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RA33004630310Z 3.10 - General: New Features and Modifications to Differential Lock



RA33004630310Z 3.10 - General: New Features And Modifications To Differential Lock

New features and modifications to differential lock (from 03/94 with touch contact switch function)

Control module

From 03.94 the control module has been modified. Up to 02/94 the differential lock switches are of rocker switch design, as of 03/94 they are touch contact switches. The facilitates the operation. You only have to touch the switch in order to switch the differential locks on and off respectively.

Control

There is a compulsory sequence for switching on the differential locks (logic circuit) and this has not been changed:
1. Transfer case (interaxle equalization)
2. Rear axle
3. Front axle

Switching off is carried out as before.

The entire electronic control of the differential locks is integrated in the new control module.

The following external components are therefore omitted:
^ Time-limit relay (N11/7)
^ ABS shut-off relay 2 (K3, No. 15)
^ Blocking diodes in fusebox for
- Interaxle equalization
- Rear axle
- Front axle
^ 3 holding relays for
- Interaxle equalization
- Rear axle
- Front axle

Illumination

The illumination of the control module as well as the
^ switch-on indicator lamps (yellow) and the
^ function indicator lamps (red) are in LED design and cannot be changed separately.

Removal/Installation

The removal and installation of the control module is carried out in the same manner as before.

Time delay

The electronics for the time delay is integrated in the control module and the time is 30 sec., as before.

ABS shut-off

The ABS shut-off via the differential locks is still carried out via the ABS shut-off relay (K32, No.7).

The ABS shut-off relay receives negative from the differential lock control module for shutting off when the transfer case lock is selected or a further differential lock is engaged.

Manual ABS shut-off is carried out as before via the switch (S76/1) in the middle console, however via positive and not as previously via negative.

Inputs

KI.30/1 Battery voltage 12V
^ from overvoltage protection relay (K1/1 or K1/2) 87L

KI. 15/5 Ignition
^ from overvoltage protection relay (K1/1 or K1/2) 30a

KI. 31/3 Negative
^ from steering column, W29/7

KI. 58/6 Illumination
^ from terminal block X6

LA/12 Function indicator lamp, transfer case differential lock
^ on when negative connected from pilot switch (S76/7) on transfer case and the
^ ignition is switched on

HA/13 Function indicator lamp of rear axle differential lock
^ on when negative connected from pilot switch (S76/8) at rear axle and
^ ignition is switched on

VA/14 Function indicator lamp of front axle differential lock
^ on when negative connected from pilot switch (S76/7) on transfer case and
^ ignition is switched on

Outputs

LA/9 Driving of electromagnetic switchover valve (Y68) with positive for actuating the transfer case lock.
Driving of the electr. auxiliary vacuum pump with positive via relay K36 (only gasoline engine)
Driving of the warning lamp in the instrument cluster with positive
internal Actuation of LED (yellow) for switch-on indicator lamp FA
HA/10 Driving of the electromagnetic switchover valve (Y68/1) with positive for actuating the rear axle lock internal Actuation of the LED (yellow) for switch-on indicator lamp RA
VA/11 Driving of the electromagnetic switchover valve (Y68/2) with positive for actuating the front axle lock internal Actuation of the LED (yellow) for switch-on indicator lamp FA
ABS/7 Output for ABS shut-off
^ Driving of the ABS relay no. 7 (32) with negative

Negative is applied to this output when:
^ transfer case lock is actuated or
^ a differential lock is engaged.

In this way the positive line from the overvoltage protection relay (diesel engine K1/1, gasoline engine K1/2) to the ABS control unit (N30) PIN 1 is interrupted and the ABS indicator lamp is actuated.

New features and modifications to the differential lock - Comparison





Note:
For schematic wiring diagrams refer to "Electronic circuit diagrams" - Cross-country vehicle, Volume 1 1
For diagnostics (model 463) refer to "Diagnostics manual" - Cross-country vehicle, Volume 1