ELECTRONIC ENGINE CONTROLLER - Chrysler

The Mopar advantage ELECTRONIC ENGINECONTROLLERAIS Motor Driver8–Volt DistributorSupply CircuitrySealed cessorIgnition CoilControlEPROMAlternator FieldControl Driver(underneath heat or Control Driver(underneath heat sink)

ELEC T RO N I CS T RO U BLE S H O O T IN G G U ID ESINGLE MODULEENGINE CONTROLLERModel Year 1988–1989The following are often misdiagnosed as defectiveSMEC/SBEC units:   Intermittent grounds: Loose or corroded grounds may cause falsesensor readings.   Auto-shutdown (ASD) relay: Corroded wires or faulty relay.   Manifold Absolute Pressure (MAP) sensor and Throttle PositionSensor (TPS) voltages: Check voltages over the entire range,not just the extremes. Verify minimum TPS voltage. Minimum air flow: Check for air leaks or airflow obstruction.   Automatic Idle Speed (AIS) motor: Shorted windings will set DTSs.Open circuits and intermittent connections will not.   Vacuum system: Contaminants or leaks in vacuum lines, notably inline connected to MAP sensor can set MAP pneumatic Fault #13. Fuel pressure and leak down.   Vehicle speed sensor operation.   Heater voltage for oxygen sensor.   Charging system malfunction: Alternator defective or battery notfully charged will set faults.SINGLE BOARDENGINE CONTROLLERModel Year 1989–1991 SBECModel Year 1992–1995 SBECII   Crankshaft and camshaft sensors: Some aftermarket pickups havenot worked properly with Mopar engine controllers.   Check for high circuit resistance associated with splices and fusiblelinks; check for open and/or shorted wires. Closed throttle switch operation on AB, AD, AN bodies, ’88–91 MY.TBI Dodge Trucks only.   Damaged connector terminals: Remove orange gasket from bottomof SMEC/SBEC 60-way connector, reseat connector, and check forsymptom/problem. If symptom/problem has been corrected, check60-way harness and/or connector for terminal damage or looseconnection. Wiring harness pin diameter should be .055". Use themale terminals on your PCM as a gauging tool.   Excessive current on certain connector pins may damage theSMEC/SBEC. Use of a test lamp or a short in the wiring harnessof the vehicle can cause this condition. Always use a DVM whenchecking the unit/system.   Check Technical Service Bulletins applicable to model year andsystem malfunction. Dirty or carboned throttle bodies are often misdiagnosed as PCMor fuel delivery problems.Model Year 1996–2003 SBEC III / IIIA / IIIB Vehicle Identification Number (VIN) and the vehicle’s originalmileage must be entered into the PCM to avoid drivability problemsand erroneous diagnostic trouble codes. If you are not using a DRBIII, please check with your scan tool manufacturer to verify youhave the capability to enter this information. Crankshaft and camshaft position sensors: Some aftermarketpickups have not worked properly with Mopar engine controllers. Check for high circuit resistance associated with splices andfusible links; check for open and/or shorted wires. Damaged connector terminals: Visually inspect both 40-wayconnectors for terminal damage. Excessive current on certain connector pins may damage theSBEC. Use of a test lamp or a short in the wiring harness of thevehicle can cause this condition. Always use a DVM whenchecking the unit/system. Check Technical Service Bulletins applicable to model yearand system malfunction. D irty or carboned throttle bodies are often misdiagnosed asPCM or fuel delivery problems. Loose timing belts or belts that have jumped a tooth can alsobe misdiagnosed as PCM or camshaft/crankshaft positionsensor problems.IMPORTANT!Mopar Remanufactured SINGLE BOARD ENGINE CONTROLLER (sbec III)WARNING: Use the DRB scan tool to reprogram the replacement SBEC III (PCM) with the vehicle’s original identification number (VIN)and the vehicle’s original mileage. Failure to do so may cause idling and/or drivability problems and may set a diagnostic trouble code (DTC).Note: The photos shown on this page may not be representative of the actual part.www.mopar.com/electrical/electronics/31

ELECTRO N I C S T R O U B LE S H O O T I N G G U I D E(continued)Spark Control ComputersModel Year 1978–1989The following are often misdiagnosed as defective SCC: C harging system malfunction: Alternator defective or battery notfully charged. NOTE: SCC does not control charging system incarbureted vehicles. There is an external voltage regulator. Magnetic pickups: Check air gap and resistance of pickup(s).Some aftermarket pickups have not worked properly with Moparengine controllers. V acuum systems: Contaminants or leaks in vacuum lines, notablyin line connected to transducer on SCC. Excessive current on certain connector pins may damage the SCC.Use of a test lamp or a short in the wiring harness of the vehiclecan cause this condition. Always use a DVM when checking theunit/system. Pin connections: Harness connector pins to SCC or sensorsspread apart or corroded, causing open or intermittent connections. S econdary ignition: Aftermarket replacement parts not inspecification with OEM. Example: Spark plug wire resistanceor wire length. Check Technical Service Bulletins applicable to model year andsystem malfunctions. Exhaust system: Catalytic converter malfunctioning or clogged.TBI/Turbo Power andLogic ModulesModel Year 1984–1987The following are often misdiagnosedas defective TBI/Turbo Modules: C harging system malfunction: Alternator defective or battery not fullycharged. NOTE: In 1985 and later vehicles, the voltage regulator iscontrolled by BOTH the Logic and Power modules. In many vehicles,the voltage regulator is in the alternator. V erify model year of vehicle electronics: Some 1987 P-bodies withturbocharged engines were built with 1986 logic modules. A 1986 logicmodule can be identified by the MAP sensor mounted on the logicmodule case, unless TSB #18-03-86 has been performed. Then,the MAP sensor is separate. The 1987 logic modules used MAPsensors mounted in the engine compartment. I ntermittent grounds: Loose or corroded grounds may cause falsesensor readings. L oose or corroded pin connections: Water leakage throughkick panel may cause logic module pins to corrode. M anifold Absolute Pressure (MAP) and Throttle Position Sensor(TPS) voltages: Check voltage over the entire range, not just theextremes. Verify minimum TPS voltage. A uto-shutdown (ASD) relay operation: Verify distributor connectionsand proper voltages. Some aftermarket pickups have not workedproperly with Mopar engine controllers. A utomatic idle speed (AIS) motor: Shorted windings will set DTCs.Open circuits and intermittent connections will not. Vacuum system: Contaminants or leaks in vacuum lines, notablyin line connected to MAP sensor. Excessive current on certain connector pins may damage themodules. Use of a test lamp or a short in the wiring harness ofthe vehicle can cause this condition. Always use a DVM whenchecking the unit/system. C heck Technical Service Bulletins applicable to model year andsystem mNote: The photos shown on this page may not be representative of the actual part.

ELECTR O N I C S T R O U B L E S H O O T I N G G U I D E(continued)MOPAR REMANUFACTURED ELECTRONICAUTOMATiC TRANSAXLE CONTROLLER (EATX II) Transaxle Quick Learn Procedure T his program allows the electronic transaxle system to recalibrateitself to provide the best possible transaxle operation. The QuickLearn procedure should be performed if any of the followingactions have been implemented: Transaxle assembly replacement Transmission control module replacement Solenoid pack replacement Clutch plate and/or seal replacement Valve body recondition or replacementPinion Factor Procedure(Model years ’93–95 only, except LH vehicle.) The vehicle speedreadings for the speedometer are taken from the output speed sensor.The transmission control module must be calibrated to reflect thedifferent combinations of equipment available. A procedure has beendeveloped called Pinion Factor. It allows the technician to set thetransmission control module initial setting so that the speedometerreadings will be correct.This procedure must be performed if the transmission control modulehas been replaced.Failure to perform this procedure will result in a “NO SPEEDOMETEROPERATION” condition.EATX II Troubleshooting Tips For vehicles that have both a limp-in condition and a no communicationwith scan tool problem, the EATX II relay may be at fault. Swap thebackup lamp relay with the EATX II relay to verify. If the limp-in andno communication problem go away then replace the defective relay. No speedometer operation after EATX II module replacement: Seethe pinion factor procedure. Certain fault codes are caused by internal transmission problems,but replacing the EATX II module will not fix these problems.Reference the installation booklets for more information.MOPAR REMANUFACTURED BENDIX ABX-4ANTILOCK BRAKE CONTROLLER Removal and Installation InstructionsIMPORTANT! WARNING: If a new Controller Antilock Brake (CAB) is being/hasbeen installed, it must be initialized prior to driving the vehicle. TheCAB is initialized using the DRB scan tool and the initializing proceduredescribed upon selecting Bendix ABX-4 diagnostics. New controllersare programmed to flash the ABS Warning Lamp until unit initializedby the installing technician.Intermittent Diagnostic Trouble CodesAs with virtually any electronic system, intermittent faults in the ABSsystem may be difficult to accurately diagnose.Most intermittent faults are caused by faulty electrical connections orwiring. When an intermittent fault is encountered, check suspectcircuits for:1. Poor mating of connector halves or terminals not fully seated in theconnector body.2. Improperly formed or damaged terminals. All connector terminalsin a suspect circuit should be carefully reformed to increasecontact tension.3. Poor terminal-to-wire connection. This requires removing the terminalfrom the connector body to inspect.Note: The photos shown on this page may not be representative of the actual part.4. Pin presence in the connector assembly.5 Proper ground connections. Check all ground connections for signsof corrosion, tight fasteners, or other potential defects. Refer to wiringdiagram manual for ground locations.6. If a visual check does not find the cause of the problem, operate thecar in an attempt to duplicate the condition, and record the fault code.7. Most failures of the ABS system will disable ABS function for theentire ignition cycle even if the fault clears before key-off. There aresome failure conditions, however, which will allow ABS operation toresume during the ignition cycle in which a failure occurred if thefailure conditions are no longer present. The following conditions mayresult in intermittent illumination of the ABS warning lamp. All otherfailures will cause the lamp to remain on until the ignition switch isturned off. Circuits involving these inputs to the (CAB) should beinvestigated if a complaint of intermittent warning system operationis encountered.8. Low system voltage. If Low System Voltage is detected by the CAB,the CAB will turn on the ABS warning lamp until normal systemvoltage is achieved. Once normal voltage is seen at the CAB, normaloperation resumes.9. Additionally, any condition which results in interruption of electricalcurrent to the CAB or modulator assembly may cause the ABSwarning lamp to turn on s/33