Haltech Nexus R3 Intermittent DTC2135

Hello all,

I'm having an issue that's got me pulling my hair out. I had an issue several months back with my Nexus R3 not reading knock sensors, after some laborious diag with a labscope it turned out it was in fact the ECU. Haltech was kind enough to replace it, but ever since I've had intermittent issues with DTC2135 and disabling the throttle. This happens on fireup, and also driving, needless to say it's not being driven much with the little time I have.

Things I've done: I've calibrated the APP and Throttle body several times. If it needs to move sometimes that's how I have to get it to. I've voltage drop tested powers, grounds, and sensor wires. The APS 1 and 2 circuits are a straight shot to the ECU, via a flying lead harness from Haltech with factory crimped ends. I also removed the terminals from the DBW connector, inspected terminal crimps, replaced a couple I didn't like and installed in a new connector. No change. I was able to capture a log file of the car driving just fine and then faulting out, which I have attached. 2135 sets when APS voltage 1 and 2 aren't moving together. I was going to say I'm just not seeing it in the log file, but maybe I am? If I use 5.00 as a ref there is about a 20mV difference between both values. Is this enough to throw a fault? Seems like it shouldn't be. I have attached two screenshots of the log when the DBW status hits Status 6. Status 6 reads like there is a tracking error for both the throttle AND APP happening at the same time. I'm not getting any APPs faults though. Any insight would be greatly appreciated, I've got to be missing something silly.

I would look at the channel Drive By Wire Throttle 1 Sensor Match Error. It looks to me like your sensor A/B voltages are tracking, but that keeps showing wild differences. I would share that with Haltech, perhaps they have a firmware bug....