P2652 on 2017 Honda Ridgeline: Rocker Arm Oil Pressure Switch Causes and Fixes

What's Unique About the 2017-2017 Honda RIDGELINE

The 2017 Ridgeline's 3.5L J-series engine relies heavily on its VCM system for fuel economy, which uses oil pressure to deactivate cylinders. This code, especially when paired with P3400, is a known issue on this platform. Honda even issued a Technical Service Bulletin (TSB ATI&01192022901) specifically searching for 2017 🎬 Watch: Diagnostic walkthrough for rough idling and P2652 codes. Ridgelines, Pilots, and Odysseys with this exact code combination to better understand the root cause, indicating a specific focus by the manufacturer on this problem for this model year.

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 (Malfunction Indicator Lamp) is on
• Flashing Check Engine Light
• Vehicle enters 'limp mode' with reduced power and acceleration.
• Rough running or rough idle.
• Reduced fuel economy
• Poor engine performance, especially at higher RPMs.
• Engine hesitates or feels like it won't shift properly.

Most Likely Causes

1. Failed Rocker Arm Oil Pressure Switch 'B' (Bank 1) 🔴 High Probability This is a very common failure point on Honda's J35 engines. The switch can fail internally from wear or get clogged with oil sludge, causing it to send a continuous 'on' signal.
   How to confirm: After confirming the oil level is correct, the most common diagnostic step is to replace the switch, as testing can be inconclusive and the part is relatively inexpensive. A mechanic can test the wiring for a short to ground or an open circuit and test the switch for continuity. In many cases, replacing the switch resolves the issue immediately.
   Typical fix: Replace the Bank 1 'B' rocker arm oil pressure switch and the associated O-ring. The switch is located on the rear cylinder head (the one closer to the firewall). A 24mm deep socket is required for removal and installation.
   Est. part cost: $35-$100
2. Low or Dirty Engine Oil 🟡 Medium Probability The VTEC/VCM system is entirely dependent on clean oil at the correct level and pressure. Neglected oil changes can lead to sludge that clogs the small passages in the spool valve assembly and the switch itself. Using the incorrect oil viscosity can also trigger this code.
   How to confirm: Check the engine oil dipstick. The oil level should be between the marks, and the oil should not be excessively dark, thick, or gritty. This is the first and most important check.
   Typical fix: Perform an engine oil and filter change using the correct viscosity oil (0W-20 for this vehicle). If the oil was very dirty, some mechanics recommend a short oil change interval for the next cycle to help clean out any remaining sludge.
   Est. part cost: $40-$80
3. Wiring or Connector Issue ⚪ Low Probability The switch is located on the back of the engine, where heat can make wiring brittle over time. Rodents can also chew on wiring. The connector itself can become corroded or loose.
   How to confirm: Visually inspect the wiring harness and connector leading to the pressure switch for any signs of damage, corrosion, or loose connections. A multimeter can be used to check for a short to ground or an open in the wire between the switch and the PCM.
   Typical fix: Repair the damaged section of wire or clean/replace the connector.
   Est. part cost: $5-$50

Rare But Worth Checking

• Clogged VCM Oil Passages or Faulty Spool Valve: If a new switch and fresh oil don't solve the problem, the issue may be deeper within the VCM system, such as a clogged passage in the spool valve assembly that the switch is mounted to. In this case, the entire rear rocker arm oil control valve (spool valve) assembly may need to be removed for cleaning or replacement.

Diagnosis Steps

1. Check the engine oil level and condition. Top off or change the oil if necessary. This is the most important first step.
2. Scan the computer for any other codes. Note if P3400 is also present, which is highly likely.
3. Clear the codes and test drive the vehicle to see if the code returns. If it does, proceed with further diagnosis.
4. Locate the Bank 1 Rocker Arm Oil Pressure Switch 'B'. It is on the rear cylinder head, closer to the firewall, and is part of the spool valve assembly.
5. Inspect the electrical connector and wiring going to the switch for any visible damage, corrosion, or looseness.
6. If the wiring looks good, the most common and cost-effective next step is to replace the oil pressure switch and its O-ring. A 24mm deep socket is the required tool.
7. After replacement, clear the code again and perform another test drive to confirm the fix.

Parts You'll Likely Need

• Rocker Arm Oil Pressure Switch (Bank 1, Switch B) (OEM #37240-R70-A04) — This is the sensor that fails and directly causes the P2652 code. This part number supersedes previous versions 37240-R70-A02 and 37240-R70-A03.
  Trusted brands: Honda (Genuine), Standard Motor Products, NTK, Dorman
  OEM price range: $45-$70
  Aftermarket price range: $35-$60
• Oil Pressure Switch O-Ring (OEM #91319-PAA-A01) — This seal should always be replaced with the switch to prevent oil leaks. It is often sold separately.
  Trusted brands: Honda (Genuine)
  OEM price range: $3-$7
  Aftermarket price range: $1-$5

Related Codes That Often Appear With This One

• P3400 — P3400 means 'Valve Pause System (VPS) Stuck Off Bank 1'. This code is a direct result of the oil pressure issue detected by the P2652 switch. The system logs P2652 for the switch being stuck on, which then causes the VCM system to fail its self-test, logging P3400. They almost always appear together for this fault, as confirmed by Honda's TSB.
• U0401 — This code means 'Invalid Data Received From ECM/PCM'. It can be set in the Transmission Control Module (TCM) when the P2652 code is present. The engine's fault condition causes the PCM to send unexpected data, which the TCM flags as invalid, sometimes causing a flashing 'D' (Drive) indicator on the dashboard.

Technical Service Bulletins (TSBs) & Recalls

• ATI&01192022901: A request from Honda to dealerships to gather information on specific 2017 vehicles, including the Ridgeline, with codes P2652 and P3400 stored, to better understand the cause of the issue.

Platform-Specific Known Issues

• A Honda Technical Service Bulletin (ATI&01192022901) was issued to investigate 2017 Ridgeline, Odyssey, and Pilot models that specifically exhibit codes P2652 and P3400, along with potential rough running conditions. This indicates a known pattern of failure recognized by the manufacturer.
• Oil leaks from the spool valve assembly (where this switch is located) are common on J35 engines and can drip onto the alternator below, causing premature alternator failure. When replacing the switch, it's a good time to inspect the entire spool valve gasket for leaks.

Mechanic-Grade Diagnostic Values

• Rocker Arm Oil Pressure Switch 'B' (Bank 1) Circuit Voltage — expected: Approximately 12V (system voltage) with the key on, engine off, and connector back-probed.. Failure: If voltage is not present, it indicates an open in the wiring between the PCM and the switch. If the switch is internally shorted to ground, the voltage will be low or 0V.
• Rocker Arm Oil Pressure Switch 'B' (Bank 1) Continuity to Ground — expected: With the connector unplugged, there should be NO continuity between the switch's terminal and the engine block (ground).. Failure: If continuity is present with the switch unplugged, the switch is internally shorted and has failed.
• VCM System Oil Pressure (at switch location) — expected: At least 45 kPa (6.5 psi) during a VTEC/VPS test commanded by a Honda HDS scan tool.. Failure: If pressure is below this threshold, it indicates a problem with oil delivery, such as a clogged passage or a faulty rocker arm oil control valve, not the switch itself.
• Rocker Arm Oil Pressure Switch Torque Specification — expected: 22 N.m (16 lb-ft). Failure: Over-tightening can damage the switch or threads; under-tightening can cause oil leaks.

Scan Tool Commands That Help

• Honda Diagnostic System (HDS): VTEC TEST / VPS TEST — This is a guided test in the HDS inspection menu used to command the VCM system on and off to verify its mechanical and hydraulic function. It's used to confirm if the oil pressure is being generated correctly when the solenoid is activated, which helps differentiate between a switch/wiring failure and a hydraulic/mechanical failure.

Wiring & Ground Locations

• PCM Connector C, Pin 34 — This is the pin on the Powertrain Control Module (PCM) that the signal wire from the Bank 1 'B' rocker arm oil pressure switch connects to.. A technician would test for continuity between this pin and the switch connector to diagnose an open or short in the wiring harness.
• G101 — A primary engine harness ground, typically located on the driver's side of the engine bay, often on the thermostat housing or cylinder head.. While the switch grounds through its body, a poor main engine ground (G101) can cause a variety of unpredictable electrical issues and erratic sensor readings. If multiple electrical faults are present, inspecting this ground connection is a wise step.

Real Owner Repair Stories

• KIT'S Auto and Truck Repair on YouTube (2016 Honda Pilot (same J35 engine and VCM system)) — Check engine light on, high idle, flashing 'D' (Drive) indicator, rough running.
  ❌ Tried (didn't work) Initial diagnosis confirmed the code P2652 'Rocker Arm Oil Pressure Switch B Circuit High Voltage' and a related transmission code U0401 'Invalid Data Received from PCM'.
  ✅ What actually fixed it The technician tested the wiring and found 12V at the switch connector, proving the wiring was good. The switch itself was diagnosed as faulty. Replacing the Bank 1 (rear) rocker arm oil pressure switch resolved all symptoms and cleared the codes.

OEM Part Supersession History

• 37240-R70-A02, 37240-R70-A03 → 37240-R70-A04 — Honda often updates parts to improve reliability or change suppliers. The -A04 version is the latest revision recommended for service.
  Heads up: The newer part number (37240-R70-A04) is a direct replacement for the older versions and should be used for all repairs.