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Home >> Plymouth >> 1988 >> Voyager Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> 2.5L CEC System >> DRIVEABILITY (Dr) Tests >> Dr1 - Checking System For Fault Codes
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Dr1 - Checking System For Fault Codes

  1. Connect DRB II. Put system in Diagnostic Test Mode. Record all codes. If "88-12-55" (no fault codes) is displayed, go to DR2. For following fault codes, proceed to specified tests:
    • Code 15 - Speed sensor, go to DR3  .
    • Code 17 - Coolant sensor, go to DR5  .
    • Code 21 - Oxygen sensor, go to DR4  .
    • Code 33 - A/C cut-out relay, go to DR11  .
    • Code 51 - Oxygen feedback system locked lean, go to DR18  .
    • Code 52 - Oxygen feedback system locked rich, go to DR18  .
  2. Erase fault codes. Without depressing accelerator, start engine. Raise engine speed to 2000 RPM for 10 seconds and then return to idle. Cycle transmission gear selector. Turn A/C on and off (if equipped).
  3. Turn ignition off. Put system into Diagnostic Test Mode. Record all codes. If the same code appears before and after the engine is started, the problem still exists. Proceed as follows:
    • Code 12-16 - Battery voltage circuit to SMEC., go to CH3  .
    • Code 13 - MAP sensor, go to DR2, CODES 13 OR 14  .
    • Code 14 - MAP sensor, go to DR2, CODES 13 OR 14  .
    • Code 17-22 - Coolant sensor, go to DR5  .
    • Code 22 - Coolant sensor, go to DR5  .
    • Code 23 - Throttle body temperature sensor (Non-Turbo), Charge temperature sensor (Turbo), go to DR6  .
    • Code 24 - Throttle position sensor, go to DR7  .
    • Code 25 - Idle speed control motor, go to DR8  .
    • Code 31 - Purge solenoid, go to DR9  .
    • Code 32 - EGR system (California only), go to DR10  .
    • Code 35 - Radiator fan assembly, go to DR12  .
    • Code 37 - Transmission lock-up solenoid, go to DR13  .
    • Code 44 - Fused or damaged circuit "J2", go to DR14  .
    • Code 53 - Replace SMEC unit.
      NOTE: If code does not reappear, problem is not recorded, go to step 16).
  4. With DRB II connected, enter Actuator Test Mode (ATM). Perform the following tests:
    • Actuator Test "04"  - The radiator fan should be cycling ON/OFF every 2 seconds. If fan cycles, press and hold ATM key until code "07" (equipped with A/C) or code "05" (without A/C) appears. If fan is not on, check fan relay. If relay clicks, repair wiring to fan. If relay does not click, replace relay.
    • Actuator Test "05"  - The A/C cut-out relay should click, every 2 seconds. If relay clicks, hold ATM key until code "07" appears. Replace relay if it does not click. During this test the A/C compressor clutch will also cycle and the cooling fans will run continuously.
    • Actuator Test "07"  - Listen for clicking from canister purge solenoid. On vehicles equipped with manual transmission, hold ATM key until code "10" appears. On vehicles equipped with automatic transmission, go to step 6). Replace solenoid if it does not click.
    • Actuator Test "10"  - This test is for vehicles equipped with manual transmissions. Shift indicator light should cycle ON/OFF. If light does not cycle, go to next step. If light cycles, go to step 6).
    • Actuator Test "11"  - Turbo Only - This test is for vehicles equipped with turbochargers. Wastegate solenoid may be heard clicking. If solenoid clicks, go to next step. If solenoid does not click, replace it.
  5. Non-Turbo Only - With ignition off, disconnect 60-pin connector from SMEC. Connect a jumper wire to Orange/Black wire in connector cavity No. 55. Ensure pin contact or wiring is not damaged. Turn ignition on. Touch jumper wire to battery negative post. If shift indicator light is on, replace SMEC. If shift indicator light does not light, check for an open circuit, check bulb, check 12-volt supply to bulb with ignition on.
    Fig 1: Jumper Wire Connection to 60-Pin Connector
    G72015
  6. With DRB II connected, enter Switch Test Mode. Check switch inputs as follows
    • Depress brake pedal.
    • Move gear selector from Park, to Reverse, to Neutral, to Drive.
    • With A/C on, turn blower on and press A/C button.

    DRB II display should change as each switch is activated. Disregard what is displayed, ensure only that a change in display occurs. If switch inputs are okay, go to step 11). If one or all of the switches do not pass, proceed to the following tests:

    • Brake switch w/o speed control, go to next step.
    • Brake switch with speed control, go to step 8).
    • Park/Neutral switch, go to step 9).
    • A/C button, go to step 10).

  7. With ignition off, disconnect 60-pin connector from SMEC. Connect a voltmeter to White/Pink wire in connector cavity No. 29. On Omni and Horizon models connect voltmeter to White/Tan wire in connector cavity No. 29. Ensure connecting pins and harness are not damaged. Turn ignition switch to "RUN" position. Depress brake pedal. If voltmeter shows within one volt of battery voltage, replace SMEC, for a defective logic board. If voltmeter reads zero volts, check brake switch, switch circuits and voltage supply.
    Fig 2: Voltmeter Connection to 60-Pin Connector
    G72016
  8. With ignition off, disconnect 60-pin connector from SMEC. Connect ohmmeter between White/Pink wire in connector cavity No. 29 and ground. On Omni and Horizon models connect ohmmeter to White/Tan wire in connector cavity No. 29 and ground. Depress and release brake pedal. If ohmmeter shows an open when pedal is depressed and has continuity when pedal is released, replace SMEC, for a defective logic board. If ohmmeter reads as described above, check brake switch, switch circuits and stoplight bulbs.
  9. With ignition off, disconnect 60-pin connector from SMEC. Connect ohmmeter between Brown/Yellow wire in connector cavity No. 30 and ground. Disconnect the battery quick disconnect. Turn ignition switch to "RUN" position. Shift gear selector to, Park, Reverse, Neutral, and Drive positions and check ohmmeter readings in each position. Ohmmeter should show continuity in Park and Neutral positions. Ohmmeter should show open, (no continuity), in Reverse and Drive positions. If ohmmeter shows continuity in each position, check for defective Neutral Safety Switch (NSS) or short to ground in Brown/Yellow wire in connector cavity No. 30. If ohmmeter shows an open circuit in all positions, repair Brown/Yellow wire in connector cavity No. 30 or replace NSS. If the ohmmeter reads as specified replace SMEC for a defective logic 29:
    • Park = Continuity
    • Reverse = Open
    • Neutral = Continuity
    • Drive = Open
  10. With ignition off, disconnect 60-pin connector from SMEC. Connect ohmmeter between Brown wire in connector cavity No. 45 and ground. Turn blower switch on, press A/C button and then press "OFF" button.
    NOTE: A/C system must have adequate freon charge to complete this test.

    If ohmmeter shows continuity when A/C button is pressed, and open when "OFF" button is pressed, replace SMEC for a defective logic board. If ohmmeter is not as described, repair Brown wire in connector cavity No. 45 for an open or short to wiring harness splice.

  11. Connect DRB II, ensure "READ" is displayed. Connect a tachometer to engine. Start engine and disconnect coolant sensor. Press Read/Hold key and display "HOLD". Record engine RPM variations. Press key and display "READ". If engine speed increases to about 1500 RPM on "HOLD" and returns to idle on "READ", go to step 16). If engine speed does not increase and decrease as described, go to next step.
  12. NON-TURBO  - With ignition off and DRB II connected, disconnect ISC motor connector. Connect voltmeter between Gray/Red wire (terminal No. 1) and Violet/Black wire (terminal No. 4) at ISC harness connector. Enter Actuator Test Mode "03". If voltmeter is pulsating between "0" and "12" volts every 2 seconds, go to next step. If voltmeter does not pulsate, go to step 14).

    TURBO  - With ignition off and DRB II connected, disconnect ISC motor connector. Connect voltmeter between Brown/White wire (connector cavity No. 2) and Yellow/Black wire (connector cavity No. 3) at ISC harness connector. Enter Actuator Test Mode "03". If voltmeter is pulsating every 4 seconds, SMEC and wiring is okay, replace ISC motor. If voltmeter does not pulsate, go to step 14).

  13. NON-TURBO  - With DRB II connected and ISC motor disconnected. Connect voltmeter between Brown/White wire and Yellow/Black wire at terminals No. 2 and 3 of ISC. Enter ATM "03". If voltmeter is pulsating between "0" and "12" volts every 2 seconds, replace ISC motor. If voltmeter does not pulsate, go to step 15).

    TURBO  - With ignition off, disconnect 60-pin connector from SMEC. Ensure ISC motor is connected. Connect ohmmeter between Gray/Red wire in connector cavity No. 19 and Violet/Black wire in cavity No. 20 of 60-pin connector. If ohmmeter shows continuity, replace SMEC for a defective logic board. If circuit is open, repair open in ISC circuit wiring of connector cavity No. 18 or 19.

  14. With ignition off, disconnect 60-pin connector from SMEC. Ensure ISC motor is connected. Connect ohmmeter between Gray/Red wire in connector cavity No. 19 and Violet/Black wire in connector cavity No. 20. If ohmmeter shows continuity, replace SMEC for a defective logic board. If circuit is open, repair open in ISC circuit wiring.
    Fig 3: Ohmeter Connection to 60-Pin Connector [A]
    G72017
  15. With ignition off, disconnect 60-pin connector from SMEC. Ensure ISC motor is connected. Connect ohmmeter between Brown/White wire in connector cavity No. 17 and Yellow/Black wire in connector cavity No. 18. If ohmmeter shows continuity, replace SMEC for a defective logic board. If circuit is open, repair open in ISC circuit.
    Fig 4: Ohmeter Connection to 60-Pin Connector [B]
    G72018
  16. With ignition off, disconnect both SMEC connectors. Connect one lead of Digital Volt/Ohm Meter (DVOM) to system ground eyelet on cylinder head. Connect other lead to the following circuits:
    • 14-Pin Connector  - Black/White wire in connector cavity No. 2 and Black wire in connector cavities No. 6 and 7.
    • 60-Pin Connector  - Black/White wire in connector cavity No. 5 and Light Blue/Red wire in connector cavities No. 15 and 16.
    Fig 5: Voltmeter Connector to ISC Connector
    G55963
    Fig 6: Testing Resistance at 14 & 60-Pin Connectors
    G72020
  17. If ohmmeter shows less than .5 ohm resistance at all cavities, go to DR15 (cold engine driveability problems) or DR17 (warm engine driveability problems). If ohmmeter reading indicates an open in one or more of the connector cavities, check for an open ground circuit and/or replace SMEC. If meter indicates a resistance greater than .5 ohms, repair ground connection.
  18. Turbo Only - Connect DRB II and disconnect fuel injector connectors (4). Put system in ATM "02" and connect and disconnect each injector, one at a time. If injector clicks, go to next step. If injector does not click, replace injector.
  19. On all engines, the majority of intermittent failures are caused by wiring and connections. One way to find them is to duplicate the problem. Since the SMEC can remember where they are, the ATM and Sensor Tests can be used in an attempt to locate them. Once in the correct test mode, wiggle all connectors and wires in the circuit. The DRB II display will change, or ATM test will be interrupted when the bad connection or wire is located. When checking MAP sensor circuit (code "14"), apply 10 inches of vacuum to MAP sensor before testing.

    If the following codes do not reappear, go to the indicated tests:

    Sensor Tests:

    • Code 14 - Test "08"
    • Code 22 - Test "04"
    • Code 23 - Test "03"
    • Code 24 - Test "05"

    ATM Tests

    • Code 25 - Test "03"
    • Code 26 - Test "02"
    • Code 27 - Test "02"
    • Code 31 - Test "07"
    • Code 32 - Test "11" (Non-Turbo)
    • Code 33 - Test "05" (Turbo)
    • Code 35 - Test "04"
    • Code 36 - Test "11"
    • Code 37 - Test "10" (Turbo)
    • Code 42 - Test "06"
    • Code 43 - Test "01"
    • Code 45 - Test "11" (Turbo)

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