Rpms not working.

craity

Member
Messages
5
Hi guys, new dc5 owner here. Bought the car yesterday, few minor stuff to be done but other than that shes perfect. One of them is that my Rpms dont work. My speedo, odometer, fuel and temps are working. I ran the diag mode where the needles recalibrate and the rpm one was working as in went up and down but during drive or idle nothing. I was thinking of checking for voltage on the rpm wire at cluster but not sure what value its supposed to be and if the needle is working during diag then it wouldnt be that would it? Also vtec engages fine. Not sure if it could be the speed sensor?
Thank you.
 

JustinEET

Member
Messages
20
Hi guys, new dc5 owner here. Bought the car yesterday, few minor stuff to be done but other than that shes perfect. One of them is that my Rpms dont work. My speedo, odometer, fuel and temps are working. I ran the diag mode where the needles recalibrate and the rpm one was working as in went up and down but during drive or idle nothing. I was thinking of checking for voltage on the rpm wire at cluster but not sure what value its supposed to be and if the needle is working during diag then it wouldnt be that would it? Also vtec engages fine. Not sure if it could be the speed sensor?
Thank you.
Hello, do you have a CEL(check engine light)?

The ECU sends information to Tachometer but ECU gets that info from crankshaft position sensor.
 

JustinEET

Member
Messages
20
No check engine light at all
So the Crankshaft Sensor should be ok. You can still test the voltage on it.
The blue wire is how the ECU sends information to the Tachometer.
So you'll have to test there.

Part of your troubleshooting can be easy if you have datalogging tuner software.
 

craity

Member
Messages
5
Im afraid i dont have access to any datalogging. I am gonna check the plug on monday when Ill get back to the car, if i am correct, there should be 3 wires? Earth, power and the signal. Do you have any clue what the voltage should be on them if i check with the meter? Could it not be the speed sensor? Thanks.
 

JustinEET

Member
Messages
20
Im afraid i dont have access to any datalogging. I am gonna check the plug on monday when Ill get back to the car, if i am correct, there should be 3 wires? Earth, power and the signal. Do you have any clue what the voltage should be on them if i check with the meter? Could it not be the speed sensor? Thanks.
Speed Sensor/VSS would effect your Speedometer, also it would throw a CEL code.
Crankshaft Position Sensor which sits down there by the Harmonic Balance Pulley on the Crank is how the ECU gets RPM information.
So the Cluster is getting pulse voltage from E26 from ECU terminal and it runs on the blue colored wire. (This voltage is gonna be dependent on how much throttle you use or if you are just idling)
GRANTED, I'm an Acura RSX owner and I'm used to working on RSX but i'm positive it should be the same on your Integra.


You might can use chassis ground to see the pulse voltage.
But typically any black colored wires are ground/earth (still getting used to yalls lingo)
And don't worry about whatever is used to power your cluster, it's irrelevant as of course your cluster is working just not your Tachometer.
 

craity

Member
Messages
5
So basically where I should start is from ecu at the pin check voltage? While idling/reving? If I will get numbers then I have to check cluster side if its getting any voltage? As it might not be getting anything from the ecu? I am going to my shed tomorrow morning and I will check it out. Thank you.
 

craity

Member
Messages
5
Update: that wire from ecu is spliced into male/female connector and was disconnected, revs work perfectly now, cheers
 

JustinEET

Member
Messages
20
Update: that wire from ecu is spliced into male/female connector and was disconnected, revs work perfectly now, cheers
Awesome, figured it had to be disconnected somehow. Because otherwise it would of been pointing to an ECU issue, and that rarely happens.
 
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