Inspection Procedure 12

INSPECTION PROCEDURE 12: No Diagnostic Trouble Codes (Does not Shift)









CIRCUIT OPERATION
PCM (terminal number 58) receives battery positive voltage from the battery.

COMMENT
If shifting does not occur while driving and no diagnostic trouble codes are output, a malfunction of the transmission range switch, or PCM may exist.

TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CASE:)
^ Malfunction of the transmission range switch
^ 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
^ MB991910: MUT-III Main Harness A

STEP 1. Check the vehicle acceleration.
Q: Does the vehicle accelerate poorly (transaxle stays in 3rd gear) when starting from a stop with the selector lever in "D" range?
YES: Go to Step 2.
NO: Go to Step 5.

STEP 2. Measure the backup power supply voltage at PCM connector C-110 by backprobing.





1. Do not disconnect connector C-110.





2. Measure the voltage between terminal 58 and ground by backprobing.
^ The voltage should measure battery positive voltage.
Q: Is the measured voltage battery positive voltage?
YES: Go to Step 5.
NO: Go to Step 3.

STEP 3. Check intermediate connector A-14 and PCM connector C-110 for loose, corroded or damaged terminals, or terminals pushed back in the connector.





Q: Are the connectors and terminals in good condition?
YES: Go to Step 4.
NO: Repair or replace the damaged components. Then check for the symptom.

STEP 4. Check the harness for open circuit between PCM connector C-110 terminal 58 and battery.





Q: Is the harness wire in good condition?
YES: Go to Step 5.
NO: Repair or replace the harness wire.

STEP 5. 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" and sport mode positions and confirm that the selected transmission ranges match the positions shown on the scan tool MB991958. (Sport mode is indicated as "D" on scan tool MB991958).
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the switch operating properly?
YES: Check for the symptom. If the symptom is not eliminated, replace the PCM.
NO: Refer to DTCs 27 or 28: Transmission Range switch system.