Engine Controls - Removal & Installation Acura MDX I

INTRODUCTION

Removal, overhaul and installation procedures are covered in this article. If component removal and installation is primarily an unbolt and bolt-on procedure, only a torque specification may be furnished.

Note. Before disconnecting battery, obtain activation code and station presets to reset anti-theft stereo.

POWERTRAIN CONTROL MODULE

Note. On vehicles equipped with Immobilizer (anti-theft) system, PCM must be reprogrammed using a Honda PGM Tester. See appropriate ANTI-THEFT & KEYLESS ENTRY SYSTEMS article in ACCESSORIES & EQUIPMENT.

Removal & Installation (MDX)

Note. PCM is located in the right side of engine compartment towards the front of vehicle.

1. With ignition on, connect the Honda PGM Tester or the HDS to the data link connector (DLC), and go into any of the live data screens.
2. Turn ignition off.
3. Turn the Honda PGM Tester off or close the HDS and then back on. Go to the SCS mode and follow the screens to ground the 16-pin DLC.
4. Remove cover from PCM.
5. Disconnect PCM harness connectors "A" and "B". Remove bolts and PCM.
6. Install PCM in reverse order of removal.

Removal & Installation (RSX)

PCM is located behind glove box. Disconnect negative battery cable. Remove right lower dashboard cover. Disconnect PCM harness connectors. Remove mounting nuts and PCM. To install, reverse removal procedure.

Removal & Installation (3.2CL & 3.2TL)

PCM is located at front of center console. Disconnect negative battery cable. Pull back carpet from both sides of center console. Disconnect PCM harness connectors and remove both mounting bolts on either side of PCM. Remove PCM. To install, reverse removal procedure.

Removal & Installation (3.5RL)

PCM is located under front passenger side foot rest. Disconnect negative battery cable. Pull carpet back to expose PCM cover. Remove 4 mounting nuts holding cover and PCM. Remove PCM cover. Disconnect PCM harness connectors and remove PCM. To install, reverse removal procedure.

Air/Fuel (A/F) sensor or Heated Oxygen Sensor (HO2S) are equipped with a permanent pigtail which must be protected from damage when sensor is removed. Ensure sensor is free of contaminants. Avoid using cleaning solvents of any type. Sensor may be difficult to remove when engine temperature is less than 120°F (48°C). Always use anti-seize compound on threads before installation. Tighten sensor to specification. See TORQUE SPECIFICATIONS .

Removal & Installation (Except RSX)

Remove intake manifold. Disconnect ECT sensor 2-pin connector. Remove ECT sensor. Install sensor in reverse order of removal using a new "O" ring. Tighten sensor to specification. See TORQUE SPECIFICATIONS .

Drain coolant. Remove air cleaner assembly. Disconnect ECT sensor 2-pin connector. Remove ECT sensor. Install sensor in reverse order of removal using a new "O" ring. Tighten sensor to specification. See TORQUE SPECIFICATIONS .

Remove intake manifold. Remove injector rails and the base. Disconnect Knock sensor 1-pin connector. Remove Knock sensor. Install sensor in reverse order of removal. Tighten sensor to specification. See TORQUE SPECIFICATIONS .

Removal & Installation (RSX - K20A2 Engine)

Remove intake manifold bracket. Disconnect Knock sensor 1-pin connector. Remove Knock sensor. Install sensor in reverse order of removal. Tighten sensor to specification. See TORQUE SPECIFICATIONS .

Removal & Installation (RSX - K20A3 Engine)

Remove intake manifold. Disconnect Knock sensor 1-pin connector. Remove Knock sensor. Install sensor in reverse order of removal. Tighten sensor to specification. See TORQUE SPECIFICATIONS .

BLEEDING COOLING SYSTEM

Always bleed air from cooling system after replacing coolant. Set heater for maximum heat. Remove radiator cap. Drain coolant reservoir. Fill coolant reservoir to MAX mark with 50/50 water-coolant mixture. Loosen bleed bolt and fill radiator to base of filler neck. Close bleed bolt when coolant flows out without bubbles. Tighten bleed bolt. With radiator cap removed, start and operate engine to normal operating temperature. Add coolant if necessary and check for leaks.

Removal & Installation (Camshaft Position Sensor - RSX)

1. Remove air cleaner assembly.
2. Disconnect Camshaft Position (CMP) sensor 3-pin harness connector.
3. Remove CMP sensor bolt.
4. To install, reverse removal procedure with NEW "O" ring.

Removal & Installation (Crankshaft Position Sensor - MDX, 3.2CL & 3.2TL)

Move auto tensioner to release tension from generator belt. Remove generator belt. Loosen power steering belt adjusting bolt, lock nut, and mounting bolt. Remove power steering pump belt. Remove oil dipstick and tube (except on MDX). Remove crankshaft pulley. Remove upper and lower timing belt covers. On 3.2CL (M/T), remove timing belt guard. Remove Crankshaft Position (CKP) sensor from oil pump. To install, reverse removal procedure.

Removal & Installation (Crankshaft Position Sensor - RSX)

Crankshaft Position (CKP) sensor is located on right side of engine block behind crankshaft pulley. Remove wheel well splash shield. Disconnect harness connector. Remove bolt securing CKP sensor to block. Remove CKP sensor. To install, reverse removal procedure.

Removal & Installation (Crankshaft/Cylinder Position Sensor - 3.5RL)

Rotate engine until No. 1 piston is at TDC. Remove crankcase breather hose, vacuum hoses and Ignition Control Module (ICM) bracket. Remove upper timing belt covers. (Scheme 1) Loosen left (front) camshaft pulley bolt. Remove timing belt from camshaft pulleys. Remove left camshaft pulley. Remove left back cover. Remove Crankshaft/Cylinder Position (CKP/CYP) sensor. To install, reverse removal procedure. See appropriate article in ENGINES for timing belt installation procedure. Tighten mounting bolts to specification. See TORQUE SPECIFICATIONS. Recheck camshaft timing and ignition timing.

Scheme 1

Removal & Installation (Top Dead Center Sensor - 3.2CL & 3.2TL)

TDC sensors are located on reverse side of camshaft pulley cover. Set No. 1 piston at TDC. Remove upper timing belt covers. Loosen camshaft pulley bolt (ensure No. 1 piston remains at TDC). Hand-tighten a battery "J" bolt against timing belt adjuster to hold adjuster in position. (Scheme 2) Loosen idler pulley adjustment bolt 5-6 turns. Remove timing belt from front camshaft pulley. Remove front camshaft pulley. Disconnect Top Dead Center (TDC) sensor harness connector. Remove camshaft pulley back cover. Remove TDC sensor from rear side of camshaft pulley back cover. To install, reverse removal procedure. See appropriate article in ENGINES for timing belt installation procedure. Tighten mounting bolts to specification. See TORQUE SPECIFICATIONS. Recheck camshaft timing and ignition timing.

Scheme 2

Removal & Installation (CMP Sensor - MDX)

CMP sensor is located on reverse side of front (left) camshaft pulley cover. Set No. 1 piston at TDC. Remove upper timing belt covers. Loosen camshaft pulley bolt (ensure No. 1 piston remains at TDC). Hand-tighten a battery "J" bolt against timing belt adjuster to hold adjuster in position. (Scheme 2) Loosen idler pulley adjustment bolt 5-6 turns. Remove timing belt from front camshaft pulley. Remove front camshaft pulley. Disconnect Camshaft Position (CMP) sensor harness connector. Remove camshaft pulley back cover. Remove CMP sensor from rear side of camshaft pulley back cover. To install, reverse removal procedure. See appropriate article in ENGINES for timing belt installation procedure. Tighten mounting bolts to specification. See TORQUE SPECIFICATIONS. Recheck camshaft timing and ignition timing.

Removal & Installation (Top Dead Center Sensor - RSX)

Remove air cleaner assembly. Top Dead Center (TDC) sensor is located below valve cover on back end of cylinder head. Disconnect harness connector from TDC sensor. Remove bolt securing TDC sensor. Remove TDC sensor. To install, reverse removal procedure.

FUEL SYSTEM

MDX

See FUEL SYSTEM PRESSURE RELEASE - MDX under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES article.

RSX, 3.2CL & 3.2TL

Disconnect negative battery cable. Loosen fuel tank filler cap. Place wrench on fuel pulsation damper at fuel rail. Place clean shop rag over fuel pulsation damper. Slowly loosen fuel pulsation damper one complete turn to relieve system pressure. Always replace washers after loosening or replacing pulsation damper.

3.5RL

Disconnect negative battery cable. Loosen fuel tank filler cap. Place clean shop rag around fuel filter. Slowly loosen service bolt (located in end of fuel filter banjo bolt on top of fuel filter), one complete turn to relieve system pressure. Always replace washers after loosening service or banjo bolt.

Removal & Installation (MDX, RSX, 3.2CL & 3.2TL)

Release fuel system pressure. See FUEL SYSTEM PRESSURE RELEASE. See FUEL FILTER LOCATIONS table. See FUEL PUMP. Remove tank unit. Remove bracket from tank unit. Remove fuel pump from fuel filter. For fuel filter identification (Scheme 5)- (Scheme 6). Remove fuel filter from tank unit. To install, reverse removal procedure. Install NEW base gasket under tank unit. On MDX and RSX, align single alignment mark on tank unit between double alignment marks on fuel tank.

FUEL FILTER LOCATIONS

Release fuel system pressure. See FUEL SYSTEM PRESSURE RELEASE. See FUEL FILTER LOCATIONS table. Support fuel filter with wrench, and remove 12-mm banjo bolt. (Scheme 8) Remove fuel feed pipe from fuel filter. Remove fuel filter bracket. Remove fuel filter stay and fuel filter. To install, reverse removal procedure. Install NEW banjo fitting washers. Clean flared joint of high pressure hoses thoroughly before reconnecting.

Remove fuel fill cap. Release fuel pressure. See FUEL SYSTEM PRESSURE RELEASE. On 3.2CL and 3.2TL, remove spare tire and compartment lid. On MDX, remove driver's side second row seat. Cut carpet along dotted line. (Scheme 3) On RSX, remove rear seat cushion. On all models, remove access panel from floor. Disconnect fuel tank unit 5-pin harness connector. Disconnect quick-connect fittings from fuel tank unit. Remove fuel tank unit. (Scheme 5)- (Scheme 6). Remove bracket from tank unit. Remove fuel pump from fuel filter. To install, reverse removal procedure. Install NEW base gasket under tank unit. On MDX and RSX, align single alignment mark on tank unit between double alignment marks on fuel tank.

Release fuel system pressure. See FUEL SYSTEM PRESSURE RELEASE. Remove rear seat cushion. Remove access floor panel. (Scheme 7) Disconnect fuel tank unit harness connector and fuel lines. Remove fuel tank unit mounting nuts. Remove fuel pump unit. To install, reverse removal procedure. Install NEW base gasket under tank unit.

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Scheme 7

Scheme 8

FUEL LINES

Quick-Connect Fittings

1. Relieve fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(/acura/mdx/i-2000-2006/remont/removal-installation/#engine-controls-removal-installation). Check quick-connect fittings for dirt, and clean if necessary. Grasp connector with one hand. With other hand, squeeze retainer tabs inward. (Scheme 9) Pull fuel lines apart and cover disconnected connector and pipe end. If quick-connect fuel line surface is rusty or damaged, replace fuel pump, fuel filter, fuel feed pipe or fuel return pipe.
2. Install NEW retainer if: Replacing fuel pump. Replacing fuel filter. Replacing fuel feed line. Replacing fuel return line. Retainer has been removed from fuel line. Retainer is damaged.
3. A clicking sound is heard when reconnecting fittings. Ensure fittings are connected visually, and by pulling connector. Pressurize fuel system by turning on ignition with engine off for 2 seconds. Repeat fuel pressurizing procedure 3 times. Check for fuel leaks.

Note. If fittings are difficult to reconnect, place a small amount of clean engine oil on pipe end. (Scheme 10)

Scheme 9

Scheme 10

Removal (MDX, 3.2CL & 3.2TL)

Release fuel pressure. See FUEL SYSTEM PRESSURE RELEASE . Remove intake manifold cover and upper intake manifold. Place a shop towel over fuel hoses. Disconnect fuel injector harness connectors. Remove fuel rail bolts. Remove fuel rails. Remove fuel injectors from fuel rails.

Slide NEW cushion rings onto fuel injectors. Coat NEW "O" rings with clean engine oil and install on injectors. Install fuel injectors into fuel rails. Coat NEW sealing rings with clean engine oil and press into intake manifold. Install fuel rails and injectors into lower intake manifold. Install and tighten fuel rail bolts. Reconnect fuel injector harness connectors. Install upper intake manifold and intake manifold cover. Pressurize fuel system by turning ignition on for about 2 seconds, then turning key back off. Repeat this procedure 2-3 times. Check for fuel leakage before starting vehicle.

Removal (RSX)

Relieve fuel pressure. See FUEL SYSTEM PRESSURE RELEASE . Disconnect injector harness connectors. Remove wire harness and holder from fuel rail. Place a shop towel over fuel hoses. Disconnect fuel line quick-connect fitting from fuel rail. Remove fuel rail retaining nuts and fuel rail. Remove fuel rail and injectors from intake manifold. Remove injector clips and remove injectors from fuel rail.

Install NEW "O" rings coated with clean engine oil onto injectors. Insert injectors into fuel rail. Install injector clips. Insert injectors and fuel rail assembly into intake manifold. Install fuel rail nuts and tighten. Install quick-connect fuel line fitting to fuel rail. Install wire harness and support. Connect harness connectors to fuel injectors. Pressurize fuel system by turning ignition on, with engine off, for 2 seconds. Repeat fuel pressurizing procedure 2-3 times. Check for fuel leakage before starting vehicle.

Removal (3.5RL)

Remove strut bar. Remove engine cover. Relieve fuel pressure. See FUEL SYSTEM PRESSURE RELEASE . Disconnect injector harness connectors. Disconnect PCV valve. Place a shop towel over fuel hoses. Disconnect vacuum and fuel return hoses from pressure regulator. Disconnect fuel line from fuel rail. Remove vacuum pipe. Remove nuts securing fuel rail and harness support. Disconnect MAP sensor 3-pin connector. Remove fuel rail. Remove injectors from intake manifold.

Slide NEW cushion rings onto injectors. Install NEW "O" rings coated with clean engine oil onto injectors. Insert injectors into fuel rail. Coat NEW injector seal rings with clean engine oil and press into intake manifold. Install injectors and fuel rail assembly into intake manifold. To complete installation, reverse removal procedure. Install NEW fuel line-to-fuel rail washers. Pressurize fuel system by turning on ignition with engine off for 2 seconds. Repeat fuel pressurizing procedure 2-3 times. Check for fuel leakage before starting vehicle.

Removal (RSX, 3.2CL & 3.2TL)

1. Disconnect IAC valve, MAP and TP sensor harness connectors. Label and disconnect coolant and vacuum hoses. Disconnect throttle and cruise control cables.
2. Disconnect air intake hose from throttle body. Remove nuts and bolts holding throttle body. Remove throttle body.

1. Fully open throttle valve. Install throttle cable to throttle link. Install cable housing into bracket. Hold throttle housing and remove slack from cable. Turn adjuster nut until there is 0.12" (3mm) deflection in throttle cable. Tighten lock nut.
2. To adjust cruise control and throttle cables, start engine. Hold engine speed at 3000 RPM, with no load and transmission in Park or neutral, until radiator fan comes on. Allow engine to idle. DO NOT adjust throttle stop screw. Hold throttle link to throttle lever. (Scheme 11) No clearance should be present.
3. Check cable actuator free play at actuator cable. Cable free play should be.39-.47" (10-12 mm). (Scheme 11) If free play is not within specification, go to next step. If cable free play is as specified, go to step 5.
4. Loosen lock nut. Turn adjusting nut until deflection is within specification. Retighten lock nut.
5. Ensure that cruise control actuator cable moves smoothly without binding or sticking. Measure amount of movement of output linkage until engine speed starts to increase. Ensure output linkage started at fully closed position. Free play should be 0.13-0.17 (3.25-4.25 mm) when measured at output linkage. (Scheme 13) If free play is not as specified, go to next step. If free play is as specified, go to step 7.
6. Loosen lock nut and tighten adjusting nut until engine speed starts to increase. Tighten lock nut. Loosen adjusting nut until it is 0.13-0.17 (3.25-4.25 mm) away from bracket. Pull cable until adjusting nut touches bracket. Tighten lock nut. (Scheme 13)
7. After cable adjustment, check throttle valve to ensure it fully opens when accelerator pedal is pushed to floor and returns to idle position when accelerator pedal is released.

Removal (MDX)

Note. DO NOT insert fingers into throttle body when ignition switch is turned on or while ignition is on. Serious injury to fingers can result if throttle valve is activated.

1. Disconnect Throttle Actuator Control Module and MAP sensor harness connectors. Disconnect coolant hoses.
2. Remove nuts and bolts holding throttle body. Remove throttle body.

1. To install, reverse removal procedure.
2. Hold engine speed at 3000 RPM, with no load and transmission in Park or neutral, until radiator fan comes on. Then perform idle learn procedure. See «PCM IDLE LEARN PROCEDURE»(/acura/mdx/i-2000-2006/remont/testing-diagnostics/#engine-performance-system-self-diagnostics__pcm-idle-learn-procedure) in SELF-DIAGNOSTICS-MDX article.

1. If vehicle is equipped with Traction Control System (TCS), disconnect TCS control valve angle sensor harness connector and actuator harness connector. Disconnect vacuum hoses, breather pipe and air hose from intake air duct. Loosen intake air duct band screws and remove intake air duct. Remove TCS control valve assembly and bracket.
2. On models without TCS, disconnect throttle cable and cruise control cable (if equipped) at throttle body. Drain coolant until level drops below throttle body. Label and disconnect coolant and vacuum hoses. Disconnect TP sensor harness connector. Remove retaining nuts and bolts securing throttle body. Remove throttle body.

1. To install, reverse removal procedure. DO NOT adjust throttle stop screw. Start engine. Hold engine speed at 3,000 RPM until radiator fan comes on. Allow engine to idle. Hold throttle cable housing and remove slack from throttle cable.
2. Turn throttle cable adjusting nut until it is 0.12" (3 mm) away from cable bracket. Tighten lock nut. Throttle cable deflection should be 0.39-0.47" (10-12 mm) when measured between throttle link and cable bracket. (Scheme 12) If deflection is not as specified, go to next step. If deflection is as specified, go to step 4.
3. Ensure throttle cable or cruise control cable (if equipped) is not binding or sticking. Loosen lock nut, and turn adjusting nut until deflection is as specified. After adjustment is completed, ensure throttle valve fully opens when accelerator pedal is pushed to floor and returns to idle position when accelerator pedal is released.
4. Check cruise control cable free play at output linkage. Cruise control cable is correctly adjusted when output linkage free play is 0.18-0.22" (4.5-5.5 mm) measured at cruise control cable end. (Scheme 13)
5. If free play is not as specified, loosen lock nut. Turn adjusting nut until engine speed starts to increase. Tighten lock nut and adjusting nut. Turn adjusting nut until it is 0.18-0.22" (4.5-5.5 mm) away from bracket. Pull cable so that adjusting nut touches bracket, and tighten lock nut. (Scheme 13)

Scheme 11

Scheme 12

Scheme 13

THROTTLE POSITION SENSOR

Note. Throttle Position (TP) sensor can only be serviced by replacing throttle body.

Scheme 14

Scheme 15

1. Remove fuel tank. Disconnect quick connect fitting and hoses. Remove fuel tank vapor control valve. (Scheme 14)or (Scheme 15).
2. To install, reverse removal procedure using NEW gasket (not required on MDX).

VTC oil control solenoid valve is located at front of cylinder head.

1. Disconnect 2-pin harness connector.
2. Remove VTC oil control solenoid valve retaining bolt and remove valve.
3. To install, reverse removal procedure and use NEW "O" ring. Tighten valve to specification. See «TORQUE SPECIFICATIONS»(/acura/mdx/i-2000-2006/remont/removal-installation/#engine-controls-removal-installation__torque-specifications) .

Removal & Installation (MDX, 3.2CL & 3.2TL)

VTEC solenoid valve is located at oil pump/oil filter adapter assembly.

1. Disconnect VTEC solenoid valve 1-pin harness connector.
2. Remove VTEC solenoid valve/oil filter assembly attaching bolts.
3. Inspect filter behind VTEC solenoid valve and replace if necessary.
4. To install reverse removal procedure. Use new "O" ring. Tighten valve to specification. See «TORQUE SPECIFICATIONS»(/acura/mdx/i-2000-2006/remont/removal-installation/#engine-controls-removal-installation__torque-specifications) . If VTEC solenoid valve filter was replaced, change engine oil and filter.

VTEC solenoid valve is located at rear of cylinder head.

1. Disconnect VTEC solenoid valve 2-pin harness connector.
2. Remove bolts holding cover and VTEC solenoid valve.
3. Inspect filter behind VTEC solenoid valve and replace if necessary.
4. To install reverse removal procedure. Use new gasket. Tighten valve to specification. See «TORQUE SPECIFICATIONS»(/acura/mdx/i-2000-2006/remont/removal-installation/#engine-controls-removal-installation__torque-specifications) . If VTEC solenoid valve filter was replaced, change engine oil and filter.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• PCM IDLE LEARN PROCEDURE
• TORQUE SPECIFICATIONS
• FUEL SYSTEM PRESSURE RELEASE