P1788

Test 1 Through 3:

Test 4 Through 5:

Symptom:
P1788-2-4 HYDRAULIC PRESSURE SWITCH CIRCUIT

When Monitored and Set Condition:
P1788-2-4 HYDRAULIC PRESSURE SWITCH CIRCUIT

When Monitored:
In 1st, 2nd, 3rd gears with engine speed above 1000 rpm shortly after a shift and every minute thereafter.

Set Condition:
TCM momentarily turns on element pressure to 2-4 clutch circuit to identify that the pressure switch closes. If press switch does not close it is retested again. if the switch does not close the second time, the code is set.

POSSIBLE CAUSES
CHECKING SYMPTOMS AND POSSIBLE CAUSES
LOW BATTERY VOLTAGE
INTERMITTENT CODE P1788

Test 1 Through 3:

Test 4 Through 5:

Symptom:
ADDITIONAL 2-4 HYDRAULIC PRESSURE SWITCH CIRCUIT (P1788)

POSSIBLE CAUSES
CONDITIONS NOT PRESENT
SHORT BETWEEN TCR OUTPUT CKT AND 2-4 PRESSURE SWITCH SENSE CKT
2-4 PRESSURE SWITCH FAILURE
2-4 SOLENOID FAILURE