CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P1386)
READ VALUE OF INTELLIGENT TESTER (EXHAUST GAS TEMPERATURE)
CHECK EXHAUST GAS (WHITE SMOKE AND FUEL SMELL)
READ VALUE OF INTELLIGENT TESTER (DPNR A/F)
READ VALUE OF INTELLIGENT TESTER (EXHAUST GAS TEMPERATURE)
READ VALUE OF INTELLIGENT TESTER (A/F RATIO)
INSPECT EXHAUST FUEL ADDITION INJECTOR ASSEMBLY
CHECK HARNESS AND CONNECTOR (EXHAUST FUEL ADDITION INJECTOR - ECM)
CHECK FOR FUEL LEAKAGE (IN EXHAUST FUEL ADDITION INJECTOR)
READ VALUE OF INTELLIGENT TESTER (COMPENSATION OF INJECTION VOLUME)
INSPECT EXHAUST FUEL ADDITION INJECTOR (INJECTION VOLUME)
PERFORM ACTIVE TEST BY INTELLIGENT TESTER (DPNR CATALYST REGENERATION)
REPLACE EXHAUST FUEL ADDITION INJECTOR ASSEMBLY
PERFORM ACTIVE TEST BY INTELLIGENT TESTER (DPNR CATALYST REGENERATION)
INSPECT EXHAUST FUEL ADDITION INJECTOR (INJECTION VOLUME)
DTC P1386 Injector for Exhaust Fuel Addition |
DESCRIPTION

The exhaust fuel addition injector is mounted on the exhaust port of the cylinder head, and low pressure is provided to the injector by the feed pump in the supply pump. This injector adds fuel by a control signal from the ECM.
This injector is used for two different controls: DPNR catalyst regeneration and nitrogen oxides (NOx) reduction.
Under the DPNR catalyst regeneration control, the injector adds fuel to raise a catalyst temperature.
In the other control, the injector helps the air-fuel ratio become RICH. As a result, NOx in the exhaust gas will be reduced in response to the RICH air-fuel ratio.
- HINT:
- For more information on the exhaust fuel addition injector and TOYOTA D-CAT (*1): (Click here)
- If P1386 is present, refer to the diagnostic trouble code (DTC) chart for TOYOTA D-CAT (Click here).
- "Learning value" used in here represents a correction learning value of the fuel addition volume to raise the DPNR (*2) catalyst temperature to a target range.
- *1: Diesel Clean Advanced Technology
- *2: Diesel Particulate-NOx Reduction system
DTC No. | DTC Detection Condition | Main Trouble Area | Related Trouble Area |
P1386 | Excess or low fuel addition volume from exhaust fuel addition injector: Air-fuel ratio deviates from a value estimated by ECM while the injector is adding fuel (1 trip detection logic) |
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Low fuel addition volume from exhaust fuel addition injector: Learning value (*3) exceeds standard level (1 trip detection logic) | |||
Exhaust fuel addition injector nozzle stuck open: Air-fuel ratio becomes RICHER than standard level, or exhaust gas temperature becomes higher than standard level (1 trip detection logic) |
- HINT:
- DTC P2047, P2048 or P2049 will be present if there is an open malfunction in the exhaust fuel addition injector circuit.
- If any one of the main injectors has a closed valve malfunction, rough idle will result. Compensatory injection volume learning values of each cylinder can be read by using the intelligent tester. When the value is more than 3.0 mm3, the cylinder is malfunctioning.
- Usually compensation injection volume is 3.0 mm3 or less.
MONITOR DESCRIPTION
- HINT:
- "Learning value" used here represents a correction learning value of the fuel addition volume to raise the DPNR (*4) catalyst temperature to a target range.
- *4: Diesel Particulate-NOx Reduction system.
- When the exhaust fuel addition injector adds fuel during NOx reduction, the ECM monitors the air-fuel ratio when the exhaust fuel addition injector adds fuel. If the air-fuel ratio is too RICH or too LEAN against the ECM predetermined air-fuel ratio, the ECM determines that the fuel addition volume is small or large, and illuminates the MIL. For this malfunction, there is no fail-safe operation.
- The ECM always monitors the DPNR catalytic converter temperature and the air-fuel ratio. When the temperature becomes higher than its usual level or the air-fuel ratio becomes extremely RICH, the ECM judges that the injector has stuck open and illuminates the MIL. If this malfunction occurs, the ECM enters the fail-safe mode to limit the acceptable vehicle speed to approximately 80 km/h (50 mph) at maximum by limiting the engine power.
- During DPNR catalyst regeneration, the ECM monitors the learning value. Normally, the learning value for the DPNR catalyst regeneration is in the vicinity of 1.0. Thus if the learning value is at 1.99 or more for a certain period of time, the ECM judges the fuel addition volume from the injector is insufficient and illuminates the MIL. If this malfunction occurs, the ECM enters the fail-safe mode to limit the acceptable vehicle speed to approximately 80 km/h (50 mph) at maximum by limiting the engine power.
Fail-Safe Operation | Malfunction Condition | Malfunction Detection Condition | Drive Pattern |
No fail-safe operation | Low or excess fuel addition volume from the exhaust fuel addition injector | Actual air-fuel ratio deviates from a value estimated by the ECM when the exhaust fuel addition injector adds fuel during NOx reduction | After warming up the engine, perform DPNR REJU (PM) in the ACTIVE TEST menu using the intelligent tester, and drive at constant vehicle speed within 50 to 100 km/h (31 to 62 mph) for more than 15 minutes |
Limits engine power by permitting driving at a maximum vehicle speed of approximately 80 km/h (50 mph) | Exhaust fuel addition injector has stuck open | DPNR catalytic converter temperature becomes higher than 800°C (1,472°F) or air-fuel ratio is less than approximately 12.0 : 1 for a couple of seconds | Idling engine for more than 5 minutes (*5) |
Limits engine power by permitting driving at a maximum vehicle speed of approximately 80 km/h (50 mph)
| Low fuel addition volume from the exhaust fuel addition injector | During DPNR catalyst regeneration, when learning value of 1.99 or more continues for a certain period of time (*6) | After warming up the engine, perform DPNR REJU (PM) in the ACTIVE TEST menu using the intelligent tester, and drive at constant vehicle speed within 50 to 100 km/h (31 to 62 mph) for more than 30 minutes |
*6: While the DPNR catalyst regeneration is performed, the ECM raises the DPNR catalytic converter temperature to more than 600°C (1,112°F) by adding fuel using the exhaust fuel addition injector. If the temperature does not reach 600°C (1,112°F) during the attempt, the correction learning value of the fuel addition volume increases by increments in order to raise the DPNR catalytic converter temperature to the target range.

WIRING DIAGRAM

INSPECTION PROCEDURE
- HINT:
- "Learning value" used in here represents a correction learning value of the fuel addition volume to raise the DPNR catalyst temperature to a target range.
1.CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P1386) |
Connect the intelligent tester to the DLC3.
Turn the engine switch ON (IG) and turn the intelligent tester ON.
Enter the following menus: "Powertrain / Engine / DTC".
Read DTCs.
- Result:
Display (DTC output) Proceed to P1386 A P1386 and other DTCs B
- HINT:
- If codes other than P1386 are output, perform troubleshooting for those DTCs first.
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A | |
2.PERFORM DRIVE TEST |
Try to drive the vehicle at 80 km/h (50 mph) or faster while the MIL is ON.
Check that the vehicle can be driven at 80 km/h (50 mph) or faster.
- Result:
Vehicle Conditionn Proceed to Permits driving at 80 km/h (50 mph) at maximum A Permits driving at faster than 80 km/h (50 mph) B
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A | |
3.READ VALUE OF INTELLIGENT TESTER (EXHAUST GAS TEMPERATURE) |
Connect the intelligent tester to the DLC3.
Turn the engine switch ON (IG) and turn the intelligent tester ON. (Do not start the engine.)
Enter the following menus: Powertrain / Engine / Data List / Initial Exhaust Temp (In) and Initial Exhaust Temp (Out) and read its value displayed on the intelligent tester.
- Result:
Temperature Displayed Proceed to OK (Same value as actual exhaust gas temperature) A 1,000°C (1,832°F) B
- HINT:
- If there is an open circuit, the intelligent tester indicates 1,000°C (1,832°F).
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A | |
4.CHECK EXHAUST GAS (WHITE SMOKE AND FUEL SMELL) |
- CAUTION:
- Stop the engine immediately if there is white smoke or a fuel smell during the following inspection. Fuel may be leaking from the exhaust fuel addition injector.
Remove the battery cable for 1 minute, and then reconnect the cable.
After the engine starts, promptly accelerate the engine to approximately 3,000 rpm with no load 3 times.
Check for white smoke in exhaust gases.
Check for a fuel smell in exhaust gases.
- Result:
Result Proceed to Either white smoke or fuel smells in exhaust gases A Other than above B
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B | |
5.READ VALUE OF INTELLIGENT TESTER (DPNR A/F) |
- CAUTION:
- Stop the engine immediately if there is white smoke or a fuel smell during the following inspection. Fuel may be leaking from the exhaust fuel addition injector.
Connect the intelligent tester to the DLC3.
Turn the engine switch ON (IG) and turn the intelligent tester ON.
Start the engine.
Enter the following menus: Powertrain / Engine / Data List / DPNR A/F.
Read the air-fuel ratio displayed on the tester after idling the engine for 3 minutes.
- Result:
A/F Ratio Proceed to More than 12 A Less than 12 B
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A | |
6.READ VALUE OF INTELLIGENT TESTER (EXHAUST GAS TEMPERATURE) |
- CAUTION:
- Stop the engine immediately if there is white smoke or a fuel smell during the following inspection. Fuel may be leaking from the exhaust fuel addition injector.
Connect the intelligent tester to the DLC3.
Turn the engine switch ON (IG) and turn the intelligent tester ON.
Start the engine.
Enter the following menus: Powertrain / Engine / Data List / Initial Exhaust Temp (In) and Initial Exhaust Temp (Out).
Check that exhaust gas temperature is within the specification below.
- Result:
Condition Exhaust Gas Temperature Idling after warming up engine Constant at approximately 50 to 700°C (122 to 1,292°F)
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OK | |
7.READ VALUE OF INTELLIGENT TESTER (A/F RATIO) |
Connect the intelligent tester to the DLC3.
Turn the engine switch ON (IG) and turn the intelligent tester ON.
Start the engine.
Enter the following menus: Powertrain / Engine / Data List.
After warming up the engine, check if the air-fuel ratio varies when accelerating the engine from idling to 3,000 rpm by fully depressing the accelerator pedal 3 times.
- Result:
Air-fuel Ratio Proceed to Varies OK Not vary NG
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OK | |
8.INSPECT EXHAUST FUEL ADDITION INJECTOR ASSEMBLY |
Disconnect the E71 exhaust fuel addition injector connector.
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Measure the resistance between the terminals of the exhaust fuel addition injector.
- Standard resistance:
Tester Connection Condition Specified Condition 1 - 2 20°C (68°F) 6.8 to 8.2 Ω
Reconnect the exhaust fuel addition injector connector.
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OK | |
9.CHECK HARNESS AND CONNECTOR (EXHAUST FUEL ADDITION INJECTOR - ECM) |
Disconnect the E71 exhaust fuel addition injector connector.
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Disconnect the E59 ECM connector.
Check the resistance between the wire harness side connectors.
- Standard resistance (Check for open):
Tester Connection Specified Condition FIV (E59-105) - (E71-1) Below 1 Ω
- Standard resistance (Check for short):
Tester Connection Specified Condition FIV (E59-105) or (E71-1) - Body ground 10 kΩ or higher
Reconnect the exhaust fuel addition injector connector.
Reconnect the ECM connector.
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OK | |
10.CHECK FOR FUEL LEAKAGE (IN EXHAUST FUEL ADDITION INJECTOR) |
Visually check if there is a fuel leak between the supply pump and exhaust fuel addition injector.
- HINT:
- Primary pressure of maximum 1 MPa (10 kgf/cm2, 145 psi) is provided from a feed pump inside the supply pump to the exhaust fuel addition injector.
- Fuel leaks are possible inside the components (supply pump, etc.).
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OK | |
11.READ VALUE OF INTELLIGENT TESTER (COMPENSATION OF INJECTION VOLUME) |
Connect the intelligent tester to the DLC3.
Turn the engine switch ON (IG) and turn the intelligent tester ON.
Start the engine.
Enter the following menus: Powertrain / Engine / Data List / Injection Feedback Value and read its value displayed on the intelligent tester.
- Result:
Result Proceed to Compensatory injection volume is more than 3.0 mm3 A Compensatory injection volume is 3.0 mm3 or less B
- HINT:
- Usually compensation injection volume is 3.0 mm3 or less.
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A | |
12.CHECK ENGINE CONTROL SYSTEM |
Check that there is no abnormality in the main injector, cylinder compression pressure, valve timing, and valve clearance.
Check that there is no leakage or blockage in the air intake, exhaust, and EGR systems.
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OK | |
13.INSPECT EXHAUST FUEL ADDITION INJECTOR (INJECTION VOLUME) |
Remove the exhaust fuel addition injector.
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Attach the exhaust fuel addition injector to a nozzle tester.
- SST
- 09268-41047(95336-08070)
09268-45014(09268-41220)
09268-41150
Apply a pressure of 0.29 MPa (3.0 kgf/cm2, 42 psi) to the nozzle tester.
Connect SST (wire) to the exhaust fuel addition injector.
- SST
- 09842-30080
Inspect the injector.
- Standard:
Condition Result Leave the injector undisturbed for 1 minute with fuel pressurized No leakage from the injector Apply battery voltage to the injector Fuel is emitted from the injector
- HINT:
- Injection volume after leaving the exhaust fuel addition injector for 10 seconds with the pressurized fuel applied is as follows:
- Reference:
- 25 cm3 (1.5 cu.in.)
- The above is a reference value, thus, your reading may differ from this value depending on the measuring conditions etc.
- Check that the nozzle of the exhaust fuel addition injector is not clogged.
Reinstall the exhaust fuel addition injector.
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OK | |
14.PERFORM ACTIVE TEST BY INTELLIGENT TESTER (DPNR CATALYST REGENERATION) |
Clear the learning value by removing the negative battery cable for more than 1 minute.
Connect the intelligent tester to the DLC3.
Turn the engine switch ON (IG) and turn the intelligent tester ON.
Enter the following menus: Powertrain / Engine / Active Test / Activate the DPNR Rejuvenate (PM).
After warming up the engine, drive the vehicle at a constant speed within 50 to 100 km/h (31 to 62 mph) (with smooth throttle operations) for more than 15 minutes.
Enter the following menus: Powertrain / Engine / Data List / AFS FT B1 S1, Initial Exhaust Temp (In), Initial Exhaust Temp (Out) and Exhaust Fuel Addition FB.
Check the exhaust gas temperatures (Initial Exhaust Temp (In) and (Out)) and the learning value (Exhaust Fuel Addition FB).
- Result:
Result Proceed to Exhaust gas temperature does not become higher than 600°C (1,112°F) A Exhaust gas temperature becomes higher than 600°C (1,112°F), and the learning value remains in the vicinity of 1.0 B
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A | |
15.REPLACE EXHAUST FUEL ADDITION INJECTOR ASSEMBLY |
NEXT | |
16.PERFORM ACTIVE TEST BY INTELLIGENT TESTER (DPNR CATALYST REGENERATION) |
Clear the learning value by removing the negative battery cable for more than 1 minute.
Connect the intelligent tester to the DLC3.
Turn the engine switch ON (IG) and turn the intelligent tester ON.
Enter the following menus: Powertrain / Engine / Active Test / Activate the DPNR Rejuvenate (PM).
After warming up the engine, drive the vehicle at a constant speed within 50 to 100 km/h (31 to 62 mph) (with smooth throttle operations) for more than 15 minutes.
Enter the following menus: Powertrain / Engine / Data List / AFS FT B1 S1, Initial Exhaust Temp (In), Initial Exhaust Temp (Out) and Exhaust Fuel Addition FB.
Check the exhaust gas temperatures (Initial Exhaust Temp (In) and (Out)) and the learning value (Exhaust Fuel Addition FB).
- Result:
Result Proceed to Exhaust gas temperature does not become higher than 600°C (1,112°F) A Exhaust gas temperature becomes higher than 600°C (1,112°F), and the learning value remains in the vicinity of 1.0 B
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A | ||
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17.INSPECT EXHAUST FUEL ADDITION INJECTOR (INJECTION VOLUME) |
Remove the exhaust fuel addition injector.
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Attach the exhaust fuel addition injector to a nozzle tester.
- SST
- 09268-41047(95336-08070)
09268-45014(09268-41220)
09268-41150
Apply a pressure of 0.29 MPa (3.0 kgf/cm2, 42 psi) to the nozzle tester.
Connect SST (Wire) to the exhaust fuel addition injector.
- SST
- 09842-30080
Inspect the injector.
- Standard:
Condition Result Leave the injector undisturbed for 1 minute with fuel pressurized No leakage from the injector Apply battery voltage to the injector Fuel is emitted from the injector
- HINT:
- Injection volume after leaving the exhaust fuel addition injector for 10 seconds with the pressurized fuel applied as follows:
- Reference:
- 25 cm3 (1.5 cu.in.)
- The above is a reference value, thus, your reading may differ from this value depending on the measuring conditions etc.
- Check that the nozzle of the exhaust fuel addition injector is not clogged.
Reinstall the exhaust fuel addition injector.
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OK | ||
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