Pinpoint Tests
1. Seat power supplya. Check fuses F3, F4, F9 and F12 in RH and fuse F6 in LH heelboard fuse boxes are intact. If blown determine reason for failure and renew.
b. Unplug harness connector from SCM and check for battery supply voltage to ground, at pins 4, 6, 7 & 12 (B1 connector) and pin 11 (B2 connector) with ignition on. If supply is not recorded on all pins switch off ignition and check harness wiring continuity from heelboard fuse boxes to faulty lines as follows:
Connector B1
Pin 4 - fuse F 3, RH fuse box
Pin 6 - fuse F 4, RH fuse box
Pin 7 - fuse F 6, LH fuse box
Pin 12 - fuse F9, RH fuse box
Connector B2
Pin 11-fuse F12, RH fuse box
SCM Power Supplies:
2A. Seat movement motors (memory seals)
a. Check motor operation is not obstructed, and that mechanical linkage is not damaged or disconnected.
b. Examine wiring harness, checking continuity between SCM Connector Al and motor unit connector pins as follows:
SCM Motor Function Unit Pin
Pin 8 Seat forward 1
Pin 7 Seat rearward 3
Pin 5 Seat rear raise 1
Pin 6 Seat rear lower 3
Pin 3 Seat front raise 1
Pin 4 Seat front lower 3
c. Check resistance between motor pins 1 and 3, a value of approximately 2 Ohm should be indicated.
d. Check motor position potentiometer as described in test 4.
2B. Seat movement motor (manual seats)
a. Check motor operation is not obstructed, and that mechanical linkage is not damaged or disconnected.
b. Check continuity from motor connector pins (1 & 3) to each relay contact connector (pin 3, raise relay, pin 8, lower relay) respectively.
c. Check power supply (+12 V) from LH heelboard fuse box, fuse F6, to seat switch connector pin 9.
d. Check power supply (+12 V) from RH heelboard fuse box, fuse F3, to pin 5, raise relay connector and pin 10, lower relay connector.
e. Check continuity from switch pack connector pin 4 to raise relay connector pin 5 and from switch pack connector pin 5 to lower relay connector pin 6
f. Check continuity to ground from raise relay connector pins 2 and 4 and lower relay connector pins 7 and 9
3. Seat squab/headrest motors
a. Check motor operation is not obstructed, and that mechanical linkage is not damaged or disconnected.
b. Examine wiring harness, checking continuity between SCM Connector Al and motor unit connector pins as follows:
SCM Motor Pin
Pin 1 Squab recline/incline +ve 3
Pin 2 Squab recline/incline -ve 1
Pin 11 Headrest raise/lower +ve 1
Pin 12 Headrest raise/lower -ve 3
c. Check resistance between motor pins 1 and 3; a value of approximately 2 Ohm should be indicated.
d. Check motor position potentiometers as described in step 4.
Seat Motors, Fig.1:
Seat Motors (Manual), Fig.2:
4. Seat motor position potentiometers
a. Examine wiring harness, checking continuity between SCM Connector A2 and motor unit connector pins as follows:
SCM Motor potentiometer Unit Pin
Pin 1 All units +ve 5
Pin 2 All units -ve 6
Pin 3 Headrest position 3
Pin 4 Squab position 3
Pin 5 Seat fore/aft position 3
Pin 6 Seat rear raise/lower position 3
Pin 7 Seat front raise/lower position 3
Seat Motor Potentiometers, Fig.1:
b. Check resistance of each motor position potentiometer pins 5 and 6; a value of approximately 10 K Ohm should be indicated.
c. Check resistance between motor position potentiometer pin 2 and both pins 5 and 6. Values in the region of 100 Ohm-9.9 K Ohm should be recorded, dependent upon motor position.
5. Seat lumbar pump
a. Check pneumatic circuit is intact and free from obstructions or blockages. Check lumbar pad is not damaged or punctured.
b. Examine harness wiring, checking continuity between connector pins as follows:
Switch pack Pump Unit SCM
Pin 1 Pin 2 Pin 9 (connector A1)
Pin 11 Pin 3
Pin 3 Pin 1
c. Test pump resistance between unit pins 1 and 2; a value of approximately 2 Ohm should be recorded. Check operation of pressure switch by attempting to continually inflate the lumbar pad. On achieving maximum pad pressure the pressure switch should operate and switch off the pump supply.
d. Test solenoid valve resistance between unit pins 3 and 2; a value of approximately 2 Ohm should be recorded.
Seat Lumber Pump, Fig.1:
6A. Heating (powered seats)
a. Examine harness wiring, checking continuity between SCM connector Al pins 9 and 10. A resistance value of 1.5-3.2 Ohm should be recorded indicating all heating elements intact and thermostat closed.
b. Check continuity from BPU black 48-way connector B, pin 38 to center console seat heater switch module connector pin 5. Operate switch and check continuity from BPU black 48-way connector B pin 38 to ground.
c. Check continuity between cushion heater module and squab heater module pins; resistance values of 1.0-2.0 Ohm and 0.5-1.2 Ohm respectively should be achieved.
d. Check continuity from SCM connector B2 pin 2, through console switch LED to ground; a resistance value of 0-0.5 Ohm should be recorded.
Memory Seat Heaters, Fig.1:
6B. Heating (manual seats)
a. Examine harness wiring, checking fuse F9 in heelboard fuse box. Ensure continuity between heater relay connector pin 85 and BPU yellow 48-way connector pin 23. Measure resistance from heater relay pin 87 and console switch connector pin 10.
b. Check continuity from BPU black 48-way connector B pin 38 to center console seat heater switch module connector pin 4. Operate switch and check continuity from BPU black 48-way connector pin 38 to ground.
c. Check for +12 V supply at seat heater relay connector pins 30 and 86.
d. Check continuity between cushion heater module and squab module pins; resistance values of 1.0-2.0 Ohm and 0.5-1.2 Ohm respectively should be achieved. Ensure secure ground connection from squab connector pin 3.
e. Check continuity from console switch connector pin 10 through console switch LED to ground; a resistance value of 0-0.5 Ohm should be recorded.
Manual Seat Heaters, Fig.1:
7. Seat switch pack
a. Examine harness wiring, checking continuity between SCM multi-pin connector A2 and switch pack connector pins as follows:
A2 Pin Function Pack pin
08 Squab recline 08
09 Seat reward 13
10 Seat forward 06
11 Common +ve 09
14 Headrest lower 15
15 Headrest raise 16
16 Seat rear lower 05
17 Seat rear raise 04
18 Seat front lower 14
19 Seat front raise 12
20 Squab incline 07
b. Disconnect harness from switch pack and check continuity of each pin to common +ve (pin 9) when relevant switch is operated e.g. operation of seat forward switch will give continuity between pin 9 and pin 6 of the pack.
c. Test the operation of the lumbar pump switches (at pins, 03 and 11) by checking that voltage on each pin toggles between ground and +12 V with each switch operation.
Seat Switch Pack, Fig.1:
8. Column movement motors
a. Examine harness wiring, checking continuity between C/M CM multi-pin connector and column motor unit connector pins as follows:
C/M CM Motor Function Unit Pin
Connector block A
Pin 2 Tilt+ve 1
Pin 14 Tilt-ve 6
Pin 12 Reach +ve 1
Pin 15 Reach -ve 8
b. Test resistance between tilt motor unit pins 1 and 6; a value of approximately 2 Ohm should be recorded. Test resistance between reach motor unit pins 1 and 8; a value of approximately 2 Ohm should be recorded.
c. Check motor position potentiometers as described in step 9.
Column Adjustment Motors, Fig.1:
9. Column movement motor position potentiometers
a. Examine wiring harness, checking continuity between C/M CM multi-pin connector and motor unit connector pins as follows:
C/M CM Motor potentiometer Unit Pin
Connector block B
Pin 4 Tilt motor feedback 3
Pin 5 Reach motor feedback 4
Connector block A
Pin 24 Tilt position +ve 2
Reach position +ve 3
Pin 16 Tilt position -ve 5
Reach position +ve 6
b. Check resistance across tilt motor position potentiometer pins 2 and 5, a value of 2.2 K Ohm should be indicated. Check resistance across reach motor position potentiometer pins 3 and 6, a value of 10k should be indicated.
c. Check resistance between tilt motor position potentiometer pin 3 and both pins 2 and 5. Values in the range of 100 Ohm-2.1 K Ohm should be recorded, dependent on motor position. Check resistance between reach motor position potentiometer pin 4 and both pins 3 and 6. Values of 100 Ohm-9.9 K Ohm should be recorded, dependent on motor position.
Column Adjustment Motors, Fig.1:
10. Column movement switches
a. Examine harness wiring, checking continuity between connector pins as follows:
C/M CM Switch Pack RH 'A' post base fuse box
- Pin 15 Fuse F2
Connector block A
Pin 5 Pin 14 -
Connector block B
Pin 7 Pin 17 -
b. Check resistance values between pins 14 and 15 when switch is operated, in all planes. Values should be as follows; switch up - 220 Ohm, switch down - 100 Ohm, switch forward 470 Ohm and 820 Ohm.
c. Check for continuity between switch pack pin 17 and ground when mode switch is in auto'.
Column Movement Switches, Fig.1:
11. Mirror movement motors
a. Examine harness wiring, checking continuity between C/M CM multi-pin connector and mirror connectors as follows:
C/M CM Function Unit Pin
Connector block A
Pin 1 Passenger's Mirror U/D 3
Pin 11 Driver's Mirror U/D 3
Pin 25 Passenger's Mirror R/L 10
Pin 13 Driver's Mirror R/L 10
Pin 26 Common (both mirrors) 4
b. Test resistance between motor units pin 4 and both pins 3 and 10; a value of approximately 2 Ohm should be recorded.
c. Check motor position potentiometers as described in step 12.
Mirror Movement Motors, Fig.1:
12. Mirror movement motor position potentiometers
a. Examine wiring harness, checking continuity between C/M CM multi-pin connector and motor unit connector pins as follows:
C/M CM Motor potentiometer Unit Pin
Connector block B
Pin 2 Passenger mirror vertical feedback 8
Pin 3 Driver mirror vertical feedback 8
Pin 1 Driver mirror horizontal feedback 5
Connector block A
Pin 4 Passenger mirror horizontal feedback 5
d. Check resistance across each motor position potentiometer pins 2 and 6; a value of 3.7 K Ohm should be indicated.
c. Check resistance between each motor position potentiometer pin 8 and both pins 2 and 6. Values in the range of 100 Ohm - 3.6 K Ohm should be recorded, dependent on motor position.
Mirror Movement Motor Position Potentiometers, Fig.1:
13. Mirror movement switches
a. Examine harness wiring, checking continue between C/M CM multi-pin connector and drivers door switch pack connector as follows:
C/M CM Function Switch Pack
Connector block A
6 Passenger mirror U/D Pin 12
7 Driver mirror U/D Pin 02
8 Passenger mirror R/L Pin 13
9 Driver mirror R/L Pin 03
10 Common Pin 01
b. Check operation of switch as follows:
Select driver's mirror and operate joystick up and down7 checking that voltage on common line toggles between ground and +12V and that voltage on driver's mirror U/D line toggles in opposition.e.e when common = +12V, driver U/D = ground and vice versa. Repeat test moving joystick left and right and monitoring common line against driver R/L line; the same results should be achieved. Select passenger mirror and repeat both tests on passenger mirror lines.
Mirror Movement Switches, Fig.1:
14. Memory facility
a. Examine harness wiring, checking continuity between SCM, C/M CM and drivers door switch pack connectors as follows:
SCM Pin C/M CM Pin Switch Pack
B2 Block A
4 19 Pin 15
5 18 Pin 16
6 17 Pin 04
8 - Pin 14
21 20 Pin 05
B2 Block B
12 12 -
b. Check operation of switches by operating each switch in turn and checking voltage at relevant pin toggles between ground and +12 V on each switch change of state.
c. Check continuity on remote recall line from SCM pin connector B2 pin 12 to C/M CM connector B pin 11 and security/locking control module connector D pin 12.
d. Check continuity from BPU black 4 way connector pin 25 to SCM connector B2 pin 16 and BPU yellow 48-way connector pin 23 to. SCM connector B2 pin 10.
Memory Facility, Fig.1:
15. Exit/Entry facility
a. Examine harness wiring checking continuity between C/M CM block B connector pin 7 and column mode switch pack connector pin 17.
b. Operate switch and check continuity between C/M CM connector block B pin 7 and ground with switch in 'auto' mode.
Column Movement Switches, Fig.1: