P1788

Test 577-580:

Test 581:

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, or 3rd gear with engine speed above 1000 RPM shortly after a shift and every minute there after. The following conditions must be met for successful OBDII trip: the engine speed must be greater than 1000 RPM. The trans must be warm or hot.
Set Condition: The vehicle must be driven in 1st gear continuously for 8 seconds, or in 2nd gear for 8 seconds and in 3rd gear continuously for 8 seconds. No MIL lamp trouble codes have occurred or recurred.

POSSIBLE CAUSES
- CHECKING SYMPTOMS AND POSSIBLE CAUSES
- LOW BATTERY VOLTAGE CAUSING SYMPTOM
- INTERMITTENT CODE P1788

Test 1-4:

Test 5-6:

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

POSSIBLE CAUSES
- CONDITIONS NOT PRESENT
- 2-4 TCR OUTPUT CIRCUIT SHORT AT INLINE CONNECTOR
- SHORT BETWEEN TCR OUTPUT CKT TO 2-4 PRESSURE SENSE SW CKT
- 2-4 SOLENOID FAILURE
- 2-4 SOLENOID INTERNAL FAILURE CAUSED BY PRESSURE SWITCH