P2451 on 2010-2014 Land Rover LR4: EVAP Switching Valve & DMTL Pump Guide

What's Unique About the 2010-2014 Land Rover LR4

The 2010-2014 Land Rover LR4 is particularly susceptible to this code due to a known issue with the DMTL pump. Land Rover issued a Technical Service Bulletin (SSM71298) acknowledging that an internal failure within the DMTL pump 🎬 Watch: See how a DMTL pump failure looks on a Land Rover. is a primary cause for P2451 and a host of other related EVAP codes. The bulletin advises that if standard diagnostics for wiring or blockages do not reveal a fault, the pump itself should be replaced. This makes the pump a much more likely culprit than on other vehicles where wiring or blockages might be more common.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Check Engine Light is on.
• Failure of vehicle emissions tests.
• In rare cases, a faint fuel odor may be noticeable near the rear of the vehicle.
• A "Check Fuel Filler Cap" message may appear on the dashboard, even if the cap is tight.

Most Likely Causes

1. Failed DMTL (Leak Detection) Pump 🔴 High Probability A Land Rover Technical Service Bulletin (SSM71298) directly identifies internal DMTL pump failure as the likely cause for this code when other circuit faults are not present. The switching valve is an integral, non-serviceable part of the pump assembly.
   How to confirm: After checking wiring, use a high-end scan tool to command the DMTL pump's switching valve to actuate. If it doesn't respond (no audible click) and power/ground are present at the connector, the pump is faulty. The pump is located behind the passenger-side rear wheel well liner.
   Typical fix: Replace the DMTL pump assembly. 🎬 See this walkthrough for replacing the DMTL pump on a Land Rover. It is often recommended to also replace the small foam filter that attaches to the pump, as it can be degraded. One owner noted that their old filter was "NASTY" and wished they had ordered a new one at the same time.
   Est. part cost: $75-$240
2. Wiring or Connector Issue 🟡 Medium Probability The DMTL pump is located under the vehicle, behind the rear passenger wheel, exposing its wiring and connector to moisture, corrosion, and road debris.
   How to confirm: Visually inspect the wiring harness and connector leading to the DMTL pump for any signs of damage, corrosion, or loose pins. Test for 12V power and ground at the connector with the key on. The electrical connector has a tab on one side that must be squeezed to release.
   Typical fix: Repair the damaged section of the wiring harness or clean/replace the connector.
   Est. part cost: $10-$50
3. Blocked EVAP System Hose or Filter ⚪ Low Probability Hoses connected to the charcoal canister or DMTL pump can become clogged with dirt, debris, or insect nests. The small foam filter on the pump itself can also become saturated or fall apart, causing a blockage. A TSB suggests contaminant ingress through the dust filter is a known issue.
   How to confirm: Disconnect the hoses from the DMTL pump and charcoal canister and inspect them for blockages. Attempt to blow low-pressure air through them. Check the condition of the pump's external filter.
   Typical fix: Clear the blockage or replace the clogged hose or filter.
   Est. part cost: $20-$60

Rare But Worth Checking

• Faulty Powertrain Control Module (PCM): This is extremely rare. The PCM should only be considered if all other possibilities, including the pump and its entire circuit, have been exhaustively tested and proven to be working correctly.

Diagnosis Steps

1. Read all stored fault codes with an OBD-II scanner.
🎬 Watch: A quick 5-step guide to basic Land Rover diagnostics.
2. Visually inspect the DMTL pump, its connector, and the surrounding wiring harness for any obvious damage, corrosion, or loose connections. Access is gained by removing the spare tire and/or the passenger-side rear wheel and wheel well liner.
3. Using a bidirectional scan tool, command the EVAP switching valve (often labeled as the DMTL pump or vent valve) to open and close. Listen for an audible click from the pump assembly.
4. If no click is heard, disconnect the electrical connector at the pump.
5. Check for 12V power and a good ground at the connector pins using a multimeter. If power and ground are present but the pump does not actuate when commanded, the DMTL pump has failed and must be replaced.
6. If power or ground is missing, trace the wiring back towards the PCM to find the break or short in the circuit.
7. If the pump works when commanded, inspect the attached EVAP hoses and the pump's external filter for any blockages, kinks, or degradation.

Parts You'll Likely Need

• EVAP Leak Detection Pump (DMTL) (OEM #WTR500030) — This is the most common failure point for code P2451 on this vehicle, as confirmed by manufacturer TSB SSM71298. The switching valve is internal to this pump. This part number has been superseded by LR174757 for some newer models, but WTR500030 is correct for this LR4.
  Trusted brands: Bosch (OEM), Genuine Land Rover
  OEM price range: $150-$240
  Aftermarket price range: $75-$120

Related Codes That Often Appear With This One

• P2450 — This code indicates the switching valve is stuck open, which is the opposite fault but relates to the same component within the DMTL pump. TSB SSM71298 also lists this code.
• P0442 — This code for a small EVAP leak can sometimes accompany P2451 if the system has multiple faults, though P2451 is specific to the valve's function.
• P2401, P2402, P2404, P240A — These are other EVAP system codes related to the DMTL pump's circuitry and function. TSB SSM71298 lists them as potentially being caused by the same internal pump failure.

Technical Service Bulletins (TSBs) & Recalls

• SSM71298: States that if no fault is found after following diagnostics for codes P2401 through P2451, the cause is likely an internal DMTL pump failure. It applies to the LR4 (L319) and Range Rover Sport (L320).

Platform-Specific Known Issues

• Technical Service Bulletin SSM71298 was issued for a range of EVAP codes, including P2451, on the 2010 LR4 and Range Rover Sport. It states that if standard diagnostics don't reveal a fault, the cause is likely an internal failure of the DMTL pump and instructs technicians to replace the pump and retain it for factory analysis.
• Owner experiences on forums like landroverforums.com confirm the TSB's findings. In a thread discussing code P2402, a user with a 2013 LR4 confirmed replacing the DMTL pump (Bosch part 0261222022) resolved their issue.

Mechanic-Grade Diagnostic Values

• DMTL Pump Connector Power Supply — expected: 12V with key on. Failure: 0V or significantly lower voltage indicates a wiring issue upstream.

Scan Tool Commands That Help

• Land Rover SDD (Symptom Driven Diagnostics): Evaporative System Diagnostic Test — This is the manufacturer-specific routine to test the EVAP system. According to TSB JTB00361NAS1, this updated test can differentiate between a leak failure and an electrical/hardware failure, which is critical for diagnosing P2451.
• Land Rover SDD (Symptom Driven Diagnostics): Powertrain - High pressure fuel pump test — While named for the fuel pump, TSB LTB00495v6 mentions this routine can be used to audibly diagnose pump performance issues by sequencing components, which may be helpful in confirming if the DMTL pump is actuating at all.

Real Owner Repair Stories

• Reddit user Apprehensive-Tea4419 (2016 Land Rover LR4) — EVAP code P0442 (small leak)
  ❌ Tried (didn't work) Replacing the gas cap.
  ✅ What actually fixed it The user noted that in addition to the DMTL pump itself, the small rubber gasket where the pump mounts to the EVAP canister is a likely failure point, as it will "more than likely be cracked or disintegrated." This implies checking or replacing this seal is a critical step.
• landroverforums.com user Freshlikedougy (2011 LR4 5.0L V8) — Check Engine Light, "burping" sound from gas tank.
  ❌ Tried (didn't work) The shop replaced the DMTL pump, but the symptoms persisted.
  ✅ What actually fixed it The final resolution was not posted by the user, but the shop's next diagnostic step was to recommend replacing the purge valve due to an intermittent code, after the new DMTL pump did not resolve the issue. This highlights the purge valve as a potential secondary or alternative cause.

OEM Part Supersession History

• WTR500030 → LR174757 — Standard part number update by Land Rover. The new part is a direct replacement.
  Heads up: No incompatibility is noted. LR174757 is the current genuine part number, while WTR500030 is still widely referenced and available from the OEM (Bosch).