Lexus NX: How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT
HINT:
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Use these procedures to troubleshoot the smart access system with push-button start (for Entry Function).
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*: Use the Techstream.
PROCEDURE
1. | VEHICLE BROUGHT TO WORKSHOP |
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2. | CUSTOMER PROBLEM ANALYSIS |
HINT:
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In troubleshooting, confirm that the problem symptoms have been accurately identified. Preconceptions should be discarded in order to make an accurate judgment. To clearly understand what the problem symptoms are, it is extremely important to ask the customer about the problem and the conditions at the time the malfunction occurred.
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Gather as much information as possible for reference. Past problems that seem unrelated may also help in some cases.
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The following 5 items are important points for problem analysis:
What? | Vehicle model, system name |
When? | Date, time, occurrence frequency, whether the problem occurred recently or has been occurring for a long time |
Where? | Whether the problem occurs at a specific location |
Under what conditions? | Whether the doors were locked or unlocked, whether the power switch was on, whether the hybrid control system was starting |
How did it happen? | Problem symptoms* |
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*: Be sure to ask the customer in detail about the following points concerning the vehicle operating conditions, environment and problem, and then check for DTCs.
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If the entry lock/unlock function does not operate for all doors.
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If the entry lock function does not operate.
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If the entry unlock function does not operate.
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If both the entry lock and unlock functions do not operate.
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If the wireless lock and unlock functions do not operate.
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If there is no power even when the power switch is pressed (does not turn on (ACC)).
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If the hybrid control system does not start with the push-button start function.
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If the outside warning buzzers do not sound.
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If a hybrid control system start was attempted by holding the electrical key transmitter sub-assembly near the power switch and then pressing the power switch.
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If the interior warning buzzers do not sound.
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If the steering does not unlock.
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Any other details concerning the problem.
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If it is suspected that wave interference is likely, be sure to ask the customer in detail about the following points concerning the vehicle operating conditions, environment and problem.
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Specific locations where the system does not operate (such as near TV towers, large video displays, wireless garage door opener systems, wireless security cameras, home security systems, etc.).
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Specific times when the system does not operate: If the symptoms occurred immediately after purchase or only recently. If the symptoms occurred when the electrical key transmitter sub-assembly was near the vehicle (electrical key antenna).
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If the system does not operate only when near specific vehicles (there may be wave interference from the wireless systems of other vehicles).
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If the system operates intermittently.
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If the electrical key transmitter sub-assembly is bundled together with other items.
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If the electrical key transmitter sub-assembly is carried together with other electronic devices, such as cell phones, personal computers, portable music players, other electrical key transmitter sub-assemblies, etc. (keep the electrical key transmitter sub-assembly at least 0.1 m (0.328 ft.) away from such items).
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Where the electrical key transmitter sub-assembly is being kept when not in use: If the electrical key transmitter sub-assembly is being placed within 1 m (3.28 ft.) of items such as TVs, DVD recorders, induction cookers, rice cookers, dishwashers, modems, cell phones, personal computers, microwave ovens, desk or floor lamps, cordless telephones, etc.
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If there are electronic devices that transmit radio waves placed in the vehicle.
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When the transmitter battery was last replaced. The transmitter battery can be checked roughly using the "Key Low Battery" item in the Data List.
Click here
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If the steering does not unlock.
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If the customer installed any optional components (theft deterrent devices, wireless fog lights, etc.) to the vehicle.
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3. | INSPECT AUXILIARY BATTERY |
(a) Measure the auxiliary battery voltage with the power switch off.
Standard voltage:
11 to 14 V
If the voltage is below 11 V, recharge or replace the auxiliary battery before proceeding to the next step.
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4. | CHECK COMMUNICATION FUNCTION OF CAN COMMUNICATION SYSTEM* |
(a) Using the Techstream, check for CAN communication system DTCs.
Click here
Result | Proceed to |
CAN DTCs are not output | A |
CAN DTCs are output | B |
A | | |
5. | CHECK METER / GAUGE SYSTEM* |
(a) Use the Techstream to check if the meter / gauge system is functioning normally.
HINT:
If the certification ECU (smart key ECU assembly) mistakenly receives a vehicle speed signal, communication between the vehicle and the Techstream fails. Be sure to check "Vehicle Speed Meter" displayed on the Data List to make sure that the vehicle speed is not abnormal.
Result | Proceed to |
No vehicle speed signal is mistakenly received | A |
A vehicle speed signal is mistakenly received | B |
B | | GO TO METER / GAUGE SYSTEM |
A | | |
6. | CHECK COMMUNICATION FUNCTION OF LIN COMMUNICATION SYSTEM* |
(a) Using the Techstream, check for LIN communication system DTCs.
Click here
Result | Proceed to |
LIN DTCs are not output | A |
LIN DTCs are output | B |
B | | GO TO LIN COMMUNICATION SYSTEM |
A | | |
7. | CHECK FUNCTION OF WIRELESS DOOR LOCK CONTROL SYSTEM* |
(a) Using the Techstream, check for wireless door lock control system DTCs.
Click here
Result | Proceed to |
Wireless door lock control system DTCs are not output | A |
Wireless door lock control system DTCs are output | B |
B | | GO TO WIRELESS DOOR LOCK CONTROL SYSTEM |
A | | |
(a) Check for DTCs.
Body Electrical > Smart Access > Trouble Codes
Result | Proceed to |
DTCs are not output | A |
Steering lock system DTCs are output | B |
Immobiliser system DTCs are output | C |
Smart access system with push-button start (for Entry Function) DTCs are output | D |
C | | GO TO IMMOBILISER SYSTEM |
D | | GO TO DIAGNOSTIC TROUBLE CODE CHART |
A | | |
9. | PROBLEM SYMPTOMS TABLE |
(a) Refer to Problem Symptoms Table.
Click here
Result | Proceed to |
Fault is not listed in problem symptoms table | A |
Fault is listed in problem symptoms table | B |
B | | ADJUST REPAIR OR REPLACE IN ACCORDANCE WITH PROBLEM SYMPTOMS TABLE |
A | | |
10. | OVERALL ANALYSIS AND TROUBLESHOOTING* |
(a) Operation Check
Click here
(b) Data List / Active Test
Click here
(c) Terminals of ECU
Click here
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11. | REPAIR OR REPLACEMENT |
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(a) Clear the DTCs.
Body Electrical > Smart Access > Clear DTCs
(b) Check for DTCs.
Body Electrical > Smart Access > Trouble Codes
Result | Proceed to |
DTCs are not output | A |
Smart access system with push-button start (for Entry Function) DTCs are output | B |
A | | END |
B | | GO TO DIAGNOSTIC TROUBLE CODE CHART |
READ NEXT:
CUSTOMIZE PARAMETERS CUSTOMIZE SMART ACCESS SYSTEM WITH PUSH-BUTTON START (for Entry Function) HINT: The following items can be customized. NOTICE:
When the customer requests a change in a function
PROBLEM SYMPTOMS TABLE HINT:
If a problem occurs in certain locations or at certain times of day, check for the possibility of wave interference.
When the electrical key transmitter sub-assembly
TERMINALS OF ECU CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (a) Disconnect the I53 certification ECU (smart key ECU assembly) connector. (b) Measure the voltage and resistance according to the
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DESCRIPTION
When the absorber control ECU has not acquired the vehicle identification information, DTC C1789 is stored. When the vehicle identification information is correctly acquired, this DTC is cleared. Vehicle identification information is automatically acquired when the system enters test