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 greater than 1000 RPM, the TCM momentarily turns on element pressure to the clutch circuits that don't have pressure to verify that the correct pressure switch closes. If the pressure switch does not close 2 times the DTC sets

Test 1-4:

Test 5-7:

Test 8-10:

Test 11-12:

POSSIBLE CAUSES
- LOSS OF PRIME - P0944 PRESENT
- TRANSMISSION CONTROL RELAY OUTPUT CIRCUIT OPEN
- OD PRESSURE SWITCH SENSE CIRCUIT SHORT TO GROUND
- OD PRESSURE SWITCH SENSE CIRCUIT OPEN
- OD PRESSURE SWITCH SENSE CIRCUIT SHORT TO VOLTAGE
- TRANSMISSION SOLENOID/PRESSURE SWITCH ASSEMBLY
- INTERNAL TRANSMISSION
- POWERTRAIN CONTROL MODULE
- INTERMITTENT WIRING AND CONNECTORS