Josiky Posted March 4, 2021 Report Share Posted March 4, 2021 Hello, I'm using a depo racing water temp gauge but readings won't match the ecu temp sensor. They are placed in the same location. Is there any way I could use the stock sensor to move the gauge? Or using the dedicated sensor to the ecu then to the gauge? It's a classic ohm resistance sensor. I'm having around 10° difference in readings. Tried guessing a suitable resistor in parallel (5k around) , but it will just give accurate readings for a desired temp. I have the calibration table from Depo. Thank you guys. Ps. I'm attaching the calibration image. Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 4, 2021 Report Share Posted March 4, 2021 The first thing I would suggest is drop both sensors in a kettle of boiling water to confirm which one is correct. Quote Link to comment Share on other sites More sharing options...
Josiky Posted March 4, 2021 Author Report Share Posted March 4, 2021 Hello i used a digital thermometer today with the water pot. Ecu sensor is spot on with the digital thermometer 1° up/down. Checked at 80 and 60. Thank you. Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 4, 2021 Report Share Posted March 4, 2021 Im not sure if this trick will work with all temp gauges, but for some you can connect them directly to an aux output and drive them with a GP PWM. So you then have complete control over how the gauge reads. On the couple of done this way they were happy at 100Hz. Quote Link to comment Share on other sites More sharing options...
Josiky Posted March 4, 2021 Author Report Share Posted March 4, 2021 Thank you I will try this. Quote Link to comment Share on other sites More sharing options...
Adoom Posted March 10, 2021 Report Share Posted March 10, 2021 On 3/5/2021 at 10:07 AM, Adamw said: Im not sure if this trick will work with all temp gauges, but for some you can connect them directly to an aux output and drive them with a GP PWM. So you then have complete control over how the gauge reads. On the couple of done this way they were happy at 100Hz. I want to try this, to drive a temp gauge using an aux out. I think there is supposed to be a table of some kind for the GP PWM to do duty cycle stuff. That's where I get lost. I've worked out how to edit a table, but I've got no idea what the axis should be or what kind of numbers should go in the fields. Could you post a picture of an example table where ECT is used to control duty cycle for a temp gauge? Quote Link to comment Share on other sites More sharing options...
Vaughan Posted March 10, 2021 Report Share Posted March 10, 2021 constant frequency, ECT on oen axis of the Duty Cycle table, nothing on the other axis of the Duty Cycle table. I figured out what values to use in the duty cycle table through trial and error, try a value and see where the sits, make a note of it and repeat. Something like 70 to 85 for the middle of the gauge would be about right if it is just a factory one without units. Extra for experts would be adding batt voltage to the other axis as I have noticed some variation in position based on battery voltage (affects the aux pullup voltage) The attached image is a very half assed attempt in my MR2 Quote Link to comment Share on other sites More sharing options...
Adoom Posted March 10, 2021 Report Share Posted March 10, 2021 @Vaughan Cool. Got it working. Thanks Vaughan 1 Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 10, 2021 Report Share Posted March 10, 2021 The car I done worked out similar to Vaughan's example but I dont have a copy of the final map saved. I did it similar to his - it was a stock cluster gauge with no numbers so I just set it up so 90 deg gave me somewhere around the middle of the gauge and 100°C was 3/4 scale and at 105 the gauge was pegged. Adoom 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.