Toyota Land Cruiser Blocked DPF Warranty Refused P246300 & P245800

Toyota Land Cruiser DPF Full (How to Fix It Without a New Gearbox)

A DPF full warning on a Toyota Land Cruiser can set off a chain of faults. Add a harsh gear shift with a loud bang, and it feels like a gearbox failure. In most cases, it isn’t. Here’s how the fault was diagnosed and fixed, what actually causes it, and how to avoid costly guesswork.

Spotting the Warning Signs

On this automatic Land Cruiser, the dash showed DPF full and check engine with a visit dealer message. Gear changes were erratic, with hard bangs and a heavy jolt.

Other tell-tales:

* Cruise control stops working
* Flat tyre warning appears
* Traction control disabled, risky on rear-wheel drive in wet weather

Why These Signs Matter

A blocked DPF confuses the ECU, so gear changes go rough even though the gearbox is fine.

The Customer’s Frustrating Journey

Two garages tried resets and forced regens with no success. One suggested a new gearbox; Toyota quoted around £4,800 for a new DPF and refused warranty.


Avoiding Risky Repairs

The owner did some research and chose a targeted diagnosis, not parts roulette.

Tools and Scan Setup

A Launch X431 Euro from www.launchtech.co.uk was used. Intelligent scan on these needs internet; if it spins, use standard diagnostics.

* Connect tool and select Toyota Land Cruiser Prado
* Run intelligent or standard scan
* Review live data before acting

Expected Fault Patterns

These jobs often show the same DPF-related patterns.

Decoding the Fault Codes
P245800 Particle filter regeneration duration (this was cleared by previous garage)

P246300 Particulate Filter Restriction, Soot Accumulation

P2463

after unplugged 5th injector it shows fault..
P20CD

The scan also showed:

* Reductant pump stuck off
* Particle filter reductant pump control A
* Reductant level too low

These often appear with a blocked DPF. Live data showed roughly 2.9 litres remaining, fluctuating when the vehicle was rocked. AdBlue parts are hard to source, often with long waits.

AdBlue Complications

Low fluid can set pump faults, but the priority here is the DPF.

Removing the Fifth Injector (Vaporizer)

The common cause is the fifth injector (vaporiser) blocked with carbon.
can also be called exhaust after treatment fuel injector.
1. Remove engine cover and boost hoses
2. Undo 14 mm bolts and disconnect the fuel line
3. Remove two coolant hoses
4. Take out the studs, slide the water-cooled unit out
5. Undo the three bolts and the T40 Torx, separate and access the injector

Spotting the Blockage

The spray nozzle tip clogs, so diesel can’t heat the DPF.

Cleaning the Injector Tip

Heat the tip with a heat induction tool until red hot for about a minute to burn the carbon. Check it’s visibly clear and clean the port, then reassemble.

Why Cleaning Works

The DPF needs a precise diesel spray to reach 580 to 650°C.

DPF Cleaning Process

With the engine back together, clean the DPF through the larger pipe.

1. Remove the clip and hose
2. Fit the cleaning gun at 120 PSI with Launch UK fluid
3. Add a 5 seconds trigger hold of fluid, soak 2 minutes
4. Run the engine and feed in the rest
5. Reconnect the sensor

Monitoring Pressure

Back on live data, pressure dropped from about 150 mbar to under 50 mbar at 3,000 rpm. Steam out the tailpipe is normal.

Resetting the DPF System

Toyota often locks regen at 170% soot. Special functions may not clear it. Tricks that help:

* Clear codes and try DPF functions
* Disconnect the battery, which re-enables the manual regen button
* Retry code clear after restart

It works on these Toyotas.

Soot Accumulation Explained

The ECU bases soot on pressure. It needs around 600°C to allow the percentage to drop.

Temporary Workaround for Temperature Sensor

If temps stick at 350°C, the vaporiser still isn’t doing its job. Try tricking the sensor to complete the reset:

1. Heat the exhaust temperature sensor tip with the induction tool
2. Watch temps climb to 600°C
3. Soot drops to about 50%, then clear the fault

Why Temps Matter

Sensor 2 or 3 must see 600°C for the ECU to reduce soot.

Parts Sourcing Struggles with Toyota

Two days later, the dealer supplied the wrong part: an AdBlue injector, about £980 with gaskets. Codes like P2463 and P20CD pointed to the exhaust aftertreatment fuel injector, not the AdBlue UREA injector. They’re adamant there’s no fifth injector, but there is.

Extra Cleaning Attempts

The vaporiser was soaked in DPF cleaner and brake cleaner, reheated, then refitted. This time it hit 692°C and regen completed.

Final Successful Regen and Results

With temperatures above 600°C, the soot figure fell to 8%, then 6%. Warnings cleared and the graph settled.

* Temps peaked near 692°C
* Soot continued to drop as it cooled
* Gear shifts returned to normal

Lessons for Owners

Fix the cause, not just the symptom. On these, that often means the vaporiser.