Engine Controls - Removal, Overhaul & Installation: Other Jeep Cherokee III

POWERTRAIN CONTROL MODULE

Note. If replacing Powertrain Control Module (PCM), the correct vehicle mileage and Vehicle Identification Number (VIN) must be programmed into PCM to prevent Diagnostic Trouble Codes (DTC) from being stored in Anti-Lock Brake System (ABS) module and Air Bag Control Module (ACM). If replacing PCM on models equipped with a Sentry Key Immobilizer Module (SKIM), the secret key data must also be updated to enable engine starting.

Programming PCM & Clearing DTCs From ABS & SRS Modules

Connect scan tool to Data Link Connector (DLC), located under left side of instrument panel. (Scheme 32)- (Scheme 34). Using scan tool, enter correct VIN and mileage into PCM. Using scan tool manufacturer's instructions, clear DTCs from ABS module and ACM.

Updating Secret Key Data

1. Connect scan tool to Data Link Connector (DLC), located under left side of instrument panel. (Scheme 32)- (Scheme 34).
2. Ensure transmission is in Park. Turn ignition on. Using scan tool, select THEFT ALARM, SKIM and then MISCELLANEOUS. Select PCM REPLACED. Place the SKIM in SECURED ACCESS MODE by entering the appropriate Personal Identification Number (PIN) for this vehicle. PIN may be obtained from the owner, vehicle's invoice, or from the manufacturer. Press ENTER to transfer secret key data from Sentry Key Immobilizer Module (SKIM) to the PCM. This will enable the vehicle to start.
3. If 3 attempts are made to enter the SECURED ACCESS MODE by using an incorrect PIN, the SECURED ACCESS MODE will be locked out for one hour. To exit lock out mode, leave ignition on with all accessories turned off. After one hour, enter correct PIN. It may be necessary to monitor battery voltage and connect a battery charger.

Scheme 32

Scheme 33

Scheme 34

BRAKE SWITCH

Note. Brake switch may also be referred to as brakelight switch or stoplight switch.

1. Brake switch is located near top of brake pedal. To access brake switch, remove cover below steering column and lower instrument panel cover (knee blocker) if necessary. Press and hold brake pedal downward to its fully applied position.
2. Rotate brake switch counterclockwise approximately 30 degrees so alignment tab on brake switch aligns with opening on mounting bracket. Pull brake switch rearward and out from mounting bracket. Disconnect brake switch connector. Remove switch from vehicle.

1. Pull plunger on brake switch outward to its fully extended position. Install brake switch connector. Press and hold brake pedal downward to its fully applied position.
2. Ensure alignment tab on brake switch aligns with opening on mounting bracket. Install brake switch in mounting bracket. When brake switch is fully installed in mounting bracket, rotate brake switch clockwise approximately 30 degrees to lock it into place. Release brake pedal.
3. To ensure proper brake switch adjustment, gently pull up on brake pedal. Brake pedal arm will set plunger to correct position as pedal arm pushes plunger into switch body. Switch will make ratcheting sound as it self-adjusts. Release brake pedal. To complete installation, reverse removal procedure.

DOWNSTREAM HEATED OXYGEN SENSOR

Note. Sensors downstream of catalytic converter may be referred to as 1/2. If vehicle has more than one downstream sensor, they may be referred to as 2/1 (left bank) and 2/2 (right bank).

Heated Oxygen Sensor (HO2S) is mounted on exhaust pipe, behind catalytic converter. Raise and support vehicle. Disconnect HO2S connector. Using Socket (C4907), remove HO2S from exhaust pipe.

1. If installing original HO2S, apply anti-seize compound on HO2S threads. A new HO2S should already be coated with anti-seize compound.
2. Tighten HO2S to specification. See «TORQUE SPECIFICATIONS»(ref-63418-S19577485662001020500000) . Install HO2S connector.

ENGINE COOLANT TEMPERATURE SENSOR

INTAKE AIR TEMPERATURE SENSOR

Note. Intake air temperature sensor may also be referred to as intake manifold air temperature sensor.

OIL PRESSURE SENSOR

Note. Oil pressure sensor may also be referred to as engine oil pressure sensor.

PARK/NEUTRAL SWITCH (A/T)

Note. Park/Neutral (P/N) switch may also be referred to as Park/Neutral Position (PNP) switch.

UPSTREAM OXYGEN SENSOR

Note. Sensors upstream of catalytic converter may be referred to as 1/1. If vehicle has more than one upstream sensor, they may be referred to as 1/1 (left bank) and 1/2 (right bank).

HO2S is mounted on exhaust manifold or exhaust downpipe in front of catalytic converter. Raise and support vehicle. Disconnect HO2S connector. Using Socket (C4907), remove HO2S from exhaust manifold/downpipe.

If installing original HO2S, apply anti-seize compound on HO2S threads. A new HO2S should already be coated with anti-seize compound. Install and tighten HO2S to specification. See TORQUE SPECIFICATIONS . Install HO2S connector.

4.7L

Tighten radiator draincock and cylinder block drain plug(s), if removed. Open cooling system air bleed screw located in upper radiator hose housing. Fill cooling system with a 50/50 concentration of coolant and distilled water. Slowly fill cooling system until a steady stream of coolant flows from air bleed hole. Close air bleed valve. Fill coolant reservoir bottle to full mark. Place heater in full heat position. Start engine and allow it to reach normal operating temperature.

A/C RELAY, AUTO SHUTDOWN RELAY & FUEL PUMP RELAY

Note. A/C relay may also be referred to as A/C clutch relay or A/C compressor clutch relay.

DISTRIBUTOR

Note. 4.0L and 4.7L engines are distributorless. For 4.0L oil pump drive shaft assembly, see CAMSHAFT POSITION SENSOR .

FUEL SYSTEM PRESSURE RELEASE

1. Remove fuel cap from fuel tank. Ensure all pressure is released from fuel tank.
2. Remove fuel pump relay from engine compartment Power Distribution Center (PDC). PDC is located in engine compartment, next to battery. Fuel pump relay may be identified by label on inside of PDC cover.
3. Start engine and allow engine to idle until engine stalls. Attempt to restart engine until engine will no longer run. Turn ignition off. NOTE: One or more Diagnostic Trouble Codes (DTC) may set when fuel pump relay is removed.
4. Disconnect any fuel injector connector. Connect a jumper wire between either fuel injector terminal and positive battery terminal. Connect another jumper wire to other fuel injector terminal. Momentarily touch other end of jumper wire to negative battery terminal. CAUTION: DO NOT supply power to fuel injector for more than 4 seconds, or fuel injector may be damaged.
5. Place a shop towel under fuel line quick-connector at fuel rail. Use care when disconnecting fuel lines, as some fuel pressure may still exist in fuel lines. Disconnect fuel line quick-connector at fuel rail. Reinstall fuel pump relay in PDC. Reconnect fuel line quick-connector. Using scan tool, erase any DTCs that may have set after fuel pressure release procedure.

FUEL LINE DISCONNECT FITTINGS

Note. Fuel lines may contain single tab, dual tab or plastic retainer ring disconnect fitting. see scheme 26 Determine type of disconnect fitting used and use proper procedure for proper disconnect fitting.

FUEL LEVEL SENSOR

Note. Fuel level sensor may also be referred to as fuel gauge sending unit.

1. Fuel level sensor is mounted on fuel pump module. (Scheme 35)or (Scheme 36). Remove fuel pump module. See «FUEL PUMP MODULE»(ref-63418-S08970133782001020500000).
2. Disconnect sending unit connector at sending unit. Note location of notch and release tab at end of fuel level sensor. (Scheme 37) Carefully press on release tab and remove fuel level sensor.

Install fuel level sensor on channels on fuel pump module. Slide fuel level sensor onto fuel pump module until fuel level sensor snaps into place. Ensure locking tab is fully seated. Connect electrical connector at sending unit. Reinstall fuel pump module and fuel tank. To complete installation, reverse removal procedure.

Scheme 35

Scheme 36

Scheme 37

FUEL PRESSURE REGULATOR

Fuel pressure regulator is incorporated with fuel filter. To service fuel filter/fuel pressure regulator, see FUEL FILTER/FUEL PRESSURE REGULATOR .

FUEL PUMP

Fuel pump is incorporated into fuel pump module. See FUEL PUMP MODULE .

FUEL RAILS & INJECTORS

Note. On 2.5L and 4.0L engines, fuel rail damper is incorporated into fuel rail. Fuel damper is used to help control fuel pressure pulsations. Fuel damper is not used as a pressure regulator. Fuel damper is not serviceable separately.

CHEROKEE

TORQUE SPECIFICATIONS (CHEROKEE)

GRAND CHEROKEE

TORQUE SPECIFICATIONS (GRAND CHEROKEE)

WRANGLER

TORQUE SPECIFICATIONS (WRANGLER)