Repair Procedure
Verify Vehicle Condition1. Did M.I.L. "ON" DTC P0770 occur under any one of the following conditions?
A. Operation of vehicle in ambient temperatures above 90°F
B. While towing or carrying a heavy load.
C. While climbing a long uphill grade.
If YES - go to STEP 2.
If NO - TSB does not apply - refer to TIS or appropriate 2002 Repair Manual DTC P0770 Diagnostic Chart to repair vehicle.
2. Check for Authorized Modifications label affixed to the vehicle in the location shown in Figure 1. Confirm if ECM (PCM) calibration has been updated.
If no label or label does not list the "New Calibration ID Number" listed above - Go to Step 3.
3. Connect the Diagnostic Tester to the vehicle and select CURRENT ECU CAL from the ECU REPROGRAM MAIN MENU. Determine the vehicle's current ECU calibration (see Figure 2).
NOTE:
^ If Calibration ID matches "Previous Calibration ID" as shown, proceed with flash reprogramming.
^ If Calibration ID matches "New Calibration ID" as shown, this vehicle has already been reprogrammed. Refer to Repair Manual for diagnosis.
4. If ECU calibration ID is not "New Calibration ID" proceed to Step 5.
If ECU calibration ID is "New Calibration ID," refer to TIS or appropriate 2002 Repair Manual DTC P0770 Diagnostic Chart to repair vehicle.
5. Perform Active Test of lockup Solenoid (SL Solenoid or Solenoid "E") using Diagnostic Tester.
A. Set up Diagnostic Tester (see Figure 3).
B. Drive vehicle to a speed above 40 mph.
C. Maintain constant throttle input and speed while using Active Test of SL Solenoid on Diagnostic Tester (see Figure 4).
D. When SL Solenoid is turned "ON" torque converter should lock up within 5 seconds and engine rpm should drop 100-200 rpm.
E. When SL Solenoid is turned "OFF" Engine rpm should rise 100-200 rpm within 5 seconds.
F. Repeat several times to confirm proper operation of SL Solenoid/torque converter.
If SL Solenoid operation/torque converter lockup operation is normal - GO TO Step 6.
If SL Solenoid operation/torque converter lockup does not occur, takes excessive time or rpm drop is insufficient - Follow diagnostics on TIS for DTC P0770 or appropriate Repair Manual.
6. Proceed to Flash Reprogram ECM (PCM).
Flash Reprogram ECM (PCM)
1. 4Runner only: Remove the ABS1 and ABS2 fuses from Engine Room Junction Block (see Figure 5.)
2. Follow the procedures outlined in TSB SSOO2-01, "ECU Flash Reprogramming Process," and flash the ECM (PCM) with the new calibration file update.
3. Enter the required information on the Authorized Modifications Label and affix it to the vehicle at the location shown in Figure 1. The Authorized Modifications Label is available through the MDC, P/N 00451-00001-LBL.
4. 4Runner only: Reinstall the ABS1 and ABS2 fuses (Figure 5.)
5. Use the Diagnostic Tester to delete any ABS/VSC DTCs that may have been set during this repair procedure.
6. Calibration update is complete.
Valve Body Replacement
1. Replace valve body assembly per TIS or applicable Repair Manual (2002 Tacoma, Volume 2, Automatic Transmission [A340E, A340F] or 2002 4Runner, Volume 2, Automatic Transmission).
2. Reset the ECM (PCM) learned arid memory values. Refer to the procedures below (Figure 6).
3. Start the engine and warm it up to normal operating temperature before test-driving.
NOTE:
The effect of the new calibration may become more apparent after several days of driving as the ECM (PCM) "learned values" are re-established from the customer's driving.
4. Test drive and confirm lockup operation and no recurrence of DTC P0770.