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DTC 27: Park/Neutral Position Switch System (Open Circuit)
CIRCUIT OPERATION
- Battery positive voltage is applied to the Park/ Neutral position switch (terminal 8) when the ignition switch is turned "ON."
- Battery positive voltage is applied to the PCM (terminal 101. when the selector lever is in the "P" range. The PCM judges that the selector lever is in the "P" range when the battery positive voltage is applied.
- Battery positive voltage is applied to the PCM terminal 108 [121, 102,109,122 or 110] when the selector lever is in the "R" range ("N," "D", "3", "2", or "L" range). The PCM judges that the selector lever is in the "R" range ("N," "D", "3", "2" or "L" range) when the battery positive voltage is applied.
DTC SET CONDITIONS
If the PCM detects no Park/Neutral position switch input signal from any selector position for continuous period of thirty seconds, it is judged that there is an open circuit in the Park/Neutral position switch and diagnostic trouble code number "27" is output.
TROUBLESHOOTING HINTS (The most likely causes for this code to be set:)
- Malfunction of the Park/Neutral position switch
- Malfunction of the ignition switch
- Damaged harness, connector
- Malfunction of the PCM
DIAGNOSIS
Required Special Tool:
- MB991502: Scan Tool (MUT-II)
STEP 1. Using scan tool MB991502, check data list item 61: Park/Neutral Position Switch.
CAUTION: To prevent damage to scan tool MB991,502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
1. Connect scan tool MB991,502 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991502 to data reading mode for item 61: Park/Neutral Position Switch.
Move the selector lever to "P," "R," "N," "D, "3", "2", "L" and sport mode,positions to confirm whether shown the scan tool. (The sport mode is indicated as "D" on the MUT-II.)
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the switch operating properly?
YES: This malfunction can be intermittent.
NO: When indication disagrees at all positions: Go to Step 2. When indication disagrees at "P" position: Go to Step 6. When indication disagrees at "R" position: Go to Step 13. When indication disagrees at "N" position: Go to Step 20. When Indication disagrees at "D" position: Go to Step 26; When indication disagrees at "3" position: Go to Step. 33 When indication disagrees at "2" position: Go to Step 37. When indication disagrees at "L" position: Go to Step 41. When indication disagrees at sport mode position (agrees at "D" position): Go to Step 45.
STEP 2. Check the Park/Neutral position switch.
Check for continuity between terminals for each selector position.
NOTE: For vehicles with sport mode, four positions (P, R, N, D) are used.
Q: Is the switch operating properly?
YES: Go to Step 3.
NO: Replace the Park/Neutral position switch.
STEP 3. Check connectors B-111 at Park/Neutral position switch, C-25 at Intermediate connector and C-312 at junction block for damage.
Q: Are the connectors in good condition?
YES: Go to Step 4.
NO: Repair or replace the defective connector(s).
STEP 4. Check harness for open circuit or short circuit to ground between Park/Neutral position switch connector 13111 terminal 8 and junction block connector C-312 terminal 12.
Q: Is the harness wire in good condition?
YES: Go to Step 5.
NO: Repair it.
STEP 5. Using scan tool MB991502, check data list item 61: Park/Neutral Position Switch.
CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991502 to data reading mode for item 61: Park/Neutral Position Switch. Move the selector lever to "P," "R,", "N", "D", "3", "2", "L" and sport mode positions to confirm whether shown on the scan tool. (The sport mode is indicated as "D" on the MUT-II.)
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the switch operating properly?
YES: This malfunction can be intermittent.
NO: Replace the PCM.
STEP 6. Check the Park/Neutral position switch.
Check for continuity between terminals for each selector position.
NOTE: For vehicles with sport mode, four positions (P, R, N, D) are used.
Q: Is the switch operating properly?
YES: Go to Step 7.
NO: Replace the Park/Neutral position switch.
STEP 7. Check connector B-111 at the Park/Neutral position switch for damage.
Q: Is the connector in good condition?
YES: Go to Step 8.
NO: Repair or replace it.
STEP 8. Check the switch output voltage at PCM connector C-121 <2.4L Engine> or C-123 <3.0L Engine> by backprobing.
1. Do not disconnect connector C-121 <2.4L Engine> or C-123 <3.0L Engine>.
2. Turn the ignition switch to the "ON" position.
3. Move the selector lever to "P" position.
4. Measure the voltage between terminal 101 and ground by backprobing.
Voltage should be battery positive voltage.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 12.
NO: Go to Step 9.
STEP 9. Check connector C-121 <2.4L Engine> or C-123 <3.01. Engine> at PCM for damage.
Q: Is the connectors in good condition?
YES: Go to Step 10
NO: Repair or replace it.
STEP 10. Check harness for open circuit or short circuit to ground between Park/Neutral position switch connector 13111 terminal 3 and PCM connector C-123 terminal 101
Q: Is the harness wire in good condition?
YES: Go to Step 11.
NO: Repair it.
STEP 11. Check connectors C-24 at intermediate connector and C-103 at combination meter for damage
Q: Are the connectors in good condition?
YES: Repair harness short circuit to ground between Park/Neutral position switch connector B-111 terminal 3 and combination meter connector C-103 terminal 11.
NO: Repair or replace the defective connector(s).
STEP 12. Check connector C-121 <2.4L Engine> or C-123 <3.011- Engine> at PCM for damage.
Q: Is the connector in good condition?
YES: Go to Step 5.
NO: Repair or replace it.
STEP 13. Check the Park/Neutral position switch.
Check for continuity between terminals for each selector position.
NOTE: For vehicles with sport mode, four positions (P, R, N, D) are used.
Q: Is the switch operating properly?
YES: Go to Step 14.
NO: Replace the Park/Neutral position switch.
STEP 14. Check connector B-111 at the Park/Neutral position switch for damage.
Q: Is the connector in good condition?.
YES: Go to Step 15.
NO: Repair or replace it.
STEP 15. Check the switch output voltage at PCM connector C-121 <2.4L Engine> or C-123 <10L Engine> by backprobing.
1. Do not disconnect connector C-121 <2.4L Engine> or C- 123 <3.0L Engine>.
2. Turn the ignition switch to the "ON" position.
3. Move the selector lever to "A" position.
4. Measure the voltage between terminal 108 and ground by backprobing.
Voltage should be battery positive voltage.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 12.
NO: Go to Step 16.
STEP 16. Check connector C-121 <2.4L Engine> or C-123 <3.0L Engine> at PCM for damage.
Q: Is the connectors in good condition?
YES: Go to Step 17
NO: Repair or replace it.
STEP 17. Check harness for open circuit or short circuit to ground between Park/Neutral position switch connector 13Ill terminal 7 and PCM connector C-123
Q: Is the harness wire in good condition?
YES: Go to Step 18.
NO: Repair it.