P090

DTC PO90:

PCM Circuit:

DESCRIPTION
This diagnostic test assumes that the brake must be applied to bring the vehicle to a stop from 30 mph or greater. If such a condition occurs the counter is incremented. When the counter reaches 10, Code P090 is set. The counter will be reset to zero if a transition of the Torque Converter Clutch (TCC) Brake Switch is detected by the Powertrain Control Module (PCM) before the counter reaches 10.

TEST CONDITIONS
1. Code P024 not set.
2. Engine running.
3. Vehicle speed 30 mph or greater.

FAILURE CONDITIONS
1. Vehicle speed changes from 30 mph or greater to 0 mph with NO TCC brake switch input, then increment counter.
2. When counter reaches 10, set Code P090.

ACTION TAKEN
1. PCM turns "ON" the "SERVICE VEHICLE SOON" Malfunction Indicator Lamp (MIL).
2. PCM disables cruise control.

NOTES ON FAULT TREE
1. Testing torque converter clutch brake switch input to the PCM PI71. If the input is working correctly, the display will change from "HI" to "LO" to "HI." If display remains "HI," check CKT 420 and TCC brake switch for a short to voltage. If display remains "LO," check CKT 420 for an open or short to ground.

2. Checking for voltage present at TCC brake switch connector pin "A."

3. Checking CKT 741 for a short to ground or a blown Fuse D1.

4. Checking CKT 741 for an open or CKT 420 for a short to ground or a blown Fuse D1.

5. Checking CKT 420 for an open or a poor connection at the PCM.