P2402 on 2004-2012 Volvo S40: EVAP Leak Detection Pump Circuit High Causes and Fixes

What's Unique About the 2004-2012 Volvo S40

The second-generation Volvo S40 (P1 platform) uses a specific style of Diagnostic Module Tank Leakage (DMTL) pump, supplied by Bosch (part number 0261222018). These pumps are a known failure point across the entire P1 platform, which also includes the V50, C30, and C70. While wiring can be a cause, the pump itself is the most frequent culprit, often failing internally and causing this specific 'circuit high' fault code. Owners often find this code paired with P043E, which also points directly to a fault with the pump assembly, further strengthening the diagnosis.

Symptoms You May Notice

• Check Engine Light is on
🎬 Watch: A quick guide to understanding the P2402 code.
• Inability to pass an emissions test

Most Likely Causes

1. Failed EVAP Leak Detection Pump (DMTL Pump) 🔴 High Probability → Shop Vapor Canister The pump is a common failure item on this platform. Internal electronics on the pump's circuit board short out over time, leading to the 'circuit high' condition detected by the ECM.
   How to confirm: After ruling out fuse and wiring issues, the pump is the presumed cause. There is no simple test for the pump itself; replacement is the standard diagnostic step. A rattling sound when the old pump is shaken can also indicate internal failure.
   Typical fix: Replace the EVAP leak detection pump assembly. The pump is typically located near the rear axle and fuel tank, often behind the spare tire well. 🎬 See: Locating the charcoal canister and pump near the subframe.
   Est. part cost: $100-$330
2. Damaged Wiring or Connector 🟡 Medium Probability The pump and its wiring are located under the vehicle, exposed to road debris, moisture, and corrosion which can damage the harness or connector pins.
   How to confirm: Visually inspect the wiring harness leading to the leak detection pump for any signs of fraying, melting, or breaks. Unplug the connector and check for corrosion or damage on the pins.
   Typical fix: Repair the damaged section of the wiring harness or clean/replace the connector.
   Est. part cost: $5-$50
3. Blown Fuse ⚪ Low Probability An internal short in the leak detection pump can cause a surge in current, blowing the fuse that protects the circuit.
   How to confirm: Check the fuse box in the engine compartment (the Central Electronic Module or CEM, located under the glove box). Specifically, inspect fuse F35 (15A), which is often designated for the 'absorption tank' (EVAP system).
   Typical fix: Replace the blown fuse. If the new fuse blows immediately, it confirms a short circuit in the pump or wiring that must be addressed.
   Est. part cost: $1-$5

Rare But Worth Checking

• Faulty Engine Control Module (ECM): → Shop Engine Control Module (ECM) This is extremely rare. The ECM should only be considered after all other possibilities, including the pump and wiring, have been exhaustively checked and ruled out. Misdiagnosing an ECM is a costly mistake.

Diagnosis Steps

1. Read the codes with an OBD-II scanner to confirm P2402 is present and note any other codes, like P043E.
2. Check the fuses in the engine compartment fuse box (CEM). Pay close attention to fuse F35 (15A) for the EVAP system. Replace it if it's blown.
3. If the fuse is good, safely raise the vehicle to access the leak detection pump, which is located near the fuel tank and spare tire well.
4. Visually inspect the electrical connector and wiring harness going to the pump. Look for any signs of corrosion, melted plastic, or physical damage.
5. If the wiring and connector appear to be in good condition, the leak detection pump is almost certainly the cause of the fault.
6. Replace the leak detection pump. An owner on a Volvo forum noted the job was 'super easy' and involved removing two bolts and a few hose clamps.
7. After replacement, clear the codes with the OBD-II scanner and perform a drive cycle to allow the EVAP system monitor to run and confirm the Check Engine Light does not return.

Parts You'll Likely Need

• EVAP Leak Detection Pump (OEM #30760863) — This is the component that fails most frequently, causing the P2402 code. It contains both the pump motor and the control electronics that short out.
  Trusted brands: Bosch, Dorman
  OEM price range: $250-$330
  Aftermarket price range: $100-$150

Related Codes That Often Appear With This One

• P043E — This code, 'EVAP Leak Detection Reference Orifice Low Flow', is often triggered along with P2402. Both codes point to a malfunction within the leak detection pump assembly itself, strengthening the diagnosis that the pump has failed.

Platform-Specific Known Issues

• DIY Repair Experience: An owner on volvoforums.com with a 2013 model (similar platform) reported getting code P2402. They fixed it by replacing the Bosch LDP, which they purchased online for $66. The repair was described as 'super easy,' involving lowering the spare tire to access the pump, removing two 9mm bolts, and releasing the hose clamps. After clearing the codes, the car passed its emissions inspection.

Mechanic-Grade Diagnostic Values

• DMTL Pump Motor Current Draw — expected: The ECM establishes a baseline amperage value by running the pump against a known reference orifice (e.g., 0.5mm). It then compares this stored value to the amperage draw while pressurizing the entire EVAP system to detect leaks.. Failure: A 'Circuit High' code like P2402 is not diagnosed by this amperage test but by a direct electrical fault. However, understanding this amperage-based logic is key to diagnosing other DMTL codes like P043E that often accompany P2402. The P2402 fault prevents this test from even running correctly.
• DMTL Pump Connector Voltage — expected: With the ignition on and engine off (KOEO), the power supply pin at the pump connector should read battery voltage, typically 11.5V - 12.5V.. Failure: A P2402 'Circuit High' fault means the control/signal wire is likely stuck at battery voltage when it should be commanded low or be open circuit, indicating a short to power either in the wiring or, more commonly, inside the pump's electronics module.

Scan Tool Commands That Help

• Volvo VIDA (Vehicle Information & Diagnostics for Aftersales): Component Activation — After checking fuses and wiring, a technician can use the 'Activations' tab in VIDA to command the DMTL pump to turn on. If the pump runs with this command, it suggests the pump motor is functional and the problem may be intermittent or lie in the control signal from the ECM. If it does not activate, and power/ground are confirmed good, it strongly points to a failed pump.

Wiring & Ground Locations

• 31/115 — Left A-post. This is a primary chassis ground point listed in the S40 wiring diagram. While not explicitly for the EVAP pump, a poor ground here could affect various systems.
• 31/116 — Right A-post. This is another primary chassis ground point. Verifying major ground points are clean and tight is a good practice when diagnosing any electrical fault.
• DMTL Pump Harness — Runs from the main body harness to the pump, located near the rear axle and charcoal canister.. This harness is exposed to road debris and moisture. A common failure point is chafing or corrosion, which can cause a short to power on the control wire, directly triggering P2402.

Real Owner Repair Stories

• YouTube user 'Volvo XC90' (Volvo XC90 (P2 Platform, but uses a similar Bosch DMTL pump)) — Check Engine Light with code P2402.
  ❌ Tried (didn't work) The owner suspected cracked lines but determined they were intact.
  ✅ What actually fixed it Replacing the leak detection pump itself resolved the code. The owner noted the pump itself was 'broken' and the fix was straightforward, located behind the spare tire.

OEM Part Supersession History

• 8683709 → 30760863 — Standard part revision and replacement by the manufacturer.

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• Clogged Sunroof Drains Leading to Water Ingress 🔴 High — Very common across all P1 models. The drain tubes can shrink, disconnect, or clog, causing rainwater to overflow into the passenger footwell, directly onto the Central Electronic Module (CEM).
• Central Electronic Module (CEM) Failure 🔴 High — A frequent and expensive failure, often a direct result of water damage from clogged sunroof drains. Symptoms are widespread and erratic, including non-starting, dead instrument clusters, and random accessory behavior.
• PCV System / Oil Trap Clogging 🟠 Medium — Common on the 5-cylinder engines. The diaphragm in the oil filter housing can tear, causing a loud whistling or howling noise at idle. This creates excessive crankcase vacuum, which can eventually damage engine seals. (Ref: Volvo had an extended warranty (205) for this issue on earlier models, but it has since expired for most vehicles.)
• Cracked Coolant Expansion Tank 🟡 Low — The plastic coolant reservoir is prone to developing hairline cracks over time, leading to slow coolant leaks. It's a simple and relatively inexpensive part to replace.

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: A used part is generally NOT recommended for this specific component. The Bosch DMTL pump is a known high-failure part on the P1 platform. The risk of a used pump failing shortly after installation is high. It should only be considered as a last resort or for a temporary fix if sourced from a very low-mileage, verifiable donor vehicle.

Donor-vehicle mileage cap: roughly under 50000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• Check the electrical connector pins for any signs of green or white corrosion.
• Inspect the plastic housing for cracks or signs of heat stress (discoloration).
• Ask for the donor vehicle's mileage; avoid parts from high-mileage cars.
• Gently shake the pump; a significant rattling sound can indicate broken internal components.

OEM-only on this vehicle (don't cheap out):

• While not strictly 'OEM-only', using the OEM Bosch pump (PN: 0261222018 or Volvo PN: 30760863) is the most reliable and recommended path to ensure a lasting repair.

Aftermarket brands forum-validated for this vehicle:

• Bosch (OEM supplier)
• Dorman (A common and generally accepted aftermarket alternative)

Brands owners have reported issues with on this vehicle:

• No-name, unbranded parts from online marketplaces should be avoided due to unknown quality control and high likelihood of premature failure.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P043E — Frequently appears as a secondary code with P2402. It indicates a low flow condition in the EVAP system's reference orifice, which is triggered by the same faulty leak detection pump during its diagnostic routine.
• P2401 — Indicates a 'Circuit Low' condition for the same leak detection pump. Both P2401 and P2402 point to an electrical failure within the pump's internal circuit board or the external wiring harness.
• P2400 — Indicates an open circuit for the leak detection pump. This can be caused by a broken wire, a corroded connector pin, or a complete internal failure of the pump motor, sharing the same root causes as P2402.

Frequently Asked Questions