Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000VIZM
Model Year Start: 2016 Model: Sienna Prod Date Range: [12/2015 -           ]
Title: POWER ASSIST SYSTEMS: POWER STEERING SYSTEM: C1552,C1554; PIG Power Supply Voltage Malfunction; 2016 - 2020 MY Sienna [12/2015 -        ]

DTC

C1552

PIG Power Supply Voltage Malfunction

DTC

C1554

Power Supply Relay Failure

DESCRIPTION

When a problem occurs in the system, the power source relay circuit and the motor relay circuit are shut off to stop the power assist. The ECU must be replaced when there is a problem with the relays because each relay is built into the ECU.

DTC No.

DTC Detection Condition

Trouble Area

C1552

PIG power source circuit malfunction
  • PIG power source circuit
  • Steering column assembly

C1554

Power source relay circuit malfunction

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • When the steering column assembly is replaced, perform the assist map writing (See page 2016 - 2020 MY Sienna [12/2015 -        ]; POWER ASSIST SYSTEMS: POWER STEERING SYSTEM: REGISTRATION ).
  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (STEERING COLUMN ASSEMBLY - BATTERY AND BODY GROUND)

(a) Disconnect the connector from the steering column assembly (power steering ECU).

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

D36-1 (PIG) - Body ground

Always

11 to 14 V

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

D36-2 (PGND) - Body ground

Always

Below 1 Ω

Text in Illustration

*a

Front view of wire harness connector:

(to Steering Column Assembly (Power Steering ECU))
OK

REPLACE STEERING COLUMN ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR