Inspection Procedure 12

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

Backup Power Supply System Circuit:

Connector: B-19:

CIRCUIT OPERATION
PCM (terminal number 42) 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 CONDITION:)
- Malfunction of the transmission range switch
- Damaged harness, connector
- Malfunction of the PCM

DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-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 B-19 by using check harness special tool MB991923.

Connector: B-19:

(1) Disconnect all the connectors from the PCM.





(2) Connect special tool MB991923 (check harness) between the PCM and the body-side harness connector.
(3) Turn the ignition switch to the "ON" position.





(4) Measure the voltage between terminal 42 and ground.
- The voltage should measure battery positive voltage.
(5) Turn the ignition switch to the "LOCK" (OFF) position.
Q:Is the measured voltage battery positive voltage?
YES: Go to Step 5.
NO: Go to Step 3.

STEP 3. Check PCM connector B-19 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Connector: B-19:

Q:Is the connector in good condition?
YES: Go to Step 4.
NO: Repair or replace the damaged components. Refer to Harness Connector Inspection. Then retest the system.

STEP 4. Check the harness for open circuit between PCM connector B-19 terminal 42 and battery.

Connector: B-19:

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 34: 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 the data reading mode.
- Item 34: Transmission Range Switch.
-Move the selector lever to "P," "R," "N," "D" positions and confirm that the selected transmission range match the positions shown on scan tool MB991958 (The scan tool displays "D" range when the selector lever is shifted to the sport mode).
(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: Adjust the transmission range switch and control cable.