Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual: Dtc Check / Clear

Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual / Engine & Hybrid System / Cruise Control / Dynamic Radar Cruise Control System / Dtc Check / Clear

DTC CHECK / CLEAR

NOTICE:

When the diagnosis system is changed from normal mode to check mode or vice versa, all DTCs and freeze frame data recorded in normal mode are cleared. Before changing modes, always check and make a note of DTCs and freeze frame data.

HINT:

  • DTCs which are stored in the ECM can be displayed on the Techstream. The Techstream can display the confirmed, pending and permanent DTCs.
  • If a malfunction is detected during the current driving cycle, confirmed and permanent DTCs are stored.
  • Some DTCs are not stored if the ECM does not detect the same malfunction again during a second consecutive driving cycle. However, such malfunctions, detected on only one occasion, are stored as pending DTCs.
  • Confirmed and pending DTCs can be cleared by using the Techstream or by disconnecting the cable from the negative (-) battery terminal. However, permanent DTCs cannot be cleared using either of these two methods.
  • After clearing current DTCs using the Techstream (or by disconnecting the cable from the negative (-) battery terminal), permanent DTCs can be cleared when the universal trip is performed and then the system is determined to be normal for the relevant DTCs. The driving pattern to obtain a normal judgment is described under the "Confirmation Driving Pattern" for the respective DTC.

    To clear permanent DTCs, all of the following conditions must be met:

    • There is a history that universal trip driving was performed.
    • The vehicle has been judged as normal for 2 trips. (Normal judgment does not have to be performed in 2 consecutive trips, but normal judgment should have occurred in the latest trip.) (not for misfire and fuel system DTCs)
    • No malfunctions are detected.
2 Trip Detection Logic Examples

Pending DTC

Store condition

Malfunction detected

Clear condition

System determined to be normal

or

DTCs cleared using Techstream

or

Cable disconnected from negative (-) battery terminal

Confirmed DTC

Store condition

Malfunction detected (2nd trip)

Clear condition

No malfunctions in 40 driving cycles

or

DTCs cleared using Techstream

or

Cable disconnected from negative (-) battery terminal

Permanent DTC

Store condition

Malfunction detected (2nd trip)

Clear condition

Engine switch is turned on (IG) after normal judgment obtained in 3 consecutive driving cycles

or

After DTCs cleared using Techstream or cable disconnected from negative (-) battery terminal, universal trip performed and normal judgment obtained for 2 trips (not for misfire and fuel system DTCs)

or

After DTCs cleared using Techstream or cable disconnected from negative (-) battery terminal, malfunction not detected when universal trip driving performed (misfire and fuel system DTCs)

MIL

ON

Malfunction detected (2nd trip)

OFF

Engine switch is turned on (IG) after normal judgment obtained in 3 consecutive driving cycles

or

DTCs cleared using Techstream

or

Cable disconnected from negative (-) battery terminal

HINT:

  • Obtaining a normal judgment and performing a universal trip driving pattern can be done in the same driving cycle or in different driving cycles.
  • It is unnecessary to obtain a normal judgment if the output DTCs are misfire or fuel system DTCs.

CHECK FOR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Radar Cruise 1*1 or Radar Cruise 2*2 / Trouble Codes.

Powertrain > Cruise Control > Trouble Codes Powertrain > Radar Cruise2 > Trouble Codes
  • *1: Stored in the ECM
  • *2: Stored in the forward recognition camera

(e) Check for DTC(s) and freeze frame data, and write them down.

Techstream Display

Description

Test Failed

Shows the malfunction judgment results during the current trip.

Pending

Shows the malfunction judgment results up to now. (Indicates the possibility of a malfunction when no DTC is confirmed.)

Confirmed

Shows the DTCs confirmed up to now. (The number of current trips differs for each DTC.)

CLEAR DTC (Pending and Confirmed DTC)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Radar Cruise 1*1 or Radar Cruise 2*2 / Clear DTCs.

Powertrain > Cruise Control > Clear DTCs Powertrain > Radar Cruise2 > Clear DTCs
  • *1: Stored in the ECM
  • *2: Stored in the forward recognition camera

(e) Clear the DTCs.

CLEAR PERMANENT DTC

OUTLINE
  • After clearing current DTCs using the Techstream (or by disconnecting the cable from the negative (-) battery terminal), permanent DTCs can be cleared when the universal trip is performed and then the system is determined to be normal for the relevant DTCs. The driving pattern to obtain a normal judgment is described under the "Confirmation Driving Pattern" for the respective DTC.
  • To clear permanent DTCs, all of the following conditions must be met:
    • There is a history that universal trip driving was performed.
    • The vehicle has been judged as normal for 2 trips. (Normal judgment does not have to be performed in 2 consecutive trips, but normal judgment should have occurred in the latest trip.)
    • No malfunctions are detected.

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Radar Cruise 1 / Trouble Codes.

Powertrain > Cruise Control > Trouble Codes

HINT:

If "YES" is displayed for the value of "PERMANENT" at the top right of the Techstream screen, permanent DTCs are stored.

(e) Select the "Generic" tab.

(f) Check if permanent DTCs are stored.

HINT:

If permanent DTCs are not output, it is not necessary to continue this procedure.

(g) Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

Powertrain > Cruise Control > Clear DTCs

NOTICE:

Do not clear the DTCs or disconnect the cable from the battery terminal after performing this step.

(h) Perform the universal trip.

CAUTION:

When performing the driving pattern, obey all speed limits and traffic laws.

HINT:

The universal trip driving pattern and normal judgment procedure can be performed consecutively in the same driving cycle.

  1. Start the engine and wait for 30 seconds or more.
  2. Drive the vehicle at 40 km/h (25 mph) or more for a total of 5 minutes or more.

    HINT:

    It is possible to complete the drive pattern even if the vehicle decelerates to less than 40 km/h (25 mph) during the driving cycle provided that the vehicle is driven at 40 km/h (25 mph) or more for a total of 5 minutes.

  3. Allow 10 minutes or more to elapse from the time the engine started.

(i) Turn the engine switch off and wait for 2 minutes or more.

(j) Perform the normal judgment procedure in the respective confirmation driving pattern of each output DTC.

HINT:

Do not turn the engine switch off by mistake during this step.

(k) Start the engine and wait for 5 seconds or more.

(l) Turn the engine switch off and wait for 2 minutes or more.

(m) Turn the engine switch on (IG).

(n) Enter the following menus: Powertrain / Radar Cruise 1 / Trouble Codes.

Powertrain > Cruise Control > Trouble Codes

(o) Check that the permanent DTCs have been cleared.

HINT:

If permanent DTCs are not output, it is not necessary to continue this procedure.

(p) Perform the normal judgment procedure in the respective confirmation driving pattern of each output DTC.

HINT:

Do not turn the engine switch off by mistake during this step.

(q) Start the engine and wait for 5 seconds or more.

(r) Turn the engine switch off and wait for 2 minutes or more.

(s) Turn the engine switch on (IG).

(t) Enter the following menus: Powertrain / Radar Cruise 1 / Trouble Codes.

Powertrain > Cruise Control > Trouble Codes

(u) Check that the permanent DTCs have been cleared.

HINT:

Permanent DTCs will be cleared if a normal judgment is obtained during 3 consecutive driving cycles with the MIL illuminated.

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