Engine Controls - Remove/install/overhaul - 6.5l Diesel. GMC Suburban 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.

ON-VEHICLE ADJUSTMENTS

Note. For adjustments, see ADJUSTMENTS - 6.5L DIESEL article in the ENGINE PERFORMANCE section.

POWERTRAIN CONTROL MODULE (PCM)

Note. All vehicles are equipped with either an Engine Control Module (ECM), Powertrain Control Module (PCM) or Vehicle Control Module (VCM) for engine control. Unless specifically stated, references to PCM also apply to ECM and VCM equipped vehicles. Some vehicles equipped with an electronically-controlled transmission also use a Transmission Control Module (TCM) for transmission control.

CONTROL MODULE

STATIC CHARGE

Servicing PCM While Using 3M Anti-Static Mat. Scheme 1

Note. Before replacing PCM, carefully inspect all wiring and control components. Ensure ignition switch is in OFF position when connecting or disconnecting PCM connector.

Removal

Disconnect negative battery cable. Unplug electrical connectors from PCM. (Scheme 1) Remove PCM from vehicle. Remove PROM and CALPAK (if equipped) or MEM-CAL from PCM. See CALPAK, MEM-CAL, or PROGRAMMABLE READ-ONLY MEMORY (PROM).

Note. If PCM is to be replaced, remove MEM-CAL or PROM for fitting is new PCM.

Installation

Install PROM or MEM-CAL in NEW PCM. See MEM-CAL, or PROGRAMMABLE READ-ONLY MEMORY (PROM). Install PCM into vehicle. Connect electrical connectors to PCM. Install access panels. Reconnect negative battery cable. See TDC OFFSET for resetting PCM.

Disconnect negative battery cable. Remove PCM from vehicle. See REMOVAL under CONTROL MODULE . Using 2 fingers, push retaining clips back from MEM-CAL. At the same time, grasp it at both ends and lift out of socket. DO NOT remove MEM-CAL cover.

1. Carefully align MEM-CAL pins with PCM pin holes. DO NOT press in middle of MEM-CAL. Push downward evenly on ends of MEM-CAL until retaining clips on ends of MEM-CAL snap into place.
2. Install PCM. Reconnect negative battery cable. Turn ignition on and ground DLC terminal "B". DTC 12 should be flashed at least 4 times. If DTC 12 is not flashed at least 4 times, other codes are present. If DTC 51 is present, or if MIL stays on constantly with code(s) present, MEM-CAL is not fully seated, or is defective.

1. Remove PCM from vehicle. See REMOVAL under «CONTROL MODULE»(/gmc/suburban/i-1992-1999/remont/removal-installation/#engine-controls-removeinstalloverhaul-65l-diesel__control-module) . Position PCM so bottom cover is facing upward. Remove slide-off PROM access cover by depressing locking tab.
2. Using PROM removal tool, grasp PROM at narrow ends. Gently rock PROM from end to end while pulling up. If installing new PROM, remove old PROM from PROM carrier.

Note. Note reference notch locations in PROM, carrier and PCM for reassembly reference.

1. Ensure new PROM has same service number as old one or correct factory upgrade. Place NEW PROM in PROM carrier, and position squarely over PCM PROM socket. Press on PROM carrier until PROM is firmly seated in PCM. NOTE: Ensure reference notches in PCM and PROM are properly aligned. If PROM is installed backwards and ignition is turned on, PROM will be destroyed.
2. Install PROM access cover on PCM. Install PCM in vehicle. See INSTALLATION under «CONTROL MODULE»(/gmc/suburban/i-1992-1999/remont/removal-installation/#engine-controls-removeinstalloverhaul-65l-diesel__control-module) . Turn ignition on and ground DLC terminal "B". DTC 12 should flash three times if PROM is installed correctly and no other DTCs are present.
3. Check for DTC 51. If DTC 51 is present, PROM is not fully seated in PCM, installed backwards, has bent pins, or is defective. If bent pins are cracked while straightening, replace PROM. If PROM is installed backwards or is defective, replace PROM.

Scheme 2

TDC OFFSET PROGRAMMING

This procedure allows the PCM memory to be updated with the correct top dead center offset for the vehicle. DTC 88 will be stored until this procedure has been completed.

Ensure that battery is charged. Run engine at idle until it is at operating temperature. Connect TECH-1 scan tool. Select OUTPUT TESTS and INJ. PUMP. Start TDC LEARN. Run LEARN for 20 seconds. Verify TDC OFFSET in data list.

Note. If procedure is not performed correctly, DTC 88 will set.

If TDC OFFSET is not programmed perform the following

1. Check all PCM connections.
2. Check Techline for latest software version.
3. Try to program PCM again.

If PCM does not accept programming, replace PCM.

1. Disconnect negative battery cable. Remove air cleaner, noise cover and air inlet (as equipped). Remove fuel filler cap. Open air bleed valve on top of fuel manager/filter to release any pressure in fuel supply system. Remove fuel manager/filter. Remove generator rear bracket.
2. Remove EGR/boost solenoids with bracket from intake manifold studs (if equipped). Disconnect crankcase depression regulator hose at manifold. Disconnect EGR and PCV hoses (if equipped). Remove fuel line bracket and ground strap. Remove intake manifold bolts and fuel line clips. Remove intake manifold and gasket. Install Protective Covers (J-29664-1) in intake ports.
3. Remove injection line clips. Disconnect and cap injection lines at injector nozzles. Do not bend injection lines. Disconnect and cap injection lines at pump. Tag injection lines for reassembly reference. Cap all openings.

Remove caps and install injection lines. Ensure lines are properly positioned. (Scheme 3) Reverse removal procedure to complete installation. Start engine and check for leaks.

Scheme 3

Fuel manager/filter is mounted on rear of intake manifold. Remove fuel filler cap. Open air bleed valve on top of fuel manager/filter to release any pressure in fuel supply system. Turn filter element nut counterclockwise and remove. Remove filter element by lifting straight out of filter housing. (Scheme 4) It is not necessary to drain fuel from filter housing when changing filter element.

1. Ensure mating surface between filter element and filter housing is clean. Install NEW filter element by aligning widest key slot located under element assembly cap with widest key in filter housing assembly.
2. Tighten filter element nut by hand. Bleed air from fuel manager/filter. To bleed air, open air bleed valve on top of fuel manager/filter. Connect a hose to air bleed valve and place other end of hose in a container.
3. Remove F/SOL ("C" & "K" Series) or FPMP ("G" Series) fuse from fuse panel, or disconnect engine shutoff solenoid ("P" Series). Crank engine for 10-15 seconds. Allow starter to cool down for one minute between cranking intervals. Repeat procedure until clear fuel is observed at the air bleed hose.
4. Close air bleed valve. Install fuse or connect solenoid, and reinstall fuel filler cap. Start engine and allow to idle for 5 minutes. Check fuel manager/filter for leaks.

Removal & Installation (Electric)

1. Disconnect negative battery cable. Disconnect electrical wiring from fuel pump and fuel pump support bracket.
2. Disconnect fuel lines from fuel pump. Remove support bracket screws and remove support bracket from fuel lines. Remove fuel pump and bracket from frame rail. To install, reverse removal procedure. Check for fuel leak at fuel line fittings.

Removal & Installation (Mechanical)

Disconnect fuel lines from fuel pump. Remove mounting screws and remove fuel pump from block. To install, reverse removal procedure. Check for fuel leak at fuel line fittings.

Scheme 4

1. Disconnect negative battery cable. Remove intake manifold. Install Protective Covers (J-29664-1) in intake ports. Remove fuel injection lines. Disconnect electrical wiring, fuel return line, fuel inlet line, and fuel injection lines at pump. Cap all openings.
2. Remove oil filler tube and grommet for oil filler tube. Scribe or paint alignment mark on front cover and injection pump flange. Manually rotate engine to access injection pump-to-drive gear retaining bolts through oil filler neck hole. Remove injection pump-to-drive gear retaining bolts. Remove injection pump mounting nuts. Remove injection pump and gasket. (Scheme 5)

1. Install NEW injection pump gasket. Align locating pin on injection pump hub with slot in injection pump driven gear. At the same time, align injection pump timing marks. Ensure cylinder No. 1 is set at TDC.
2. Attach injection pump to front cover. Ensure alignment marks made during removal are aligned. Tighten nuts. Attach pump to drive gear and tighten bolts. Reverse removal procedure to complete installation. Check injection pump timing. See INJECTION PUMP TIMING in «ADJUSTMENTS - 6.5L DIESEL»(/gmc/suburban/i-1992-1999/remont/adjustments/#engine-controls-adjustments-65l-diesel) article in the ENGINE PERFORMANCE section.

Scheme 5

Disconnect negative battery cable. Disconnect fuel line clip. Remove fuel return line. Remove fuel injection line. Cap all openings. Using Injector Socket (J-29873), remove injector nozzle(s). Place socket on 1 3/16" (30 mm) hex flats of injector body to prevent damaging injector nozzle.

Remove caps from injector nozzles and fuel lines. Install injector nozzle(s). Install fuel line. Install fuel return line and fuel line clip. Connect battery cable. Start engine and check for leaks.

PURGING WATER FROM FUEL SYSTEM

1. Disconnect negative battery cable. Remove fuel filler cap. Place a hand operated pump into fuel filler neck and drain fuel from fuel tank. Reinstall fuel filler cap. Remove fuel tank and fuel sender. Replace fuel tank if internally rusted. Replace fuel strainer (as necessary).
2. Remove fuel feed hose at fuel pump. Remove fuel return line at injection pump. Using low air pressure, blow out fuel lines toward rear of vehicle. Replace fuel lines if internally rusted. Remove F/SOL ("C" & "K" Series) or FPMP ("G" Series) fuse from fuse panel, or disconnect engine shutoff solenoid ("P" Series). Remove fuel manager/filter element.
3. Install fuel sender and fuel tank. Install fuel feed hose to fuel pump. Fill fuel tank with diesel fuel until tank is 1/4 full. Install fuel filler cap. Connect negative battery cable. Crank engine for 15 seconds. Allow starter to cool down for one minute between cranking intervals. Use a suitable container to collect fuel. Repeat procedure until clear fuel is pumped out.
4. Install NEW fuel filter element. Connect a hose from fuel injection pump return line to a closed metal container with a 2 gallon capacity. Crank engine for 15 seconds. Allow starter to cool down for one minute between cranking intervals. Repeat procedure until clear fuel is observed at fuel return line.
5. Install fuse or connect solenoid. Crack open each injection line at each nozzle. Crank engine for 15 seconds. Allow starter to cool down for one minute between cranking intervals. Repeat procedure until clear fuel is observed at each nozzle Install injection line to nozzle fitting and tighten to 18 ft. lbs. (25 N.m).
6. Start engine and idle for 15 minutes. Ensure fuel return line is in metal container and that container does not overflow. Remove hose from metal container. Install fuel return line to injection pump. Check for leaks.

WATER-IN-FUEL WARNING LIGHT

1. Fuel manager/filter should be drained every 5000 miles, or when WATER-IN-FUEL warning light comes on. Diesel fuel can damage asphalt and painted surfaces. Always place a drain pan under filter drain hose to collect fuel.
2. Stop vehicle and turn engine off. Apply parking brake. Open drain valve. Start and allow engine to idle for 2 minutes or until clear fuel is observed. Turn engine off and close drain valve.
3. If WATER-IN-FUEL warning light comes on after fuel manager/filter is purged of water, remove water sensor and wipe tip of sensor clean. Reinstall water sensor. If WATER-IN-FUEL warning light remains on, replace water sensor.

1. Disconnect negative battery cable. On TBI models, remove air cleaner assembly. Remove upper intake manifold assembly.
2. On all models, disconnect electrical connectors to distributor. Remove distributor cap and move aside. Remove distributor hold-down bolt and hold-down clamp. Note position of rotor. Pull up slightly on distributor until rotor stops turning counterclockwise and again note position of rotor. Remove distributor from engine.

Disassembly & Reassembly

1. Disassembly procedure is not available from manufacturer. For disassembly, use exploded views of distributors. (Scheme 6)
2. When reassembling, ensure pick-up assembly arm is correctly installed on pin. If not, arm can float and cause ignition timing to vary. To prevent corrosion, lubricate terminals with petroleum jelly before installation.
3. To prevent heat damage, coat bottom of module and module rest pad in distributor housing with silicone grease. Before installing roll pin in driven gear, ensure timing mark on roll pin and rotor tip align. (Scheme 6)

Scheme 6

1. To install, reverse removal procedure. To ensure correct timing of distributor, install with rotor correctly positioned as it was before distributor was removed.
2. If engine was cranked after distributor was removed, remove No. 1 spark plug. Place finger over No. 1 cylinder spark plug hole. Crank engine slowly until compression is felt. Align timing mark on pulley to "0" on engine timing indicator. Turn rotor to point to cylinder No. 1 spark plug tower on distributor cap. Complete distributor installation. Start engine and check ignition timing.

REMOVAL & INSTALLATION

1. Remove air cleaner assembly. Disconnect electrical connector from TP sensor. Remove attaching screws, lock washers, retainers, and TP sensor.
2. To install, reverse removal procedure. Adjust TP sensor to specification. See «ADJUSTMENTS - 6.5L DIESEL»(/gmc/suburban/i-1992-1999/remont/adjustments/#engine-controls-adjustments-65l-diesel) article in the ENGINE PERFORMANCE section. When replacing a TP sensor, ensure correct part number is used. Use Loctite on TP sensor attaching screws.

OXYGEN SENSOR

1. Oxygen sensor is mounted in the exhaust pipe, below exhaust manifold. 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 oxygen sensor is removed, coat threads with anti-seize compound before reinstalling. New oxygen sensors already have this compound applied to threads.
2. Install oxygen sensor in exhaust pipe and tighten sensor to 30 ft. lbs. (41 N.m). Reconnect electrical connector to oxygen sensor. Reconnect negative battery cable.

TURBOCHARGER

Note. Turbocharger overhaul information is not available from manufacturer.

1. Disconnect negative battery cable. Remove engine cover. Raise and support vehicle. Remove right front wheel and inner splash shield for easier access to turbocharger and exhaust manifold. Remove air intake duct between air cleaner and turbocharger. Remove Crankcase Depression Regulator (CDR) valve vent tube bracket on top of turbocharger.
2. Remove CDR valve and vent tube from air intake duct. Remove oil feed line at top of turbocharger, outlet to intake duct rubber connector and loosen exhaust pipe-to-turbocharger exhaust outlet elbow clamp.
3. Remove vacuum hose to wastegate actuator. Remove oil drain tube from turbocharger. Remove turbocharger-to-exhaust manifold nuts. Remove turbocharger.

1. To install, reverse removal procedure. Ensure no foreign objects are present in intake and exhaust passages to turbocharger. Use a high temperature Anti-Seize Compound (GM 1052771) on all threaded fasteners. Fill oil feed hole at top of turbocharger with clean engine oil and manually rotate compressor wheel. This will pre-lube turbocharger shaft bearings.
2. Complete installation of components. Tighten retaining bolts and nuts. See «TORQUE SPECIFICATIONS»(/gmc/suburban/i-1992-1999/remont/removal-installation/#engine-controls-removeinstalloverhaul-65l-diesel__torque-specifications) . Start engine and operate at low idle for 2 minutes. Check for oil leak at turbocharger fittings.

1. Remove turbocharger heat shield. Remove retaining pin or clip to wastegate actuator rod. Remove vacuum hose to wastegate actuator. Remove bolts securing wastegate actuator to turbocharger.
2. Remove wastegate actuator from turbocharger. To install, reverse removal procedure.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• ADJUSTMENTS - 6.5L DIESEL
• TDC OFFSET
• CONTROL MODULE
• TORQUE SPECIFICATIONS