No CDL or ABS lights (1 Viewer)

[Munsta]

No CDL light or ABS light in L range

Hi all
I just bought this beautiful restored 93 HDJ80R Sahara with the 1HDT engine.
It's full time AWD but hasn't been in L for about 5 years.
It has ABS brakes and no CDL switch.

When I turn the ignition on I got no CDL or ABS lights on the dash at all and when I put the TC in L I get no lights either. Therefore can not engage front and rear diff locks.
I have bridged the connector plug on the fwd top of the TC, the lights for the CDL & ABS come on and enable the diff locks to be engaged
This proves that part of the circuit works.

Is the CDL actuator on this model electronic controlled and if so what sends the signal to the transmission relay

I can not hear a relay activating or see it the drivers kick panel

Cheers

 

[LFD2037]

It may take a few miles (off road), in 4 low, for it to engage since it hasn't been activated in so long.

 

[Tools R Us]

For diagnoses I prefer to jack it up so the drive shafts can be turned. What happens when the L4 position switch wires are jumper-ed (a small paperclip works), with the key to run? It is what initiates the CDL locking, if bad nothing works.

 

[Rifleman]

The truck i bough, the original owner never engaged the low range once in the 20 plus years she owned it. What i found, the CDL switch on the transfer case was gummed up. I took it out and cleaned it, reinstalled it, and once i put it in low, i got the CDL and ABS lights to light up.

 

[Munsta]

With L engaged I drove around in a dirt car park left n right and figure 8s.
Still didn't help and did not feel like the centre was locked.
Felt no different then in H with CDL disengaged.
I'm thinking I would of felt the difference if the CDL was working

 

[Munsta]

I can see 3 plugs on the TC.
Aft end of the TC looking fwd there is a plug at 1 o'clock pull the plug and bridge it and the 'A/T P' light comes on indicating that the TC is in neutral.

There is another plug next to this at the 2 o'clock position I bridge this and nothing happens ? It does have 12v feed. Am thinking this is the switch to activate the CDL relay when L is engaged ???

On the fwd end of the TC looking fwd at 1 o'clock there is another switch when this is bridged my CDL & ABS lights come on.
I believe this switch sends the signal to confirm the CDL is engaged. It is fwd of what looks to be the electronic actuator on top of the TC.

I haven't removed any of the switches to test their open/close contacts yet has I did not have a 27mm Spanner to suit.

But I'm thinking the CDL relay because either engaging L or bridging the switching circuits I still haven't heard the relay click

 

[LFD2037]

You said Hi & Low fell no different. As in it's not going into low? High & low should feel a lot different than each other even if the CDL isn't functioning properly.

 

[Munsta]

Sorry should of said turning circle felt no different.
H and L range is working you can definitely feel and hear the difference.
I will jack the car up and spin the wheels to confirm if the CDL is working.
But not hearing the relay I suspect not

 

[Munsta]

The truck i bough, the original owner never engaged the low range once in the 20 plus years she owned it. What i found, the CDL switch on the transfer case was gummed up. I took it out and cleaned it, reinstalled it, and once i put it in low, i got the CDL and ABS lights to light up.

Which switch did u remove ?

 

[97LandonCruiser]

The truck i bough, the original owner never engaged the low range once in the 20 plus years she owned it. What i found, the CDL switch on the transfer case was gummed up. I took it out and cleaned it, reinstalled it, and once i put it in low, i got the CDL and ABS lights to light up.

Quick question for you. I have a the same issue as the OP, I am not seeing the abs or CDL light when in low gear. When I turn the car on I don't see the CDL light up on the dash. Did yours have this same problem? I have driven in beach sand, figure 8's and checked the fuses.

The 97 land cruiser I bought has probably never been put into low gear (what a shame) so I figured the CDL switcheck is gummed up. But I was worried that it might be something electrical since the CDL light doesn't come on at startup. So my question for you guys with a functional CDL, when you turn your car ON does the CDL light come on (alone with the rest of the lights)?

Thanks fellas

 

[ppc]

Front and Rear indicators briefly will light but Center does not.

 

[Rifleman]

I copied all this info from George TLC web site, i wanted to make sure he got credit.
Here's a link to is home page.
George's 80 Series Land Cruiser and Nissan MQ Patrol
CDL (Center diff lock) Sensor/Switch for 80 series TLC

After finding that the CDL light wasn't coming on I figured it was time for some detective work.

With the ignition key turned to the Start position (engine not running), you can press the CDL switch and listen for the actuator on the transfer case to cycle (a second or so electric motor sound). I could hear the motor cycle so that meant that it was most likely the CDL Sensor/Switch malfunctioning.

FIrst step is to remove the Sensor/Switch from the transfer case. You can access it from under the USPS and there's just enough room to fit a spanner on it (hex head) and 27mm. Remove the connector to the harness first and move it out of the way. The following picture shows the CDL Sensor/Switch - don't mistake it for another connector, there are several in the same general area.

And next a zoom in of the Sensor/switch. There's a tab on the side of the connector that you squeeze to be able to pull the connector off the Sensor/switch. Standard right hand thread on the Sensor - so just turn anticlockwise to remove. It's not on too tight but will probably need a strike on the spanner end to break it loose.

The next picture shows the actual Sensor/switch after removal from the vehicle. On measuring the contact resistance at the connector it was open circuit even when the ball end was pressed in. Basically all the Sensor is is just a switch, open circuit when out, closed circuit when pressed in. I figured it was highly unlikely that the Sensor was actually broken, more likely the contacts had just glazed over. I have found that many switch contacts can fail when insufficient current flows which would be likely in this case since the switch action is just a status input to the ECU.

So, my first (cro-magnon) attempt at 'repairing' the switch was to strike it a quick blow with the spanner end with the Sensor laying flat on my vise. A couple of strikes on the flat sice and the meter now showed continuity when the ball end was pressed in. Neat, installed back into the 80 and it all seemed good (read on...)

A couple of days go by and I test the CDL switch every so often but find it didn't always light up on the dash. So, removed it again and this time checked the resistance carefully as I cycled the ball end in and out. It acted like a 'dirty' switch, i.e. the resistance waivered around as the switch was slowly pressed in. So, I figured that if the contacts were still 'dirty' it would be a good idea to run some current through the switch as it cycled. I have a bench supply (for my electronics work) and set it to around 200mA current limit and 12V. I applied this across the contacts of the switch (off the vehicle of course) and pressed the ball end in slowly and cycled it a 20 - 30 times. Hooked the meter up again and now it was 0 ohms through the entire stroke of the ball end - no waivering around - SOLID. Back onto the vehicle and after 7+ years (fixed 2005) it has been solid and fully operational. Update, 2016 and it failed again, used 24V and 300mA current limit to 'clean' the contacts again and all operational. 12V wouldn't start the cleaning cycle this time.

This is a reasonably common problem with switches that are designed for higher current use. The contacts rely on the higher currents to 'clean' the contacts. It would appear that the CDL switch falls into this category, but since it is being used as a sensor in this application, the currents are likely very small and unable to 'clean' the contacts.

So, before you rush out to buy a new Sensor/switch, consider trying this 'repair'. You could more than likely use a (couple of series) 9V battery to do the 'cleaning' since it won't be able to supply currents high enough to damage the switch contacts, but should be able to provide a few hundred milliamps in a short circuit like would be needed for the 'cleaning' cycle.

A picture of the connector end of the CDL Sensor/switch. Don't lose the aluminium washer when you remove and reinstall it.

.

 

[Munsta]

I get no ABS or CDL lights flash on the dash when ignition is turned on

If you bridge the shown switch connector plug with a paper clip you should get the ABS and CDL lights displayed on the dash.
This confirms that part of the circuit works.

But in my case (I have no CDL switch but factory operation is to engage L to operate CDL) I can not hear the relay click or electric actuator operating. Which is pointing towards the CDL relay

I have not pulled the relay to test as currently away at work

 

[LFD2037]

My CDL does not illuminate when ignition is on either. That's normal. I'm pretty sure the ABS does, though.

 

[97LandonCruiser]

The ABS light does (or should) light up on start up. I've seen it on mine each time.