P0783
P0783-3-4 SHIFT SOL, NO RPM DROP AT LOCKUP (GAS)
For a complete wiring diagram refer to Diagrams/Electrical. Electrical Diagrams
Theory of Operation
The Torque Converter Clutch (TCC) Solenoid is used to engage the TCC which improves fuel economy. The Overdrive Solenoid is used to engage the gear change from third to Overdrive.
- When Monitored:
Continuously with the ignition on and the engine running.
- Set Condition:
This DTC will set if the expected engine RPM drop does not occur within 4 seconds of the gear change being requested by the PCM three consecutive failed tests.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Trouble Shooting Procedure - 48RE Gas
Diagnostic Test
1. CHECK IF THERE ANY TRANSMISSION CONTROL DTCS PRESENT
Ignition on, engine not running.
With the scan tool, read Engine DTCs.
Are there any TIPM TCM Power Control Circuit DTCs also present?
Yes
- Refer to the Transmission or Engine category and perform the appropriate symptom(s).
No
- Go To 2
2. CHECK IF THE DTC IS CURRENT
With the scan tool, read Engine DTCs.
Record the Freeze Frame data for the reported DTC.
With the scan tool, erase DTCs.
Turn the ignition off to the lock position.
Using the Freeze Frame data recorded earlier, try to duplicate the conditions in which the DTC originally set.
NOTE: It may be necessary to road test the vehicle to duplicate the original set conditions.
With the scan tool, read Engine DTCs.
Did the DTC reset?
Yes
- Go To 3
No
- Go To 6
3. CHECK THE GOVERNOR AND OVERDRIVE PRESSURE
Turn the ignition off to the lock position.
Connect a 0 - 2068 KPa (0 - 300 PSI) pressure gauge to the Overdrive Clutch test port.
Connect another 0 - 2068 KPa (0 - 300 PSI) pressure gauge to the Governor Pressure test port.
Start the engine and allow the transmission temperature to rise to normal operating temperature.
CAUTION: Apply the parking brake.
Firmly apply the brakes and place the gear selector in Drive.
While observing the pressure gauges, with the scan tool, select 4th gear from the Gov and 3-4 Shift Valve Test.
NOTE: The governor pressure should rise above 138 kPa (20 PSI). Shortly after the O/D pressure should rise above 276 kPa (40 PSI).
Did the pressures act as previously described?
Yes
- Go To 4
No
- Go To 5
4. CHECK THE TRANSMISSION OIL CONDITION
Turn the ignition off to the lock position.
Remove the transmission oil pan and inspect for excessive debris and burnt oil.
Is the oil burnt or does the transmission oil pan contain excessive debris?
Yes
- Repair the transmission as necessary.
- Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (GAS). Transmission Verification Test
No
- Go To 6
5. CHECK THE GOVERNOR AND OVERDRIVE PRESSURE AFTER REPLACEMENT OF THE 3-4 SHIFT SOLENOID
Turn the ignition off to the lock position.
Replace the 3-4 Shift Solenoid.
With the pressure gauges still attached, start the engine and allow the transmission temperature to rise to normal operating temperature.
CAUTION: Apply the parking brake.
Firmly apply the brakes and place the gear selector in Drive.
While observing the pressure gauges, with the scan tool, select 4th gear from the Gov and 3-4 Shift Valve Test.
NOTE: The governor pressure should rise to above 138 kPa (20 PSI). Shortly after the O/D pressure should rise above 276 kPa (40 PSI).
Did the pressures act as previously described?
Yes
- Test Complete.
- Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). Transmission Verification Test
No
- Overhaul the transmission. Pay attention to seals and clutches related to the OD clutch.
- Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (GAS). Transmission Verification Test
6. INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Use the Freeze Frame Data to help duplicate the conditions in which the DTC originally set. Pay particular attention to the DTC set conditions, such as, VSS, MAP, ECT, and Load
The vehicle must be driven (road load) to set this code. Drive the vehicle 4 times from 0 to 89 kmh (0 to 55 MPH) with a constant 20 % throttle position through all gears. Stop the vehicle, shut the engine off and then repeat the procedure.
Using the schematics as a guide, visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.
Wiggle the wiring and connectors while checking for any possible open or shorted circuits.
Check for any Service Information Tune-ups or Technical Service Bulletins that may apply.
Were there any problems found?
Yes
- Repair as necessary.
- Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (GAS). Transmission Verification Test
No
- Test Complete.
- Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (GAS). Transmission Verification Test