Friday, March 1, 2013

International 4300 intermittent power loss

      This post deals with an International model 4300 electrical problem that will cause driveability and starting issues, including an intermittent no start, check engine light with no codes or with multiple ECM/injector codes, and engine cutout/stop with hard or no start. The cause, especially on high mileage vehicles, is often loss of clean power to the ECM or IDM. Clean power connectors are found in the battery box and by the starter. Note that much of the following information is specific to this model and will not apply to another brand/model.
      There are 2 connectors in the battery box, one with (usually) two red and one white wires, (or 3 red wires) and the other with two white wires. The red wires, of course, are spliced to the positive battery harness, the white to ground. All are 10GA wires with inline weatherpack connectors. Anyone who has been in this business for a while has seen weatherpacks cause problems, especially when they get older or have had excessive power run through them. There are 2 (sometimes 3) more connectors in the harness down by the starter. These are also weatherpacks on 10GA wires, both power and ground. These circuits feed the ECM (electronic control module) and the IDM (injector driver module) via relays in the power center above the driver steer tire. Loss of power or ground, even for an instant, will set a code.

IHC 4300 clean power battery box connections

IHC 4300 clean power starter connections
      I have repaired two 4300 models with this problem in the past 3 months. The symptoms of each were typical for loss of clean power. The vehicle typically will start but shut down intermittently, usually with no pattern to the incidents. In extreme cases the frequency of shutdowns will make the vehicle unusable. Often the MIL light will be lit during a no start condition and codes will be stored, often for all injectors and B+ voltage, but the light will not stay on after a restart showing an active code. Diagnosis of the problem is pretty simple after you have seen it a couple of times, given the symptoms and the particular set of codes stored. 
      The OEM repair process is outlined in two TSL (technical service letter) publications. These specify taking the connectors apart and inspecting visually for damage, testing pin tension with a pin gauge, then removing failed connectors. In my opinion, these efforts waste time. When I get a truck in the shop that exhibits the given symptoms and codes, I just go ahead and cut out all the connectors and be done with it. I don’t have much faith in testing connectors in this application and to risk missing the one causing the problem will cause another shutoff, maybe in a hazardous traffic situation. 
      Repair is easy, just cut the wires off close to the connector and solder the ends together. There is plenty of wire length available (unusual for International wire harnesses!) and it should take about an hour to do them all. I usually connect the ends of each wire with an uninsulated butt connector, then fill the connector with rosin core solder and seal the connection with good-quality, glue filled shrink tube. Do not use acid core solder, and don’t try to seal the connection with electrical tape. These connections are exposed to the weather and are critical for vehicle operation, so only a good quality repair will last.    
      Hopefully the truck has exhibited symptoms often enough that you can verify the repair, which is usually the case if the problem has been happening for some time. Sometimes a customer will bring in a truck after the issue has only occurred one or two times, in which case it may be just a matter of faith that the vehicle is fixed. This is where the value of seeing the problem a few times comes in. You need to be sure going in that there isn’t another issue that is actually causing the problem. A cam sensor can have a similar failure pattern, often failing only at operating temperature with an accompanying no start. A glitching ICP (injection control pressure) sensor can also show similar symptoms, but often these will not cause a shutdown, as the ECM will try to use substitute sensor values to keep the engine running. Failure of either of these sensors should always be accompanied by a stored or active code. 
      Stored codes will indicate the source of the problem, so it is important to check for them before jumping to conclusions. If I don’t know the vehicle in question, I write down all the stored codes then clear them and try to reproduce the symptoms. Some of the stored codes could be old, for instance if they were related to a repair after which the mechanic didn’t clear old codes, or if the batteries were unhooked or run to very low voltage with the key on.  

An additional note: Click on the DT466E No Start tab above the posts to go to the sales point for my No Start Diagnostic book.
Bruae Christopherson
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