IHfarmboy Posted April 10, 2022 Share Posted April 10, 2022 What are the voltages supposed to be for the cam, crank, and speed sensors? I am getting 0.26v at the cam and crank sensors and 12v at the speed sensor. Should they all be 5.0v? Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/ Share on other sites More sharing options...
theakerstwo Posted April 11, 2022 Share Posted April 11, 2022 on the three wire sensor the harness will have only one wire with reference voltage 1 Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-494931 Share on other sites More sharing options...
IHfarmboy Posted April 11, 2022 Author Share Posted April 11, 2022 Any idea what the reference voltage is supposed to be? All three sensors in question are two wire. Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-494932 Share on other sites More sharing options...
Joey Mack Posted April 11, 2022 Share Posted April 11, 2022 my guess is you have a V-Mac III truck.. I have seen you post here before.. My suggestion is to buy, (V-MacIII Book # 8-211) ... it is a wealth of info.. jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-494933 Share on other sites More sharing options...
Onyx610 Posted April 11, 2022 Share Posted April 11, 2022 There just Hall effect sensors, 12v on off Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-494934 Share on other sites More sharing options...
Joey Mack Posted April 11, 2022 Share Posted April 11, 2022 tried again to post pics of the specs.. cant get it done.. sorry... jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-494935 Share on other sites More sharing options...
Onyx610 Posted April 11, 2022 Share Posted April 11, 2022 I’ll post the tests/specs tomorrow morning. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-494938 Share on other sites More sharing options...
Onyx610 Posted April 11, 2022 Share Posted April 11, 2022 2 Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-494948 Share on other sites More sharing options...
Onyx610 Posted April 11, 2022 Share Posted April 11, 2022 What are you trying to do? That’s the only info I could find. The other tests are for the blink code for each sensor. Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-494950 Share on other sites More sharing options...
Joey Mack Posted April 11, 2022 Share Posted April 11, 2022 Onyx, I'm glad you were able to post that.. I have a hard time posting pics lately,, jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-494957 Share on other sites More sharing options...
Onyx610 Posted April 11, 2022 Share Posted April 11, 2022 6 minutes ago, Joey Mack said: Onyx, I'm glad you were able to post that.. I have a hard time posting pics lately,, jojo Go into to your account and then my attachments. What’s your quota at? Mines getting up there so I may not be able to post pics much longer either. Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-494958 Share on other sites More sharing options...
Joey Mack Posted April 11, 2022 Share Posted April 11, 2022 i think you are right.. jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-494960 Share on other sites More sharing options...
Joey Mack Posted April 11, 2022 Share Posted April 11, 2022 thanks onyx, I started a topic about my attachments, I will stop posting on this in this thread now,,, jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-494963 Share on other sites More sharing options...
IHfarmboy Posted April 12, 2022 Author Share Posted April 12, 2022 13 hours ago, Onyx610 said: Thanks Onyx610. That helps me check the sensors. From this info it seems the sensors are within spec. Does your book show what the voltage should be coming from ECU? Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-495019 Share on other sites More sharing options...
Onyx610 Posted April 12, 2022 Share Posted April 12, 2022 I’ll look tomorrow morning haha. Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-495025 Share on other sites More sharing options...
Onyx610 Posted April 12, 2022 Share Posted April 12, 2022 Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-495062 Share on other sites More sharing options...
Onyx610 Posted April 12, 2022 Share Posted April 12, 2022 Other then that it doesn’t mention specific voltage. There are tests for testing shorts/opens at different locations. Let me know if that interests you. Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-495064 Share on other sites More sharing options...
Joey Mack Posted April 12, 2022 Share Posted April 12, 2022 Batt voltage, 12.6 or 13.8-14.3 when running... the 3rd reference wire should be around 5.2ish... Glenn had posted that earlier.. good luck,, Jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-495112 Share on other sites More sharing options...
Vmac3 Posted April 13, 2022 Share Posted April 13, 2022 Those speed sensors are variable reluctance. They induce their own A/C voltages. There is no specific voltage to test that is being generated by the sensor. The 5V signal that you see in the schematic is a sensing voltage to inform the ECU if the circuit is good or not. The only way to see if the signal is good or not is to hook up an oscilloscope and watch the A/C signal that is being generated. V 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-495168 Share on other sites More sharing options...
Onyx610 Posted April 13, 2022 Share Posted April 13, 2022 17 minutes ago, Vmac3 said: Those speed sensors are variable reluctance. They induce their own A/C voltages. There is no specific voltage to test that is being generated by the sensor. The 5V signal that you see in the schematic is a sensing voltage to inform the ECU if the circuit is good or not. The only way to see if the signal is good or not is to hook up an oscilloscope and watch the A/C signal that is being generated. V Variable reluctance sensor….that’s it! I couldnt think of it so Hall effect was the closest thing that came to mind. Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-495169 Share on other sites More sharing options...
Joey Mack Posted April 13, 2022 Share Posted April 13, 2022 shoot I forgot about the ocillascope.. Good call again 'V'.... jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-495172 Share on other sites More sharing options...
IHfarmboy Posted April 14, 2022 Author Share Posted April 14, 2022 14 hours ago, Vmac3 said: Those speed sensors are variable reluctance. They induce their own A/C voltages. There is no specific voltage to test that is being generated by the sensor. The 5V signal that you see in the schematic is a sensing voltage to inform the ECU if the circuit is good or not. The only way to see if the signal is good or not is to hook up an oscilloscope and watch the A/C signal that is being generated. V Why would I be getting 12v from the ECU and not 5v? Could the ECU be bad? Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-495241 Share on other sites More sharing options...
Vmac3 Posted April 14, 2022 Share Posted April 14, 2022 You may have a short to power. V Quote Link to comment https://www.bigmacktrucks.com/topic/69515-2001-mack-ch-sensor-voltages/#findComment-495269 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.