IGNITION SYSTEM 8D - 1 IGNITION SYSTEM TABLE OF CONTENTS

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1 LH IGNITION SYSTEM 8D - 1 IGNITION SYSTEM TABLE OF CONTENTS page AND IGNITION SYSTEM...1 SPARK PLUGS-PLATINUM....1 COIL ON PLUG...1 CRANKSHAFT POSITION SENSOR....2 CAMSHAFT POSITION SENSOR....3 KNOCK SENSOR....5 LOCK KEY CYLINDER....5 IGNITION INTERLOCK...5 AND SPARK PLUG...5 IGNITION COIL...6 AND IGNITION SYSTEM NOTE: All engines use a fixed ignition timing system. Basic ignition timing is not adjustable. All spark advance is determined by the Powertrain Control Module (PCM). The distributorless ignition system used on these engines is referred to as the Direct Ignition System (DIS). The system s three main components are the coils, crankshaft position sensor, and camshaft position sensor. The coil on plug ignition system utilizes an ignition coil for every cylinder, it is mounted directly over the each spark plug. The crankshaft position sensor and camshaft position sensor are hall effect devices. The camshaft position sensor and crankshaft position sensor generate pulses that are inputs to the PCM. The PCM determines crankshaft position from these sensors. The PCM calculates injector sequence and ignition timing from crankshaft position. For a description of both sensors, refer to Camshaft Position Sensor and Crankshaft Position Sensor in this section. page AUTOMATIC SHUTDOWN RELAY...6 CAMSHAFT POSITION SENSOR 2.7L...6 CAMSHAFT POSITION SENSOR 3.2/3.5L...6 CRANKSHAFT POSITION SENSOR...7 KNOCK SENSOR...7 COIL CAPACITOR...8 IGNITION SWITCH...8 LOCK KEY CYLINDER...9 SPECIFICATIONS TORQUE...11 SPARK PLUGS...11 SPARK PLUGS-PLATINUM The 2.7, 3.2, and 3.5L engines use platinum resistor spark plugs. They have resistance values of 6,000 to 20,000 ohms when checked with at least a 1000 volt tester. For spark plug identification and specifications, Refer to the Specifications section. Do not use an ohm meter to check the resistance of the spark plugs. This will give an inaccurate reading. The spark plugs are double platinum and have a recommended service life of 100,000 miles for normal driving conditions per schedule A in this manual. The spark plugs have a recommended service life of 75,000 miles for severe driving conditions. A thin platinum pad is welded to both or center electrode end(s) as show in (Fig. 1). Extreme care must be used to prevent spark plug cross threading, mis-gaping and ceramic insulator damage during plug removal and installation. CAUTION: Cleaning of the platinum plug may damage the platinum tip. COIL ON PLUG The engines are equipped with a coil on plug ignition system. Each cylinder has a dedicated coil that sits atop each plug. No secondary wires are required and connection from the coil to plug is made with a boot that is attached to the coil. The combination of

2 8D - 2 IGNITION SYSTEM LH AND (Continued) Fig. 1 Platinum Pads 1 APPLY ANTI-SEIZE COMPOUND HERE ONLY 2 PLATINUM SPARK SURFACE the coil, boot, and fasteners is known as the ignition coil assembly. The Powertrain Control Module (PCM) determines which coil to charge and fire at the correct time. Fig /3.5L Coil The coil s low primary resistance ( ohm) allows the PCM to fully charge the coil for each firing. There is a coil capacitor added to each bank of cylinders for radio noise suppression. Fig L Coil The Auto Shutdown (ASD) relay provides battery voltage to the ignition coil. The PCM provides a ground contact (circuit) for energizing the coil. When the PCM breaks the contact, the energy in the coil primary transfers to the secondary causing the spark. The PCM will de-energize the ASD relay if it does not receive the crankshaft position sensor and camshaft position sensor inputs. For limp home capability, the engine can run on crankshaft sensor input only. Refer to Auto Shutdown (ASD) Relay PCM Output, in this section for relay operation. Fig. 4 Coil Capacitor 1 IGNITION COIL CAPACITOR CRANKSHAFT POSITION SENSOR The crankshaft sensor is located on the passengers side of the transmission housing, above the differential housing (Fig. 6). The bottom of the sensor is positioned next to the drive plate.

3 LH IGNITION SYSTEM 8D - 3 AND (Continued) other inputs, to determine injector sequence and ignition timing. The crankshaft position sensor detects slots cut into the transmission driveplate extension. There are 3 sets of slots. Two sets contain 4 slots and one set contains 5 slots, for a total of 13 slots (Fig. 7). Basic timing is set by the position of the last slot in each group. Once the Powertrain Control Module (PCM) senses the last slot, it determines which piston will be next at TDC from the camshaft position sensor input. It may take the PCM one engine revolution to determine crankshaft position. Fig. 5 Coil Capacitor 1 IGNITION COIL CAPACITOR The sensor is a hall effect device combined with an internal magnet. It is also sensitive to steel within a certain distance from it. Fig. 7 Timing Slots 1 TORQUE CONVERTER DRIVE PLATE 2 SLOTS Fig. 6 Crankshaft Position Sensor Location 1 CRANKSHAFT POSITION SENSOR Engine speed and crankshaft position are provided through the crankshaft position sensor. The sensor generates pulses that are the input sent to the powertrain control module (PCM). The PCM interprets the sensor input to determine the crankshaft position. The PCM then uses this position, along with The PCM uses crankshaft position reference to determine injector sequence and ignition timing. Once the PCM determines crankshaft position, it begins energizing the injectors and coils in sequence. The PCM uses the Crankshaft Position sensor to calculate the following: Engine rpm TDC number 1 and 4 Ignition coil synchronization Injector synchronization Camshaft-to-crankshaft misalignment (Timing belt skipped 1 tooth or more diagnostic trouble code) CAMSHAFT POSITION SENSOR The camshaft position sensor is mounted in the front of the timing case cover (Fig. 8) or (Fig. 9). It is a hall effect device.

4 8D - 4 IGNITION SYSTEM LH AND (Continued) pulses generated by the notches on the camshaft sprocket. Crankshaft pulses follow each group of camshaft pulses. When metal aligns with the sensor, voltage goes low (less than 0.3 volts). When a notch aligns with the sensor, voltage spikes high (5.0 volts). As a group of notches pass under the sensor, the voltage switches from low (metal) to high (notch) then back to low. The number of notches determine the amount of pulses. If available, an oscilloscope can display the square wave patterns of each timing event. Fig. 8 Camshaft Position Sensor Location 2.7L Engine 1 ENGINE COOLANT TEMPERATURE SENSOR 2 CAM SENSOR Fig. 10 Camshaft Position Sensor 2.7L Engine Fig. 9 Camshaft Position Sensor Location 3.2/3.5L Engine 1 CAMSHAFT SENSOR The CMP sensor contains a hall effect device called a sync signal generator to generate a fuel sync signal. The camshaft position sensor helps provide cylinder identification to the Powertrain Control Module (PCM) (Fig. 10) or (Fig. 11). The sensor generates pulses as groups of notches on the camshaft sprocket pass underneath it. The PCM keeps track of crankshaft rotation and identifies each cylinder by the Fig. 11 Camshaft Position Sensor 3.2/3.5L Engine

5 LH IGNITION SYSTEM 8D - 5 AND (Continued) KNOCK SENSOR The knock sensor threads into the cylinder block. The knock sensor is designed to detect engine vibration that is caused by detonation. When the knock sensor detects a knock in one of the cylinders, it sends an input signal to the PCM. In response, the PCM retards ignition timing for all cylinders by a scheduled amount. Knock sensors contain a piezoelectric material which constantly vibrates and sends an input voltage (signal) to the PCM while the engine operates. As the intensity of the crystal s vibration increases, the knock sensor output voltage also increases. The voltage signal produced by the knock sensor increases with the amplitude of vibration. The PCM receives as an input the knock sensor voltage signal. If the signal rises above a predetermined level, the PCM will store that value in memory and retard ignition timing to reduce engine knock. If the knock sensor voltage exceeds a preset value, the PCM retards ignition timing for all cylinders. It is not a selective cylinder retard. The PCM ignores knock sensor input during engine idle conditions. Once the engine speed exceeds a specified value, knock retard is allowed. Knock retard uses its own short term and long term memory program. Long term memory stores previous detonation information in its battery-backed RAM. The maximum authority that long term memory has over timing retard can be calibrated. Short term memory is allowed to retard timing up to a preset amount under all operating conditions (as long as rpm is above the minimum rpm) except WOT. The PCM, using short term memory, can respond quickly to retard timing when engine knock is detected. Short term memory is lost any time the ignition key is turned off. NOTE: Over or under tightening affects knock sensor performance, possibly causing improper spark control. LOCK KEY CYLINDER The lock cylinder is inserted in the end of the housing opposite the ignition switch. The ignition key rotates the cylinder to 5 different detents (Fig. 12) : Accessory Off (lock) Unlock On/Run Start Fig. 12 Ignition Lock Cylinder Detents IGNITION INTERLOCK All vehicles equipped with automatic transaxles have an interlock system. The system prevents shifting the vehicle out of Park unless the ignition lock cylinder is in the Unlock, Run or Start position. In addition, the operator cannot rotate the key to the lock position unless the shifter is in the park position. On vehicles equipped with floor shift refer to the - Transaxle for Automatic Transmission Shifter/ Ignition Interlock. AND SPARK PLUG Always remove the ignition coil assembly by grasping at the spark plug boot, turning the assembly 1/2 turn and pulling straight back in a steady motion. (1) Prior to removing the spark plug, spray compressed air around the coil area and spark plug. (2) Remove electrical connector from ignition coil. On 3.2/3.5L engines, it is necessary to loosen the screws by alternating back and forth. Do not lose the spacers under the coil when loosening the screws. (3) Remove 2 fasteners from ignition coil. (4) Remove ignition coil assembly.

6 8D - 6 IGNITION SYSTEM LH AND (Continued) (5) Remove the spark plug using a quality socket with a rubber or foam insert. (6) Inspect the spark plug condition. (1) To avoid cross threading, start the spark plug into the cylinder head by hand. (2) 3.2/3.5L engines tighten spark plugs to 28 N m (20 ft. lbs.) torque, 2.7L engine tighten spark plugs to 17.6 N m (13 ft. lbs.). (3) Install ignition coil assembly onto spark plug. (4) Install coil screws and tighten: 2.7L engine to 6.2 N m (55 in. lbs.), 3.2/3.5L engines to 6.7 N m (60 in. lbs.). (5) Connect the electrical connector. IGNITION COIL (1) Prior to removing the ignition coils, spray compressed air around the coil area and spark plug. (2) Remove electrical connector from ignition coil. On 3.2/3.5L engines, it is necessary to loosen the screws by alternating back and forth. Do not lose the spacers under the coil when loosening the screws. (3) Remove 2 fasteners from ignition coil assembly. (4) Remove ignition coil assembly. Fig. 13 Power Distribution Center (PDC) 1 PDC COVER 2 PDC (1) Install ignition coil assembly for spark plug. (2) Install coil screws and tighten: 2.7L engine to 6.2 N m (55 in. lbs.), 3.2/3.5L engines to 6.7 N m (60 in. lbs.). (3) Connect the electrical connector. AUTOMATIC SHUTDOWN RELAY The relay is located in the Power Distribution Center (PDC) (Fig. 13). For the location of the relay within the PDC, refer to the PDC cover for location. Check electrical terminals for corrosion and repair as necessary. CAMSHAFT POSITION SENSOR 2.7L The camshaft position sensor is mounted in the front of the timing case cover (Fig. 14). (1) Disconnect electrical connector from sensor. (2) Remove camshaft position sensor screw. (3) Without pulling on the connector, pull the sensor out of the chain case cover. (1) Install sensor in the chain case cover and push sensor in until contact is made with the timing chain cover. While holding the sensor in this position, Fig. 14 Camshaft Position Sensor Location 1 ENGINE COOLANT TEMPERATURE SENSOR 2 CAM SENSOR install and tighten the retaining bolt to 12 N m (105 in. lbs.) torque. (2) Attach electrical connector to sensor. CAMSHAFT POSITION SENSOR 3.2/3.5L The camshaft position sensor is installed in the timing belt housing cover above the left camshaft sprocket (Fig. 15).

7 LH IGNITION SYSTEM 8D - 7 AND (Continued) (1) Install sensor in the timing belt housing and push sensor down until contact is made with the camshaft sprocket. While holding the sensor in this position, install and tighten the retaining bolt to 12 N m (105 in. lbs.) torque. (2) Attach electrical connector to sensor. (3) Install the upper intake plenum, refer to the Intake System section. (4) Connect the negative battery cable. CRANKSHAFT POSITION SENSOR The crankshaft sensor is located on the passengers side of the transmission housing, above the differential housing (Fig. 17). The bottom of the sensor sits above the drive plate. Fig. 15 Camshaft Position Sensor 1 SHORT RUNNER VALVE 2 CAMSHAFT POSITION SENSOR 3 MANIFOLD TUNING VALVE (1) Disconnect the negative battery cable. (2) Remove the upper intake plenum, refer to the Intake System section. (3) Disconnect electrical connector from sensor. (4) Remove camshaft position sensor screw. (5) Pull sensor up out of the timing belt housing cover. If the removed sensor is reinstalled, completely remove the old spacer from the sensor face. Attach a NEW SPACER to the face of the sensor before installation. If installing a new sensor, confirm that the paper spacer is attached to the face (Fig. 16). Fig. 17 Crankshaft Position Sensor 1 CRANKSHAFT POSITION SENSOR (1) Disconnect electrical connector from crankshaft position sensor. (2) Remove sensor mounting screw. Remove sensor. (1) Install sensor and push sensor down until contact is made with the transmission case. While holding the sensor in this position, install and tighten the retaining bolt to 12 N m (105 in. lbs.) torque. (2) Connect electrical connector to crankshaft position sensor. Fig. 16 Paper Spacer 3.2/3.5L Engine 1 CAMSHAFT POSITION SENSOR 2 PAPER SPACER KNOCK SENSOR The engine uses one knock sensor(s). The sensor is bolted into the cylinder block, directly below the intake manifold.

8 8D - 8 IGNITION SYSTEM LH AND (Continued) (1) Remove intake manifold plenum and intake manifold. Refer to the Engine section. (2) For the 2.7 L engine remove the right cylinder head. Refer to the Engine section. (3) Disconnect electrical connector from knock sensor(s) (Fig. 18) or (Fig. 19). (1) Install knock sensor. Tighten bolt to 10 N m (7 ft. lbs.) torque. Over or under tightening affects knock sensor performance, possibly causing improper spark control. (2) Attach electrical connector to knock sensor. (3) Install the cylinder head. Refer to the Engine section. (4) Install intake manifold plenum and intake manifold. Refer to the Engine section. COIL CAPACITOR (1) Remove the negative battery cable. (2) Disconnect the electrical connector (Fig. 21) or (Fig. 20). (3) Remove nut and capacitor. (1) Install capacitor and tighten nut. (2) Attach electrical connector to capacitor. (3) Install the negative battery cable. Fig. 18 Knock Sensor 2.7 L 1 KNOCK SENSOR Fig. 20 Ignition Coil Capacitor 1 IGNITION COIL CAPACITOR Fig. 19 Knock Sensor 3.2/3.5 L 1 CYLINDER BLOCK 2 KNOCK SENSOR (4) Use a crows foot socket to remove the knock sensor bolt. IGNITION SWITCH The ignition switch attaches to the lock cylinder housing on the end opposite the lock cylinder (Fig. 22). For ignition switch terminal and circuit identification, refer to the Wiring Diagrams section. (1) Disconnect negative cable from battery. (2) Remove tilt lever attaching screw. Remove lever.

9 LH IGNITION SYSTEM 8D - 9 AND (Continued) Fig. 21 Ignition Coil Capacitor 1 IGNITION COIL CAPACITOR Fig. 22 Ignition Switch 1 IGNITION SWITCH 2 LOCK CYLINDER AND HALO LIGHT 3 LOCK CYLINDER HOUSING (3) Remove upper and lower cover from steering column. (4) Remove Sentry Key Immobilizer Module (SKIM) if equipped. Refer to the Power Door Locks section for removal. (5) Remove multi-function switch. (6) Disconnect electrical connector from ignition switch (Fig. 23). (7) Remove Ignition switch mounting screws. Remove switch. Fig. 23 Ignition Switch Removal/Installation 1 STEERING COLUMN 2 IGNITION SWITCH (1) A tab on the ignition switch indexes to a notch in the lock cylinder housing (Fig. 24). Also, a slot in the end of the ignition switch fits over the shaft in the end of the lock cylinder housing. Use the ignition key to rotate the lock cylinder to align the ignition switch with lock cylinder housing. (2) Install and tighten ignition switch mounting screws. (3) Attach electrical connector to ignition switch. (4) Install multi-function switch. (5) Install SKIM if equipped, refer to the Power Door Locks section for installation. (6) Install upper and lower cover on steering column. (7) Install tilt lever. (8) Connect negative cable to battery. LOCK KEY CYLINDER The lock cylinder is inserted in the end of the housing opposite the ignition switch. The ignition key rotates the cylinder to 5 different detentes (Fig. 25) : Accessory Off (lock) Unlock On/Run Start When replacing the lock cylinder, if the vehicle has a column shifter, install a new interlock cassette. If the vehicle has a floor shift, adjust the interlock cable at the floor shifter when the lock cylinder is replaced. Refer to Floor Shift Interlock Adjustment in the Transmission section.

10 8D - 10 IGNITION SYSTEM LH AND (Continued) Fig. 24 Ignition Switch Alignment 1 IGNITION SWITCH 2 TAB 3 NOTCH 4 SHAFT Fig. 26 Lock Cylinder Removal 1 TAB 2 KEY IN RUN POSITION (2) The shaft at the end of the lock cylinder aligns with the socket in the end of the housing. To align the socket with the lock cylinder, ensure the socket is in the Run position (Fig. 27). Fig. 25 Ignition Lock Cylinder Detentes (1) Disconnect negative cable from battery. (2) Remove the tilt lever attaching screw. Remove lever. (3) Remove the upper and lower covers from the steering column. (4) Turn the ignition key to the run position. When ignition switch is in the run position, the lock cylinder retaining tab will depress. (5) Depress tab and slide lock cylinder out of housing (Fig. 26). (1) Install key in lock cylinder. Turn key to run position (retaining tab on lock cylinder can be depressed). Fig. 27 Socket in Lock Cylinder Housing 1 LOCK CYLINDER HOUSING 2 SOCKET IN RUN POSITION (3) Align the lock cylinder with the grooves in the housing. Slide the lock cylinder into the housing until the tab sticks through the opening in the housing (Fig. 28). (4) Turn key to Off position. Remove key. (5) If the vehicle has column shift and a new lock cylinder was used, install and adjust a new interlock cassette. Refer to Ignition Interlock in this section. If the vehicle has a floor shift, adjust the interlock cable when the lock cylinder is replaced. Refer to the

11 LH IGNITION SYSTEM 8D - 11 AND (Continued) (7) Install tilt lever. (8) Connect negative cable to battery. SPECIFICATIONS TORQUE Fig. 28 Lock Cylinder Installation 1 LOCK CYLINDER HOUSING 2 LOCK CYLINDER 3 TAB Floor Shift Interlock Adjustment procedure in the Transmission section.. (6) Install upper and lower cover on steering column. Description Torque 2.7L Camshaft Position Sensor Screw... 12N m (105 in. lbs.) 3.2/3.5L Camshaft Position Sensor Screw.. 12 N m (105 in. lbs.) Engine Coolant Sensor... 28N m(20ft.lbs.) 2.7L Crankshaft Position Sensor Screw N m (105 in. lbs.) 3.2/3.5L Crankshaft Position Sensor Screw.. 12 N m (105 in. lbs.) 2.7L Ignition Coil N m(55in.lbs.) 3.2/3.5L Ignition Coil N m(60in.lbs.) Knock Sensor... 10N m(7ft.lbs.) 2.7L Map Sensor... 2N m(20in.lbs.) 3.2/3.5L Map Sensor... 2N m(20in.lbs.) 2.7L Spark Plugs N m (13 ft. lbs.) 3.2/3.5L Spark Plugs... 28N m(20ft.lbs.) SPARK PLUGS Engine Spark Plug Gap Thread Size 2.7L RE10PMC5 0,048 TO 0,058 in. 14mm (1 in.) reach 3.2L RC12PEC TO in. 14 mm (3/4 in.) reach 3.5L RC12PEC TO in. 14 mm (3/4 in.) reach

Ignition System Fundamentals

Ignition System Fundamentals Chapter 37 Objectives Describe the functions of ignition system parts Explain the operation of points, electronic, and computer ignition systems Give an overview of the different