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Inukshuk
11-20-2013, 10:13 PM
Need to fix my intermittently engaging CDL by Friday.

Center differential lock not reliably engaging. Pin-7 modded 12+ years ago, Toyota CDL switch.

Been happening for a while (at CM 13 for example) but I always forget to investigate after trips. Im pretty sure the actuator is fine. In my garage the other night I heard it engage and disengage when truck in on position with engine off. Switch is illuminated so its getting power to that illumination circuit. I have a spare CDL switch and swapping that in made no difference. 10A Gauge fuse has been replaced. 30A Diff Lock fuse also replaced. Both tested fine but I replaced with new Buss fuses to be sure.

I plan to unplug harness at actuator and have someone cycle the switch while I test voltage. I plan to apply +12v with a wire to the proper actuator pin. (I dont have electrical FSM - anyone have pin-outs for switch and actuator?)

I know there is a CDL ECU to investigate too.

Thanks for any suggestions

rockrod
11-21-2013, 03:35 PM
I have an electronic version if the ewd for the 93 and 94 mode year trucks. Pm me your email and I will send it out.

Corey

rockrod
11-21-2013, 03:35 PM
Does the dash light flash when you push the cdl button?

Inukshuk
11-21-2013, 05:57 PM
I have an electronic version if the ewd for the 93 and 94 mode year trucks. Pm me your email and I will send it out.

PM sent

Does the dash light flash when you push the cdl button?

no.

This AM it engaged right away. Light on, relay click in driver kickpanel and pleasant whir of motor. But, its not reliable.

Inukshuk
11-25-2013, 09:41 PM
I ran the diagnostics from a great troubleshooting website and FSM EWD (thanks Corey) pin-outs. Relay tested bad. Bought one off Dave Kaiser and so far it works every time. Thanks all!

Inukshuk
04-13-2014, 03:30 PM
Diff Lock Relay was not bad after all. It :rolleyes: apparently makes a difference if the pinout diagram you are using if for the relay side or the plug side. Anyway....

After some hours of testing and diagnosis, I think there is a problem with the switch in the CDL control motor between pins 5 & 6. I narrowed it to this because it was easy to activate the CDL from the driver's kick panel plug C4 with wires and a 9V battery to CDL control motor pins 2 & 3 (pins 1 & 4 at the relay. (You test these things with 9v per FSM) Similarly with 9V applied to CDL relay pins 6 and out pin 5, the relay operated properly. So I figured relay pinout 5 which goes to CDL control motor pin in 6 is not competing the circuit. Ideally I would test CDL control motor pin out 5, but its on top of the transfer case. So what I did was hook it all up and ground relay pinout 5, and voila, CDL switch makes it work. I buttoned it up leaving a temporary wire into relay pinout 5 so I can test the theory if it fails again - because, oddly, its working now in stock configuration.

Summary: I think after the CDL control motor unlocks (which it has never failed to do), the contacts inside that would close the circuit for the next lock cycle, do not reliably shut. :cheers:

Or I am completely wrong. :rant:

rockrod
04-13-2014, 05:25 PM
I am also occasionally having this issue. I am pretty sure it's the switch itself. I bought mine used from someone else. Since the switch that controls the trans shifting is no longer used in my truck after the engine swap, I may just swap them and see what happens.

Inukshuk
04-13-2014, 11:11 PM
I am pretty sure it's the switch itself.

Which switch?

rockrod
04-14-2014, 12:17 PM
the CDL switch in the dash.

Inukshuk
04-14-2014, 01:59 PM
the CDL switch in the dash.

Thoroughly tested. Polarity reversal works every time. My wire work around triggers every time. Also, I have a spare and did swap em earlier.