DOOR LOCK WIRELESS DOOR LOCK CONTROL SYSTEM(w/ Smart Entry and Start System) B1242 Wireless Door Lock Tuner Circuit Malfunction

DESCRIPTION

The door control with receiver ECU assembly is used to receive radio waves related to the entry functions of the electrical key transmitter sub-assembly. The certification ECU (smart key ECU assembly) decodes the requested electrical key transmitter sub-assembly operation by identifying a key code based on the radio waves received via the door control with receiver ECU assembly. The door control with receiver ECU assembly receives a signal from the electrical key transmitter sub-assembly and sends signals to the main body ECU (multiplex network body ECU) through the certification ECU (smart key ECU assembly) (ex. if a door lock operation is requested, the certification ECU (smart key ECU assembly) sends a door lock command to the main body ECU (multiplex network body ECU)).

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
B1242	Wireless Door Lock Tuner Circuit Malfunction	· Short in RDAM to ground between the certification ECU (smart key ECU assembly) and door control with receiver ECU assembly. · Short in RDAM to ground when RCO (5 V) output from the ECU is off.	· Wire harness or connector · Door control with receiver ECU assembly · Certification ECU (smart key ECU assembly)

WIRING DIAGRAM

0.25,2.979 2.927,3.625 2.677,0.646 10 false Door Control with Receiver ECU Assembly 0.26,2.802 0.875,3.156 0.615,0.354 10 false L70 5.302,2.906 7.104,3.479 1.802,0.573 10 false Certification ECU (Smart Key ECU Assembly) 1.188,0.854 1.802,1.208 0.615,0.354 10 false DATA 1.365,1.635 1.979,1.99 0.615,0.354 10 false +5 1.24,2.333 1.854,2.688 0.615,0.354 10 false GND 5.74,0.844 6.354,1.198 0.615,0.354 10 false RDAM 5.75,1.646 6.365,2 0.615,0.354 10 false RCO 5.74,2.333 6.354,2.688 0.615,0.354 10 false E 5.333,2.344 5.948,2.698 0.615,0.354 10 false E108 5.333,0.854 5.948,1.208 0.615,0.354 10 false E109 5.417,0.615 6.031,0.969 0.615,0.354 10 false 17 5.448,1.448 6.063,1.802 0.615,0.354 10 false 5 5.417,2.135 6.031,2.49 0.615,0.354 10 false 11 1.625,2.229 2.24,2.583 0.615,0.354 10 false 1 1.635,1.542 2.25,1.896 0.615,0.354 10 false 4 1.656,0.75 2.271,1.104 0.615,0.354 10 false 5 5.333,1.656 5.948,2.01 0.615,0.354 10 false E109

CAUTION / NOTICE / HINT

NOTICE:: ·

When replacing or inspecting the door control with receiver ECU assembly and wire harness, do not change the position or length of the wire harness. If the wire harness is too close to the door control with receiver ECU assembly, entry and wireless function performance may be affected.

·

This DTC is not stored within 10 seconds of the engine switch being turned from on (IG) to off.

·

Before replacing the certification ECU (smart key ECU assembly), refer to Service Bulletin.

PROCEDURE

1.CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

Disconnect the L70 door control with receiver ECU assembly connector.

Measure the voltage and resistance and check for pulses according to the value(s) in the table below.

1.813,0.75 2.229,1 0.417,0.25 3.208,0.75 3.625,1 0.417,0.25 4.75,0.75 5.167,1 0.417,0.25 2.5,1.667 2.667,2.417 2.667,2.417 2.917,2.417 false 4.052,1.667 4.167,2.5 4.167,2.5 4.333,2.5 false 4.052,1.5 4.167,0.583 4.167,0.583 4.417,0.583 false 0.333,0.271 0.646,0.427 0.313,0.156 10 false *a 3.01,2.333 3.167,2.49 0.156,0.156 10 false E 4.417,2.417 4.948,2.677 0.531,0.26 10 false RDAM 4.5,0.49 5.031,0.75 0.531,0.26 10 false RCO 1.865,0.792 2.208,1.083 0.344,0.292 10 false E108 3.25,0.781 3.594,1.073 0.344,0.292 10 false E109 4.813,0.781 5.156,1.073 0.344,0.292 10 false E110

Component with harness connected
(Certification ECU (Smart Key ECU Assembly))

Standard Voltage:

Tester Connection	Condition	Specified Condition
E109-5 (RCO) - E108-11 (E)	Always	Below 1 V → 4.5 to 5.5 V (Pulse generation)
E109-17 (RDAM) - E108-11 (E)	Always	11 to 14 V

Standard Resistance:

Tester Connection	Condition	Specified Condition
E108-11 (E) - Body ground	Always	Below 1 Ω

Result:

Result
OK
NG

REPLACE DOOR CONTROL WITH RECEIVER ECU ASSEMBLY

Click hereVehicle Interior>DOOR LOCK>DOOR CONTROL RECEIVER>REMOVAL

2.CHECK HARNESS AND CONNECTOR (DOOR CONTROL WITH RECEIVER ECU ASSEMBLY - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY))

Disconnect the E109 certification ECU (smart key ECU assembly) connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
E109-17 (RDAM) - L70-5 (DATA)	Always	Below 1 Ω
E109-5 (RCO) - L70-4 (+5)	Always	Below 1 Ω
L70-1 (GND) - Body ground	Always	Below 1 Ω
E109-17 (RDAM) or L70-5 (DATA) - Body ground	Always	10 kΩ or higher
E109-5 (RCO) or L70-4 (+5) - Body ground	Always	10 kΩ or higher

Result:

Proceed to
OK
NG

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

REPAIR OR REPLACE HARNESS OR CONNECTOR