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Shift Interlock Systems: Diagnosis Lincoln Continental IX

Automatic Trans 1 illustration ~5518 words

Preliminary Inspection

Verify customer complaint. Visually inspect the following components of the shift interlock system

  1. Shift lever assembly for damage or misadjustment.
  2. Ignition switch/interlock cable for damage or misadjustment.
  3. Switches and brackets for damaged. Electrical Components
  4. Fuses
  5. Loose Or Damaged Connections
  6. Brake On/Off (BOO) Switch Connections
  7. Wiring Harness

Diagnostic Procedure

  1. Check Fuses - Check appropriate fuses located in the interior fuse junction block. See «WIRING DIAGRAMS»(ref-149546-S18937341362002101400000). If fuses are okay, go to step 4. If fuses are not okay, go to next step.
  2. Check Electrical System - With ignition off, replace blown fuse(s). Turn ignition on. If fuse does not blow again, go to next step. If fuse blows again, go to step 8.
  3. Check Supply Voltage To BOO Switch - Turn ignition off. Locate and disconnect BOO switch connector. Using DVOM, measure and record voltage between Light Green/Red wire at BOO switch connector and ground. If voltage is more than 10 volts, reinstall fuses and go to next step. If voltage is less than 10 volts, repair open in Light Green/Red wire. Reconnect BOO switch connector and retest system.
  4. Check BOO Switch Operation - Connect DVOM positive lead to Light Green wire of BOO switch connector by backing connector. Connect negative lead to ground. Depress brake pedal. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, replace BOO switch and retest system.
  5. Check Supply Voltage To Shift Lock Actuator - Disconnect shift lock actuator connector. See «SHIFT INTERLOCK ACTUATOR»(ref-149546-S14854977172002101400000) under REMOVAL & INSTALLATION. Using DVOM, measure voltage between Gray/Yellow (Aerostar) or Purple/Orange (Ranger) wire at shift lock actuator connector terminal and ground. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair open Gray/Yellow or Purple/Orange wire.
  6. Check BOO Switch Signal To Shift Lock Actuator - Turn ignition off. Using DVOM, measure voltage between Red/Light Green (Aerostar) or Light Green (Ranger) wire at shift lock actuator connector and ground. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair appropriate open wire between BOO switch and shift lock actuator. Retest system.
  7. Check Shift Lock Actuator Ground - Ensure gearshift lever is in "P" position. Disconnect shift lock actuator connector. Using DVOM, measure resistance between shift lock actuator connector Black wire and ground. If resistance is less than 5 ohms, replace shift lock actuator. If resistance is more than 5 ohms, repair open in Black wire between shift lock actuator and ground. See «WIRING DIAGRAMS»(ref-149546-S18937341362002101400000).
  8. Check Supply Voltage For Short To Ground - Disconnect shift lock actuator connector. see scheme 7 Remove appropriate blown fuse. Using DVOM, measure continuity between fuse holder terminals and ground. If continuity exists, repair short circuit to ground. Replace fuse and retest system. If continuity does not exist, ensure all circuits connected with fuse are okay. See appropriate EXTERIOR LIGHTS article in ACCESSORIES & EQUIPMENT. If other circuits are okay, replace shift lock actuator and retest system.

Verify customer complaint. Visually inspect the following components of the shift interlock system

  1. Shift lever assembly for damage or misadjustment.
  2. Ignition switch/interlock cable for damage or misadjustment.
  3. Switches and brackets for damaged. Electrical Components
  4. Fuses (METER and STOP)
  5. Loose Or Damaged Connections
  6. Brake On/Off (BOO) Switch Connections
  7. Wiring Harness
  1. Check Fuses - Check 15A METER and 15A STOP fuses located in the interior fuse junction block. If fuses are okay, go to step 4. If fuses are not okay, go to next step.
  2. Check Electrical System - With ignition off, replace blown fuse(s). Turn ignition on. If the fuse blows again, go to next step. If the fuse does not blow again, go to step 4.
  3. Check For Short To Ground - Turn ignition off. Remove METER and STOP fuses. Locate and disconnect shift interlock actuator connectors. see scheme 5 Using DVOM, measure and record resistance between STOP fuse holder terminals and ground. Measure and record resistance between METER fuse holder terminals and ground. If each resistance is more than 10 k/ohms, reinstall fuses and go to next step. If any resistance is less than 10 k/ohms, repair short in appropriate wire. Reconnect all connectors. Install gearshift lever, console and knob.
  4. Check Supply Voltage To Shift Interlock Actuator - Turn ignition on. Using DVOM, measure voltage between shift interlock actuator 3-pin wiring harness connector Yellow (Aspire) or Yellow/Red (Probe) and Black/Yellow wires and ground. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair open in appropriate wire.
  5. Check BOO Switch Signal To Shift Interlock Actuator - Turn ignition off. Connect DVOM leads between shift interlock actuator 3-pin wiring harness connector Green (Aspire) or White/Green (Probe) wire and ground. While monitoring DVOM, press brake pedal. If voltage is more than 10 volts, go to step 7. If voltage is less than 10 volts, go to next step.
  6. Check Stoplight Operation - If stoplights operate when brake pedal is depressed, repair open Green wire between BOO switch and shift lock actuator. If stoplights do not operate when brake pedal is depressed, diagnose problem in stoplight circuit. See appropriate EXTERIOR LIGHTS article in ACCESSORIES & EQUIPMENT.
  7. Check Shift Interlock Actuator Ground - Ensure gearshift lever is in "P" position. Using DVOM, measure resistance between shift interlock actuator 1-pin connector Black wire and ground. If resistance is less than 5 ohms, replace shift interlock actuator. On Aspire models, if resistance is more than 5 ohms, repair open in Black wire between shift interlock actuator and ground. See WIRING DIAGRAMS. On Probe models, if resistance is more than 5 ohms, go to next step. NOTE: Step 8 only applies to Probe models.
  8. Check Park Range Switch - Remove transmission control selector dial bezel. Press the brake pedal and place transmission selector lever in "1" position. Disconnect park range switch connector. Using DVOM, measure and record resistance between park range switch connector terminals. Depress park range switch and measure resistance between park range switch connector terminals. Resistance should be 5 ohms or less with switch depressed and more than 10 k/ohms with switch released. If either resistance is not as specified, replace park range switch. If both resistance's are as specified, repair Black wire between park range switch and ground. See «WIRING DIAGRAMS»(ref-149546-S18937341362002101400000).

Verify customer complaint. Visually inspect the following components of the shift interlock system

  1. Shift lever assembly for damage or misadjustment.
  2. Ignition switch/interlock cable for damage or misadjustment.
  3. Switches and brackets for damaged. Electrical Components
  4. Fuses
  5. Loose Or Damaged Connections
  6. Brake On/Off (BOO) Or Brake Pedal Position (BPP) Switch Connections
  7. Wiring harness
  1. Check Brakelight Operation - Depress brake pedal. If brakelights illuminate, go to step 7 . If brakelights do not illuminate, go to next step.
  2. Check Fuse - Check appropriate fuse (hot at all times circuit) in fuse panel. See WIRING DIAGRAMS. If fuse is okay, go to step 4 . If fuse in blown, go to next step.
  3. Check Wire To BOO/BPP For Short To Ground - Turn ignition off. Disconnect BOO/BPP switch connector. Using DVOM, measure resistance of wire between fuse (hot at all times circuit) terminal and BOO/BPP switch harness connector terminal. If resistance is more 10 k/ohms, go to next step. If resistance is less than 10 k/ohms, repair wire between fuse panel and BOO/BPP switch for short to ground. Reconnect all connectors and retest system.
  4. Check Wire To BOO/BPP Switch For Open - Using DVOM, measure resistance of wire between fuse (hot at all times circuit) terminal and corresponding BOO/BPP switch harness connector terminal. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in wire between fuse panel and BOO/BPP switch. Reconnect all connectors and retest system.
  5. Check BOO/BPP Switch - Using DVOM, measure resistance between 2 outer BOO/BPP connector terminals. Apply brakes and recheck resistance. Resistance should be more than 10 k/ohms without brake pedal applied and less than 5 ohms with brake pedal applied. If switch operates as specified, go to next step. If switch does not operate as specified, replace BOO/BPP switch and retest system.
  6. Check Wire To Shift Interlock Actuator For Short To Ground - Disconnect shift interlock actuator connector. Using DVOM, measure resistance of BOO/BPP switch-to-shift interlock actuator harness connector wire and ground. If resistance is less than 10 k/ohms, go to next step. If resistance is more than 10 k/ohms, repair short in wire between BOO/BPP switch connector and shift interlock actuator connector. Reconnect all connectors and retest system.
  7. Check Wire To Shift Interlock Actuator For Open - Using DVOM, measure resistance of wire between BOO/BPP switch connector and shift interlock actuator connector. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in wire between BOO/BPP switch connector and shift interlock actuator connector. Reconnect all connectors and retest system.
  8. Check Voltage To Shift Interlock Actuator - Turn ignition on. Using DVOM, measure voltage between wire from appropriate fuse (hot in RUN circuit) and ground. If battery voltage is present, go to step 12 . If battery voltage is not present, go to next step.
  9. Check Fuse - Turn ignition off. Remove and check appropriate fuse (hot in RUN circuit). See «WIRING DIAGRAMS»(ref-149546-S18937341362002101400000) . If fuse is okay, go to step 11 . If fuse is blown, go to next step.
  10. Check Wire To Shift Interlock Actuator For Short To Ground - Using DVOM, measure resistance between shift interlock actuator connector terminal (hot in RUN circuit) and ground. If resistance is more than 10 k/ohms, go to next step. If resistance is less than 10 k/ohms, repair open in wire between fuse panel (hot in RUN circuit) and shift interlock actuator connector. Reconnect all connectors and retest system.
  11. Check Wire To Shift Interlock For Open - Using DVOM, measure resistance of wire between fuse terminal (hot in RUN circuit) and shift interlock actuator connector terminal. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open wire between fuse panel (hot in RUN circuit) and shift interlock actuator connector. Reconnect all connectors and retest system.
  12. Check Shift Interlock Actuator Ground For Open - Turn ignition on. Using DVOM, measure resistance between shift interlock actuator connector Black wire and ground. If resistance is less than 5 ohms, replace shift interlock actuator. Reconnect all connectors and retest system. If resistance is more than 5 ohms, repair open Black wire between shift interlock actuator connector and ground.

Verify customer complaint. Visually inspect the following components of the shift interlock system

  1. Shift lever assembly for damage or misadjustment.
  2. Ignition switch for damage or misadjustment. Electrical Components
  3. Open Or Shorted Circuits
  4. Loose Or Damaged Connections
  5. Brake On/Off (BOO) Or Brake Pedal Position (BPP) Switch Connections
  6. Fuse(s)
  7. Faulty Interface Module
  8. Faulty Key Removal Inhibit Solenoid
  9. Faulty Bulbs
  1. Check Fuse No. 23 (15A) - Check fuse No. 23 located in the interior fuse panel. If fuse if okay, go to next step. If fuse is not okay, replace fuse and recheck operation. If fuse blows again, check Purple/White wire for short to ground. Repair as necessary.
  2. Check Fuse No. 34 (7.5A) - Check fuse No. 34 located in the interior fuse panel. If fuse is okay, go to next step. If fuse is not okay, replace fuse and recheck operation. If fuse blows again, check Orange/Yellow wire for short to ground. Repair as necessary.
  3. Check Fuse No. 30 (7.5A) - Check fuse No. 30 located in the interior fuse panel. If fuse is okay, go to next step. If fuse is not okay, replace fuse and recheck operation. If fuse blows again, check Orange/Black or Purple/Yellow wire between fuse panel and gearshift lever unit for short to ground. Repair as necessary.
  4. Check Voltage To Gearshift Lever Unit - Remove gearshift lever unit and disconnect electrical connector. Turn ignition on. Using DVOM, measure voltage between gearshift lever unit wiring harness connector Purple/White (terminal No. 1), Orange/Yellow (terminal No. 3) wires and ground. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair open wire between fuse panel and gearshift lever unit.
  5. Check Circuit 31S For Open - Turn ignition off. Disconnect 16-pin instrument interface module connector located below left outer heater duct. Using DVOM, measure resistance of Black/White wire between gearshift lever unit wiring harness connector and instrument interface module connector. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open Black/White wire. Reconnect all connectors and retest system.
  6. Check Circuit 29S For Open - Using DVOM, measure resistance of Orange/Yellow wire between gearshift lever unit wiring harness connector (terminal No. 4) and instrument interface module connector. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open Orange/Yellow wire. Reconnect all connectors and retest system.
  7. Check Circuit 31S For Short - Turn ignition on. Using DVOM, measure voltage between gearshift lever unit wiring harness connector Black/White wire and ground. If voltage is less than one volt, go to next step. If voltage is more than one volt, repair short Black/White wire. Reconnect all connectors and retest system.
  8. Check Gearshift Lever Unit Operation - Ensure ignition is off. Reconnect gearshift lever unit connector. Connect a jumper wire between instrument interface module connector Black/White (terminal No. 8) wire and ground. Turn ignition on. Try to move gearshift lever from Park to Reverse. If gearshift lever moves, go to next step. If gearshift lever will not move, replace gearshift lever unit. Reconnect all connectors and retest system.
  9. Check Instrument Interface Module Ground - Using DVOM, measure resistance between instrument interface module connector Black/Yellow (terminal No. 15) wire and ground. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open Black/Yellow wire. Reconnect all connectors and retest system.
  10. Check Power Supply To Instrument Interface Module - Turn ignition on. Using DVOM, measure voltage between instrument interface module connector Purple/Black (terminal No. 11) wire and ground. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair open Purple/Black wire. Reconnect all connectors and retest system.
  11. Check BOO/BPP Switch Operation - Turn ignition off. Press down on brake pedal. If stoplights turn on, go to next step. If stoplights do not turn on, diagnose BOO/BPP switch. See appropriate EXTERIOR LIGHTS article in ACCESSORIES & EQUIPMENT.
  12. Check Circuit 29S For Open - Disconnect PCM. Install breakout box leaving PCM disconnected. Using DVOM, measure resistance between breakout box terminal No. 92 and instrument interface module connector Orange/Black (terminal No. 7) wire. If resistance is less than 5 ohms, replace instrument interface module. Reconnect all connectors and retest system. If resistance is more than 5 ohms, repair open Orange/Black wire. Remove breakout box, reconnect all connectors and retest system.

Verify customer complaint. Visually inspect the following components of the shift interlock system

  1. Shift lever assembly and cable for damage or misadjustment.
  2. Ignition switch/interlock cable for damage or misadjustment. Electrical Components
  3. Open or shorted circuits.
  4. Loose or damaged connections.
  5. Brake On/Off (BOO) or Brake Pedal Position (BPP) switch connections.
  6. Damaged shift lock actuator.
  7. Fuse(s).
  8. Faulty PCM.
  9. Faulty Bulbs.
  1. Check No. 5 Fuse - Check fuse No. 5 located in the interior fuse junction block. If fuse is okay, go to step 4 . If fuse is not okay, go to next step.
  2. Check For Short To Ground - Turn ignition off. Remove fuse No. 5. Locate shift interlock actuator on steering column under instrument panel and disconnect electrical connector. Using DVOM, measure and record resistance between fuse holder terminals and ground. If resistance is more than 10 k/ohms, reinstall fuse and go to next step. If resistance is less than 10 k/ohms, repair short Gray/Yellow (Taurus and Sable) or Purple/Orange (Crown Victoria and Grand Marquis) wire. Reconnect all connectors and retest system.
  3. Check Supply Voltage To Shift Lock Actuator - Turn ignition on. Using DVOM, measure voltage between shift interlock actuator wiring harness connector Gray/Yellow wire and ground. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair open Gray/Yellow (Taurus and Sable) or Purple/Orange (Crown Victoria and Grand Marquis) wire.
  4. Check Supply Voltage To BOO/BPP Switch - Turn ignition off. Disconnect BOO/BPP switch connector. Using DVOM, measure voltage between and ground. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair open Light Green/Red wire. Reconnect all connectors and retest system.
  5. Check BOO/BPP Switch Signal To Shift Interlock Actuator - Disconnect shift lock actuator connector. Depress brake pedal. Using DVOM, measure voltage between shift interlock actuator connector Red/Light Green (Taurus and Sable) or Light Green (Crown Victoria and Grand Marquis) wire and ground. Voltage should be more than 10 volts with brake pedal depressed and less than 1 volt with brake pedal released. If voltage is as specified, go to next step. If voltage is not as specified, repair open Red/Light Green (Taurus and Sable) or Light Green (Crown Victoria and Grand Marquis) wire between BOO/BPP switch and shift interlock actuator.
  6. Check Shift Interlock Actuator Ground - Ensure gearshift lever is in "P" position. Using DVOM, measure resistance between shift interlock actuator connector Black wire and ground. If resistance is less than 5 ohms, replace shift interlock actuator. If resistance is more than 5 ohms, repair open in Black wire between shift interlock actuator and ground. See «WIRING DIAGRAMS»(ref-149546-S18937341362002101400000) .

Verify customer complaint. Visually inspect the following components of the shift interlock system

  1. Shift lever assembly for damage or misadjustment.
  2. Ignition switch/interlock cable for damage or misadjustment.
  3. Switches and brackets for damaged. Electrical Components
  4. Fuses
  5. Loose Or Damaged Connections
  6. Brake On/Off (BOO) Or Brake Pedal Position (BPP) Switch Connections
  7. Wiring Harness
  1. Check Brakelight Operation - Depress brake pedal. If brakelights illuminate, go to step 7 . If brakelights do not illuminate, go to next step.
  2. Check Fuse - Check appropriate fuse (hot at all times circuit) in fuse panel. See «WIRING DIAGRAMS»(ref-149546-S18937341362002101400000) . If fuse is okay, go to step 4 . If fuse in blown, go to next step.
  3. Check Wire To BOO/BPP For Short To Ground - Turn ignition off. Disconnect BOO/BPP switch connector. Using DVOM, measure resistance of wire between fuse (hot at all times circuit) terminal and BOO/BPP switch harness connector terminal. If resistance is more 10 k/ohms, go to next step. If resistance is less than 10 k/ohms, repair wire between fuse panel and BOO/BPP switch for short to ground. Reconnect all connectors and retest system.
  4. Check Wire To BOO/BPP Switch For Open - Using DVOM, measure resistance of wire between fuse (hot at all times circuit) terminal and corresponding BOO/BPP switch harness connector terminal. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in wire between fuse panel and BOO/BPP switch. Reconnect all connectors and retest system.
  5. Check BOO/BPP Switch - Using DVOM, measure resistance between 2 outer BOO/BPP connector terminals. Apply brakes and recheck resistance. Resistance should be more than 10 k/ohms without brake pedal applied and less than 5 ohms with brake pedal applied. If switch operates as specified, go to next step. If switch does not operate as specified, replace BOO/BPP switch and retest system.
  6. Check Wire To Shift Interlock Actuator For Short To Ground - Disconnect shift interlock actuator connector. Using DVOM, measure resistance of BOO/BPP switch-to-shift interlock actuator harness connector wire and ground. If resistance is less than 10 k/ohms, go to next step. If resistance is more than 10 k/ohms, repair short in wire between BOO/BPP switch connector and shift interlock actuator connector. Reconnect all connectors and retest system.
  7. Check Wire To Shift Interlock Actuator For Open - Using DVOM, measure resistance of wire between BOO/BPP switch connector and shift interlock actuator connector. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in wire between BOO/BPP switch connector and shift interlock actuator connector. Reconnect all connectors and retest system.
  8. Check Voltage To Shift Interlock Actuator - Turn ignition on. Using DVOM, measure voltage between wire from appropriate fuse (hot in RUN circuit) and ground. If battery voltage is present, go to step 12 . If battery voltage is not present, go to next step.
  9. Check Fuse - Turn ignition off. Remove and check appropriate fuse (hot in RUN circuit). See «WIRING DIAGRAMS»(ref-149546-S18937341362002101400000) . If fuse is okay, go to step 11 . If fuse is blown, go to next step.
  10. Check Wire To Shift Interlock Actuator For Short To Ground - Using DVOM, measure resistance between shift interlock actuator connector terminal (hot in RUN circuit) and ground. If resistance is more than 10 k/ohms, go to next step. If resistance is less than 10 k/ohms, repair open in wire between fuse panel (hot in RUN circuit) and shift interlock actuator connector. Reconnect all connectors and retest system.
  11. Check Wire To Shift Interlock For Open - Using DVOM, measure resistance of wire between fuse terminal (hot in RUN circuit) and shift interlock actuator connector terminal. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open wire between fuse panel (hot in RUN circuit) and shift interlock actuator connector. Reconnect all connectors and retest system.
  12. Check Shift Interlock Actuator Ground For Open - Turn ignition on. Using DVOM, measure resistance between shift interlock actuator connector Black wire and ground. If resistance is less than 5 ohms, replace shift interlock actuator. Reconnect all connectors and retest system. If resistance is more than 5 ohms, repair open Black wire between shift interlock actuator connector and ground.

Verify customer complaint. Visually inspect the following components of the shift interlock system

  1. Shift lever assembly for damage or misadjustment.
  2. Ignition switch/interlock cable for damage or misadjustment.
  3. Switches and brackets for damaged. Electrical Components
  4. Fuses (METER, ROOM (Escort and Tracer) Or HORN (Escort ZX2) And STOP)
  5. Loose Or Damaged Connections
  6. Brake On/Off (BOO) Or Brake Pedal Position (BPP) Switch Connections
  7. Faulty Park Sense switch
  8. Wiring Harness
  1. Check Fuses - Check METER, ROOM or HORN and STOP fuses located in the interior fuse junction block. If fuses are okay, go to step 4 . If fuses are not okay, go to next step.
  2. Check Electrical System - With ignition off, replace blown fuse(s). Turn ignition on. If the fuse blows again, go to next step. If the fuse does not blow again, go to step 4 .
  3. Check For Short To Ground - Turn ignition off. Remove METER, ROOM or HORN and STOP fuses. Locate and disconnect shift interlock actuator connector. Using DVOM, measure and record resistance between each METER, ROOM or HORN and STOP fuse holder terminals and ground. If each resistance is more than 10k/ohms, reinstall fuses and go to next step. If any resistance is less than 10 k/ohms, repair short in appropriate wire. See «WIRING DIAGRAMS»(ref-149546-S18937341362002101400000) . Reconnect all connectors and retest system.
  4. Check Supply Voltage To Shift Lock Actuator - Turn ignition off. Disconnect shift interlock actuator connector. Turn ignition on. Using DVOM, measure voltage between shift lock actuator wiring harness connector Blue/Red or Green/Yellow wire and ground. See «WIRING DIAGRAMS»(ref-149546-S18937341362002101400000) for appropriate wire colors. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair open in appropriate wire.
  5. Check BOO Switch Signal To Shift Lock Actuator - Turn ignition off. Connect DVOM leads between shift lock actuator harness connector Green wire and ground. While monitoring DVOM, press brake pedal. If voltage is less than 10 volts, go to next step. If voltage is more than 10 volts, diagnose problem in stoplight circuit. See appropriate EXTERIOR LIGHTS article in ACCESSORIES & EQUIPMENT.
  6. Check Park Sense Switch Ground For Open - Disconnect park sense switch connector. Using DVOM, measure resistance between park range switch harness connector Black wire (right side wire with connector tab facing upward) and ground. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open Black wire. Reconnect all connectors and retest system.
  7. Check Park Sense Switch - Using DVOM, measure resistance between park sense switch connector terminals. Resistance should be less than 5 ohms with selector lever release button released and more than 10 k/ohms with selector lever release button pressed or selector lever in any position other than Park. If resistance is not as specified, replace selector lever and park sense switch. If resistance is as specified, replace shift interlock actuator. Reconnect all connectors and retest system.

Verify customer complaint. Visually inspect the following components of the shift interlock system

  1. Shift lever assembly and cable for damage or misadjustment.
  2. Ignition switch/interlock cable for damage or misadjustment. Electrical Components
  3. Open Or Shorted Circuits
  4. Loose Or Damaged Connections
  5. Brake On/Off (BOO) Or Brake Pedal Position (BPP) Switch Connections
  6. Faulty Steering Column/Ignition/Lighting (SCIL) Control Module
  7. Fuse(s)
  8. Faulty Bulbs
  1. Check Shift Interlock In ACC Position - Turn ignition to ACC position. With brake pedal released, try and move selector lever to "R" position. If lever moves to "R" position, go to step 3. If lever does not move to "R" position, go to next step.
  2. Check System Operation - Turn ignition on. Depress brake pedal and move selector lever to "R" position. If lever does not move to "R" position, go to step 4. If lever moves to "R" position, system is operating normally. Check wiring harness and connectors for intermittent operation.
  3. Check Steering Column Adjustment - Actuate steering column adjustment switch to tilt or telescope position. If steering column adjusts, go to next step. If steering column does not adjust, diagnose communication problem with SCIL Module. See appropriate MODULE COMMUNICATION NETWORK article in ACCESSORIES & EQUIPMENT.
  4. Check Stoplight Operation - Connect NGS scan tool to Datalink connector. Select SCIL PID BOO _ SCI display. While monitoring scan tool display, depress brake pedal. If PID BOO _ SCI changes from off to on, go to next step. If PID BOO _ SCI does not change, diagnose BOO/BPP switch circuit. See appropriate EXTERIOR LIGHTS article in ACCESSORIES & EQUIPMENT.
  5. Check SCIL Module Output To Shift Interlock Solenoid - Turn ignition off. Locate and disconnect shift interlock solenoid connector. Turn ignition on. Connect DVOM between shift interlock solenoid harness connector Light Blue/Black wire and ground. On NGS scan tool, select SCIL MODULE ACTIVE COMMAND BRAKE SYSTEM. While measuring voltage with DVOM, activate BRK/SHIFT on NGS scan tool. If battery voltage is present, go to step 8. If battery voltage is not present, go to next step.
  6. Check Light Blue/Black Wire For Short To Ground - Turn ignition off. Locate and disconnect SCIL module connector. Using DVOM, measure resistance between SCIL module connector C287 terminal No. 9 and ground. (Scheme 100)and see scheme 10. If resistance is more than 10 k/ohms, go to next step. If resistance is less than 10 k/ohms, repair short Light Blue/Black wire between SCIL module connector and shift interlock solenoid connector.
  7. Check Light Blue/Black Wire For Open - Using DVOM, measure resistance of Light Blue/Black wire between SCIL module terminal No. 9 and shift interlock solenoid connector. If resistance is less than 5 ohms, replace SCIL module. Reconnect all connectors and retest system. If resistance is more than 5 ohms, repair open in Light Blue/Black wire.
  8. Check Shift Interlock Solenoid Ground For Open - Using DVOM, measure resistance between shift interlock solenoid connector Black wire and ground. If resistance is less than 5 ohms, replace shift interlock solenoid. Reconnect all connectors and retest system. If resistance is more than 5 ohms, repair open Black wire between shift interlock solenoid connector and ground.
  9. Check Signal To Shift Interlock Solenoid - Disconnect shift interlock solenoid connector. Using DVOM, measure voltage between shift interlock solenoid connector Light Blue/Black wire terminal and ground. If battery voltage is present, go to next step. If battery voltage is not present, replace shift interlock solenoid. Reconnect all connectors and retest system.
  10. Check SCIL Module For Short To Power - Disconnect SCIL module connector. Using DVOM, measure voltage between Light Blue/Black wire and ground. If battery voltage is present, repair short in Light Blue/Black wire. Reconnect all connectors and retest system. If battery voltage is not present, replace SCIL module. Reconnect all connectors and retest system.

Scheme 100

Scheme 100
Scheme 100

Verify customer complaint. Visually inspect the following components of the shift interlock system

  1. Shift lever assembly and cable for damage or misadjustment.
  2. Ignition switch/interlock cable for damage or misadjustment. Electrical Components
  3. Open Or Shorted Circuits
  4. Loose Or Damaged Connections
  5. Brake On/Off (BOO) Or Brake Pedal Position (BPP) Switch Connections
  6. Fuse(s)
  7. Faulty PCM
  8. Faulty Bulbs
  1. Check Fuse No. 1 (15A) - Remove and check fuse No. 1 located in the internal fuse panel. If the fuse is okay, go to step 3 . If the fuse is not okay, go to next step.
  2. Check Purple/Orange Wire Resistance - Ensure fuse No. 1 is removed. Disconnect shift lock actuator connector located near ignition switch. Using DVOM, measure resistance of Purple/Orange wire between shift lock actuator wiring harness connector terminal and ground. If resistance is more than 10 k/ohms, go to next step. If resistance is less than 10 k/ohms, repair short Purple/Orange wire. Reconnect all connectors and retest system.
  3. Check Power Supply To Shift Lock Actuator - Reinstall fuse No. 1. Disconnect shift lock actuator connector. Using DVOM, measure voltage between Purple/Orange wire terminal and ground. Turn ignition on. If battery voltage is present, go to next step. If battery voltage is not present, repair open Purple/Orange wire. Reconnect all connectors and retest system.
  4. Check Stoplight Operation - Depress brake pedal. If stoplights turn on, go to next step. If stoplights do not turn on, diagnose BOO/BPP switch. See appropriate EXTERIOR LIGHTS article in ACCESSORIES & EQUIPMENT.
  5. Check Power Supply Between BOO/BPP Switch & Shift Lock Actuator - With brake pedal depressed, measure voltage of Red/Light Green wire between shift lock actuator connector and ground. If battery voltage is present, go to next step. If battery voltage is not present, repair open Red/Light Green wire. Reconnect all connectors and retest system.
  6. Check Ground Circuit Resistance - With shift lock actuator connector disconnected, measure resistance between Black wire terminal and ground. If resistance is less than 5 ohms, replace shift lock actuator. If resistance is more than 5 ohms, repair open Black wire. Reconnect all connectors and retest system.

Verify customer complaint. Visually inspect the following components of the shift interlock system

  1. Shift lever assembly for damage or misadjustment.
  2. Ignition switch/interlock cable for damage or misadjustment.
  3. Switches and brackets for damaged. Electrical Components
  4. Fuses (RELAYS)
  5. Loose Or Damaged Connections
  6. Brake On/Off (BOO) Switch Connections
  7. Wiring Harness
  1. Check Fuse - Check 10A RELAYS fuse located in the interior fuse junction block. If fuse is okay, go to step 4 . If fuse is not okay, go to next step.
  2. Check Electrical System - With ignition off, replace blown fuse. Turn ignition on. If the fuse blows again, go to next step. If the fuse does not blow again, go to step 4 .
  3. Check For Short To Ground - Turn ignition off. Remove RELAYS fuse. Locate and disconnect Speed Control Disengage/BOO switch connector. Using DVOM, measure and record resistance between RELAY fuse holder terminal and ground. If resistance is more than 10 k/ohms, reinstall fuse and go to next step. If resistance is less than 10 k/ohms, repair short in Blue wire between fuse panel Speed Control Disengage/BOO switch. Reconnect all connectors. Install gearshift lever, console and knob.
  4. Check Shift Lock Actuator Ground - Ensure gearshift lever is in "P" position. Using DVOM, measure resistance between shift lock actuator connector Black wire and ground. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in Black wire between shift lock actuator and ground. See «WIRING DIAGRAMS»(ref-149546-S18937341362002101400000) .
  5. Check Supply Voltage To Shift Lock Actuator - Turn ignition on. Using DVOM, measure voltage between shift lock actuator wiring harness connector White wire and ground. If voltage is more than 10 volts, replace shift lock actuator. If voltage is less than 10 volts, repair open in White wire.
  6. Check Speed Control Disengage/BOO Switch - Turn ignition off. Disconnect BOO switch connector. Using DVOM, measure and record resistance between BOO switch connector terminals. Depress brake pedal and measure resistance of BOO switch terminals again. Resistance should be less than 5 ohms with brake pedal depressed and more than 10 k/ohms with brake pedal released. If resistance is as specified, repair open White wire between BOO switch and shift lock actuator. If resistance is not as specified, replace Speed Control Disengage/BOO switch. Reconnect all connectors and retest system.
  7. Check Stoplight Operation - If stoplights operate when brake pedal is depressed, repair open Green wire between BOO switch and shift lock actuator. If stoplights do not operate when brake pedal is depressed, diagnose problem in stoplight circuit. See appropriate EXTERIOR LIGHTS article in ACCESSORIES & EQUIPMENT.

More articles — Shift Interlock Systems