- Zero point calibration is performed when the conditions for calibration are not satisfied.
- Zero point calibration has failed.
| Last Modified: 11-27-2007 | 1.6 C | |
| Service Category: Vehicle Interior | Section: Supplemental Restraint Systems | |
| Model Year: 2008 | Model: LX570 | Doc ID: RM000001PK800WX |
| Title: SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: DESCRIPTION (2008 LX570) | ||
|
DTC |
B1797 |
Calibration Malfunction |
DESCRIPTION
DTC B1797 is output when one of the following conditions is met:
- Zero point calibration is performed when the conditions for the calibration are not satisfied.
- Zero point calibration has failed.
Condition for the Zero Point Calibration:
|
Item |
Condition |
|---|---|
|
DTC |
Not recorded |
|
Front passenger seat occupant |
Vacant |
|
Front passenger side buckle switch |
OFF (The seat belt is not fastened) |
|
ECU temperature |
0 to 46°C (32 to 115°F) |
|
Filtered pressure |
38 to 75 count |
|
DTC Code |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
B1797 |
One of the following conditions is met: |
|
HINT:
When DTC B1650 is stored as a result of troubleshooting for the "Airbag System", check the DTCs stored in the occupant classification ECU. When DTC B1797 is output, perform troubleshooting for it first.
INSPECTION PROCEDURE
NOTICE:
-
w/ Navigation system:
After the engine switch is turned off, the HDD navigation system requires approximately 6 minutes to record various types of memory and settings. As a result, after turning the engine switch off, wait 6 minutes or more before disconnecting the cable from the negative (-) battery terminal.
-
When disconnecting the cable from the negative (-) battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected
.
PROCEDURE
|
1. |
CHECK FOR DTC |
(a) Turn the engine switch on (IG).
(b) Clear the DTCs stored in the occupant classification ECU
.
(c) Clear the DTCs stored in the center airbag sensor
.
(d) Turn the engine switch off.
(e) Turn the engine switch on (IG), and wait for at least 10 seconds.
(f) Check for DTCs
.
OK:
DTC B1797 is not output.
HINT:
Codes other than DTC B1797 may be output at this time, but they are not related to this check.
|
|
2. |
READ VALUE USING TECHSTREAM (SPECIFIED CONDITION FOR ZERO POINT CALIBRATION) |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Using the Techstream, read the "Data List"
.
Occupant Detection
|
Tester Display |
Measurement Item/ Range |
Normal Condition |
Diagnostic Note |
|---|---|---|---|
|
Pressure sensor output |
Pressure sensor output / Min.: 0, Max.: 255 |
0 to 210 (reference value) |
- |
|
Thermistor temperature output |
Thermistor temperature output / Min.: -40°C (-40°F), Max.: 90°C (194°F) |
-40 to 85°C (-40 to 185°F) |
If the value is outside the range of Specified Condition for Zero Point Calibration, check whether any objects are placed on the seat cushion and that the seat cushion is fitted correctly. |
|
Number of Present DTC |
Number of stored trouble codes / Min.: 0, Max.: 255 |
0 |
- |
|
Number of Past DTC |
Number of past trouble codes / Min.: 0, Max.: 255 |
0 |
- |
Result
|
Result |
Proceed to |
|---|---|
|
All items correspond to range of specified condition for zero point calibration |
A |
|
Thermistor temperature output does not correspond to range of specified condition for zero point calibration |
B |
|
|
3. |
PERFORM ZERO POINT CALIBRATION |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Using the Techstream, perform zero point calibration
.
(d) Turn the engine switch off.
(e) Turn the engine switch on (IG).
(f) Clear the DTCs stored in the memory
.
HINT:
If the DTCs are not cleared at this time, past DTCs will remain.
|
|
4. |
CHECK FOR DTC |
(a) Turn the engine switch on (IG).
(b) Clear the DTCs stored in the occupant classification ECU
.
(c) Clear the DTCs stored in the center airbag sensor
.
(d) Turn the engine switch off.
(e) Turn the engine switch on (IG).
(f) Check for DTCs
.
OK:
DTC B1797 is not output.
HINT:
Codes other than DTC B1797 may be output at this time, but they are not related to this check.
|
|
5. |
REPLACE NO. 1 SEAT CUSHION ASSEMBLY (OCCUPANT DETECTION SENSOR) |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Using the Techstream, save the ECU data from the ECU which is installed in the vehicle
.
(d) Turn the engine switch off.
(e) Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
(f) Replace the No. 1 seat cushion (occupant detection sensor)
.
(g) Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
(h) Turn the engine switch on (IG).
(i) Using the Techstream, load the previous ECU data stored in the Techstream into the new ECU
.
(j) Turn the engine switch off.
(k) Turn the engine switch on (IG).
(l) Clear the DTCs stored in the occupant classification ECU
.
(m) Clear the DTCs stored in the center airbag sensor
.
|
|
6. |
PERFORM ZERO POINT CALIBRATION |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Using the Techstream, perform zero point calibration
.
(d) Turn the engine switch off.
(e) Turn the engine switch on (IG).
(f) Clear the DTCs stored in the occupant classification ECU
.
HINT:
If the DTCs are not cleared at this time, past DTCs will remain.
|
|
7. |
PERFORM SENSITIVITY CHECK |
(a) Perform the sensitivity check
.
|
|
|