Toyota Venza: Short in Driver Side Squib Circuit (B1800/51-B1803/51)

Toyota Venza Service Manual / Supplemental Restraint Systems / Airbag System / Short in Driver Side Squib Circuit (B1800/51-B1803/51)

DESCRIPTION

The driver side squib circuit consists of the center airbag sensor assembly, spiral cable and steering pad.

The center airbag sensor assembly uses this circuit to deploy the airbag when deployment conditions are met.

These DTCs are stored when a malfunction is detected in the driver side squib circuit.

DTC No.	DTC Detection Condition	Trouble Area
B1800/51	The center airbag sensor assembly receives a line short circuit signal in the driver side squib circuit during primary check. Spiral cable malfunction Driver side squib malfunction Center airbag sensor assembly malfunction	Instrument panel wire Spiral cable Steering pad (Driver side squib) Center airbag sensor assembly
B1801/51	The center airbag sensor assembly receives an open circuit signal in the driver side squib circuit. Spiral cable malfunction Driver side squib malfunction Center airbag sensor assembly malfunction	Instrument panel wire Spiral cable Steering pad (Driver side squib) Center airbag sensor assembly
B1802/51	The center airbag sensor assembly receives a short circuit to ground signal in the driver side squib circuit. Spiral cable malfunction Driver side squib malfunction Center airbag sensor assembly malfunction	Instrument panel wire Spiral cable Steering pad (Driver side squib) Center airbag sensor assembly
B1803/51	The center airbag sensor assembly receives a short circuit to B+ signal in the driver side squib circuit. Spiral cable malfunction Driver side squib malfunction Center airbag sensor assembly malfunction	Instrument panel wire Spiral cable Steering pad (Driver side squib) Center airbag sensor assembly

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

Perform the simulation method by selecting check mode (Signal Check) using the Techstream (See page ).
After selecting check mode (Signal Check), perform the simulation method by wiggling each connector of the airbag system or driving the vehicle on a city or rough road (See page ).

PROCEDURE

1.	CHECK CONNECTORS

(a) Turn the ignition switch off.

(b) Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

(c) Check that the connectors are properly connected to the steering pad, spiral cable and center airbag sensor assembly.

OK:

The connectors are properly connected.

HINT:

If the connectors are not connected securely, reconnect the connectors and proceed to the next inspection.

(d) Disconnect the connectors from the steering pad, spiral cable and center airbag sensor assembly.

(e) Check that the terminals of the connectors are not damaged.

OK:

The terminals are not deformed or damaged.

(f) Check that the spiral cable connector (on the steering pad side) is not damaged.

OK:

The lock button is not disengaged, or the claw of the lock is not deformed or damaged.

(g) Check that the short springs for the instrument panel wire and spiral cable with the activation prevention mechanism are not deformed or damaged.

OK:

The short springs are not deformed or damaged.

Text in Illustration

*1	Driver Side Squib
*2	Spiral Cable
*3	Center Airbag Sensor Assembly
*4	Instrument Panel Wire

REPLACE WIRE HARNESS

2.	CHECK STEERING PAD (DRIVER SIDE SQUIB)

(a) Connect the instrument panel wire to the center airbag sensor assembly and spiral cable.

(b) Connect SST (resistance 2.1 Ω) to connector E (orange connector).

CAUTION:

Never connect an electrical tester to the steering pad (driver side squib) for measurement, as this may lead to a serious injury due to airbag deployment.

NOTICE:

Do not forcibly insert SST into the terminals of the connector when connecting.
Insert SST straight into the terminals of the connector.

SST: 09843-18061

(d) Turn the ignition switch to ON, and wait for at least 60 seconds.

(e) Clear the DTCs stored in memory (See page ).

(f) Turn the ignition switch off.

(g) Turn the ignition switch to ON, and wait for at least 60 seconds.

(h) Check for DTCs (See page ).

OK:

DTCs B1800, B1801, B1802, B1803 or 51 is not output.

Text in Illustration

*1	Driver Side Squib
*2	Spiral Cable
*3	Center Airbag Sensor Assembly
*4	Front view of wire harness connector (to Steering Pad)
*5	Connector E
*6	Color: Orange

HINT:

Codes other than DTCs B1800, B1801, B1802, B1803 and 51 may be output at this time, but they are not related to this check.

REPLACE STEERING PAD

3.	CHECK DRIVER SIDE SQUIB CIRCUIT

(a) Turn the ignition switch off.

(b) Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

(d) Disconnect the instrument panel wire from the center airbag sensor assembly.

(e) Check for a short to B+ in the circuit.

(1) Connect the cable to the negative (-) battery terminal.

(2) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
z1-2 (D+) - Body ground	Ignition switch ON	Below 1 V
z1-1 (D-) - Body ground	Ignition switch ON	Below 1 V

(f) Check for an open in the circuit.

(1) Turn the ignition switch off.

(2) Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
z1-2 (D+) - z1-1 (D-)	Always	Below 1 Ω

(g) Check for a short to ground in the circuit.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
z1-2 (D+) - Body ground	Always	1 MΩ or higher
z1-1 (D-) - Body ground	Always	1 MΩ or higher

(h) Check for a short in the circuit.

(1) Release the activation prevention mechanism built into connector B (See page ).

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
z1-2 (D+) - z1-1 (D-)	Always	1 MΩ or higher

Text in Illustration

*1	Driver Side Squib
*2	Spiral Cable
*3	Center Airbag Sensor Assembly
*4	Front view of wire harness connector (to Steering Pad)
*5	Connector E
*6	Color: Orange

GO TO STEP 5

4.	CHECK CENTER AIRBAG SENSOR ASSEMBLY

(a) Restore the released activation prevention mechanism of connector B to the original condition.

(b) Connect the connectors to the steering pad and center airbag sensor assembly.

(d) Turn the ignition switch to ON, and wait for at least 60 seconds.

(e) Clear the DTCs stored in memory (See page ).

(f) Turn the ignition switch off.

(g) Turn the ignition switch to ON, and wait for at least 60 seconds.

(h) Check for DTCs (See page ).

OK:

DTC B1800, B1801, B1802, B1803 or 51 is not output.

Text in Illustration

*1	Driver Side Squib
*2	Spiral Cable
*3	Center Airbag Sensor Assembly

HINT:

Codes other than DTCs B1800, B1801, B1802, B1803 and 51 may be output at this time, but they are not related to this check.

USE SIMULATION METHOD TO CHECK

REPLACE CENTER AIRBAG SENSOR ASSEMBLY

5.	CHECK INSTRUMENT PANEL WIRE

(a) Restore the released activation prevention mechanism of connector B to the original condition.

(b) Disconnect the instrument panel wire from the spiral cable.

(1) Connect the cable to the negative (-) battery terminal.

(2) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
D7-1 (D+) - Body ground	Ignition switch ON	Below 1 V
D7-2 (D-) - Body ground	Ignition switch ON	Below 1 V

(d) Check for an open in the circuit.

(1) Turn the ignition switch off.

(2) Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
D7-1 (D+) - D7-2 (D-)	Always	Below 1 Ω

(e) Check for a short to ground in the circuit.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
D7-1 (D+) - Body ground	Always	1 MΩ or higher
D7-2 (D-) - Body ground	Always	1 MΩ or higher

(f) Check for a short in the circuit.

(1) Release the activation prevention mechanism built into connector B (See page ).

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
D7-1 (D+) - D7-2 (D-)	Always	1 MΩ or higher

Text in Illustration

*1	Driver Side Squib
*2	Spiral Cable
*3	Center Airbag Sensor Assembly
*4	Instrument Panel Wire
*5	Front view of wire harness connector (to Spiral Cable)
*6	Connector C

REPLACE INSTRUMENT PANEL WIRE

6.	CHECK SPIRAL CABLE

(a) Check for a short to B+ in the circuit.

(1) Connect the cable to the negative (-) battery terminal.

(2) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
z1-2 (D+) - Body ground	Ignition switch ON	Below 1 V
z1-1 (D-) - Body ground	Ignition switch ON	Below 1 V

(b) Check for an open in the circuit.

(1) Turn the ignition switch off.

(2) Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
z1-2 (D+) - z1-1 (D-)	Always	Below 1 Ω

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
z1-2 (D+) - Body ground	Always	1 MΩ or higher
z1-1 (D-) - Body ground	Always	1 MΩ or higher

(d) Check for a short in the circuit.

(1) Release the activation prevention mechanism built into connector D (See page ).

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
z1-2 (D+) - z1-1 (D-)	Always	1 MΩ or higher

Text in Illustration

*1	Driver Side Squib
*2	Spiral Cable
*3	Center Airbag Sensor Assembly
*4	Instrument Panel Wire
*5	Front view of wire harness connector (to Steering Pad)
*6	Connector E
*7	Color: Orange

USE SIMULATION METHOD TO CHECK

REPLACE SPIRAL CABLE

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