2002 Road King FLHRI. So I'm chasing a electrical gremlin from a chk engine light/d10set code. Code states that there is a d10set = speed output shorted low or open. I replace the speed sensor already. still codes to d10set. The white/green wire shows it is from the speedometer plug to the ECM. One of the mechanics at my work said I should ohm the white/green wire from the speedometer plug to the ECM and that it should read.2ohm. I tried flashing the ECM at the diagnostic port but get nothing. Maybe I'm doing it wrong??? I don't want to go and start pinning anywhere on the plug until I know which hole to pin. electrical diagram states that it's #33 of 36 terminals.

Any help appreciated.

 

There is no rocket science in the connectivity check. ECM connector have pin number mark-up on it so you can either count down from 36 to find pin 33 or remove the back cover on the connector and find the White/Green wire visually. Set your multimeter to sound mode and put one probe into ECM connector pin 33 and other on into speedo connector pin 12. If tester beeps then most likely you've got a speedo problem. Also w/gn wire goes to the cruise control module if your bike have it. To exclude its possible influence disconnect it (under left side cover) and measure to its connector too or try check if you still have the DTC with CC module disconnected.

 

Apparently it is rocket science. You need to check the white wire going from the speed sensor to speedometer. I'd also check power and ground going to the sensor from the speedo.. On a 2002 up to 2003 (iirc) the speedo handles the speed sensor. The speedo then sends a simple count to the ECM and TSM/TSSM through the White / green wire.

 

TCM/TSSM has speed data via datalink from ECM. Speedo pulses are only for ECM and CC

 

Not on a 2002, Look at the wiring diagram for a 2002. Speed sensor wired to the Speedo.. ECM does not have any connection.

 

I didnt say sensor is not connected to speedo. I said speedo is pulsing to ECM and CC. Look deeper into wiring diagram and you will see that w/gn wire from speedo comes to the ECM and CC (if it is installed). TSM/TSSM has speed data from ECM by gy/y wire. Furthermore, EDM says it "The vehicle speed sensor is powered and monitored by the speedometer. The speedometer sends a vehicle speed signal (9000 pulses/mile) to the ECM. The ECM processes the vehicle speed signal and transmits this signal to the TSM/TSSM through the serial data line."

 

You are right.. Tried going from memory, Had to look at the manual. At first glance the carbed bikes use the serial data line to send speed to the TSSM/TSM as a simple pulse..

 

Soooo.... Getting back to my question. If I hold the ECM terminal plug in my hand and I'm looking at the plug with the wire loom on the right side, Which one is #33? That is where the diagram says it terminates at the ECM plug. I want to OHM it to see if the green/white wire is shorted. If it is not I would suppose speedometer is bad.

 

There may be numbers on the connector. If not Pin 1 will be marked. It will be probably a staggered numbering scheme.. 2 will be the opposite side so 33 will be same side 1 in from the other end.. A good way to verify is check for the ground pins on the connector.. The should be where the numbering scheme say they are.

 

There may be numbers on the connector. If not Pin 1 will be marked. It will be probably a staggered numbering scheme.. 2 will be the opposite side so 33 will be same side 1 in from the other end.. A good way to verify is check for the ground pins on the connector.. The should be where the numbering scheme say they are.

And I was wrong.. Ref looking at ECM connector from the bottom. The numbers are shown on the 4 corners of the ECM connector.

xxxxx 18 : 36
Front ------- Back
Fins -------
xxxxx 1 : 19

4th in would be 33.