Lexus RX (RX 350L, RX450h) 2016-2024 Repair Manual: On-vehicle Inspection

ON-VEHICLE INSPECTION

PROCEDURE

1. PERFORM SPARK TEST

CAUTION:

To prevent injury due to contact with an operating V-ribbed belt or cooling fan, keep your hands and clothing away from the V-ribbed belt and cooling fans when working in the engine compartment with the engine running or the engine switch on (IG).

(a) Check for DTCs.

Click here

NOTICE:

If any DTCs are output, perform troubleshooting in accordance with the procedure for each DTC.

(b) Remove the 6 ignition coil assemblies and 6 spark plugs.

Click here

NOTICE:

If an ignition coil assembly or spark plug has been struck or dropped, replace it.

HINT:

Arrange the removed parts in the correct order.

(c) Disconnect the 2 No. 5 engine wire connectors (for Port Injection). NOTICE: Perform this step in order to stop fuel injection to prevent damage to the catalyst due to unburned fuel.

(d) Disconnect the No. 6 engine wire connector and No. 7 engine wire connector (for Direct Injection). NOTICE: Perform this step in order to stop fuel injection to prevent damage to the catalyst due to unburned fuel.

(e) Install the spark plug to the ignition coil assembly, and then connect the ignition coil assembly connector.

(f) Ground the spark plug.

(g) Check that spark occurs at each spark plug while the engine is being cranked.

HINT:

If spark does not occur, perform the following procedure.

(h) Connect the No. 6 engine wire connector and No. 7 engine wire connector (for Direct Injection).

(i) Connect the 2 No. 5 engine wire connectors (for Port Injection).

(j) Install the 6 spark plugs and 6 ignition coil assemblies.

Click here

NOTICE:

If an ignition coil assembly or spark plug has been struck or dropped, replace it.

HINT:

Install the same parts to their original positions.

(k) Check for DTCs.

Click here

(l) Clear the DTCs.

Click here

2. INSPECT IGNITION COIL ASSEMBLY AND SPARK TEST

HINT:

Perform "Inspection After Repair" after replacing a spark plug or ignition coil assembly.

Click here

(a) Check that the ignition coil assembly connector is securely connected.

Result	Action
NG	Connect securely
OK	Go to next step

(b) Perform a spark test on each ignition coil assembly.

(1) Replace the ignition coil assembly with a known good one.

(2) Perform the spark test again.

Result	Action
NG	Go to next step
OK	Replace ignition coil assembly

NOTICE:

If an ignition coil assembly or spark plug has been struck or dropped, replace it.

(c) Perform a spark test on each spark plug.

(1) Replace the spark plug with a known good one.

(2) Perform the spark test again.

Result	Action
NG	Inspect the ignition system Click here
OK	Replace spark plug

NOTICE:

If an ignition coil assembly or spark plug has been struck or dropped, replace it.

(d) Connect the No. 6 engine wire connector and No. 7 engine wire connector (for Direct Injection).

(e) Connect the 2 No. 5 engine wire connectors (for Port Injection).

(f) Install the 6 spark plugs and 6 ignition coil assemblies.

Click here

NOTICE:

If an ignition coil assembly or spark plug has been struck or dropped, replace it.

HINT:

Install the same parts to their original positions.

(g) Check for DTCs.

Click here

(h) Clear the DTCs.

Click here

3. INSPECT SPARK PLUG

HINT:

Perform "Inspection After Repair" after replacing a spark plug.

Click here

(a) Check the electrode. (1) Using a megohmmeter, measure the insulation resistance. Standard Insulation Resistance: Tester Connection Condition Specified Condition Spark plug (terminal part) - Body ground Always 10 MΩ or higher HINT: If the result is not as specified, clean the spark plug with a spark plug cleaner and measure the resistance again. If a megohmmeter is not available, perform the following simple inspection instead.

*a Body Ground

(b) Alternative inspection method.

(1) Start the engine.

NOTICE:

Do not perform this step when any of the following DTCs are output: P030000, P030027, P030085, P030100, P030200, P030300, P030400 (Cylinder Misfire Detected).

(2) Quickly accelerate the engine to 4000 rpm 5 times.

NOTICE:

Do not perform this step when any of the following DTCs are output: P030000, P030027, P030085, P030100, P030200, P030300, P030400 (Cylinder Misfire Detected).

(3) Remove the spark plug.

Click here

(4) Visually check the spark plug.

HINT:

If the electrode is dry, the spark plug is functioning properly. If the electrode is damp, proceed to the next step.

(c) Check the spark plug for any damage to its threads and insulator.

If there is any damage, replace the spark plug.

Recommended Spark Plug:

Manufacturer	Spark Plug Type
DENSO	FK20HBR8

(d) Check the spark plug electrode gap. Maximum Electrode Gap for Used Spark Plug: 1.1 mm (0.0433 in.) NOTICE: Never attempt to adjust the electrode gap of a used spark plug. If the electrode gap is more than the maximum, replace the spark plug. Standard Electrode Gap for New Spark Plug: 0.7 to 0.8 mm (0.0276 to 0.0315 in.)

*a Spark Plug Electrode Gap *b Iridium Tip *c Platinum Tip

(e) Install the spark plug.

Click here

4. PERFORM INITIALIZATION

(a) Perform "Inspection After Repair" after replacing a spark plug or ignition coil assembly.

Click here