1Gd-Ftv Engine Control. Dtc P20Ee Scr Nox Catalyst Efficiency Below Threshold Bank 1

The urea Selective Catalytic Reduction (SCR) system injects urea (NH3) into the catalyst to purify NOx.
After the engine is started, the SCR catalyst is heated up for a short period of time before the urea SCR system is activated.
After the SCR catalyst reaches a temperature appropriate for purifying NOx, the urea pump raises the pressure of the urea solution to approximately 500 kPa, delivering pressurized urea solution from the urea tank assy to the urea injector set.
The urea injector opens the needle valve according to operation signals sent by the urea pump control ECU. When a catalyst temperature is reached at which NOx expelled from the engine will react with ammonia, engine exhaust gas (NOx) and an optimal quantity of urea solution based on the catalyst temperature are injected from the urea injector set to the mixer. In the mixer, atomized and dispersed urea solution is converted to ammonia through hydrolysis, which reacts with the NOx, rendering it harmless.

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Dtc
P20Ee Scr Nox Catalyst Efficiency Below Threshold Bank 1

*1	Urea Injector Set	*2	Mixer
*3	SCR Catalyst	*4	SCR Catalyst
*5	ASC Catalyst	*6	No. 4 Exhaust Gas Temperature Sensor
*7	Nitorogen Oxigen Sensor	*8	Nitorogen Oxigen Sensor Control Unit
*9	Urea Solution	*10	Urea pump Temperature sensor Pressure sensor Pump Tank heater Level sensor
*11	Urea Pump Control ECU	*12	ECM
*13	CAN Communication Line	*14	Urea Tube with Heater Assembly
*15	to ECM	*16	Exhaust Gas

DTC Detection Drive Pattern	DTC Detection Condition	Trouble Area
PM forced regeneration	After comparing the NOx estimated value with the nitorogen oxigen sensor value while the urea SCR system is operating, the NOx purification rate is equal to or less than a fixed value. (2 trip detection logic)	Urea injector set Front exhaust pipe assembly (SCR catalyst) Nitorogen oxigen sensor Urea solution

When P20EE is output, it may be the result of the following malfunction modes.

The urea injector set cannot perform injection as commanded.
The concentration of urea solution is thick, or the urea solution has deteriorated.
The output of the NOx sensor is offset on the high side.
The SCR catalyst has deteriorated.

INSPECTION PROCEDURE

NOTICE:

Handling urea solution

Wear protective equipment as necessary (protective glasses and gloves).
Do not dilute urea solution.
If urea solution contacts your eyes or skin, immediately wash the contacted area with a large amount of water and consult a doctor as necessary.
If urea solution dries, it deposits a white powder. Also, if urea solution contacts metals such as copper and aluminum for a long period of time, it may promote corrosion. Therefore, if urea solution is spilled, dampen a cloth or other item and wipe it up or rinse the area with cool or warm water.

Handling the urea injector set

The urea injector set is a precision instrument. Take necessary precautions for installation and shipping. Do not use the part if it has been struck or dropped.
If the urea solution remaining inside the urea injector set dries out, it may become unable to inject urea solution. Therefore, conduct urea tube with heater assembly installation and removal quickly.
If the urea solution dries out and deposition occurs, urea may cling to the O-ring of the pipe and cause seal problems. Therefore, clean the urea tube with heater assembly and intake port of the urea injector set with water before attaching them.
Perform this procedure in an environment where urea solution will not freeze.

HINT:

Read freeze frame data using the GTS. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.

1.CUSTOMER PROBLEM ANALYSIS

Ask the customer whether the vehicle has previously been refilled with something other than AdBlue (conforming to ISO 22241-1) due to a lack of urea solution.
HINT:
If the urea solution has been diluted due to the addition of something such as water, purification performance will decrease.

Result:

Result
Proceed to
Vehicle has been refilled with something other than AdBlue (conforming to ISO 22241-1)
A
Except above
B

Go to step 15

B

2.CHECK DTC OUTPUT

Connect the GTS to the DLC3.

Turn the engine switch on (IG) and turn the GTS on.

Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

Read the DTCs.

Result:

Result
Proceed to
DTC P20EE is output
A
DTC P20EE and other DTCs are output*
B
HINT:
*: If codes other than P20EE are output, perform troubleshooting for those DTCs first.

Go to step 13

A

3.READ VALUE USING GTS (MAF)

Connect the GTS to the DLC3.

Turn the engine switch on (IG) and turn the GTS on.

Enter the following menus: Powertrain / Engine and ECT / Data List / MAF.

Start the engine and read the value when 30 seconds has elapsed.
Standard:
GTS Display
Switch Condition
Standard
MAF
Idling
3.0 to 15.0 gm/sec (EGR on)
10.0 to 21.0 gm/sec (EGR off)
Running without load (3000 rpm):
45.0 to 89.0 gm/sec (EGR on)
72.0 to 94.0 gm/sec (EGR off)

Go to step 11

OK

4.CHECK UREA INJECTION PIPES (CHECK DEPOSIT)

HINT:

If there are deposits around the urea injector, injection may be inhibited, reducing purification performance.

Connect the GTS to the DLC3.

Turn the engine switch on (IG) and turn the GTS on.

Enter the following menus: Powertrain / Engine and ECT / Active Test / Reductant Pump Check (Backward).

Perform the Active Test.

Enter the following menus: Powertrain / Engine and ECT / Active Test / Reductant Purge.

Perform the Active Test.
HINT:
Perform the Reductant Purge to draw the urea solution back into the urea tank sub-assembly from the urea injector set.

After performing the Active Test, remove the urea injector set from the front exhaust pipe assembly (LandCruiser RM000005UKV000X.html).
HINT:
Do not disconnect the urea injector from the urea tube with heater assembly.

Check that there is no white matter deposited by urea solution on the connection area of the exhaust pipe.

HINT:

After checking for deposits, use a cover, etc., to prevent foreign matter from entering the exhaust pipe.

Result:

Result
Proceed to
No white matter is deposited by urea solution on connection area of exhaust pipe
A
White matter is deposited by urea solution on connection area of exhaust pipe
B

Go to step 9

A

5.PERFORM ACTIVE TEST USING GTS (UREA INJECTOR SET OPERATION CHECK)

HINT:

If there is a malfunction in the urea injector set, NOx purification performance will be reduced.

Use a cover, etc., to prevent foreign matter from entering the exhaust pipe where the urea injector was removed.

Enter the following menus: Powertrain / Engine and ECT / Active Test / Reductant Injection Valve.

Perform the Active Test and check that operation sounds can be heard from the urea injector.
OK:
Sound of urea injector set operation can be heard (a ticking sound).
HINT:
Even after checking is complete, do not install the urea injector removed from the exhaust pipe yet.

Go to step 14

OK

6.PERFORM ACTIVE TEST USING GTS (UREA INJECTOR INJECTION STATE CHECK)

Enter the following menus: Powertrain / Engine and ECT / Active Test / Reductant Filling (Pressure Keep).

Execute "Reductant Filling (Pressure Keep)" and prepare to inject urea.
HINT:
1. While "Reductant Filling (Pressure Keep)" is being executed, the pressure inside the pipe increases and the urea injector set intermittently opens, which may cause a certain amount of urea solution to leak out.
2. If the urea injector set is stuck open, urea solution will leak out continuously because intermittent operation cannot be performed once this operation starts.

Enter the following menus: Powertrain / Engine and ECT / Active Test / Reductant Injection Valve.

30 seconds after executing the Active Test, check the injection condition.
HINT:
Urea solution is intermittently injected by the urea injector.

*a
Urea injector set normal
*b
Urea injector set abnormal
*1
Urea Injector Set
-
-

Result:

Result
Proceed to
Urea injector set normal*
A
Urea injector set abnormal
B
HINT:
*:
1. Wash off any matter deposited by the urea solution.
2. Make sure to leave the connector connected when washing to prevent water from entering via the connector.
3. Sufficiently wipe the area so that no urea solution remains on the flange sealing surface.
4. After completing work, check that 3 streams of liquid are sprayed from the urea injector set.
5. Even after checking is complete, do not install the urea injector removed from the exhaust pipe yet.

Go to step 14

OK

7.PERFORM SYSTEM CHECK (NOX SENSOR CHECK)

HINT:

When NOx sensor output deviates toward the high side, the NOx purification rate decreases.

Check that the engine switch is off.

Use an air blow gun to blow air from the mounting hole of the urea injector set toward the NOx sensor, expelling remaining NOx in the exhaust pipe.

Install the urea injector set (LandCruiser RM000005UKS000X.html).

Turn the engine switch on (IG) and turn the GTS on.

Enter the following menus: Powertrain / Engine and ECT / Utility / NOx Sensor Check.

Perform the NOx Sensor Check.

Check the output value.
Standard:
Below approximately 20 ppm
HINT:
Blowing air expels the NOx in the exhaust pipe. Therefore, if a large volume of NOx is detected, the NOx sensor may be malfunctioning.

Go to step 12

OK

8.PERFORM ACTIVE TEST USING GTS (ACTIVATE THE DPF REJUVENATE (PM) )

Connect the GTS to the DLC3.

Clear the DTCs (LandCruiser RM000000PDK1E5X.html).

Turn the engine switch off and wait for at least 30 seconds.

Turn the engine switch on (IG) and turn the GTS on.

Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the DPF Rejuvenate (PM) / Data List / NOx Density B1S1 and SCR Temperature.

Perform the Active Test.
HINT:
1. Before performing PM forced regeneration control, check that the atmospheric pressure is 94 kPa (705 mmHg, 27.8 in.Hg) or higher, and the ambient temperature is 0°C (0°F) or higher.
2. When PM Accumulation Ratio is too low, Activate the DPF Rejuvenate (PM) cannot be performed. Therefore, rev the engine with no load at 3400 rpm for 5 to 10 minutes to increase PM Accumulation Ratio to 12% or more.
CAUTION:
Be careful of the exhaust pipe and surrounding areas, as they become extremely hot when performing PM forced regeneration control.
NOTICE:
If PM forced regeneration control is stopped before it finishes, perform PM forced regeneration control again after repairing malfunctions to complete the procedure.
HINT:
1. PM forced regeneration control takes 15 to 40 minutes to finish.
2. The time it takes to complete PM forced regeneration control changes depending on "PM Accumulation Ratio" and vehicle operating conditions.
3. If the value of "Catalyst Differential Press" increases too much during PM forced regeneration control, the fail-safe function activates and PM forced regeneration control is stopped.
4. Perform PM forced regeneration control until the display on the multi-information display turns off.
5. If actions such as depressing the accelerator pedal are performed during PM forced regeneration control, PM forced regeneration control stops. If this occurs, it is necessary to perform PM forced regeneration control again.
6. PM forced regeneration control is not complete until the display on the multi-information display turns off.

Check "NOx Density B1S1" when the SCR temperature drops to approximately 340°C (644°F).
Standard:
50 ppm or less
HINT:
If the value is above 50 ppm, replace the front exhaust pipe assembly, as it may be expelling ammonia.

Go to step 10

END

9.REMOVE DEPOSIT

Clean any deposits from communicating portions of the exhaust pipe.
HINT:
After washing, make sure to wipe off the flange surface so that no urea solution remains.

Go to step 5

10.REPLACE FRONT EXHAUST PIPE ASSEMBLY

Replace the front exhaust pipe assembly (LandCruiser RM00000456A00NX.html).

Go to step 16

11.REPLACE MASS AIR FLOW METER SUB-ASSEMBLY

Replace the mass air flow meter sub-assembly (LandCruiser RM000000VHD05PX.html).
HINT:
Before replacing the mass air flow meter sub-assembly, check the connections of the wire harness and connectors. If there is any abnormality, replace or repair the wire harness or connector.

Go to step 4

12.REPLACE NITROGEN OXIDES SENSOR

Replace the nitrogen oxides sensor (LandCruiser RM000004KGB00NX.html).

Go to step 8

13.GO TO DTC CHART

Diagnose relevant DTCs (LandCruiser RM0000031HW07OX.html).

Repair any malfunctioning parts indicated by related DTCs.

Go to step 3

14.REPLACE UREA INJECTOR SET

Replace the urea injector set (LandCruiser RM000005UKV000X.html).

Go to step 7

15.REPLACE UREA SOLUTION

Connect the GTS to the DLC3.

Turn the engine switch on (IG) and turn the GTS on.

Enter the following menus: Powertrain / Engine and ECT / Active Test / Reductant Pump Check (Backward).

Perform the Active Test.

Enter the following menus: Powertrain / Engine and ECT / Active Test / Reductant Purge.

Perform the Active Test.
HINT:
Perform the Reductant Purge to draw the urea solution back into the urea tank sub-assembly from the urea injector set.

After performing the Active Test, remove the urea injector set from the urea tube with heater assembly (LandCruiser RM000005UKV000X_01_0001.html).
HINT:
If the urea solution remaining inside the urea injector set dries out, it may become unable to inject urea solution. Therefore, seal the urea injector set with an item such as a cover or rubber cap so that the inside does not dry out.

Prepare a bucket or other receptacle for collecting urea solution from the urea tube with heater assembly.

Enter the following menus: Powertrain / Engine and ECT / Active Test / Reductant Discharge.

Perform the Active Test to drain all the urea solution.

After fully draining the urea solution, refill with AdBlue (conforming to ISO 22241-1).

Go to step 8

16.PERFORM ACTIVE TEST USING GTS (ACTIVATE THE DPF REJUVENATE (PM))

Connect the GTS to the DLC3.

Clear the DTCs (LandCruiser RM000000PDK1E5X.html).

Turn the engine switch off and wait for at least 30 seconds.

Turn the engine switch on (IG) and turn the GTS on.

Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the DPF Rejuvenate (PM) / Data List / NOx Density B1S1 and SCR Temperature.

Perform the Active Test.
HINT:
1. Before performing the Active Test, press the snapshot button and record the data.
2. Before performing PM forced regeneration control, check that the atmospheric pressure is 94 kPa (705 mmHg, 27.8 in.Hg) or higher, and the ambient temperature is 0°C (0°F) or higher.
3. When PM Accumulation Ratio is too low, Activate the DPF Rejuvenate (PM) cannot be performed. Therefore, rev the engine with no load at 3400 rpm for 5 to 10 minutes to increase PM Accumulation Ratio to 12% or more.
CAUTION:
Be careful of the exhaust pipe and surrounding areas, as they become extremely hot when performing PM forced regeneration control.
NOTICE:
If PM forced regeneration control is stopped before it finishes, perform PM forced regeneration control again after repairing malfunctions to complete the procedure.
HINT:
1. PM forced regeneration control takes 15 to 40 minutes to finish.
2. The time it takes to complete PM forced regeneration control changes depending on "PM Accumulation Ratio" and vehicle operating conditions.
3. If the value of "Catalyst Differential Press" increases too much during PM forced regeneration control, the fail-safe function activates and PM forced regeneration control is stopped.
4. Perform PM forced regeneration control until the display on the multi-information display turns off.
5. If actions such as depressing the accelerator pedal are performed during PM forced regeneration control, PM forced regeneration control stops. If this occurs, it is necessary to perform PM forced regeneration control again.
6. PM forced regeneration control is not complete until the display on the multi-information display turns off.

Check "NOx Density B1S1" when the SCR temperature drops to approximately 340°C (644°F) according to the recorded data (snapshot).
Standard:
50 ppm or less

END

Result	Proceed to
Vehicle has been refilled with something other than AdBlue (conforming to ISO 22241-1)	A
Except above	B

Result	Proceed to
DTC P20EE is output	A
DTC P20EE and other DTCs are output*	B

GTS Display	Switch Condition	Standard
MAF	Idling	3.0 to 15.0 gm/sec (EGR on) 10.0 to 21.0 gm/sec (EGR off)
MAF	Running without load (3000 rpm):	45.0 to 89.0 gm/sec (EGR on) 72.0 to 94.0 gm/sec (EGR off)

Result	Proceed to
No white matter is deposited by urea solution on connection area of exhaust pipe	A
White matter is deposited by urea solution on connection area of exhaust pipe	B

*a	Urea injector set normal	*b	Urea injector set abnormal
*1	Urea Injector Set	-	-

Result	Proceed to
Urea injector set normal*	A
Urea injector set abnormal	B