MoTeC Global Forum

Hi All,

I have a CDL3 in my track car and have just fitted a Bosch temp sensor to my gearbox. I have a fly lead connecting the sensor to the main loom (this connection has been assigned to channel AT1).

I now have the challenge of understanding why the gearbox temp is shooting straight to 210degC after 10 seconds of idle!

The Fly lead is connected for transmission temp, CDL calibration load as per direction from gearbox seller who ran this temp sensor and gearbox in his EVO.

Summary:

- 10 seconds into engine running- Alarm for gearbox temp (alarm set at 120degC) flashes up
- CDL is reading 210°C. According to loaded calibration this equates to 0 ohm reading
- Transmission temp sensor back probed. Giving multimeter reading of 2.5 kΩ, loaded calibration equates to approx. 20°C, which was ambient temp. Sensor Ok.
- Transmission temp sensor checked for type (Bosch 028 113 002 6). Matched loaded calibration table. Makes us believe the CDL is ok
- Probing sensor lead (inc. fly lead), have 0Ω resistance/Connectivity to ground on both wires. (2 wire sensor, ground & Signal).
- Removing & checked fly lead. No cross talk between channels. Fly lead Ok.
- Probing Wiring loom. Removed pins from connector block. Both give 0Ω resistance/connectivity to ground.

In summary, CDL is reading 0Ω resistance and sensor end of loom is showing 0Ω resistance.

Before I go thinking there's a short in my you-beaut motorsport wiring harness, is there anything else I should check/configure/calibrate first?

Does your CDL3 have the I/O enabled?

Are you absolutely sure you are on the correct pin numbers? The AT1 input should be pin 16. So your lead to the gearbox temp should be connected to Pin 16 (AT1) and Pin 9 (Sensor 0V). Perhaps you have connected to the Aux Output 1 (pin 29?).

With the CDL3 powered on, and no sensor connected, you should measure 5 volts at pin 16 (AT1) as well as pin 17 (AT2).

If you're sure you are connected to the correct pin numbers have the terminals been inserted all the way? You should look at the CDL side of the harness connector and make sure the pins are bottomed. Usually you have to do this to get the locks in place, but you could have them above the locks I suppose.

Hope this helps.

David Ferguson
Veracity Racing Data
http://veracitydata.com

It seems I don't have the I/O enabled!

Do I need to get a code to enable AT1 and AT2 inputs?

Yes you need to have the I/O Enable code entered for your CDL3. Contact MoTeC to see if an I/O Enable was issued for that dash serial number. If so, they will provide the code. If not, then you'll need to purchase the code in order to use external sensors.