DTC 28
DTC 28: Park/Neutral Position Switch System (Short Circuit)Park/Neutral Position Switch System Circuit
DTC SET CONDITIONS
If the PCM detects more than one kind of park/ neutral position switch input signals for continuous period of thirty seconds, it is judged that there is a short circuit in the Park/Neutral position switch and A/T diagnostic trouble code number "28" 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. Check the Park/Neutral position switch.
Check for continuity between terminals for each selector position.
NOTE: For vehicles with sport model, four positions (P, R, N, D) are used.
Q: Is the switch operating properly?
YES: Go to Step 2.
NO: Replace the Park/Neutral position switch.
STEP 2. Check connector 0-111 at the Park/Neutral position switch for damage.
Q: Is the connector in good condition?
YES: Go to Step 3.
NO: Repair or replace it.
STEP 3. Check connector C-121 <2.4L Engine> or C-123 <3.01L Engine> at PCM for damage.
Q: Is the connector in good condition?
YES: Go to Step 4.
NO: Repair or replace it.
STEP 4. Check the switch output voltage at PCM connector C-121 <2.4L Engine> or C-123 <3.01L Engine> by backprobing ("P" position)
1. Do not disconnect,connector C-1 2-1 <2.4L Engine> or C-123 <3.0L Engine>.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal 101 and ground by backprobing.
- When selector lever position is T," voltage should be battery positive voltage.
- When selector lever position is "R," voltage should be 0.5 volt or less.
- When selector lever position is "N," voltage should be 0.5 volt or less.
- When selector lever position is "D," voltage should be 0.5 volt or less.
- When selector lever position is "3," voltage should be 0.5 volt or less.
- When selector lever position is "2," voltage should be 0.5 volt or less.
- When selector lever position is "L," voltage should be 0.5 volt or less.
- When selector lever position is sport mode, voltage should be 0.5 volt or less.
Q: Is the voltage normal?
YES: Go to Step 7.
NO: Turn the ignition switch to the "LOCK" (OFF) position. Go to Step 5.
STEP 5. Check harness for damage between Park/Neutral position switch connector B-111 terminal 3 and PCM connector C-123 terminal 101.
Q: Is the harness wire In good condition?
YES Go to Step 6.
NO: Repair it.
STEP 6. 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 damage between the Park/Neutral Position Switch connector B-111 terminal 3 and combination meter connector C-1 03 terminal 11.
NO: Repair or replace the defective connector(s).
STEP 7. Check the switch output voltage at PCM connector C-121 <2.4L Engine> or C-123 <3.0L Engine> by backprobing. ("R" position)
Measure the voltage between terminal 108 and ground by backprobing.
- When selector lever position is "P," voltage should be 0.5 volt or less.
- When selector lever position is "R," voltage should be battery positive voltage.
- When selector lever position is "N," voltage should be 0.5 volt or less.
- When selector lever position is "D," voltage should be 0.5 volt or less.
- When selector lever position is "3," voltage should be 0.5 volt or less.
- When selector lever position is "2," voltage should be 0.5 volt or less.
- When selector lever position is "L," voltage should be 0.5 volt or less.
- When selector lever position is sport mode, voltage should be 0.5 volt or less.
Q: Is the voltage normal?
YES: Go to Step 11.
NO: Turn the ignition switch to the "LOCK" (OFF) position. Go to Step 8.
STEP 8. Check harness for damage between Park/Neutral position switch connector B-111 terminal 7 and PCM connector C-123 terminal 108.
Q: Is the harness wire in good condition?
YES: Go to Step 9.
NO: Repair it.
STEP 9. Check connectors C-24 at intermediate connector and C-103 at combination meter for damage.
Q: Are the connectors In good condition?
YES: Go to Step 10.
NO: Repair or replace the defective connector(s).
STEP 10. Check harness for damage between Park/Neutral position Switch connector B-111 terminal 7 and combination meter connector CA 03 terminal 10.
Q: Is the harness wire in good condition?
YES: Repair harness damage between output signal of Park/Neutral position switch connector B-111 terminal 7.
NO: Repair it.
STEP 11. Check the switch output voltage at PCM connector C-121 <2.4L Engine> or C-123 <3.0L Engine> by backprobing. ("N" position)
Measure the voltage between terminal 121 and ground by backprobing.
- When selector lever position is "P," voltage should be 0.5 volt or less.
- When selector lever position is "R," voltage should be 0.5 volt or less.
- When selector lever position is "N," voltage should be battery positive voltage.
- When selector lever position is "D," voltage should be 0.5 volt or less.
- When selector lever position is "3," voltage should be 0.5 volt or less.
- When selector lever position is "2," voltage should be 0.5 volt or less.
- When selector lever position is "L," voltage should be 0.5 volt or less.
- When selector lever position is sport mode, voltage should be 0.5 volt or less.
Q: Is the voltage normal?
YES: Go to Step 14.
NO: Turn the ignition switch to the "LOCK" (OFF) position. Go to Step 12.
STEP 12. Check harness for damage between Park/Neutral position-switch connector B-111 terminal 4 and PCM connector C-103 terminal 121.
Q: Is the harness wire in good condition?
YES: Go to Step 13.
NO: Repair it.
STEP 13. Check connectors C-24 at intermediate connector C-1 03 at combination meter for damage.
Q: Are the connectors In good condition?
YES: Repair harness damage between the Park/Neutral Position Switch connector B-111 terminal 4 and combination meter connector C-103 terminal 9.
NO: Repair or replace the defective connector(s).
STEP 14. Check the switch output voltage at PCM connector C-121 <2.41L Engine> or C-123 <3.01L Engine> by backprobing. ("D" position) Measure the voltage between terminal 102 and ground by backprobing.
- When selector lever position is "P," voltage should be 0.5 volt or less.
- When selector lever position is "R," voltage should be 0.5 volt or less.
- When selector lever position is "N," voltage should be 0.5 volt or less.
- When selector lever position is "D," voltage should be battery positive voltage.
- When selector lever position is "3," voltage should be 0.5 volt or less.
- When selector lever position is "2," voltage should be 0.5 volt or less.
- When selector lever position is "L," voltage should be 0.5 volt or less.
- When selector lever position is sport mode, voltage should be 0.5 volt or less.
Q: Is the voltage normal?
YES: Go to Step 21
NO: Tern the ignition switch to the "LOCK" (OFF) position. Go to Step 15.
STEP 15. Check harness for damage between Park/Neutral position switch connector B-111 terminal 1 and PCM connector C,123 terminal 102.
Q: Is the harness wire In good condition?
YES: Go to Step 16.
NO: Repair it.
STEP 16. Check connectors C-132 at shift switch assembly, C-24 at intermediate connector and C-101 at combination meter for damage.
Q: Are the connectors in good condition?
YES: Go to Step 17.
NO: Repair or replace the defective connector(s).
STEP 17. Check harness for damage between Park/Neutral position switch connector B-111 terminal 1 and shift switch assembly connector C-132 terminal 1.
Q: Is the harness wire in good condition?
YES: Repair -harness damage between shift switch assembly connector C-1 32 terminal 2 and combination meter connector C- 101 terminal 50.
NO: Repair it.
STEP 18. Check the switch output voltage at PCM connector C-121 <2.4L Engine> or C-123 <3.0L Engine> by backprobing. ("3" position)
Measure the voltage between terminal 109 and ground by backprobing.
- When selector lever position is "P," voltage should be 0.5 volt or less.
- When selector lever position is "R," voltage should be 0.5 volt or less.
- When selector lever position is "N," voltage should be 0.5 volt or less.
- When selector lever position is "D," voltage should be 0.5 volt or less.
- When selector lever position is "3," voltage should be battery positive voltage.
- When selector lever position is "2," voltage should be 0.5 volt or less.
- When selector lever position is "L," voltage should be 0.5 volt or less.
Q: Is the voltage normal?
YES: Go to Step 19.
NO: Tern the ignition switch to the "LOCK" (OFF) position. Repair harness damage between the Park/Neutral position switch connector B-111 terminal 5 and PCM connector C-121 <2.4L Engine> or C-123 <3.0L Engine> terminal 109.
STEP 19. Check the switch output voltage at PCM connector C-121 <2.4L Engine> or C-123 <3.0L Engine> by backprobing. ("2" position)
Measure the voltage between terminal 122 and ground by backprobing.
- When selector lever position is "P," voltage should be 0.5 volt or less.
- When selector lever position is "R," voltage should be 0.5 volt or less.
- When selector lever position is "N," voltage should be 0.5 volt or less.
- When selector lever position is "D," voltage should be 0.5 volt or less.
- When selector lever position is "3," voltage should be 0.5 volt or less.
- When selector lever position is "2," voltage should be battery positive voltage.
- When selector lever position is "L," voltage should be 0.5 volt or less.
Q: Is the voltage normal?
YES: Go to Step 20.
NO: Tern the ignition switch to the "LOCK" (OFF) position. Repair harness damage between the Park/Neutral position switch connector B-111 terminal 2 and PCM connector C-121 <2.4L Engine> or C-123 <3.0L Engine> terminal 122.
STEP 20. Check the switch output voltage at PCM connector C-121 <2.4L Engine> or C-123 4.0L Engine> by backprobing. ("L" position)
Measure the voltage between terminal 110 and ground by backprobing.
- When selector lever position is "P," voltage should be 0.5 volt or less.
- When selector lever position is "R," voltage should be 0.5 volt or less.
- When selector lever position is "N," voltage should be 0.5 volt or less.
- When selector lever position is "D," voltage should be 0.5 volt or less.
- When selector lever position is "3," voltage should be 0.5 volt or less.
- When selector lever position is "2," voltage should be 0.5 volt or less.
- When selector lever position is "L," voltage should be battery positive voltage.
Q: Is the voltage normal?
YES: Go to Step 21.
NO: Tern the ignition switch to the "LOCK" (OFF) position. Repair harness damage between the Park/Neutral position switch connector B-111 terminal 6 and PCM connector C-121 <2.4L Engine> or C-123 <3.0L Engine> terminal 110.
STEP 21. 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 and confirm 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.