts and runs, but shuts down after awhile
- Won't show engine parameters
- Controller shuts down for various reasons
- Controller has shutdown, and won't restart
- Engine parameters are consistently wrong
- Engine parameters are erratic
- Problems with Run/Idle mode
- J1939 messages are nonsense
1. Will not allow a manual start
a. Is security level set to prevent all manual starts?
b. Is security level set to prevent a mode change from AUTO to MANUAL?
c. Is one of the digital inputs programmed for a manual start switch? - This always overrides the front panel keypad
d. Did engine shut down last time on an error?
i. Press "ACK ALARM" several times, until controller indicates that it has been reset
ii. Alternately, cycle power to the controller
2. "ECU not responding" message - This message will be seen anytime the ECU is not communicating properly, and as such there are a lot of possible reasons to get this error. (See also the wiring schematics below)
a. Check power to ECU (typically thru relay #7)
b. Check wiring for good connections. Especially look for:
i. Cuts
ii. Scraped insulation
iii. Crushed wiring
iv. Loose connectors
v. Bad crimps
vi. Arced or burnt places in the wire or connectors
vii. ¼" quick connects not fully seated
viii. ¼ turn connectors not fully engaged
c. Check fuses and/or circuit breakers
i. Fuses should be checked with an ohmmeter, as they sometimes look fine but are open
ii. Circuit breakers should be reset, and then watched carefully to see if they stay reset. Severe over current events will sometimes cause breakers to fail and act like fuses instead.
d. Is there an electrical connection between the ECU & the iGUARD on the J1939 databus? Verify with an ohmmeter
e. Are the terminating resistors installed?
i. With the power off & both ends of the J1939 cable disconnected -
ii. Measure across the CAN HI and CAN LO wires, there should be ~60 ohms
f. Are the J1939 wires correct? CAN HI to CAN HI, CAN LO to CAN LO
g. Is the ECU programmed to communicate via J1939?
a. Check the J1939 status screen - Even though the system receives a start signal, if the ECU is sending a "WAIT TO START" message, the iGUARD will not attempt to crank until the WTS message clears
b. Check the Status/Warning screen (Press the BACK/NEXT keys to get there)
i. Are there any warnings active? If so, clear them by correcting the problem indicated, and press the ACK ALARM key to clear them.
c. Did engine shut down last time on an error?
i. Press "ACK ALARM" several times, until controller indicates that it has been reset
ii. Alternately, cycle power to the controller
d. Is the emergency stop switch activated? (J8) This de-powers the relays
e. Is there a connection from relay K2 (The default crank control relay) to the starter motor slave relay?
f. Is there power (+V battery) to the common of the K2 relay?
g. Is the crank relay still the default relay? (K2)
4. Engine cranks but won't start - Since the ECU has to be communicating before the iGUARD will attempt to start, it will logically have to have power and be operational. The only practical way to get this condition with an ECU controlled engine is if the fuel rack or fuel solenoid control wire from the ECU is not connected, broken, or the connection is loose.
5. Engine cranks, starts and then stops almost immediately
a. Check the status/Warning screen (Press the BACK/NEXT key)
i. If there are warnings/alarms showing take the necessary corrective actions (see also #7 below)
6. Engine cranks, starts, and runs, but shuts down after awhile.
a. Check the status/Warning screen (Press the BACK/NEXT key)
i. If there are warnings/alarms showing take the necessary corrective actions (see also #7 below)
b. Check the fuel level and the rest of the fuel system
c. Check the electrical connections from the ECU to the fuel relay and verify that they are secure
7. Won't show specific engine parameters - There are two possible paths:
a. The ECU may not be broadcasting a specific variable. The only way to check this is with the engine service tool. Be aware that some service tools still use the J1587 databus for diagnostics and that it is completely possible (and very common!) that what is being broadcast on J1587, will be different than what is or is not broadcast on J1939. If the parameter is not being broadcast on J1939, contact your engine supplier and have them enable the broadcast of that parameter.
b. The iGCON software tool may have been used to 'turn off' the local display. iGCON allows control over which parameters, the order and the display style. Please contact the source of the controller about getting the displays arranged to your liking, or contact FW Murphy technical services (918) 317-4100
8. Controller shuts down on various errors. Keep in mind that most of the parameters are broadcast by the ECU and then displayed by the iGUARD. If you wish the iGUARD to act in a display or advisory capacity only, set the various warnings and shutdowns completely out of the operating range, and rely only on the ECU. Alternately, you can use the setpoints and shutdowns on the iGUARD as a sort of backstop to the ECU setpoints, or in the cases where the ECU/engine manufacturer has a policy of not allowing a restart in the case of a shutdown until a factory rep is available to do it, the iGUARD may form the primary shutdown mechanism, thus preventing delays and expenses associated with getting the factory rep on-site.
a. Low oil pressure
i. Check the shutdown history to see the value of the parameter at shutdown. Verify that this is the correct value for your application
ii. Check the Warning/Status screen for currently active errors and warnings. Take the necessary steps to correct the warnings and/or errors
iii. Check the J1939 status screen for information about the exact fault and the severity or possible resolution. (In the operating language)
b. High engine temperature
i. Check the shutdown history to see the value of the parameter at shutdown. Verify that this is the correct value for your application
ii. Check the Warning/Status screen for currently active errors and warnings. Take the necessary steps to correct the warnings and/or errors
iii. Check the J1939 status screen for information about the exact fault and the severity or possible resolution. (In the operating language)
c. Sender open/shorted - This is typically a Failure Mode Indicator (FMI) message.
d. Underspeed
i. Check the shutdown history to see the value of the parameter at shutdown. Verify that this is the correct value for your application
ii. Check the J1939 Status screen for warning about loss of speed signal or speed sensor failure
iii. If the set is spark ignited, verify that the spark plugs and spark plug wires are resistive type, and the ignition is properly grounded.
iv. Even though the iGUARD passes the EC requirement for immunity to radiated noise, beyond a certain point - *very* strong field strengths - EMI/RFI can still cause problems. Turn off any radio gear and try running again.
e. Overspeed
i. Check the shutdown history to see the value of the parameter at shutdown. Verify that this is the correct value for your application
ii. Check the J1939 Status screen for warning about loss of speed signal or speed sensor failure
iii. If the set is spark ignited, verify that the spark plugs and spark plug wires are resistive type, and the ignition is properly grounded.
iv. Even though the iGUARD passes the EC requirement for immunity to radiated noise, beyond a certain point - *very* strong field strengths - EMI/RFI can still cause problems. Turn off radio gear and try running again.
f. Overcrank - With ECU controlled systems, this is a very rare occurrence. Generally, if the system doesn't start on the first start cycle, it will not start until it has been repaired, or refueled.
i. Verify that any fuel control valves are open
ii. Verify that there is fuel in the fuel system (day tanks, supply tanks tec.)
g. Low fuel level - In ECU systems, there is a possibility of getting fuel level information from a resistive sender attached to an analog input of the iGUARD, or by connecting a sender to the ECU itself.
i. Verify that the fuel level source is selected correctly.
(1) If the system will be reading fuel level from a resistive sender connected to the iGUARD proper, make sure that the sender wires are connected to one of the first 4 analog inputs, the make of sender is correctly selected in the analog channel setup, and the setpoints for warning and shutdown are correct
(2) If the system will be reading fuel level as a J1939 parameter broadcast from the ECU, make certain that the setpoints for low fuel warning and shutdown are correct.
ii. Check the shutdown history to see the value of the parameter at shutdown. Verify that this is the correct value for your application
iii. Check the Warning/Status screen for currently active errors and warnings. Take the necessary steps to correct the warnings and/or errors
iv. Check the J1939 status screen for current active errors or warnings. Take the necessary steps to correct the warnings and/or errors.
h. Low oil level - Sometimes, a loose wire can cause a shutdown that will masquerade as a totally different problem.
i. Check that the wires to the oil level device are connected securely.
ii. Check that the signal wire from the low oil level device to the controller is intact - no nicks, cuts, or crushing of the cable.
i. Low coolant level
i. iii. Check that the wires to the coolant level device are connected securely.
ii. iv. Check that the signal wire from the low coolant level device to the controller is intact - no nicks, cuts, or crushing of the cable.
j. ECU not responding
i. Does the ECU have power to its supply terminals? - Check by measuring from the supply terminal to the -V battery terminal
ii. Is there a relay in the iGUARD programmed for "ECU enable"? - Check by entering the programming mode and under the Relay menu, scroll through the relays and confirm that relay 7 (Or whichever other relay you choose) is programmed for "ECU enable".
iii. Is the iGUARD relay supplied with power or ground as appropriate to enable the ECU? - Check by measuring the between -V battery and the common of Relay 7
iv. Is there a cable from the ECU J1939 CANbus output to the J2 CAN connections? - Physically check that there is a cable plugged into J2
v. Is the bus wired correctly (J1939 CAN hi and CAN low are not reversed)?
(1) Verify that CAN hi is connected to J2 terminal 7
(2) Verify that CAN lo is connected to J2 terminal 2
vi. Is the CANbus terminating resistor missing, broken or incorrect value? (Any Ohm measurements will need to be made with the ECU and iGUARD unpowered, otherwise the signals from the ECU or iGUARD on the CANbus connection will make all Ohm readings invalid)
(1) Check by removing the J2 wire harness from the circuit board connector
(2) Using an Ohm meter carefully measure the impedance between J2 terminals 2 & 7. If the connection is properly impedance terminated you should measure approximately 60 ohms from CAN hi to CAN lo (J1939 systems)
(3) If the impedance is approximately 120 ohms, one terminating resistor for the CANbus is missing. The J1939 databus may either not operate at all, or not properly and reliably, without the impedance measured at the connector reading 60 Ohms.
(4) If the impedance is approximately38K Ohms (anywhere in the range from about 20k Ohms to 60k Ohms) then there are *no* terminating resistors in the system. You will need to put a 120 Ohm resistor at each end of the J1939 databus
(5) If the impedance is essentially open, verify that your controller actually has a J1939 port. This *cannot* necessarily be determined by whether or not the factory diagnostic tool works - most of them use a J1587 connection which is not a guarantee of J1939 at all. It may be necessary to get the ECU serial number, revision number and software revision number and contact the ECU manufacturer and verify.
vii. Verify that the ECU is programmed correctly
(1) Check that the ECU has been programmed to allow J1939 messages to be broadcast/received (J1939 communications enabled)
(2) If you have access to a factory service tool, disconnect the iGUARD and verify that the service tool communicates with the ECU.
viii. If everything checks out OK but still no communications verify the following:
(1) Is the ECU programmed to communicate via some other protocol?
(2) In particular there are some ECU's that do use CANbus as the physical interconnect, but the data transport layer is not J1939, it is a proprietary format. The other case, the ECU uses J1587/J1708, or RS-485/MODbus protocol for communications.
9. Controller has shutdown, and won't restart - The iGUARD must be reset:
a. Press the "ACK ALARM" key three times - The display will indicate that you must press the acknowledge key some number of times to cause a reset.
b. Cycle power to the controller (OFF, wait a few seconds and then back ON)
10. Engine parameters are consistently wrong -
a. Make sure that the analog inputs are disabled. The ECU is providing oil pressure, engine temperature and oil temperature, and no analog channel should be programmed for those senders. Since the iGUARD will allow parallel operation (ECU data + senders for backup or secondary sensing) the fastest way to tell if it is a real problem is to disable all the senders, which forces the iGUARD to only use digital data.
b. If the inputs are disabled - This data is coming directly from the ECU itself, so the only way that this can be the actual case is that the sensor for the parameter is bad - or at least malfunctioning - or there is a problem with the wiring. It may indicate a problem with the ECU itself.
11. Engine parameters are erratic - Since the ECU is providing all the engine parameters, the only way that this can be the actual case is that the sensor for the erratic parameter is bad - or at least malfunctioning - or there is an problem with the wiring. It is not a 'problem' with the iGUARD, but it may indicate one with the ECU.
12. Problems with Run/Idle mode - If your application uses the RUN/IDLE mode input control and you are having problems with it such as:
a. Shutting down on undervoltage/under frequency while in IDLE position
b. NOT shutting down on undervoltage/under frequency while in RUN position
c. NOT going to IDLE speed
d. NOT going to RUN speed
i. Verify that a digital input has been programmed to the "IDLE Mode Selection"
ii. Verify that a relay output has been programmed to "RUN/IDLE"
iii. The switch labeled RUN/IDLE should be set to the IDLE position
iv. On the iGUARD, scroll BACK (or NEXT) until the STATUS/ALARM screen is displayed.
v. If one line does not say "IDLE BYPASS", then flip the RUN/IDLE switch.
vi. If is still does not say "IDLE BYPASS", then either the switch is not wired properly, or the input is not programmed to "IDLE mode selection".
vii. This can be verified by entering a password that will allow access to the level 3 (or higher) parameters. (Default is PAS3 - Check your documentation!), and then navigating to the Operating Parameters Screen. Once there, use the UP/Down arrows to navigate to the "I/O TEST" menu item, and press enter.
(1) Scroll through the digital inputs until you see one labeled "IDLE mode selection". Toggle the switch and verify that the input shows "0" or "1" as the switch is toggled back and forth.
(2) If the switch state does not change then there is a wiring error between the switch and the controller.
viii. If the display does say "IDLE BYPASS", then we need to check the relay:
(1) If you are in a low ambient noise environment where you can hear the relays click as they change states, toggle the switch and listen for the relay to click as it changes.
(2) If there is a high noise environment, you will have to use either an Ohmmeter or a volt meter to verify that the relay is following the switch.
ix. If you can't confirm that the relay is operating, go to the RELAY screen in the programming mode. (See step h above)
x. Step through the relay settings and verify that one relay is programmed for "RUN/IDLE mode"
xi. Verify that there is a wire from the relay programmed for RUN/IDLE to the ECU.
xii. Verify that the wire from the ECU is connected to the appropriate terminal (Normally Open/Normally Closed) of the relay programmed for RUN/IDLE
xiii. Verify that there is a wire from the COMMON of the RUN/IDLE relay to either +V battery or Ground - As appropriate for YOUR controller! - In general, the common of the relay should be tied to a +V battery to actuate the run/idle mode, but not all controllers are alike. Check the documentation on your engine ECU to find out which setting is correct for your engine
xiv. Start the set with the RUN/IDLE switch set to IDLE
xv. If the set immediately goes to run speed:
(1) Stop the set
(2) Change the wire from the ECU to the relay to the other terminal (NO if it was NC, NC if it was NO)
e. If the set stays at idle, then toggle the RUN/IDLE switch. The set should go to rated speed. If the set does not, then consult the ECU data and verify that this exact ECU will support RUN/IDLE operation in this specific application, and verify that the ECU is programmed for this as well.
13. J1939 messages are nonsense
a. If you are getting ECU error codes that are very large numbers (greater than 65535) or
b. If you are getting numbers that are nonsense faults (transmission temperature fault for example on a standard generator set)
i. Try setting the ECU manufacturer to Deere or Detroit
(1) If the problem goes away, your ECU is broadcasting active faults in version 2 of the J1939 protocol.
(2) If the problem does not go away, your ECU is broadcasting version 1 of the J1939 protocol
ii. If the messages are still not making sense, Please contact the Murphy technical services group (918) 317-4100.
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