P1780 (blink 97) on Toyota Corolla E120: NEUTRAL START SWITCH MALFUNCTION

Short answer: P1780 means “NEUTRAL START SWITCH MALFUNCTION”. The car’s computer has found a fault in the ECT U340E system and turns on the Malfunction indicator lamp (Check Engine). First check: workshop check order (RM821E): READ VALUE OF HAND−HELD TESTER -> CHECK ENGINE ECU FUNCTION -> INSPECT NEUTRAL START SWITCH ASSY -> CHECK WIRE HARNESS AND CONNECTOR(Neutral Start Switch Assy − ECU).

Code

P1780 · blink 97

System

ECT U340E

Dashboard light

Malfunction indicator lamp (Check Engine)

Applies to

4-speed A/T U340E. PK: ZZE122R-GEPNKP 1.8 auto from 07.2005 (EPC fig 3501/3512 note (0507- )ATM..PKN); JDM NZE121 1NZ autos

Market note

Hong Kong only

Confidence

high (official Toyota RM821E)

Source

toyotamanuals.gitlab.io

Symptoms and when it is set

1. 2 or more switches are ON simultaneously for ”N”, ”R”, ”2” or ”L” range. (2−trip detection logic) When driving under the conditions (a), (b) and (c) for 30 se- conds or more, the park/neutral position switch is ON (N posi- tion). (2−trip detection logic) (a) Vehicle speed: 80 km/h (50 mph) or more (b) Engine speed: 1,500 − 5,000 rpm (c) Manifold absolute pressure: 300 mmHg or more

Likely causes

1. Wire harness; Neutral start switch; Engine ECU

What to check, in order

1. Workshop check order (RM821E): READ VALUE OF HAND−HELD TESTER -> CHECK ENGINE ECU FUNCTION -> INSPECT NEUTRAL START SWITCH ASSY -> CHECK WIRE HARNESS AND CONNECTOR(Neutral Start Switch Assy − ECU)

Related on this car

• All fault codes for this car
• Warning lights
• Where the parts are (parts map)
• Common problems

Same code on other cars

• P1780 · Toyota Passo (1st gen)
• P1780 · Toyota Vitz (1st gen)
• P1780 on all cars compared

← P1760/77 P1790/65 →

Clearing the code does not fix the fault. If it comes back, the problem is still there. For brakes, airbags and steering, see a trained mechanic.