2011 Electrical fault gremlins

[Waterloo]

I dug out the sending unit, pulled the two wires out of the harness right up to the firewall. Then I cut the wires to length, leaving a bit of slack, making sure I marked them to stay in their original position in regards to attaching to the sending unit. So far so good! I used butt connectors, squeezed a bit of dialectic grease into them, crimped and then used heat shrink to seal the connectors.

[kmk]

Your instrument cluster and its wiring by the steering is likely the culprit. Check all the plugs for corrosion. Any sensor wiring i would solder and insulate with marine heatshrink. On many of the sensor circuits there is bias voltage that can be affected by even miniscule voltage drops.

[Muchos189]

Hey guys I want to give an update on my electrical gremlins and how I finally found the problem. YES!!!!! The Cummins mechanic that helped asked me not to give his name to reduce the possibility of him getting in trouble for using the laptop for side work.

The quick answer is there was a small section of harness that had chafed through and was shorting out only when the truck got wet. The actual section of harness was about 3 inches past the ambient air temperature sensor located on the front bumper in between that and the OnGard radar system. The way International sends power and ground through that section and the fact that both the power and grounds were rubbing is what was causing the constant Check engine light for the ambient air temperature sensor and then with short out the body control module there by killing anything that ran through that. I actually had a friend who works for Cummins meet me about a month ago at the house and hooked up his computer with Insight on it. He didn’t know anything about how international wired the chassis which she referred to as OEM wiring because he specializes in only Cummins engines because that’s exactly who he works for. He was not able to solve the problem by replacing the sensor and checking the pins in the harness but he was able to make a temporary jumper wire from that sensor straight up to the trucks computer so that the sensor would read correctly. That gave me the idea that I need to look a little closer in that section of harness as it made sense that there was probably an issue with the wires shorting out along that stretch.

After I found the bad wiring I repaired it using good quality heat shrink butt connectors and then I completely wrapped all of that harness with new wire loom and routed it in a slightly different way so that it doesn’t rub the frame support just under the radar. I disconnected the trucks battery to reset the body control module and After reconnecting and going for a drive everything was perfect. I’ve driven through two fairly heavy rain storms and I had a truck wash and there has been no issues or faults that have come up. For the first time in almost 170,000 miles I have no ABS lights or check engine lights or codes of any kind.

The Cummins mechanic also did a forced regen and did let me know that my exhaust back pressure is a little bit elevated but still in spec and recommended pulling the filter and have it cleaned.

He helped me run the valves and injectors and said my injectors were very far out of spec and he was a bit surprised it wasn’t showing codes for cylinder inbalance issues. The tq on all the injectors was in the 25-30 inch lb range and he reset them to 72 inch lbs. The lobes on the camshaft were in excellent condition and show only normal signs of wear.

As a bonus he also pointed out that the turbo charger has been replaced already along with the EGR cooler and the head on the air compressor.

He did mention my engine was 19 updates behind and is going to meet with me in the next couple weeks to update the ECM.

I bought this truck almost 2 years ago with the odometer turning 456,789 miles on the drive home from the dealership, it’s currently at 629,982. The truck was previously owned by Crete Carriers and he mentioned they tend to take pretty good care of their equipment which was also encouraging.

Can’t explain how good it feels to have finally found the problem and fixing it properly.

[Rawze]

Thanks for sharing your solution with everyone on the forum.

I know I have had my own share of wiring short out under the front end of my own truck, especially where it reaches its lowest points under the front framework. Same kind of issues including headlights not working.

[Gadget]

I would check with insite to see if the ambient air temp sensor is enabled or disabled on insite. Mine is disabled and just playing around on day I enabled the sensor which immediately gave me the upside down triangle and code for the sensor in insite.
Disabled it and everything was ok

[Gadget]

Oops missed that you got it fixed. LOL !! MY BAD!