For 1990-2009 cars

# Tech - Service Engine Soon (SES) Light Illuminates (Repl Switch Assy)

Subject: | Service Engine Soon (SES) Light Illuminates, DTC P1810 Set (Replace TFP Switch Assembly)

Models: | 1999 Cadillac Escalade

| 1998-99 Chevrolet Camaro, Corvette

| 1998-99 Pontiac Firebird

| 1998-99 Chevrolet and GMC C/K, M/L, S/T, G Models

| 1998-99 Oldsmobile Bravada

| 1998-99 Holden Commodore

| with Hydra-Matic 4L60-E Transmission (RPO M30)

### Condition

Some customers may comment about the Service Engine Soon light illuminating. The PCM will have stored a Diagnostic Trouble Code P1810, Transmission Fluid Pressure Manual Valve Position (TFP) Switch assembly circuit malfunction.

### Cause

Debris from aluminum shavings, bronze material, and certain clutch material may cause the pressure switches in the TFP switch assembly to stick or electrically short out.

### Correction

A new TFP switch assembly with a plastic shield has been released. The plastic shield is designed to protect the pressure switch from debris. This improvement will reduce the likelihood of a DTC P1810. This product change went into production on April 8, 1999 (Julian date 098). The existing TFP switch assembly remains relatively unchanged except for the addition of the new shield, creating a new part number for the assembly. The shield fits over the existing TFP switch assembly and is not sold separately.

Follow diagnostics for the P1810 Diagnostic Trouble Code in the Transmission Section of the appropriate Service Manual. If the diagnostics indicate that switch replacement is necessary, use the correct switch P/N as listed below.

### Service Parts Information

Part Number | Usage | Description
--- | --- | ---
24215111 | 1998-1999 | TFP Switch Assembly with Shield

Parts are currently available from GMSPO.

### Warranty Information

For vehicles repaired under warranty, use:

Labor Operation | Labor Time
--- | ---
K6351 (Switch, Assembly, Auto Trans Fluid Pressure -- Replace) | Use published labor operation time