Clattie Posted March 3, 2023 Report Share Posted March 3, 2023 Hi guys, I'm looking to start my project car this week but I'm getting no signal from either my Cam or Crank Sensor on an aftermarket COP kit.Cranking.llgx However, I am getting a constant voltage of around 3.66 with and without cranking... I'm running two hall effect sensors (GS1005-GS1007) with a 60-2 missing tooth trigger wheel, note that the hall effect sensors need a 2.4k ohm resistor but I'm not sure what the internal resistor is on the link ecu. Does anyone have any bright ideas? I'm going to retest tomorrow because I must not of saved the change from the reluctor to the hall effect sensor. Edit #1 - The documentation states that the sensors require an external pull-up resistor between the signal wire and the power wire (I was under the impression I could just activate the internal one on the signal wire), it also says on the document that it's compatible with 5v. Is this common? I'm going to rewire it tomorrow and hopefully save an output on my PDM by switching it over to 5V and get these working! Without Cranking.llgx A MR2 MAP.pclx Quote Link to comment Share on other sites More sharing options...
keizsr Posted March 4, 2023 Report Share Posted March 4, 2023 Hello, the internal resistance is as described in the article I used the g4x internal 8V sensor specified resistor 1.6kΩ without the g4x pull-up Quote Link to comment Share on other sites More sharing options...
Clattie Posted March 5, 2023 Author Report Share Posted March 5, 2023 Sorry, I don't understand what you mean. Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 5, 2023 Report Share Posted March 5, 2023 Those sensors will work with the ecu's internal pull-up well enough to show a signal and at least run. They do sometimes need the stronger pull-up as recommended on the datasheet for high tooth count wheels at high RPM, but that is not your problem right now. They will work with anything from 5-24V so not fussy on power supply. Quote Link to comment Share on other sites More sharing options...
Clattie Posted March 5, 2023 Author Report Share Posted March 5, 2023 But the document also states the external pull-up should be bridged between two wires. Output and power, I don't have any resistors in the wiring, and the internal pull-up is on the output wire only. I've checked the continuity between all the wires and they are fine, I've also made sure my cable shielding is grounded properly too, as you said my voltage looks good as well so I'm not sure what else to check. Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 5, 2023 Report Share Posted March 5, 2023 The ZF sensors are very common, they have been widely used with ecu’s for the last 20years so I’m very familiar with them and how a pull-up works. The ecu internal pull-up resistor forms exactly the same circuit and the same functionality as the external one drawn on the sensor data sheet. The only difference is it is lower resistance than recommended and it is connected to a regulated power supply rather the often variable sensor supply that the data sheet shows so the internal one will give more accurate timing. The fact you still have 3.6V showing in the trigger scope when you short the signal wire to ground means that signal wire is not connected to the trigger 1 pin at the ecu. Quote Link to comment Share on other sites More sharing options...
Clattie Posted March 5, 2023 Author Report Share Posted March 5, 2023 Yes, that was my point, I was thinking that not bridging an external resistor between the power and signal was a wiring error of my own fault. But as you've just explained it doesn't matter. I still get 3.6v but I get no wavelength on the graph. I'll get someone to hold the wire in place of the short tomorrow incase something wasn't 100% contacting the pins and go from there. Quote Link to comment Share on other sites More sharing options...
Clattie Posted March 13, 2023 Author Report Share Posted March 13, 2023 Today I switched the sensor over to a 5v power from the ECU and put two 1kohm resistors between signal and 5v on both cam and crank sensor as per specification sheet. Now thankfully... I am getting a trig signal 'yes' for both triggers, although no voltage and 1 or 2 spikes on the scope. Someone has mentioned it could be my resistor but I've only followed the spec sheet from the manufacturer. Quote Link to comment Share on other sites More sharing options...
Clattie Posted March 19, 2023 Author Report Share Posted March 19, 2023 Update - I've now whittled it down to the sensor grounding, the wiring is all 100% fine but I'm not getting any ground unless I manually short the ground to the signal wire. it may be that both sensors have been fried during the wiring or setting up. Any other bright ideas as to what it could potentially be? Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 20, 2023 Report Share Posted March 20, 2023 I would try powering the sensor up on the bench for a quick test with all car wiring eliminated. You can connect the +/- direct to a battery, you will need a pull-up between the + and signal wire. Then put a volt meter on the signal wire and see if it changes when you move some steel past the front of the sensor. Quote Link to comment Share on other sites More sharing options...
Clattie Posted March 20, 2023 Author Report Share Posted March 20, 2023 I'm working away now, could I also test this with resistance too? If so I could get someone at home to do quick test. Pull the sensor out, probe signal ground and signal wire and then move something in front? Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 20, 2023 Report Share Posted March 20, 2023 No, they need to be powered for the circuit inside to work. Quote Link to comment Share on other sites More sharing options...
Clattie Posted March 26, 2023 Author Report Share Posted March 26, 2023 I tried this today Adam and the voltage stays at +12v with 0 change. Does this mean a bust sensor? Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 26, 2023 Report Share Posted March 26, 2023 It sounds like it. The signal wire should be pulled down to near 0V when you have metal in front of it. Quote Link to comment Share on other sites More sharing options...
Clattie Posted March 26, 2023 Author Report Share Posted March 26, 2023 Heres some photos and video to show you, just so we're on the same page. That was using a 1k ohm resistor which wasn't recommended for 12v. Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 26, 2023 Report Share Posted March 26, 2023 Your wiring is correct. No video attached but assuming the volt meter still showed the same 13V with something steel/iron in front of the sensor then yes the sensor is dead. The 1K pull-up is fine, those sensors are rated to sink 20mA and that resistor would be about 13mA. Quote Link to comment Share on other sites More sharing options...
Clattie Posted March 26, 2023 Author Report Share Posted March 26, 2023 Yes, the video was too large. I've ordered two replacements which I'm hoping to test this weekend. fingers crossed... Quote Link to comment Share on other sites More sharing options...
Clattie Posted April 9, 2023 Author Report Share Posted April 9, 2023 Sooo, I tested one of the replacements today and I'm still getting a solid 4.5v I've tried it inside the cam housing and with a few tools infront of it but nothing. I'll have to get the other one out of the packaging and bench test it. Quote Link to comment Share on other sites More sharing options...
Adamw Posted April 9, 2023 Report Share Posted April 9, 2023 Can you snip or disconnect your pull-up easily? Just in case you have something much different than it should be? Just enable the ecu one. Quote Link to comment Share on other sites More sharing options...
Clattie Posted April 9, 2023 Author Report Share Posted April 9, 2023 Not really, but I guess I'll have to do it somehow. I've already tested it on the bench and it's showing 1k resistance too. Would my shielded cable ran Into the signal ground cause any issues? I've got it wired this way but I'm thinking it should be on power ground now. Quote Link to comment Share on other sites More sharing options...
Adamw Posted April 9, 2023 Report Share Posted April 9, 2023 42 minutes ago, Clattie said: Would my shielded cable ran Into the signal ground cause any issues? I've got it wired this way but I'm thinking it should be on power ground now. No. Any ground is fine. Quote Link to comment Share on other sites More sharing options...
Clattie Posted April 9, 2023 Author Report Share Posted April 9, 2023 Must be something to do with either the voltage or resistor then... I'll ask on the MR2 forums and see if anyone has had a similar issue. Quote Link to comment Share on other sites More sharing options...
Clattie Posted April 10, 2023 Author Report Share Posted April 10, 2023 So I've tested everything again and it all seems just fine. Sensors powered from 5v at the ecu Sensor Signal are the right pinout at ecu Sensor signal ground to ecu signal ground 5v from signal at the harness 5v from ecu 5v supply at the harness 0v from signal ground at the harness 1k ohm resistor between 5v and signal which is reading around 0.988 ohms. Sensor is also dropping from 4.5v to 0v on the bench test which indicates its grounding. When using the trigger scope and not cranking I'm just getting waves of what I think is noise on the scope? Shouldn't it just be a steady 4.5 or atleast somewhat steady? Honestly can't think what the issue could be. I've just noticed the signal wire is sat at around 5v too? Surely this is a problem? ALL TEST ON HARNESS SIDE IN ENGINE BAY. SIGNAL - Multimeter on Signal and Grounded to engine head (Around 5v) SIGNAL GROUND - Multimeter on Signal Ground and Grounded to engine head (Around 0v) 5V SUPPLY - Multimeter on 5v Supply and Grounded to Engine Head (Around 5v) Quote Link to comment Share on other sites More sharing options...
Clattie Posted April 10, 2023 Author Report Share Posted April 10, 2023 I've shoved the prongs down the back of the connector with the sensor installed and everything is powered up, sensor is dropping from 5v to 0v just fine... I've included this diagram to show you my exact setup... is something wrong? Quote Link to comment Share on other sites More sharing options...
DerekAE86 Posted April 10, 2023 Report Share Posted April 10, 2023 That isn't how you want to wire it. You're mixing 12v supply and 5v pull-up onto the Signal. You either want to supply the sensor power from the ECU 5v with and have the optional single 1k ohm resistor between the ECU 5v and Signal. Or supply the sensor power from switched/ignition 12v and have the optional 2.4-3k ohm resistor between 12v and the Signal. But according to Adam the pull-up resistor shouldn't even be required as the Link has an internal pull-up you can enable in the Trigger settings. Quote Link to comment Share on other sites More sharing options...
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