Via Tap In for CLT/AD2-1 ?

[ErnieJones]

Hi!

Is there a via somewhere on the board that I can tap into for access for the CLT/AD2-1 Input?
Also, while I'm here, is there via that I can tap into for access to ALED ?

[dontz125]

I'll bite - what ARE you planning?

[ErnieJones]

There's a method to my madness.

My coolant gauge in Tuner Studio stopped working. I have continuity all the way from the sensor to the top terminal on the Microsquirt Module - so it should work but it doesn't. This leads me to believe that the problem must be before the J1 terminal on the Microsquirt. ie. between the CPU and the J1 connector. This is why I asked if anyone knows if there is a via between the J1 and the CPU that I can tap into....

[dontz125]

The processor pin itself is probably the easiest to find - U1-29, counting counter-clockwise from the dot. You should have 2.2k resistance (inline filter resistor) between the processor pin and the header pin, and 2.49k (bias resistor) between the CLT header pin (J2-5) and VRef (J2-15); this assumes that F2 has low resistance in an off state.

[ErnieJones]

OK, there's a via right under that CPU pin (half way between C13 and the CPU) and I can see the trace from the CPU to that via so I am sure the via is correct.
There is continuity between the CPU and that via but there is no continuity between the via/cpu pin and the Coolant Temp terminal on J2
R11 = 2.19 Ohms (spec is 2.2)

There is continuity between the via and R11

There is no continuity between J2 Pin 5 (CTS) and R11 ....

[ErnieJones]

Problem solved. I managed to find a via between R10 and J2-Pin 5. A jumper wire between J2-Pin 5 and the via resulted in a completion of the circuit and proper coolant temp sensor display

Conclusion - there is an issue between J2 Pin 5 and the rest of the circuit on the Microsquirt Module.

[dontz125]

Hmmm ... very odd.

Inspect the two pads on R11 for condition - are there proper solder fillets? Obvious dry joint? Try reflowing the two pads (one at a time) on R11. Also, inspect the pads and trace to R10 - a bad connection to the bias resistor will also screw up the reading.

Actually, I have to wonder if you didn't have a bad joint at J2-5, and by adding the jumper you sorted that out.


I am unaware of any pattern of complaints on the uSM and the coolant ADC ...

[ErnieJones]

I thought the very same thing - that there was a connection issue on J2-5 so I removed all the solder from it and the 'circle' is still there underneath it all. So there does not appear to be anything obvious (to the magnified eye) there. I soldered it back up and still no continuity, and thus the jumper - problem solved.

I'm now on the trail of why my external baro pressure sensor seems to be intermittently operating. I checked for continuity for all three lines including the output line all the the way up to the CPU - it's all there. I guess the question is (now) has the relatively new sensor gone south....