Auto
Climate Control Diagnostics:
| The auto climate control has an
on-board self diagnostic to solve control problems. One of the more complex
subsystems in the Z32 is the climate control. The on-board diagnostics
actually allows full readout of it's data and adjustments to how it functions
besides just returning error codes. This is worked out from the '95 manual.
'90 Climate Control is slightly different.
To enter a diagnostic mode:
1. With the ignition switch turned ON, Press AUTO and OFF simultaneously
for 5 seconds (step 2 in 1.). This will activate the Monitor Diagnosis
Mode (step 3 in 1.)
2. Pressing AUTO again will switch to the Actuator Test Mode (step 4
in 1.).
3. Pressing AUTO again will switch to the Upper and Lower Temperature
Difference Adjustment Mode (step 5 in 1.).
4. Pressing AUTO again will switch to a readout of Trouble Codes
(step 6 in 1.).
5. Pressing AUTO again loops back to Monitor Diagnosis Mode (step 3
in 1.). |
1. |
Monitor Diagnosis Mode:
The control unit will display temperature data in this mode. The step
monitor will have the right single dash lit (step 3 in 1.). Temperature
data is returned in the display's 'Set' digits.
Use the Mode switch and the Fan switch to toggle through the menu items.
| Def icon only |
Ambient temperature |
ºC(ºF) |
| Upper vent icon only |
Upper cabin temperature |
ºC(ºF) |
| Lower vent icon only |
Lower cabin temperature |
ºC(ºF) |
| 0 Fan & Def icon |
DEFROST outlet air temperature |
ºC(ºF) |
| 0 Fan & Upper vent icon |
VENT outlet air temperature |
ºC(ºF) |
| 0 Fan & Lower vent icon |
FOOT outlet air temperature |
ºC(ºF) |
| 1/4 Fan & Def icon |
Sunload |
*1 |
| 1/4 Fan & Upper vent icon |
water temperature *3 |
ºC(ºF) |
| 1/4 Fan & Lower vent icon |
Mode door voltage *4 |
*2 |
| 1/2 Fan & Def icon |
N/A |
|
| 1/2 Fan & Upper vent icon |
N/A |
|
| 1/2 Fan & Lower vent icon |
N/A |
|
| 3/4 Fan & Def icon |
N/A |
|
| 3/4 Fan & Upper vent icon |
N/A |
|
| 3/4 Fan & Lower vent icon |
N/A |
|
| Full fan & Upper vent icon |
Difference in upper & lower temperatures |
ºC(ºF) |
| Full fan & Lower vent icon |
N/A |
|
*1: One tenth of the value in kcal/h*m² unit
*2: Ten times the value in V
*3: When coolant temp. is below 40ºC(104ºF), indicates 20ºC
(68ºF). When coolant temp. is above 40ºC(104ºF), indicates
80ºC (176ºF)
*4 Mode door voltage: 0 = VENT, 5 = DEFROST
Actuator Test Mode:
The climate controller will force actuators to work in this mode. The
step monitor should be the right two dashes lit (step 4 in 1.).
The 'Set' digits in the display are the Mode door voltage, 0 = VENT, 5
= DEFROST. I'm not really sure what mine means with a 49 listed.
Mode and fan speed can be set independently. When the upper and lower vent
icon appears, a stabilized outlet temperature 30ºC(86ºF) is reached
after the air mix door has be working for about a minute.
Use the Mode switch to toggle through the menu items.
|
Display
Actuator
|
Defrost icon |
Defrost and lower vent icon |
Upper and lower vent icon |
Upper vent icon |
| Mode door |
DEF |
DEF/Lower |
B/L |
VENT |
| Intake door |
FRE |
FRE |
50% FRE |
REC |
| Air mix door |
Full hot |
Full hot |
30ºC(86ºF) |
Full cold |
| Compressor |
OFF |
OFF |
ON |
ON |
operating condition of the actuators cannot be checked by indicators alone.
Use the Fan switch to toggle through the menu items.
|
Display
Blower Motor
|
1/4 Fan |
1/2 Fan |
3/4 Fan |
Full fan |
| Voltage |
4V |
6V |
9V |
12V |
Upper and Lower Temperature Difference Mode:
Adjustments can be made to the difference in upper and lower target
temperatures in this mode. The step monitor should be 3 dashes (step 5
in 1.). The 'Set' digits in the display will show how much of a
difference by 'data' numbers in relation to temperature difference.
Using the Fan and Mode switches to raise or lower the data number:
| ºC spec. |
Data |
-20 |
to |
-1 |
0 |
1 |
to |
20 |
| ºC spec. |
Difference between upper and lower target temperatures |
-2.0ºC |
to |
-0.1ºC |
0 |
0.1ºC |
to |
2.0ºC |
| ºF spec. |
Data |
-36 |
to |
-2 |
0 |
2 |
to |
36 |
| ºF spec. |
Difference between upper and lower target temperatures |
-3.6ºF |
to |
-0.2ºF |
0 |
0.2ºF |
to |
3.6ºF |
The programmed differences are stored until changed again, or the battery
is disconnected.
Trouble Codes:
The auto climate control stores error codes for later retrieval. The
step monitor should be 2 dashes with a space in-between (step 6 in 1.).
The 'Set' digits will show the number of ignition ON/OFF cycles since the
problem was last detected. A dash '-' in the step monitor to the far left
indicates a short circuit. A '|' hash in the step monitor on the left indicates
an open circuit.
Use the Fan and Mode switches to raise or lower the code to change the
desired data or status reading returned.
| Code |
Sensor |
Open circuit |
Short circuit |
| Defrost icon |
Ambient sensor |
Less than -70ºC(94ºF) |
Greater than 141ºC(286ºF) |
| Upper vent icon |
Cabin upper sensor |
Less than -38ºC(-36ºF) |
Greater than 141ºC(286ºF) |
| Lower vent icon |
Cabin lower sensor |
Less than -38ºC(-36ºF) |
Greater than 141ºC(286ºF) |
| 0 Fan & Def/lower vent icon*1 |
DEF duct sensor |
Less than -38ºC(-36ºF) |
Greater than 141ºC(286ºF) |
| 0 Fan & Upper vent icon |
VENT duct sensor |
Less than -38ºC(-36ºF) |
Greater than 141ºC(286ºF) |
| 0 Fan & Upper/lower vent icon*2 |
Lower duct sensor |
Less than -38ºC(-36ºF) |
Greater than 141ºC(286ºF) |
| 1/4 Fan and Def icon |
Sunload sensor |
Open circuit can not be detected w/ self diagnostic |
Greater than 1.784kW (1,534kcal/h, 6,087BTU/h)/m²
[0.1657kW (142.51 kcal/h, 565.5 BTU/h)/sq ft.] |
*1 One chart in the service manual shows 0 fan with Def/lower vent icon,
while another shows 0 fan with Def icon alone.
*2 One chart in the service manual shows 0 fan with Upper/lower vent
icon, while another shows 0 fan with Lower icon alone.
Originally posted: 3-5-00
DamonZ
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