Shift Interlock System: Diagnosis Mercury Sable IV

PRELIMINARY INSPECTION

Verify the customer concern by operating the shift interlock system. Visually inspect for obvious signs of mechanical and electrical damage. If the fault is not visually evident, diagnose by symptom. See SYMPTOM DIAGNOSIS .

SYMPTOM DIAGNOSIS

SYMPTOM TEST INDEX

Diagnostic Procedure

1. Turn ignition switch to OFF position. Check interior panel fuse No. 23 (15-amp). Is fuse okay? If so, reinstall fuse and go to next step. If not, replace fuse. If fuse fails again, check circuit for short to ground and test the system for normal operation.
2. Check interior panel fuse No. 24 (7.5-amp). Is fuse okay? If so, reinstall fuse and go to next step. If not, replace fuse, then attempt to shift gearshift lever. If fuse fails again, check circuit for short to ground and test the system for normal operation.
3. Check interior panel fuse No. 30 (7.5-amp). Is fuse okay? If so, replace fuse and go to next step. If not, replace fuse. If fuse fails again, check circuit for short to ground and test the system for normal operation.
4. Disconnect gearshift lever unit. Turn ignition switch to ON position. Measure the voltage between gearshift lever unit harness connector terminals No. 1 (ignition feed circuit), No. 3 (battery feed circuit) and ground. (Scheme 43) Is voltage greater than 10 volts? If so, go to next step. If not, repair open in appropriate circuit and test the system for normal operation.
5. Turn ignition switch to OFF position. Disconnect instrument interface module. Measure the resistance in park lock solenoid circuit between gearshift lever unit harness connector terminal No. 2 and instrument interface module harness connector terminal No. 8. (Scheme 44) Is the resistance less than 5 ohms? If so, go to next step. If not, repair open in park lock solenoid circuit and test the system for normal operation.
6. Measure the resistance between gearshift lever unit harness connector terminal No. 4 and instrument interface module harness connector terminal No. 9. (Scheme 45) Is the resistance less than 5 ohms? If so, go to next step. If not, repair open in appropriate wire and test the system for normal operation.
7. Turn ignition switch to ON position. Measure the voltage in park lock solenoid circuit between gearshift lever unit harness connector terminal No. 2 and ground. (Scheme 46) Is voltage less than one volt? If so, go to next step. If not, repair short to voltage in park lock solenoid circuit and test the system for normal operation.
8. Turn ignition switch to OFF position. Connect gearshift lever unit. Connect a jumper wire between instrument interface module connector terminal No. 8 and ground. (Scheme 47) Turn ignition switch to ON position. Attempt to move gearshift lever from Park to Reverse. Does the gearshift lever move from Park to Reverse? If so, go to next step. If not, replace gearshift lever unit. See «GEARSHIFT LEVER UNIT»(ref-140004-S09945352702002051500000) under REMOVAL & INSTALLATION. Remove jumper wire. Reconnect all components and test the system for normal operation.
9. Turn ignition switch to OFF position. Disconnect instrument interface module harness connector. Measure the resistance in ground circuit between instrument interface module harness connector terminal No. 15 and ground. (Scheme 48) Is the resistance less than 5 ohms? If so, go to next step. If not, repair open in ground circuit and test the system for normal operation.
10. Turn ignition switch to ON position. Measure the voltage in ignition feed circuit between instrument interface module connector terminal No. 11 and ground. (Scheme 49) Is the voltage greater than 10 volts? If so, go to next step. If not, repair open in ignition feed circuit. Disconnect breakout box. Reconnect all components and test the system for normal operation.
11. Turn ignition switch to OFF position. Depress brake pedal. Observe brakelights. Are brakelights on? If so, go to next step. If not, diagnose the brakelight concern. See EXTERIOR LIGHTS article in ACCESSORIES & EQUIPMENT.
12. Disconnect PCM harness connector. Install breakout box to PCM wiring harness connector. Leave PCM disconnected. Measure the resistance between the breakout box test terminal No. 92 and instrument interface module harness connector terminal No. 7. (Scheme 50) Is the resistance less than 5 ohms? If so, replace instrument interface module and test the system for normal operation. If not, repair open in Green/Black wire. Disconnect breakout box. Reconnect all components and test the system for normal operation.

Scheme 43

Scheme 44

Scheme 45

Scheme 46

Scheme 47

Scheme 48

Scheme 49

Scheme 50

1. If the shift interlock system does not lock correctly, go to step 3. If shift interlock system does not release correctly, go to next step.
2. Turn ignition switch to OFF position. Disconnect shift interlock actuator harness connector C2008. Turn ignition switch to ON position. Apply the brake pedal. Measure the voltage in Brake Pedal Position (BPP) switch signal circuit between the shift interlock actuator harness connector terminal No. 1 and ground. (Scheme 51) Is the voltage greater than 10 volts? If so, replace shift interlock actuator. See «SHIFT INTERLOCK ACTUATOR»(ref-140004-S02147698232002051500000) under REMOVAL & INSTALLATION. After repairs, test the system for normal operation. If not, repair open in BPP switch signal circuit between shift interlock actuator and BPP switch, reconnect all components and test the system for normal operation.
3. Turn ignition switch to OFF position. Disconnect shift interlock actuator harness connector C2008. Turn ignition switch to ON position. Measure the voltage in ignition feed circuit between the shift interlock actuator harness terminal No. 3 and ground. (Scheme 51) Is the voltage greater than 10 volts? If so, go to next step. If not, repair open in ignition feed circuit, reconnect all components and test the system for normal operation.
4. Turn ignition switch to OFF position. Measure the resistance in ground circuit between the shift interlock actuator harness connector terminal No. 2 and ground. (Scheme 52) Is the resistance less than 5 ohms? If so, replace shift interlock actuator. See «SHIFT INTERLOCK ACTUATOR»(ref-140004-S02147698232002051500000) under REMOVAL & INSTALLATION. After repairs, test the system for normal operation. If not, repair open in ground circuit, reconnect all components and test the system for normal operation

Scheme 51

Scheme 52

1. Depress the brake pedal while the brakelights are being observed. Do the brakelights operate correctly? If so, go to next step. If not, go to step 8.
2. Test shift interlock actuator and ignition relay. See «SHIFT INTERLOCK & IGNITION RELAY»(ref-140004-S35654952892002052200000) under COMPONENT TESTS. Are the shift interlock actuator and ignition relays okay? If so, go to next step. If not, replace faulty relay and test the system for normal operation.
3. Turn ignition switch to OFF position. Disconnect Central Junction Box (CJB) harness connector C270D. Turn ignition switch to ON position. Measure the voltage between CJB harness connector C270D terminal No. 7 and ground. (Scheme 55) Is the voltage greater than 10 volts? If so, go to step 5. If not, go to next step.
4. Turn ignition switch to OFF position. Disconnect CJB harness connector C270D and ignition switch. Measure the resistance between CJB harness connector C270D terminal No. 15 and ignition switch terminal No. 1. (Scheme 56) Is the resistance less than 5 ohms? If so, diagnose ignition switch concern. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If not, repair open in ignition feed circuit and test the system for normal operation.
5. Disconnect CJB harness connector C270E. Measure the resistance in ground circuit between CJB harness connector C270E terminal No. 10 and ground. (Scheme 57) Is the resistance less than 5 ohms? If so, go to next step. If not, repair open in ground circuit and test the system for normal operation.
6. Connect CJB harness connectors C270E and C270D. Disconnect shift interlock actuator relay harness connector C2068. Turn ignition switch to ON position. Measure the voltage between shift interlock actuator relay terminal No. 86 and ground. (Scheme 58) Is the voltage greater than 10 volts? If so, go to next step. If not, repair open in shift interlock actuator relay ignition feed circuit and test the system for normal operation.
7. Disconnect shift interlock actuator relay harness connector. Measure the voltage between shift interlock actuator relay terminal No. 87 and ground while the brake pedal is depressed. (Scheme 59) Is the voltage greater than 10 volts? If so, go to step 10. If not, go to next step.
8. Disconnect Brake Pedal Position (BPP) switch. Measure voltage in battery feed circuit at BPP switch harness connector terminal No. 2. Is the voltage greater than 10 volts? If so, go to next step. If not, repair open in battery feed circuit and test the system for normal operation.
9. Measure resistance between terminals No. 1 and 2 of BPP switch while the brake pedal is depressed. Is the resistance less than 5 ohms? If so, repair open in Light Green wire between shift interlock actuator relay and BPP switch and test the system for normal operation. If not, replace BPP switch. See «BRAKE PEDAL POSITION SWITCH»(ref-140004-S11825150462002052100000) under REMOVAL & INSTALLATION. After repairs, test the system for normal operation.
10. Turn ignition switch to OFF position. Connect shift interlock actuator relay. Disconnect shift interlock actuator diode harness connector. Turn ignition switch to ON position. Measure the voltage between shift interlock actuator diode terminal No. 1 and ground. Is the voltage greater than 10 volts? If so, go to next step. If not, repair open in Gray/Yellow wire between shift interlock actuator diode and shift interlock actuator relay. After repairs, test the system for normal operation.
11. Turn ignition switch to OFF position. Disconnect instrument cluster harness connector C220B. Connect shift interlock actuator diode. Turn ignition switch to ON position. Measure the voltage between instrument cluster harness connector C220B terminal No. 2 and ground. (Scheme 60) Is the voltage greater than 10 volts? If so, go to next step. If not, repair open in White/Red wire between instrument cluster and shift interlock actuator diode. After repairs, test the system for normal operation.
12. Turn ignition switch to OFF position. Connect instrument cluster harness connector C220B. Disconnect shift interlock actuator/module harness connector C2008. Turn ignition switch to ON position. Measure the voltage between shift interlock actuator/module harness connector C2008 terminal No. 7 and ground. (Scheme 61) Is the voltage greater than 10 volts? If so, go to step 14. If not, go to next step.
13. Turn ignition switch to OFF position. Disconnect instrument cluster harness connector C220B. Measure the resistance between shift interlock actuator/module harness connector C2008 terminal No. 7 and instrument cluster harness connector C220B terminal No. 5. (Scheme 62) Is the resistance less than 5 ohms? If so, replace instrument cluster. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. After repairs, test the system for normal operation. If not, repair open in Light/Blue wire between shift interlock actuator/module and instrument cluster and test the system for normal operation.
14. Measure the resistance between shift interlock actuator/module C2008 terminals No. 3 and 7 (component side) while selecting each gearshift position. (Scheme 63) Is the resistance greater than 10 k/ohms while in the Park position, and less than 5 ohms while in any other selected gearshift position? If so, go to next step. If not, replace shift interlock actuator/module. See «SHIFT INTERLOCK ACTUATOR»(ref-140004-S02147698232002051500000) under REMOVAL & INSTALLATION. After repairs, test the system for normal operation.
15. Measure the resistance between shift interlock actuator/module harness connector C2008 terminal No. 3 and ground. (Scheme 64) Is the resistance less than 5 ohms? If so, go to next step. If not, repair open in shift interlock actuator/module ground circuit and test the system for normal operation.
16. Turn ignition switch to OFF position. Connect shift interlock actuator/module harness connector. Disconnect Transmission Range (TR) sensor harness connector C167. Turn ignition switch to ON position. Measure the voltage between TR sensor harness connector C167 terminal No. 11 and ground. (Scheme 65) Is the voltage greater than 10 volts? If so, go to next step. If not, repair open in ignition feed circuit and test the system for normal operation.
17. Ensure gearshift lever is in Park position. Measure the resistance between TR sensor C167 terminals No. 1 and 11 (component side). Is the resistance less than 5 ohms? If so, go to next step. If not, replace TR sensor. See «TRANSMISSION RANGE SENSOR»(ref-140004-S31779616662002052200000) under REMOVAL & INSTALLATION. After repairs, test the system for normal operation.
18. Measure the resistance between TR sensor harness connector C167 terminal No. 1 and ground. (Scheme 66) Is the resistance less than 5 ohms? If so, go to next step. If not, repair open in ground circuit and test the system for normal operation.
19. Turn ignition switch to OFF position. Connect TR sensor harness connector C167. Disconnect shift interlock actuator/module harness connector C2008. Turn ignition switch to ON position. Measure the voltage between shift interlock actuator/module harness connector C2008 terminal No. 5 and ground. (Scheme 67) Is the voltage greater than 10 volts? If so, go to next step. If not, repair open in Red wire between shift interlock actuator/module and shift interlock actuator relay. After repairs, test the system for normal operation.
20. Turn ignition switch to OFF position. Measure the resistance between shift interlock actuator/module harness connector C2008 terminal No. 2 and ground. (Scheme 68) Is the resistance less than 5 ohms? If so, replace shift interlock actuator/module. See «SHIFT INTERLOCK ACTUATOR»(ref-140004-S02147698232002051500000) under REMOVAL & INSTALLATION. After repairs, test the system for normal operation. If not, repair open in shift lock solenoid ground circuit and test the system for normal operation.

Scheme 53

Scheme 54

Scheme 55

Scheme 56

Scheme 57

Scheme 58

Scheme 59

Scheme 60

Scheme 61

Scheme 62

Scheme 63

Scheme 64

Scheme 65

Scheme 66

Note. See appropriate wiring diagram to diagnose electrical circuits and identify fuses and circuit numbers. See CONNECTOR IDENTIFICATION and WIRING DIAGRAMS .

1. Turn ignition switch to OFF position. On Escort, check METER fuse (10-amp), ROOM fuse (10-amp) and STOP fuse (15-amp). On ZX2 Coupe models, check HORN fuse (15-amp), METER fuse (10-amp) and STOP fuse (20-amp). Are the fuses okay? If so, go to next step. If not, replace the fuse in question and test the system for normal operation. If the fuse fails again, check for short to ground in appropriate circuit. Repair as necessary and test the system for normal operation.
2. Ensure ignition switch is in OFF position. Disconnect shift interlock actuator harness connector. Turn ignition switch to ON position. Measure the voltage between ground and shift interlock actuator harness connector terminals No. 3 and 4. (Scheme 69) Are the voltages greater than 10 volts? If so, go to next step. If not, repair open in appropriate circuit and test the system for normal operation.
3. Turn ignition switch to OFF position. Depress and hold the brake pedal. Measure the voltage between shift interlock actuator harness connector terminal No. 1 (Green wire) and ground. (Scheme 70) Is the voltage greater than 10 volts? If so, release the brake pedal and go to step 6. If not, go to next step.
4. Disconnect Brake Pedal Position (BPP) switch. Measure voltage in Green/White wire at BPP switch harness connector. Is the voltage greater than 10 volts? If so, go to next step. If not, repair open in Green/White wire and test the system for normal operation.
5. Measure resistance between terminals No. 1 and 2 of BPP switch while the brake pedal is depressed. Is the resistance less than 5 ohms? If so, repair open in Green wire between shift interlock actuator relay and BPP switch and test the system for normal operation. If not, replace BPP switch. See «BRAKE PEDAL POSITION SWITCH»(ref-140004-S11825150462002052100000) under REMOVAL & INSTALLATION. After repairs, test the system for normal operation.
6. Disconnect park range switch harness connector. Measure the resistance between park range switch and ground. (Scheme 71) Is the resistance less than 5 ohms? If so, go to next step. If not, repair open in Black wire and test the system for normal operation.
7. Measure the resistance between the park range switch terminals (component side), while pressing and releasing the park release button, then measure the resistance between the park range switch terminals with the shifter in the Reverse, Drive and Low positions. Is the resistance less than 5 ohms with the park release button out, and greater than 10 k/ohms with the park release button in or the shifter in the Reverse, Drive and Low positions? If so, replace the shift interlock actuator. See «SHIFT INTERLOCK ACTUATOR»(ref-140004-S02147698232002051500000) under REMOVAL & INSTALLATION. After repairs, test the system for normal operation. If not, replace the gearshift selector lever and test the system for normal operation. See «GEARSHIFT LEVER UNIT»(ref-140004-S09945352702002051500000) under REMOVAL & INSTALLATION.

Scheme 67

Scheme 68

Scheme 69

1. Apply brake pedal and view brakelights. Do brakelights illuminate? If so, go to step 7. If not, go to next step.
2. Measure the resistance in fuse No. 23 (15-amp). Is resistance of fuse 5 ohms or less? If so, go to step 4. If not, go to next step.
3. Disconnect Brake Pedal Position (BPP) switch. Measure the resistance between BPP switch harness connector terminal No. 2 and ground. (Scheme 72) Is the resistance 10 ohms or less? If so, repair short to ground in Light Green/Red wire and test the system for normal operation. If not, go to next step.
4. Measure the resistance between output side of fuse No. 23 (15-amp) and BPP switch. (Scheme 73) Is the resistance 5 ohms or less? If so, go to next step. If not, repair open in Light Green/Red wire and test the system for normal operation.
5. Measure resistance of BPP switch while open (OFF) and closed (ON). (Scheme 74) Is resistance of switch greater than 10 ohms while OFF, and 5 ohms or less while ON? If so, go to next step. If not, replace BPP switch and test the system for normal operation. See «BRAKE PEDAL POSITION SWITCH»(ref-140004-S11825150462002052100000) under REMOVAL & INSTALLATION.
6. Disconnect shift interlock actuator harness connector. Measure resistance between shift interlock actuator harness connector terminal No. 2 and ground. (Scheme 75) Is resistance 10 ohms or less? If so, repair short to ground and test the system for normal operation. If not, go to next step.
7. Measure resistance between shift interlock actuator harness connector terminal No. 2 and BPP switch harness connector terminal No. 1. (Scheme 76) Is resistance 5 ohms or less? If so, go to next step. If not, repair open and test the system for normal operation.
8. Turn ignition switch to ON position. Measure voltage between shift interlock actuator harness connector terminal No. 3 and ground. (Scheme 77) Is the voltage greater than 10 volts? If so, go to step 12. If not, go to next step.
9. Turn ignition switch to OFF position. Measure resistance in fuse No. 26 (7.5-amp). Is resistance of fuse 5 ohms or less? If so, go to step 11. If not, go to next step.
10. Measure resistance between shift interlock actuator harness connector terminal No. 3 and ground. (Scheme 78) Is resistance 10 ohms or less? If so, repair short to ground in Gray/Yellow wire and test the system for normal operation. If not, go to next step.
11. Measure resistance between output side of fuse No. 26 (7.5-amp) and shift interlock actuator harness connector terminal No. 3. (Scheme 79) Is resistance 5 ohms or less? If so, go to next step. If not, repair open in Gray/Yellow wire and test the system for normal operation.
12. Measure the resistance between ground and shift interlock actuator harness connector terminals No. 1 and 6. (Scheme 80)and (Scheme 81). Are the resistances less than 5 ohms? If so, shift interlock actuator is not serviceable separate from steering column. Replace steering column. See appropriate STEERING COLUMNS article in STEERING. After repairs, test the system for normal operation. If not, repair open in appropriate ground circuit and test the system for normal operation.

Scheme 70

Scheme 71

Scheme 72

Scheme 73

Scheme 74

Scheme 75

Scheme 76

Scheme 77

Scheme 78

Scheme 79

Note. Brake Pedal Position (BPP) switch is also referred to as brakelight switch.

1. Turn ignition switch to ON position. Depress brake pedal. Are the brakelights ON? If so, go to step 5. If not, go to next step.
2. Measure resistance in fuse No. 42 (15-amp), located in Central Junction Box (CJB). Is fuse No. 42 okay? If so, go to next step. If not, replace fuse No. 42 and recheck system. If fuse fails again, repair short to ground in Green/White wire.
3. Turn ignition switch to OFF position. Disconnect brakelight switch harness connector. Turn ignition switch to ON position. Measure voltage at brakelight switch harness connector terminal No. 3. Is voltage greater than 10 volts? If so, go to next step. If not, repair open in Green/White wire. Reconnect all components and test the system for normal operation.
4. Measure the resistance of the brakelight switch while open (OFF) and closed (ON). Is the resistance of switch greater than 10 k/ohms while OFF, and 5 ohms or less while ON? If so, go to next step. If not, replace brakelight switch and test the system for normal operation. See «BRAKE PEDAL POSITION SWITCH»(ref-140004-S11825150462002052100000) under REMOVAL & INSTALLATION.
5. Turn ignition switch to ON position. Place gearshift in Park position. Can ignition switch be turned to OFF position and can key be removed only when gear selector in Park? If so, go to next step. If not, go to step 10.
6. Turn ignition switch to OFF position. Disconnect gearshift lever unit harness connector. Measure the voltage between gearshift lever unit harness connector terminal No. 3 and ground. (Scheme 82) Is the voltage zero volts when brake pedal is not depressed, and battery voltage when brake pedal is depressed? If so, go to next step. If not, repair open between gearshift lever unit and brakelight switch.
7. Measure resistance between gearshift lever unit harness connector terminal No. 1 and ground. (Scheme 83) Is resistance less than 5 ohms? If so, go to next step. If not, repair open in Black wire and test the system for normal operation.
8. Measure resistance at the gearshift lever unit terminals No. 1 and 3 (component side). Place gearshift lever in Park position. Is resistance between 20 and 35 ohms? If so, go to next step. If not, replace shift interlock actuator. See «SHIFT INTERLOCK ACTUATOR»(ref-140004-S02147698232002051500000) under REMOVAL & INSTALLATION. After repairs, test the system for normal operation.
9. Position gearshift lever into Reverse, Neutral, Drive, 1 and 2 positions. If necessary, release gearshift mechanically. See «DESCRIPTION & OPERATION»(ref-140004-S10663330462002051500000). Is resistance greater than 10 ohms in all mentioned positions? If so, shift interlock actuator is electrically okay. Check for mechanical fault. If not, replace shift interlock actuator. See «SHIFT INTERLOCK ACTUATOR»(ref-140004-S02147698232002051500000) under REMOVAL & INSTALLATION. After repairs, test the system for normal operation.
10. Measure resistance in fuse No. 8 (20-amp), located in CJB. Is the fuse No. 8 (20-amp) okay? If so, go to next step. If not, replace fuse and recheck the system.
11. Disconnect gearshift lever unit harness connector. Connect a jumper wire between gearshift lever unit harness connector terminal No. 2 and ground. (Scheme 84) Be sure that only terminal No. 2 and not another pin is grounded. Can ignition key be removed when jumper wire is connected? If so, go to next step. If not, go to step 13.
12. Measure resistance between gearshift lever unit harness connector terminal No. 1 and ground. (Scheme 83) Is resistance less than 5 ohms? If so, replace the gearshift lever unit. See «GEARSHIFT LEVER UNIT»(ref-140004-S09945352702002051500000) under REMOVAL & INSTALLATION. After repairs, test the system for normal operation. If not, repair open in Black wire and test the system for normal operation.
13. Measure voltage at fuse No. 8 (20-amp). Is battery voltage indicated? If so, go to next step. If not, repair open in battery feed circuit.
14. Turn ignition switch to OFF position. Disconnect ignition switch harness connector. Measure the voltage between ignition switch harness connector terminal No. 4 and ground. (Scheme 85) Is battery voltage indicated? If so, go to next step. If not, repair open in Red wire and test the system for normal operation.
15. Measure resistance between ignition switch harness connector terminal No. 3 and gearshift lever unit harness connector terminal No. 2. (Scheme 86) Is resistance less than one ohm? If so, key removal inhibit solenoid within the ignition switch is damaged. Replace the ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If not, repair open in Black/Yellow wire and test the system for normal operation.

Scheme 80

Scheme 81

Scheme 82

Scheme 83

Scheme 84

1. Apply the brake pedal and view brakelights. Do the brakelights illuminate? If so, go to step 7. If not, go to next step.
2. Ensure ignition switch is in OFF position. Measure resistance in fuse No. 15 (5-amp). Is the resistance 5 ohms or less? If so, go to step 4. If not, go to next step.
3. Disconnect Brake Pedal Position (BPP) switch harness connector. Measure the resistance between BPP switch harness connector terminal No. 3 and ground. Is the resistance 10 k/ohms or less? If so, repair short to ground in White/Yellow wire and test the system for normal operation. If not, go to next step.
4. Measure the resistance between output side of fuse No. 15 (5-amp) and the BPP switch harness connector terminal No. 3. (Scheme 87) Is the resistance 5 ohms or less? If so, go to next step. If not, repair open in White/Yellow wire and test the system for normal operation.
5. Measure the resistance of the BPP switch while open (OFF) and closed (ON). (Scheme 89) Is the resistance of switch greater than 10 k/ohms while OFF, and 5 ohms or less while ON? If so, go to next step. If not, replace BPP switch. See «BRAKE PEDAL POSITION SWITCH»(ref-140004-S11825150462002052100000) under REMOVAL & INSTALLATION. After repairs, test the system for normal operation.
6. Measure the resistance between BPP switch harness connector terminal No. 1 and ground. see scheme 16 Is the resistance 10 k/ohms or less? If so, repair short to ground in Red/Light Green wire and test the system for normal operation. If not, go to next step.
7. Measure the resistance between the shift interlock actuator harness connector terminal No. 1 and the BPP switch harness connector terminal No. 2. (Scheme 88) Is the resistance 5 ohms or less? If so, go to next step. If not, repair open in Red/Light Green wire and test the system for normal operation.
8. Measure the voltage between shift interlock actuator harness connector terminal No. 3 and ground. see scheme 18 Does battery voltage exist? If so, go to step 12. If not, go to next step.
9. Measure resistance in fuse No. 6 (5-amp). Is the resistance 5 ohms or less? If so, go to step 11. If not, go to next step.
10. Measure the resistance between shift interlock actuator harness connector terminal No. 3 and ground. (Scheme 53) Is the resistance 10 k/ohms or less? If so, repair short to ground in Gray/Yellow wire and test the system for normal operation. If not, go to next step.
11. Measure the resistance between output side of fuse No. 6 (5-amp) and the shift interlock actuator harness connector terminal No. 3. (Scheme 90) Is the resistance 5 ohms or less? If so, go to next step. If not, repair open in Gray/Yellow wire and test the system for normal operation.
12. Measure the resistance between the shift interlock actuator harness connector terminal No. 2 and ground. (Scheme 52) Is the resistance 5 ohms or less? If so, replace shift interlock actuator and test the system for normal operation. See «SHIFT INTERLOCK ACTUATOR»(ref-140004-S02147698232002051500000) under REMOVAL & INSTALLATION. If not, repair open in Black wire and test the system for normal operation.

Scheme 85

Scheme 86

Scheme 87

Scheme 88

1. Ensure ignition switch is turned to OFF position and gearshift lever is in Park position. Connect scan tool to DLC. Turn ignition switch to ON position. Retrieve Front End Module (FEM) DTCs. Do any DTCs exist for the Brake Pedal Position (BPP) switch? If so, diagnose brakelight concern. See EXTERIOR LIGHTS article in ACCESSORIES & EQUIPMENT. If not, go to next step.
2. Turn ignition switch to OFF position. Disconnect shift interlock actuator harness connector. Turn ignition switch to ON position. Press and hold the brake pedal. Measure the voltage between shift interlock actuator harness connector terminal No. 2 and ground. (Scheme 91) Is the voltage greater than 10 volts? If so, go to step 5. If not, go to next step.
3. Turn ignition switch to OFF position. Disconnect FEM harness connector C201F. Measure the resistance between shift interlock actuator harness connector terminal No. 2 and ground. (Scheme 92) Is the resistance greater than 10 k/ohms? If so, go to next step. If not, repair short to ground in Yellow/Violet wire and test the system for normal operation.
4. Measure the resistance between shift interlock actuator harness connector terminal No. 2 and FEM harness connector C201F terminal No. 15. (Scheme 93) Is the resistance less than 5 ohms? If so, replace FEM. See «FRONT END MODULE»(ref-140004-S03711998392002053100000) under REMOVAL & INSTALLATION. If not, repair open in Yellow/Violet wire and test the system for normal operation.
5. Measure the resistance between shift interlock actuator harness connector terminal No. 1 and ground. (Scheme 94) Is the resistance less than 5 ohms? If so, replace shift interlock actuator and test the system for normal operation. See «SHIFT INTERLOCK ACTUATOR»(ref-140004-S02147698232002051500000) under REMOVAL & INSTALLATION. If not, repair open in Black wire and test the system for normal operation.

Scheme 89

Scheme 90

Scheme 91

Scheme 92

1. Apply the brake pedal and view the brakelights. Do the brakelights illuminate? If so, go to step 7. If not, go to next step.
2. Measure resistance in fuse No. 17 (15-amp). Is the resistance of the fuse 5 ohms or less? If so, go to step 4. If not, go to next step.
3. Ensure ignition switch is in OFF position. Disconnect Brake Pedal Position (BPP) switch harness connector. Measure the resistance in Light Green/Red wire between BPP switch harness connector and ground. Is the resistance less than 10 k/ohms? If so, repair short to ground in Light Green/Red wire and test the system for normal operation. If not, go to next step.
4. Measure the resistance in Light Green/Red wire between output side of fuse No. 17 and BPP switch harness connector. Is the resistance less than 5 ohms? If so, go to next step. If not, repair open in Light Green/Red wire and test the system for normal operation.
5. Measure the resistance between BPP switch terminals No. 1 and 2 (component side), while open (OFF) and closed (ON). Is the resistance of the switch greater than 10 k/ohms while OFF, and 5 ohms or less while ON? If so, go to next step. If not, replace BPP switch and test the system for normal operation. See «BRAKE PEDAL POSITION SWITCH»(ref-140004-S11825150462002052100000) under REMOVAL & INSTALLATION.
6. Disconnect shift interlock actuator harness connector. Measure the resistance in Red/Light Green wire between shift interlock actuator harness connector and ground. see scheme 16 Is the resistance less than 10 k/ohms? If so, repair short to ground in Red/Light Green wire and test the system for normal operation. If not, go to next step.
7. Measure the resistance in Red/Light Green wire between shift interlock actuator harness connector and BPP switch harness connector. Is the resistance less than 5 ohms? If so, go to next step. If not, repair open in Red/Light Green wire and test the system for normal operation.
8. Measure the voltage in Orange wire between shift interlock actuator harness connector and ground. see scheme 18 Does battery voltage exist? If so, go to step 12. If not, go to next step.
9. Turn ignition switch to OFF position. Measure resistance in fuse No. 32 (10-amp). Is the resistance less than 5 ohms? If so, go to step 11. If not, go to next step.
10. Measure the resistance in Orange wire between shift interlock actuator harness connector terminal No. 3 and ground. (Scheme 53) Is resistance less than 10 k/ohms? If so, repair short to ground in Orange wire and test the system for normal operation. If not, go to next step.
11. Measure the resistance in Orange wire between output side of fuse No. 32 (10-amp) and shift interlock actuator harness connector terminal No. 3. see scheme 61 Is the resistance less than 5 ohms? If so, go to next step. If not, repair open in Orange wire and test the system for normal operation.
12. Measure the resistance in Black wire between shift interlock actuator harness connector terminal No. 2 and ground. (Scheme 52) Is the resistance less than 5 ohms? If so, replace shift interlock actuator and test the system for normal operation. See «SHIFT INTERLOCK ACTUATOR»(ref-140004-S02147698232002051500000) under REMOVAL & INSTALLATION. If not, repair open in Black wire and test the system for normal operation.

Scheme 93

1. If the shift interlock system does not release correctly, go to next step. If the shift interlock system does not lock correctly, go to step 4.
2. Turn ignition switch to OFF position. Disconnect shift interlock actuator harness connector. Apply the brake pedal. Measure the voltage between the shift interlock actuator harness connector terminal No. 1 and ground. (Scheme 51) Is the voltage greater than 10 volts? If so, replace shift interlock actuator and test the system for normal operation. See «SHIFT INTERLOCK ACTUATOR»(ref-140004-S02147698232002051500000) under REMOVAL & INSTALLATION. If not, go to next step.
3. Apply the brake pedal. Measure the voltage between fuse No. 20 (7.5-amp) and ground. see scheme 62 Is the voltage greater than 10 volts? If so, repair open in Red/Light Green wire, reconnect all components and test the system for normal operation. If not, repair open in Light Green wire, then reconnect all components and test the system for normal operation.
4. Turn ignition switch to OFF position. Disconnect shift interlock actuator harness connector. Turn ignition switch to ON position. Measure the voltage between the shift interlock actuator harness connector terminal No. 3 and ground. see scheme 18 Is the voltage greater than 10 volts? If so, go to next step. If not, repair open in White/Violet wire, then reconnect all components and test the system for normal operation.
5. Measure the resistance between the shift interlock actuator harness connector terminal No. 2 and ground. (Scheme 52) Is the resistance less than 5 ohms? If so, replace shift interlock actuator. See «SHIFT INTERLOCK ACTUATOR»(ref-140004-S02147698232002051500000) under REMOVAL & INSTALLATION. If not, repair open in Black wire, then reconnect all components and test the system for normal.

Scheme 94

1. Turn ignition switch to OFF position. Disconnect shift interlock actuator harness connector. Measure the resistance between the shift interlock actuator harness connector terminal No. 1 and ground. Is the resistance less than 5 ohms? If so, go to next step. If not, repair open in Black wire and test the system for normal operation.
2. Turn ignition switch to ON position. Measure the voltage between the shift interlock actuator harness connector terminal No. 2 and ground. Depress the brake pedal. Is the voltage less than one volt with the brake pedal depressed, and greater than 10 volts with the brake pedal released? If so, replace shift interlock actuator and test the system for normal operation. See «SHIFT INTERLOCK ACTUATOR»(ref-140004-S02147698232002051500000) under REMOVAL & INSTALLATION. If not, go to next step.
3. Turn ignition switch to OFF position. Disconnect Brake Pedal Position (BPP) switch. Measure the resistance between the shift interlock actuator harness connector terminal No. 2 and the BPP switch harness connector terminal No. 2. Is the resistance less than 5 ohms? If so, go to next step. If not, repair open in White wire and test the system for normal operation.
4. Turn ignition switch to ON position. Measure the voltage between the BPP switch harness connector terminal No. 1 and ground. Is the voltage greater than 10 volts? If so, replace BPP switch and test the system for normal operation. See «BRAKE PEDAL POSITION SWITCH»(ref-140004-S11825150462002052100000) under REMOVAL & INSTALLATION. If not, repair open in Blue wire and test the system for normal operation.

Component Testing Procedure (No Voltage Applied)

For shift interlock relay testing with no voltage applied, see SHIFT INTERLOCK RELAY TESTING table. For shift interlock relay testing with voltage applied, see COMPONENT TESTING PROCEDURE (VOLTAGE APPLIED) .

SHIFT INTERLOCK RELAY TESTING

Component Testing Procedure (Voltage Applied)

Connect terminals No. 30 and 85 to battery voltage and terminal No. 86 to ground. Measure voltage between terminals No. 87 and 86. If battery voltage exists, continue with the test. If battery voltage does not exist, replace the relay. Disconnect battery voltage from terminal No. 85 and measure voltage between terminals No. 87A and 86. If battery voltage exists, the relay is okay. If battery voltage does not exist, replace the relay.