C1551 (blink 51) on Toyota Corolla E120: IG Power Source Circuit Malfunction

Short answer: C1551 means “IG Power Source Circuit Malfunction”. The car’s computer has found a fault in the EMPS system and turns on the EPS (electric power steering) warning. First check: workshop check order (RM821E): CHECK FUSE (ECU−IG) -> CHECK POWER STEERING COMPUTER ASSY (EMPS ECU) -> CHECK WIRE HARNESS. OPEN AND SHORT CIRCUIT (PGND − BODY GROUND).

Code

C1551 · blink 51

System

EMPS

Dashboard light

EPS (electric power steering) warning

Applies to

Cars with electric power steering only. NOT fitted on PK cars: the EPC fig 4502 hydraulic vane pump covers ZZE12#..PKN and NZE120.

Market note

EMPS (electric power steering) is not fitted on PK cars; PK cars use hydraulic steering.

Confidence

high (official Toyota RM821E)

Source

toyotamanuals.gitlab.io

Symptoms and when it is set

1. The abnormal IG voltage value which is not within the specifi- cation is input to EMPS ECU.

Likely causes

1. EMPS ECU; Power source circuit; Charging system

What to check, in order

1. Workshop check order (RM821E): CHECK FUSE (ECU−IG) -> CHECK POWER STEERING COMPUTER ASSY (EMPS ECU) -> CHECK WIRE HARNESS. OPEN AND SHORT CIRCUIT (PGND − BODY GROUND)

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

• C1551 · Toyota Passo (1st gen)
• C1551 on all cars compared

← C1545/45 C1552/52 →

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.