Riviera V6-231 3.8L VIN L SFI (1991)
5.
Identify faulty component and repair or replace as necessary.
SERVICE INFORMATION:
1.
Check condition and level of transmission fluid
Use the "4T60-E Transaxle Fluid Checking Procedure" in Section 7A-5A 4T60-E AUTOMATIC TRANSAXLE DIAGNOSIS of the appropriate
Service Manual. If the fluid is contaminated, burned or contains excessive clutch material or metal, this bulletin no longer applies and
mechanical/hydraulic diagnosis should be followed per the Service Manual.
2.
Diagnose and repair all ECM/PCM Diagnostic Trouble Codes
Check for ECM/PCM DTC's using the TECH 1/0n-board Diagnostics as described in Section 6E-A of the appropriate Service Manual. Diagnose
and repair all DTC's prior to continuing to step three.
3.
Identify which shift solenoid is being affected
Install the Transmission Test Box J 38791 and the correct harness (J 38791-10, J 38791-20 or J 38791-60) and monitor "A" and "B" Shift
Solenoid LED status during condition. Compare the actual LED status with the commanded gear status indicated by the TECH 1. The Shift
Solenoid that is energized when it is not commanded to be energized is the affected component. (On Pontiac models, use Transaxle Electrical
Jumper J 38835 and Multimeter J 39200.)
4.
Determine if cause is internal or external to transaxle
If the condition can be eliminated or changed by manually overriding the selected gear with the Transmission Test Box, then the electrical fault is
external to the transaxle. If the condition cannot be eliminated using the Test Box, then the fault is internal to the transaxle. It is possible with some
Shift Solenoid conditions that the affected solenoid will behave as if it was energized (check ball seats) without actually being energized. In this
case, the TECH 1 commanded status and Transmission Test Box LED status will be the same and the condition will not be affected by the Test
Box.
5.
Identify faulty component and repair or replace as necessary
Once the fault has been identified as internal or external to the transaxle and one Shift Solenoid is affected, the following suggestions will help to
identify the exact component and required repair:
Wiring faults external to the transaxle:
^
Check for pinched wiring or worn through insulation underhood at exposed sheet metal, harness retainers or at pass-through connectors at the
cowl. Underdash wiring as it routes to the ECM/PCM could also be damaged.
^
If the condition occurs during powertrain torque loads (acceleration), check for harnesses that are pulled tight against a component when the
powertrain moves fore or aft.
^
Check any pass-through or in-line harness connectors for bent or damaged terminals.
^
Repair damaged wiring and repair or replace terminals and connectors per Section 8A-5 of the appropriate Service Manual.
^
On 1991-1993 Cadillac DeVille/Fleetwood/Sixty Special (FWD) models, refer to Cadillac bulletin T-93-105 or Canada bulletin 93-6E-125
(Corporate bulletin 316510).
Wiring faults internal to the transaxle:
^
Check for wiring pinched between the side cover and channel plate/valve body.
^
Check for bent or damaged connector pins.
^
Check suspect Shift Solenoid for high/low resistance using nominal readings from Section 7A-5A 4T60-E AUTOMATIC TRANSAXLE
DIAGNOSIS in the appropriate Service Manual.
^
The transaxle Wiring Harness or Shift Solenoid must be replaced if faulty; they are not currently repairable.
Non-electrical Shift Solenoid faults:
^
Check for sediment in Shift Solenoid.
