The DELPHI throttle body for the 1.6 HDi range is a direct-fit intake throttle valve designed for Citroën and Peugeot diesel engines. It controls airflow to the engine and works together with the engine management system to regulate idle speed, load response and regeneration cycles. This part is commonly searched by OE numbers 9655971980 and 0345E5, so listing these codes helps technicians and DIY enthusiasts find the correct replacement quickly.

Application And Compatibility

Designed for 1.6 HDi engines used in a range of Citroën and Peugeot models, including (but not limited to): Citroën C4, Citroën C4 Picasso, Citroën C5, Peugeot 207, Peugeot 307 and Peugeot 308. Always verify engine type (1.6 HDi) and part number before installation.

Function And Typical Symptoms

The throttle body modulates intake airflow according to signals from the engine control unit. Common symptoms of a failing or contaminated throttle body include unstable idle, delayed throttle response, reduced engine performance, increased fuel consumption and fault codes related to throttle position or idle control. On diesel HDi engines, carbon deposits on the valve and bore are a frequent cause of poor operation.

Replacement Procedure (Overview)

• Park the vehicle on a level surface and allow the engine to cool.
• Disconnect the negative battery terminal to prevent electrical faults while working on the intake system.
• Remove the air intake ducting and filter housing to gain access to the throttle body.
• Disconnect electrical connector(s) and any vacuum/boost hoses attached to the throttle body. Label hoses if necessary for reassembly.
• Unbolt the throttle body from the intake manifold. Note that the lower mounting bracket on many used units may be deformed and require secure fitting (see note below).
• Clean mating surfaces, fit the new throttle body with a new gasket if applicable, and tighten bolts to manufacturer torque specifications.
• Reconnect hoses and electrical connectors, reassemble intake components, reconnect the battery and perform an idle relearn/engine adaptation procedure if required by the vehicle.

Maintenance And Lifespan

Throttle bodies on 1.6 HDi engines typically last many tens of thousands of kilometres but are prone to carbon build-up, especially on vehicles with long motorway use or irregular regeneration cycles. Regular inspection during service intervals and gentle cleaning (when applicable) can extend functional life. Electronic failures of the actuator or position sensor shorten service life and require replacement.

Technical Information

• Manufacturer: Delphi
• Model: 1.6 HDi
• Product Codes: 9655971980, 0345E5
• Additional Numbers: 34500000

Installation Recommendations

• Always disconnect the negative battery terminal before starting work to avoid electrical damage.
• Use new gaskets and ensure all mating surfaces are clean and free of oil/carbon.
• Inspect intake hoses and clamps; replace any brittle or leaking components to prevent future contamination.
• After fitting, perform an idle adaptation or throttle relearn if the vehicle manufacturer recommends it.
• If the supplied unit has a damaged lower mounting bracket (common on used parts), secure it properly during fitment — temporary tape is only a short-term measure; repair or replace the bracket where possible to ensure correct alignment and sealing.

Most Common Causes Of Failure

• Carbon and soot accumulation causing the throttle plate to stick or the bore to restrict airflow.
• Electrical faults in the actuator or position sensor (wear, moisture ingress or connector corrosion).
• Mechanical damage to the mounting bracket or flange (impact or improper removal), which can cause air leaks or misalignment.
• Contaminated intake air due to faulty filters or leaking hoses, accelerating deposit formation.

This description is tailored for professional mechanics and experienced DIY technicians looking for a reliable replacement throttle body for 1.6 HDi Citroën and Peugeot vehicles. Including the OE numbers 9655971980 and 0345E5 will help ensure accurate search results and correct part selection.

Product Overview

This intake throttle valve (throttle body) is a direct-fit Delphi unit for 1.6 HDi engines, commonly fitted to Citroën and Peugeot models. It regulates airflow in the intake tract to stabilise idle, assist EGR function and support smooth deceleration. The part is often searched for by its product codes 9657485480 and 0345E5, so listing these numbers in the order will help you find the correct replacement quickly.

Compatibility

• Citroën C4
• Citroën C4 Picasso
• Citroën C5
• Peugeot 207
• Peugeot 307
• Peugeot 308

Technical Information

• Manufacturer: Delphi
• Model: 1.6 HDi
• Product Codes: 9657485480, 0345E5
• Other Numbers: 34500000

Function And Symptoms

The throttle valve controls airflow through the intake manifold. In 1.6 HDi diesel engines it helps maintain stable idle, supports exhaust gas recirculation (EGR) control and contributes to engine braking behavior. When the valve or its actuator/potentiometer fails, common symptoms include rough idle, stalling, irregular throttle response, illuminated engine warning light and stored fault codes related to throttle/airflow.

Why This Part Fails Most Often

• Carbon and soot buildup in the throttle plate and housing, common on diesel engines, which restricts movement.
• Wear or failure of the electronic actuator or its position sensor (potentiometer), causing incorrect feedback to the ECU.
• Mechanical damage to the mounting bracket (the lower mounting bracket on many used units is often bent or damaged).
• Corrosion or water ingress affecting contacts and connectors.

Replacement Procedure (Overview)

• Prepare: Work on a cool engine in a well-ventilated area. Gather basic hand tools, torque wrench and, if available, a small throttle cleaner for inspection.
• Safety: Always disconnect the vehicle battery before starting to avoid short circuits and protect electronic components.
• Removal: Remove the intake hose and airbox as needed, unplug the electrical connector, remove mounting screws securing the throttle valve and extract the unit from the intake manifold.
• Installation: Fit the new unit, tighten mounting screws to manufacturer torque where specified, reconnect the electrical connector and intake hoses.
• Aftercare: Some vehicles require a throttle relearn or idle adaptation via diagnostic tool to restore correct idle and response. If you see fault codes after replacement, a diagnostic reset and adaptation may be necessary.

Installation Recommendations

• Disconnect the battery before any removal or installation and follow the vehicle manufacturer’s instructions to avoid damage.
• Check the lower mounting bracket on this part before fitting; if it is bent, secure it appropriately or replace the bracket to ensure correct alignment. Many used units show a bent lower bracket and may need temporary securing with tape during fitment.
• Do not force the throttle plate; ensure clean mating surfaces and correct gaskets/seals to prevent air leaks.
• After installation, clear stored faults and perform an idle adaptation if required by the vehicle.

Notes For Mechanics And DIYers

Part numbers 9657485480 and 0345E5 are commonly used to identify this Delphi throttle valve—include these codes when searching or ordering. Inspect related components such as intake hoses, vacuum lines and the EGR system when replacing the throttle valve, as soot or faults elsewhere can accelerate recontamination or cause recurring symptoms.