DTC 28

DTC 28 (P0705): Transmission Range Switch System (Short Circuit)

Part 1 Of 2:

Part 2 Of 2:

CIRCUIT OPERATION
^ Battery positive voltage is applied to the transmission range switch (terminal 8) when the ignition switch is turned "ON."
^ Battery positive voltage is applied to the PCM (terminal 101) when the transmission range is in the "P" range. The PCM judges that the transmission range 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.

DESCRIPTIONS OF MONITOR METHODS
^ If two types or more of signals are input from transmission range switch for more than 30 seconds, PCM judges that transmission range switch has a failure.

MONITOR EXECUTION
^ Continuous

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored)
^ Not applicable

Sensor (The sensor is determined to be normal)
^ Not applicable





LOGIC FLOW CHARTS (Monitor Sequence)

DTC SET CONDITIONS
Check Conditions, Judgement Criteria
^ Transmission range switch: multiple signal. (30 seconds)

OBD-II DRIVE CYCLE PATTERN
Start the engine, keep the vehicle stopped in "P," "R," "N," "D," "3," "2" and "L" ranges respectively for more than one minute, and turn "LOCK" (OFF) the ignition switch. Then restart the engine, and stop the vehicle in "P," "R," "N," "D," "3," "2" and "L" ranges respectively for more than one minute.

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
^ Malfunction of the transmission range switch circuit
^ Damaged harness or connector
^ Malfunction of the PCM

DIAGNOSIS

Required Special Tool:
^ MB991958: Scan Tool (MUT-III Sub Assembly)
^ MB991824: V.C.I.
^ MB991827: MUT-III USB Cable
^ MB991911: MUT-III Main harness B

STEP 1. Check the transmission range switch.











Measure the resistance between the terminals for each transmission range as indicated in the table.
Q: Is the measured resistance less than 2 ohms for each selector position?
YES: Go to Step 2.
NO: Replace the transmission range switch.

STEP 2. Check transmission range switch connector B-16 for loose, corroded or damaged terminals, or terminals pushed back in the connector.





Q: Are the connector and terminals in good condition?
YES: Go to Step 3.
NO: Repair or replace the damaged components.

STEP 3. Check PCM connector C-114 for loose, corroded or damaged terminals, or terminals pushed back in the connector.





Q: Are the connector and terminals in good condition?
YES: Go to Step 4.
NO: Repair or replace the damaged components.

STEP 4. Measure the transmission range switch output voltage at PCM connector C-114 by backprobing. ("P" position)





1. Do not disconnect connector C-114.
2. Turn the ignition switch to the "ON" position.





3. Measure the voltage between terminal 101 and ground.
^ When transmission range is "P," voltage should equal battery positive voltage.
^ When transmission range is "R," voltage should measure 0.5 volt or less.
^ When transmission range is "N," voltage should measure 0.5 volt or less.
^ When transmission range is "D," voltage should measure 0.5 volt or less.
^ When transmission range is "3," voltage should measure 0.5 volt or less.
^ When transmission range is "2," voltage should measure 0.5 volt or less.
^ When transmission range is "L," voltage should measure 0.5 volt or less.
Q: Is the measured voltage within the specified range?
YES: Go to Step 6.
NO: Turn the ignition switch to the "LOCK" (OFF) position. Go to Step 5.

STEP 5.Check harness for damage between transmission range switch connector B-16 terminal 3 and PCM connector C-114 terminal 101.








Q: Is the harness wire in good condition?
YES: Go to Step 18.
NO: Repair or replace the harness wire.

STEP 6. Measure the transmission range switch output voltage at PCM connector C-114 by backprobing. ("R" position)








Measure the voltage between terminal 108 and ground.
^ When transmission range is "P," voltage should measure 0.5 volt or less.
^ When transmission range is "R," voltage should equal battery positive voltage.
^ When transmission range is "N," voltage should measure 0.5 volt or less.
^ When transmission range is "D," voltage should measure 0.5 volt or less.
^ When transmission range is "3," voltage should measure 0.5 volt or less.
^ When transmission range is "2," voltage should measure 0.5 volt or less.
^ When transmission range is "L," voltage should measure 0.5 volt or less.
Q: Is the measured voltage within the specified range?
YES: Go to Step 8.
NO: Turn the ignition switch to the "LOCK" (OFF) position. Go to Step 7.

STEP 7. Check the harness for damage between transmission range switch connector B-16 terminal 7 and PCM connector C-114 terminal 10.








Q: Is the harness wire in good condition?
YES: Go to Step 18.
NO: Repair or replace the harness wire.

STEP 8. Measure the transmission range switch output voltage at PCM connector C-114 by backprobing. ("N" position)








Measure the voltage between terminal 121 and ground.
^ When transmission range is "P," voltage should measure 0.5 volt or less.
^ When transmission range is "R," voltage should measure 0.5 volt or less.
^ When transmission range is "N," voltage should equal battery positive voltage.
^ When transmission range is "D," voltage should measure 0.5 volt or less.
^ When transmission range is "3," voltage should measure 0.5 volt or less.
^ When transmission range is "2," voltage should measure 0.5 volt or less.
^ When transmission range is "L," voltage should measure 0.5 volt or less.
Q: Is the measured voltage within the specified range?
YES: Go to Step 10.
NO: Turn the ignition switch to the "LOCK" (OFF) position. Go to Step 9.

STEP 9. Check the harness for damage between and transmission range switch connector B-16 terminal 4 PCM connector C-114 terminal 121.








Q: Is the harness wire in good condition?
YES: Go to Step 18.
NO: Repair or replace the harness wire.

STEP 10. Measure the transmission range switch output voltage at PCM connector C-114 by backprobing. ("D" position)








Measure the voltage between terminal 102 and ground.
^ When transmission range is "P," voltage should measure 0.5 volt or less.
^ When transmission range is "R," voltage should measure 0.5 volt or less.
^ When transmission range is "N," voltage should measure 0.5 volt or less.
^ When transmission range is "D," voltage should equal battery positive voltage.
^ When transmission range is "3," voltage should measure 0.5 volt or less.
^ When transmission range is "2," voltage should measure 0.5 volt or less.
^ When transmission range is "L," voltage should measure 0.5 volt or less.
Q: Is the measured voltage within the specified range?
YES: Go to Step 12.
NO: Turn the ignition switch to the "LOCK" (OFF) position. Go to Step 11.

STEP 11. Check the harness for damage between transmission range switch connector B-16 terminal 1 and PCM connector C-114 terminal 102.








Q: Is the harness wire in good condition?
YES: Go to Step 18.
NO: Repair or replace the harness wire.

STEP 12. Measure the transmission range switch output voltage at PCM connector C-114 by backprobing. ("3" position)








Measure the voltage between terminal 109 and ground.
^ When transmission range is "P," voltage should measure 0.5 volt or less.
^ When transmission range is "R," voltage should measure 0.5 volt or less.
^ When transmission range is "N," voltage should measure 0.5 volt or less.
^ When transmission range is "D," voltage should measure 0.5 volt or less.
^ When transmission range is "3," voltage should equal battery positive voltage.
^ When transmission range is "2," voltage should measure 0.5 volt or less.
^ When transmission range is "L," voltage should measure 0.5 volt or less.
Q: Is the measured voltage within the specified range?
YES: Go to Step 14.
NO: Turn the ignition switch to the "LOCK" (OFF) position. Go to Step 13.

STEP 13. Check the harness for damage between transmission range switch connector B-16 terminal 5 and PCM connector C-114 terminal 109.








Q: Is the harness wire in good condition?
YES: Go to Step 18.
NO: Repair or replace the harness wire.

STEP 14. Measure the transmission range switch output voltage at PCM connector C-114 by backprobing. ("2" position)








Measure the voltage between terminal 122 and ground.
^ When transmission range is "P," voltage should measure 0.5 volt or less.
^ When transmission range is "R," voltage should measure 0.5 volt or less.
^ When transmission range is "N," voltage should measure 0.5 volt or less.
^ When transmission range is "D," voltage should measure 0.5 volt or less.
^ When transmission range is "3," voltage should measure 0.5 volt or less.
^ When transmission range is "2," voltage should equal battery positive voltage.
^ When transmission range is "L," voltage should measure 0.5 volt or less.
Q: Is the measured voltage within the specified range?
YES: Go to Step 16.
NO: Turn the ignition switch to the "LOCK" (OFF) position. Go to Step 15.

STEP 15. Check the harness for damage between transmission range switch connector B-16 terminal 2 and PCM connector C-114 terminal 122.








Q: Is the harness wire in good condition?
YES: Go to Step 18.
NO: Repair or replace the harness wire.

STEP 16. Measure the transmission range switch output voltage at PCM connector C-114 by backprobing. ("L" position)








Measure the voltage between terminal 110 and ground.
^ When transmission range is "P," voltage should measure 0.5 volt or less.
^ When transmission range is "R," voltage should measure 0.5 volt or less.
^ When transmission range is "N," voltage should measure 0.5 volt or less.
^ When transmission range is "D," voltage should measure 0.5 volt or less.
^ When transmission range is "3," voltage should measure 0.5 volt or less.
^ When transmission range is "2," voltage should measure 0.5 volt or less.
^ When transmission range is "L," voltage should equal battery positive voltage.
Q: Is the measured voltage within the specified range?
YES: Go to Step 18.
NO: Turn the ignition switch to the "LOCK" (OFF) position. Go to Step 17.

STEP 17. Check the harness for damage between transmission range switch connector B-16 terminal 6 and PCM connector C-114 terminal 110.








Q: Is the harness wire in good condition?
YES: Go to Step 18.
NO: Repair or replace the harness wire.

STEP 18. Using scan tool MB991958, check data list item 61: Transmission Range Switch.





CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991958 to data reading mode.
^ Item 61: Transmission Range Switch.
^ Move the selector lever to "P," "R," "N," "D," "3," "2" and "L" positions and confirm that the selected transmission range match the positions shown on scan tool MB991958.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the switch operating properly?
YES: It can be assumed that this malfunction is intermittent.
NO: Replace the PCM.