P0870

SYMPTOM
P0870 - OD HYDRAULIC PRESSURE TEST FAILURE

WHEN MONITORED
In any forward gear with engine speed above 1000 RPM shortly after a shift and every minute thereafter.

SET CONDITION
After a shift into a forward gear, with engine speed above 1000 RPM, the TCM momentarily turns on element pressure to the clutch circuits that don't have pressure to identify the correct pressure switch closes. If the pressure switch does not close 2 times the DTC sets.

POSSIBLE CAUSES
- RELATED LINE PRESSURE DTC'S PRESENT
- RELATED SPEED RATIO AND/OR PRESSURE SWITCH DTC'S PRESENT
- TCM AND WIRING - LOW LINE PRESSURE
- INTERMITTENT WIRING , CONNECTORS
- 5-VOLT SUPPLY CIRCUIT OPEN
- OD PRESSURE SWITCH SENSE CIRCUIT OPEN
- POOR LINE PRESSURE SENSOR CONNECTION
- TRANSMISSION CONTROL RELAY OUTPUT CIRCUIT OPEN
- 5-VOLT SUPPLY CIRCUIT SHORT TO GROUND
- OD PRESSURE SWITCH SENSE CIRCUIT SHORT TO GROUND
- OD PRESSURE SWITCH SENSE CIRCUIT SHORT TO VOLTAGE
- EXCESSIVE DEBRIS IN OIL PAN
- INTERNAL TRANSMISSION PROBLEM - OD PRESSURE TEST
- TCM - NO 5 VOLTS - LOW LINE PRESSURE SENSOR
- TCM - OD PRESSURE SWITCH