Transmission Power light flashes blinks on start up

[Cuong Nguyen]

the power light on the dash flashes on start up.... anyone got any idea why? I think it flashes like 14+ times. 14. maybe 15 or 17? I converted to 4wd using a 4wd transmission and kept the stock 2wd ecu. The only thing I didn't change out was the revolution sensor perhaps. They did have different part numbers. I never had this problem right after the conversion. I have a 93 Pathfinder with the mechanical/cable driven speedometer. It's not longer working---stays at zero. that have any effect? My tachnometer doesn't work either.

[Zibi]

The overdrive light on an auto tranny flashes a code to tell you whats wrong with the transmission. Mine did it when I restarted my car after the transmission went into limp mode.

[Indigent]

Follow the procedures in the FSM for the transmission diagnostics check. It gives you a break-down of what the flashes mean specifically. It is in the AT section of the FSM

[Cuong Nguyen]

The problem has resurfaced. Speedo hasn't worked since I got the transmission together. I was getting the flashing power light on start up. Odd sputtering and bogging and now it won't start. I pulled codes from the ecu and got a code 14: vehicle speed sensor. I have not pulled codes from the tcm. Yet.

[Cuong Nguyen]

[Slartibartfast]

Sixteen equal-length flashes. That, unhelpfully, does not appear to be in the manual.

 

The closest thing I see is the light just flashing--rather than the flickering that is supposed to run codes. Could be it only does the flashing thing for long enough to get sixteen flashes. That condition is supposed to mean that the battery is weak, connected backwards, or was disconnected for a long time (in which case it's not a problem and apparently clears itself). Codes are listed for the engine speed sensor or vehicle speed sensor, so it's clearly not coding for those. Then again, your battery isn't hooked up backwards, and if it keeps doing this, "disconnected for a long time" ain't right either. Looking at the circuit diagram, I do see that the TCU has two power connections, one switched and the other unswitched, and both have separate fuses. Maybe the fuse for constant power popped, so it's only getting power on the accessory line, and none when the ignition is off? Something to check, anyway.

 

Not sure why the tach isn't working (and that does seem like a signal the TCU needs!) but I might have an idea on the speedo. After I'd had my dash apart a couple times, my speedo stopped working. I took the cluster out again to verify that the speedo cable did spin when I drove, and then found that I just hadn't clipped the speedo cable back into the dash properly, so it wasn't engaging with the cluster. Clipped it back in and it's worked since. Could be an easy fix if you've had your dash/cluster out, or maybe even if the speedo cable got a good yank at some point and pulled out.

[Cuong Nguyen]

The power light flashing for 8 seconds like you see in the video means the transmission is I fail safe mode: 3rd gear no matter what shifter position it's in. Now that I remember, I think my speedo cable pin had cracked broke a long time ago and I had to superglue it back together to get it work again. It looks like I might have to get a new one or pull one from the pick n pull. The tach works fine since I replaced it with one from another vehicle a long time ago.