Isx repairs

If Insite is only showing one stage, (I think it shows by percentage), then the switches in the dash aren't sending out requests for level 2 or 3.

 

You have me thinking now, LOL. It has been awhile since I looked at those inputs with an ISX through Insite.

 

Im pretty sure it show percentages for inputs like sensors and such but it does show positikns for switches like engine brake cruise etc

 

R u sure the switch is good and this is a problem that started occuring recently or has this been something since u got the truck if there is no seitch positikns on insite i doubet jts going to be anything with ecm migh be switch wiring

 

WHEW!!!!! we got a lot to cover I'm going to start from the very beginning as if this had come to me not knowing anything of previous checks, bare with me as this will be a lot lol.

#1. When you pulled in to the shop prior to ANY work being done how did the Jakes work? Did they work at all? Were they weak? Were the strong when engine was cold and loose braking power when engine heated up?

#2. When the truck was in the shop did they or you request to "UP" the horse power with a calibration? They would have informed you it would cost roughly $50 extra for the calibration (maybe a bit more if they quoted you with the labor).

If the answer to those questions are in the realm of Jake's worked fine and no calibration change was made then let's continue with the troubleshooting. If the answer is anything other than the Jake's worked fine continue to follow my outlined troubleshooting. If they did calibrate the ECM for more horse power then first and foremost check that they installed the correct calibration. There are THOUSANDS of calibrations and they have different Jake operation configurations. Some are set up for 2 solenoids some are set up for 3 solenoids. If you have a 2 solenoid setup and a 3 solenoid calibration was installed, strange things can happen as well as vise versa.

O.k. back to T/S.

1. Connect Insite to the ECM via the dash connection or 3-pin connection. View the Data/Monitor Logger page and first view only "Engine Brake On/Off Switch" and "Engine Brake Percentage" (I believe I labeled those parameters correctly but if not you should be able to locate what I'm talking about. Now while viewing these parameters switch the On/Off switch to "On" verify the logger reads "On". Now flip switch to "Off" position and verifiy logger reads "Off". If this is good continue
2. Now with the On/Off switch in the "On" position flip the "Engine Brake Level" switch to "1". Verify the "Engine brake level (percentage)" reads 33%. If ok engage in dash switch to "2". Verfiy Insite reads "66%". If ok continue on and change switch level to "3" Insite should read "100%". If all this is correct then the switches are operating correctly and the ECM is recieving the correct signals.
3. Disconnect the electrical pass through connection at the intake side of the cylinder head (circular in design and immediately above the camshaft sensor). If you have a 2 solenoid set up you will see 2 pins when you disconnect it, if you have a 3 solenoid design you will see 3 pins (I'm about 90% sure about the pins I just described the solenoids are grounded through the cylinder head so there should NOT be a ground pin. It will be best to have the valve cover removed to verify this. If there is only one wire going to each solenoid then I am correct in saying this. If there is 2 wires going to each solenoid then physically trace the wires and the set of wires that while still in side the head join together and splice together in to a single wire that now single wire will be your ground.) with the key in the "OFF" position, or better yet not even in the ignition, take a jumper wire and connect it a 12 volt source (I generally clamp to the starter hot post) and touch the other end to one of the pins inside of the connection you separated (CAUTION: NOT THE EXTERNAL HARNESS THAT LEADS BACK TO THE ECM!!!!!!. Only the harness the is still pertruding from the cylinder head, the one that has 2 or 3 pins pointing at you. When you touch the pin with the 12 volts you should hear a clicking noise (the noise can be very quiet so its best to have the valve cover off). Now touch the other pin and you should hear the same thing, if you have 3 pins and you have verified its not a ground pin touch that one as well as you should have the same results. Now while listening you can also look at the solenoid on the top of the solenoid dead center you will see what looks like a tiny ball bearing. With the 12 volts applied you should see the ball drop. If this happens then the solenoid is being engaged when the 12 volts is applied and you are good. If you dont hear the click or see the ball drop then that solenoid is bad. Replace it.
4. If the previous steps have checked ok to this point go ahead and lay the valve cover back on top of the cylinder head dont worry about tightening the bolts as you might have to remove it later. The valve cover is only installed now so you dont sling oil everywhere due to the fuel pump gear connected to the cam shaft. Start the unit and let it idle (dont worry about the dash switches at this point as they don't matter). With the engine idling use the same 12 volt wire you used to check the solenoids and touch it to one of the pins again. You should hear and feel the engine go in to an engine braking condition. It's hard to miss it's a major change in engine operation. Now remove the 12 volts from that pin, allow the engine to regain itself and come back to idle, once it has touch the other pin with the 12 volts. On a 2 solenoid system the change in the engine should be identical. If one appears weaker than the other you more than likely have a weak solenoid (possibly mechanical problem in the Jake's themselves but I'd start with the solenoid). Now if you have a 3 solenoid set up touch the 3rd pin. If you have 3, then one of them ONLY CONTROLS the front cylinder so the braking effect will appear weaker than the other 2 and this is normal. Again if you have a 3 solenoid set up the change in the engine will not be identical throughout as the #1 solenoid only controls cylinder #1, solenoid #2 controls cylinders #2 & #3, solenoid #3 controls cylinders #4, #5, and #6. Now here's the tricky part, with the engine idling on a 2 solenoid set up apply the 12 volt wire to both pins at the same time. This should kill the engine almost immediately. Same with a 3 solenoid design touch all 3 pins with the 12 volt source. If the engine does not die immediately you have either weak solenoid(s) or the piston in side the brake housing is siezed in the bore. You can watch the pistons actuate by applying the 12 volt source to the pin and watch them move in and out the housing with the valve cover removed (be careful as now oil will fling out of the head, its not a terrible amount but it will make a mess.) The piston is over the exhaust valve closest to the exhaust manifold. If you see all pistons barely protruding on any housing when 12 volts is appied again you probably have a weak solenoid. If only 1 or 2 pistons are barely protruding you possibly have mechanical problems. Also directly underneath the solenoid when 12 volts is applied you should see SOME oil coming out (this is where previous experience comes in to play) if flow of oil appear excessive or more than the other solenoid then that solenoid is bypassing too much oil and is considered bad.
5. Ok now if all checks are ok up to this point, re-assembled engine to an operational state. Using a multimeter back probe (pierce) once of the wires on the external harness since now you are reconnected and set the multimeter to DC volts. Take the unit on a road test using the engine brakes perferably on setting "3" and when the brakes engage you should see somewhere around 12 volts appear on the meter. Do this for each supply wire and road test using engine brakes. Now the 12 volts on the meter may be very quick its all going to depend on how long the ECM decides to engage the Jakes. If you see 12 volts or atleast a flash of 12 volts on each supply wire then the ECM IS SENDING the correct signal to the Jakes. If you do not see the voltage or voltage is low youll need to start looking in to power from the ECM to the Jakes (check continuity of wires from ECM connection to external harness at pass through you disconnected earlier) if wires have good continuity (generally .1 ohms to 1 ohm MAX) then power from ECM is an issue or UNSWITCHED power to ECM has an issue.


If all these checks are completed and brakes are still weak (especially when hot or at operating temp) you run the possibility of oil pressure issues and that is another problem all in its self. I hope this helps.

 

It is a possibility that there is an o ring thats not sitting properly bring that it only happens when the oil gets warm