Engine Controls - Remove/install/overhaul Cadillac Fleetwood II

INTRODUCTION

Removal, overhaul and installation procedures (when given by manufacturer) are covered in this article. If component removal and installation is primarily an unbolt and bolt-on procedure, only a simple torque specification may be supplied.

ENGINE CONTROL MODULE (ECM)/POWERTRAIN CONTROL MODULE (PCM)

STATIC CHARGE (VOLTS)

Scheme 1

Note. Before replacing ECM/PCM, carefully inspect all wiring and control components. Failure to test for short circuits may result in repeated ECM/PCM failure due to grounds and Quad-Driver failure. To prevent internal damage to ECM/PCM, ensure ignition switch is in OFF position when disconnecting or reconnecting ECM/PCM connectors or 12-volt components.

Note. When replacing defective ECM/PCM, remove knock sensor module or PROM from defective ECM/PCM. New ECM/PCM does not come equipped with knock sensor module or PROM (if applicable). Install knock sensor module or PROM into new ECM/PCM.

Removal

Ensure ignition switch is in OFF position. Disconnect negative battery cable. Remove electrical connectors from ECM/PCM. Remove ECM/PCM from vehicle. Remove access cover and remove knock sensor module or PROM (if applicable) from ECM/PCM.

Installation

Install knock sensor module or PROM (if applicable) in new ECM/PCM. Install access cover. Install ECM/PCM into vehicle. Connect electrical connectors to ECM/PCM. Reconnect negative battery cable to battery.

1. Disconnect negative battery cable. Remove ECM/PCM from vehicle. See «ENGINE CONTROL MODULE (ECM)/POWERTRAIN CONTROL MODULE»(/cadillac/fleetwood/ii-1993-1996/remont/removal-installation/#engine-controls-removeinstalloverhaul__engine-control-module-ecmpowertrain-control-module) (PCM). Position ECM/PCM so access cover faces upward. Remove access cover from ECM/PCM.
2. Using thumb and forefinger, squeeze both ends of PROM inward (outward on some models) and pull PROM up from access hole.

Note. Note reference notch locations in PROM and ECM/PCM for reassembly reference.

1. Ensure new PROM has same service number as old one. Position PROM squarely over ECM/PCM PROM access hole. Press on outer edges of PROM until PROM is firmly seated in ECM/PCM. NOTE: Ensure reference notches in both ECM/PCM and PROM are properly aligned. If PROM is installed backwards, PROM will be destroyed when ignition is turned on.
2. Install PROM access cover on ECM/PCM. Install ECM/PCM in vehicle. See «ENGINE CONTROL MODULE (ECM)/POWERTRAIN CONTROL MODULE»(/cadillac/fleetwood/ii-1993-1996/remont/removal-installation/#engine-controls-removeinstalloverhaul__engine-control-module-ecmpowertrain-control-module) . Start engine and enter diagnostics. See the «TESTS W/CODES»(/cadillac/fleetwood/ii-1993-1996/remont/testing-diagnostics/#engine-controls-tests-wcodes) article in the ENGINE PERFORMANCE section. Check for trouble codes. Refer to the «TESTS W/CODES»(/cadillac/fleetwood/ii-1993-1996/remont/testing-diagnostics/#engine-controls-tests-wcodes) article in the ENGINE PERFORMANCE section for code identification.
3. If code(s) sets, PROM is either not fully seated in ECM/PCM or installed backwards, has bent pins or is defective. If bent pins crack when trying to straighten, replace PROM. If PROM is installed backwards or is defective, replace PROM.

Removal & Installation

1. Disconnect negative battery cable. Remove ECM/PCM from vehicle. See «ENGINE CONTROL MODULE (ECM)/POWERTRAIN CONTROL MODULE»(/cadillac/fleetwood/ii-1993-1996/remont/removal-installation/#engine-controls-removeinstalloverhaul__engine-control-module-ecmpowertrain-control-module) (PCM). Position ECM/PCM so access cover faces upward. Remove access cover from ECM/PCM.
2. Using thumb and forefinger, squeeze both ends of knock sensor module inward and pull module up from access hole. To install, reverse removal procedure. Ensure module latches into holder in ECM/PCM.

1. Disconnect negative battery cable. Drain cooling system. Disconnect Intake Air Temperature (IAT) sensor harness connector. Remove knock sensor. Remove air intake duct. Remove serpentine belt. Remove coolant hoses to water pump assembly.
2. Disconnect coolant temperature sensor harness connector. Remove water pump-to-engine block mounting bolts. Remove water pump assembly. Remove crankshaft harmonic balancer. Remove belt tensioner. Remove spark plug wires from distributor.
3. Disconnect 4-terminal ECM/PCM connector to distributor. Remove 3 distributor mounting bolts. Pull distributor forward until distributor shaft disengages from engine. Mark top surface of distributor shaft for reassembly purposes.
4. To install, ensure mark made on distributor shaft during removal is on top or facing up. To complete installation, reverse removal procedure. Refill coolant and check for leaks. Tighten distributor hold-down bolts to 96 INCH lbs. (11 N.m).

SPARK PLUG WIRE HARNESS

Note. The boots should be twisted one-half turn while removing. DO NOT pull on the wire harnesses to remove them from the spark plugs. Pull on the boots, or use a tool designed for this purpose.

1. If removing right side spark plug wire harness assemblies, remove power steering pump assembly.
2. If removing left side spark plug wire harness assembly, remove spark plug wire harness assemblies from wire harness clips by inserting screwdriver into tab on top of clip to disengage.
3. Raise and support vehicle. Remove spark plug wire harness assemblies from distributor assembly. If removing left side spark plug wire harness assemblies, remove support channel by loosening the retaining bolt/screw using 10 mm open ended wrench and sliding channel off bolt/screw. Slide cylinder 7 spark plug wire harness assembly out of support channel.
4. If removing right side spark plug wire harness assemblies, remove spark plug wire harness assemblies from wire harness clips by inserting screwdriver into tab on bottom of clip to disengage. Remove the Bolt/screw. Remove wire harness clip from wire harness support. NOTE: Due to limited access, wire harness support DOES NOT have to be reinstalled.
5. RemoveSpark plug wire harness assemblies from spark plug assemblies. Note positions of wires before removing wire harness clip from spark plug wire harness assemblies, if removing right side spark plug wire harness assembly.

1. If installing right side spark plug wire harness assemblies, attach wiring harness clip(s) to spark plug wire harness assemblies. NOTE: When replacing spark plug wire harness assemblies (secondary wiring), route the wire harnesses correctly and through the proper retainers. Failure to route the wire harnesses properly can lead to radio ignition noise and cross-firing of the spark plugs, or shorting of the leads to ground. NOTE: Route spark plug wire harness assemblies in clip in the same order as shown (Scheme 3), on distributor (1).
2. Connect spark plug wire harness assemblies to spark plug assemblies. Connect harness support to wire harness clip, if accessible. Tighten bolt/screw to 24 Ft. Lbs. (33 N.m).
3. Attach harness assemblies to wire harness clips, if installing right side spark plug wire harness assemblies. Install support channel, if installing left side spark plug wire harness assemblies. Slide cylinder 7 spark plug wire harness assembly into support channel. Slide support channel onto bolt/screw. Tighten small retaining bolt/screw to 14 Ft. Lbs. (19 N.m). Tighten large retaining bolt/screw to 20 Ft. Lbs. (27 N.m).
4. Connect harness assemblies to distributor assembly. (Scheme 3) Lower vehicle. If installing left spark plug wire harness assemblies, connect harness clips to spark plug wire harness assemblies by aligning the two pieces of the clip vertically and snapping them together.
5. If installing right side spark plug wire harness assemblies, install power steering pump assembly. (Scheme 2)

Removing Spark Plug Wire Harness Assembly, Right Side. Scheme 2

Spark Plug Wire Harness Assembly - Routing. Scheme 3

FUEL PRESSURE RELIEF

1. Fuel system is under pressure. Relieve pressure before servicing fuel system. Fuel pressure may be relieved using one of 2 different methods.
2. One method is to disconnect fuel pump connector. Start engine and allow to run until it stops. Operate starter for 3 seconds to remove remaining fuel from fuel lines. Reconnect fuel pump once repair is complete.
3. The other method is to install Fuel Pressure Gauge (J-34730-1) on fuel pressure test port. When installing fuel pressure gauge, wrap shop towel around pressure connection to absorb fuel leakage. Place gauge bleed hose in container. Open bleed valve to bleed fuel pressure.

THROTTLE BODY (MFI)

Note. Ensure residual fuel pressure is relieved before working on throttle body.

1. Relieve fuel pressure. See «FUEL PRESSURE RELIEF»(/cadillac/fleetwood/ii-1993-1996/remont/removal-installation/#engine-controls-removeinstalloverhaul__fuel-pressure-relief) . Disconnect negative battery cable. Remove air intake ducts. Disconnect and mark electrical connections and vacuum hoses from throttle body. Disconnect control cables from throttle body.
2. Drain cooling system and remove coolant hoses to throttle body (if applicable). Remove throttle body retaining bolts. Remove throttle body and gasket.

Note. Identification number is stamped on throttle body. Use identification number to order replacement components.

1. To install, reverse removal procedure using new gasket. Tighten retaining bolts to specification. See «TORQUE SPECIFICATIONS»(/cadillac/fleetwood/ii-1993-1996/remont/removal-installation/#engine-controls-removeinstalloverhaul) . Refill cooling system (if drained).
2. If installing new Idle Air Control (IAC) valve, Make sure the IAC pintle length setting is adjusted before installation. Refer to «IDLE AIR CONTROL (IAC) VALVE»(/cadillac/fleetwood/ii-1993-1996/remont/removal-installation/#engine-controls-removeinstalloverhaul__idle-air-control-iac-valve) . Adjust idle speed and TP sensor (if removed, and if adjustable). See «ADJUSTMENTS»(/cadillac/fleetwood/ii-1993-1996/remont/adjustments/#engine-controls-adjustments) article in the ENGINE PERFORMANCE section.

1. Relieve fuel pressure. See «FUEL PRESSURE RELIEF»(/cadillac/fleetwood/ii-1993-1996/remont/removal-installation/#engine-controls-removeinstalloverhaul__fuel-pressure-relief) . Disconnect the negative battery cable. Remove resonator and resonator bracket. Disconnect the pressure regulator vacuum hose. Remove the fuel return line bracket and retainer clip. Remove the fuel return line and "O" ring from the pressure regulator. Remove fuel rail. Refer to «FUEL RAIL & INJECTORS (MFI)»(/cadillac/fleetwood/ii-1993-1996/remont/removal-installation/#engine-controls-removeinstalloverhaul__fuel-rail-injectors-mfi) .
2. Remove pressure regulator screws. Remove pressure regulator from fuel rail. Remove pressure regulator retainer and spacer assembly from fuel rail. Remove fuel inlet "O" ring from pressure regulator. Remove and discard filter screen if dirty.

To install, reverse removal procedure. DO NOT reuse "O" rings. Lubricate fuel inlet "O" ring with oil and install in regulator. Replace filter screen as necessary. Tighten screws to specification. See TORQUE SPECIFICATIONS .

FUEL RAIL & INJECTORS (MFI)

Note. If injector is replaced, ensure replacement injector has the same part number as injector removed.

1. Relieve fuel pressure. See «FUEL PRESSURE RELIEF»(/cadillac/fleetwood/ii-1993-1996/remont/removal-installation/#engine-controls-removeinstalloverhaul__fuel-pressure-relief). Disconnect negative battery cable. Remove resonator and resonator bracket.
2. Disconnect quick-connect fitting at fuel rail inlet and return lines. Disconnect vacuum hose at pressure regulator. Remove any vacuum lines as necessary to gain access to fuel rail and fuel lines. Remove electrical harness from routing clips on fuel rail.
3. Remove fuel line retaining bolt. Disconnect electrical connectors from injectors. Remove fuel rail retaining bolts. Remove fuel rail from intake manifold using equal force on both sides of fuel rail. (Scheme 4) Remove injector-to-fuel rail retaining clip. Remove injector from fuel rail. Remove injector "O" rings and discard.

To install, reverse removal procedure. Lubricate NEW injector "O" rings with clean engine oil. Install injector-to-fuel rail retaining clip on right side of injector electrical connection. Position fuel rail on intake manifold. Push down on rail to seat injectors in manifold. Tighten fuel rail retaining bolts. Refer to the TORQUE SPECIFICATIONS . To complete installation, reverse removal procedure.

Scheme 4

IDLE AIR CONTROL (IAC) VALVE

Remove electrical connector from IAC valve. Remove IAC valve, gasket and "O" ring from throttle body assembly.

1. Inspect gasket or "O" ring for damage. Replace as necessary. Check the extended distance of IAC pintle before installing. Damage will occur if measurement is incorrect. Distance must not exceed 1 1/8" (28 mm). Measurement should be taken from valve housing flange to end of pintle cone.
2. To retract NEW IAC valve pintle, slowly exert finger pressure on valve. Install NEW "O" ring or gasket on valve. Coat "O" ring with clean engine oil. Install IAC valve. Tighten IAC valve to specification. See «TORQUE SPECIFICATIONS»(/cadillac/fleetwood/ii-1993-1996/remont/removal-installation/#engine-controls-removeinstalloverhaul) . Install electrical connector. To reset IAC valve, refer to «ADJUSTMENTS»(/cadillac/fleetwood/ii-1993-1996/remont/adjustments/#engine-controls-adjustments) article in the ENGINE PERFORMANCE section.

1. Disconnect negative battery cable. Relieve fuel pressure. See «FUEL PRESSURE RELIEF»(/cadillac/fleetwood/ii-1993-1996/remont/removal-installation/#engine-controls-removeinstalloverhaul__fuel-pressure-relief) under FUEL SYSTEM. Remove filler neck. Lower fuel tank. Disconnect fuel lines and electrical connection.
2. Remove fuel level sending unit and fuel pump retaining bolts or cam lock ring. Lift assembly from fuel tank and remove fuel pump from sending unit.
3. Pull fuel pump upward while pulling away from bottom support. Use care not to damage rubber insulator and strainer. To install, reverse removal procedure using NEW "O" ring and gasket.

OXYGEN SENSOR

Oxygen sensor is mounted in exhaust pipe, below exhaust manifold. It is equipped with a permanent pigtail which must remain intact when removing sensor.

1. Ensure sensor is free of contaminants. DO NOT use cleaning solvents of any type. Sensor may be difficult to remove when engine temperature is less than 120°F (48°C). Excessive removal force may damage threads in exhaust manifold or pipe.
2. Disconnect negative battery cable. Disconnect electrical connector from oxygen sensor. Carefully remove oxygen sensor from exhaust pipe.

1. Whenever an oxygen sensor is removed, coat threads with anti-seize compound before it is reinstalled. New oxygen sensors already have this compound applied to threads.
2. Install oxygen sensor in exhaust pipe. Tighten sensor to 30 ft. lbs. (41 N.m). Reconnect electrical connector to oxygen sensor. Reconnect negative battery cable.

Turn ignition switch to OFF position. Disconnect electrical connector from TP sensor. Remove TP sensor retaining screws. Remove TP sensor from throttle body.

1. With throttle valve in closed position, install TP sensor on throttle body. Ensure TP sensor lever engages with drive lever on throttle shaft. Install retaining screws and electrical connection.
2. TP sensor is self-zeroing and is not adjustable. On 4.9L with adjustable TP sensor, adjust TP sensor to specification and tighten retaining screws. See «ADJUSTMENTS»(/cadillac/fleetwood/ii-1993-1996/remont/adjustments/#engine-controls-adjustments) article in the ENGINE PERFORMANCE section.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• COMPUTER RELEARN PROCEDURES
• TESTS W/CODES
• ADJUSTMENTS
• ENGINE CONTROL MODULE (ECM)/POWERTRAIN CONTROL MODULE
• FUEL PRESSURE RELIEF
• TORQUE SPECIFICATIONS
• IDLE AIR CONTROL (IAC) VALVE
• FUEL RAIL & INJECTORS (MFI)