B1572

THEFT DETERRENT / KEYLESS ENTRY: ENGINE IMMOBILISER SYSTEM: B1572; Immobiliser System Communication Malfunction; 2013 MY FR-S [03/2012 -]
B1572 - Immobiliser System Communication Malfunction

DESCRIPTION

* The ECM stores this code if a communication problem is detected between the main body ECU (network gateway ECU) and the ECM.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
* If the main body ECU (network gateway ECU) or ECM is replaced, refer to Registration Programming and Relearning.
* Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (BATTERY, BODY GROUND)

(a) Disconnect the A73 and D6 main body ECU (network gateway ECU) connectors.

(b) Disconnect the 3A, 3B and 3C instrument panel junction block assembly connectors.

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









Standard Voltage:





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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

2. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Remove the instrument panel junction block assembly Removal.

(b) Remove the main body ECU (network gateway ECU) from the instrument panel junction block assembly.

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









Standard Resistance:





NG -- REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Removal
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR

(a) Disconnect the A73 main body ECU (network gateway ECU) connector.

(b) Disconnect the A35 and A36 ECM connectors.

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

Standard Voltage:





Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. REPLACE ECM

(a) Temporarily replace the ECM with a new or known good one Removal.

NEXT -- Continue to next step.

5. CHECK FOR DTC

(a) Turn the ignition switch to ON and wait 5 seconds.

(b) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
DTC B1571 is stored if the ECM has been replaced by one that is not new.

OK:

DTC B1572 is not output

NG -- REPLACE MAIN BODY ECU (NETWORK GATEWAY ECU) Removal

OK -- END (ECM WAS DEFECTIVE)