Understanding the P1470 Code in Your Land Rover
The OBD2 diagnostic trouble code P1470 is a manufacturer-specific code primarily associated with Land Rover and Jaguar vehicles. It indicates a malfunction within the Secondary Air Injection (AIR) System, specifically for bank 1 of the engine. This system is a critical component of your Land Rover’s emission control strategy, designed to reduce harmful exhaust emissions during a cold start. When the P1470 code is stored, the vehicle’s Powertrain Control Module (PCM) has detected an electrical or functional fault in the circuit controlling this system. Ignoring this code can lead to increased tailpipe emissions, potential damage to the catalytic converter, and failed emissions tests.
Primary Causes of the P1470 Code
Diagnosing a P1470 code requires a systematic approach, as the fault can originate from several components within the secondary air injection circuit. The system typically includes an electric air pump, relay, switching valves, vacuum solenoids, and associated piping.
1. Faulty Secondary Air Injection Pump
The electric air pump is the heart of the system. It forces fresh air into the exhaust stream. Common failures include:
- Seized or Worn Motor: Due to age, heat, or moisture ingress, the pump motor can fail.
- Internal Valve Failure: Some integrated check valves can stick or leak.
- Electrical Failure: Broken windings or corroded internal connections.
2. Defective Air Pump Relay or Fuse
The relay provides high-current power to the air pump. A failed relay or a blown fuse will prevent the pump from receiving any voltage, triggering the P1470 code instantly. This is often one of the first and easiest components to check.
3. Malfunctioning Air Switching or Check Valves
These valves direct the airflow from the pump into the exhaust ports. They can become stuck closed, stuck open, or leak due to:
- Carbon buildup from exhaust gases.
- Failed internal diaphragms (in vacuum-operated valves).
- Corroded or seized mechanical parts.
A stuck-closed valve prevents airflow; a stuck-open valve can allow hot exhaust gases to backflow and destroy the air pump.
4. Issues with Vacuum Solenoids or Hoses
On many Land Rover models, vacuum solenoids controlled by the PCM operate the air switching valves. A cracked, disconnected, or collapsed vacuum hose, or a faulty solenoid, will prevent the valves from opening or closing correctly.
5. Wiring and Connector Problems
Given the under-hood location, the wiring harness for the air pump and valves is exposed to heat, vibration, and moisture. Look for:
- Chafed, broken, or corroded wires.
- Loose or oxidized electrical connectors.
- Poor ground connections for the pump or control circuit.
Step-by-Step Diagnostic Procedure for P1470
A proper diagnosis prevents unnecessary parts replacement. Follow this technical sequence after confirming the code with a professional OBD2 scanner.
Step 1: Preliminary Checks and Live Data
With a scan tool, command the secondary air pump “ON” (often under active tests or component control). Listen for the distinct sound of the pump running. Simultaneously, monitor the commanded state and any related PID (Parameter ID) data for the AIR system. No audible operation points to a power, ground, or pump failure.
Step 2: Electrical Power and Ground Testing
If the pump is silent during the activation test:
- Check the AIR pump fuse and relay. Swap the relay with a known-good identical one (e.g., horn relay) to test.
- Using a multimeter, verify battery voltage (approx. 12V) at the pump’s power supply wire with the relay commanded on.
- Check for a clean ground at the pump’s ground wire. Perform a voltage drop test on both power and ground circuits.
Step 3: Testing the Air Pump and Valves
If power and ground are confirmed, disconnect the pump outlet hose. Command the pump on again and feel for strong airflow. Little or no airflow indicates a failed pump. If the pump runs, check the switching/check valves for proper operation, blockage, or leakage using vacuum and pressure tests as specified in the service manual.
Step 4: Inspecting Vacuum and Air Lines
Perform a thorough visual and physical inspection of all rubber hoses in the system. Look for cracks, brittleness, melting, or disconnections. Use a hand vacuum pump to test vacuum solenoids and actuators for proper hold and release.
Repair Solutions and Technical Considerations
Once the faulty component is identified, repair can proceed. Always clear the code after repair and perform a drive cycle to ensure it does not return.
Component Replacement Guidelines
- Air Pump: When replacing, ensure the new unit is correct for your specific Land Rover model and engine. Consider OEM or high-quality aftermarket brands.
- Valves and Solenoids: It is often prudent to replace the associated gaskets or O-rings during valve replacement to prevent vacuum/exhaust leaks.
- Wiring Repair: Use proper solder and heat-shrink tubing for permanent wire repairs. Never rely solely on twist connectors or electrical tape in the engine bay.
Can You Drive with a P1470 Code?
Technically, yes, the vehicle will be drivable. However, it is not recommended for extended periods. The main consequences are:
- Increased Emissions: The vehicle will emit higher levels of Hydrocarbons (HC) and Carbon Monoxide (CO) during warm-up.
- Catalytic Converter Stress: The unburned hydrocarbons can overwork and potentially clog or overheat the catalytic converter, leading to a very costly replacement.
- Failed Inspection: The vehicle will not pass mandatory emissions testing in most regions.
Address the P1470 code promptly to maintain your Land Rover’s performance, efficiency, and environmental compliance.
Preventative Maintenance Tips
While the secondary air system is largely non-serviceable, you can prolong its life:
- Use your vehicle regularly; prolonged inactivity can cause pump internals to seize.
- Address any other engine running issues (like misfires) immediately, as they can cause excessive carbon buildup in the air valves.
- During routine under-hood inspections, visually check the system’s hoses and electrical connectors for obvious damage.
By understanding the P1470 code’s technical basis and following a logical diagnostic path, you can effectively resolve this common Land Rover emission system fault.