Supplemental Restraint System (Diagnostic Codes & Symptom Tests): Overview Toyota 4Runner V

DESCRIPTION

The center airbag sensor assembly consists of a deceleration sensor, safing sensor, drive circuit, diagnosis circuit, ignition control, etc.

If the center airbag sensor assembly receives signals from the deceleration sensor, it determines whether or not the airbag squib and pretensioner squib should be activated.

DTC B1000/31 is recorded when a malfunction is detected in the center airbag sensor assembly.

The front airbag sensor RH consists of the diagnostic circuit and frontal deceleration sensor, etc.

If the center airbag sensor receives signals from the frontal deceleration sensor, it determines whether the SRS should be activated.

DTC B1610/13 is stored when a malfunction is detected in the front airbag sensor RH circuit.

Scheme 154

The front airbag sensor RH circuit consists of the center airbag sensor and front airbag sensor RH.

The front airbag sensor RH detects impacts to the vehicle and sends signals to the center airbag sensor to determine if the airbag should be deployed.

DTC B1612/83 or B1613/83 is stored when a malfunction is detected in the front airbag sensor RH circuit.

The front airbag sensor LH consists of the diagnostic circuit and frontal deceleration sensor, etc.

If the center airbag sensor receives signals from the frontal deceleration sensor, it determines whether the SRS should be activated.

DTC B1615/14 is stored when a malfunction is detected in the front airbag sensor LH circuit.

Scheme 155

The front airbag sensor LH circuit consists of the center airbag sensor and front airbag sensor LH.

The front airbag sensor LH detects impacts to the vehicle and sends signals to the center airbag sensor to determine if the airbag should be deployed.

DTC B1617/84 or B1618/84 is stored when a malfunction is detected in the front airbag sensor LH circuit.

The front collision sensor circuit (front airbag sensor RH circuit and front airbag sensor LH circuit) is composed of the center airbag sensor assembly, front airbag sensor RH and front airbag sensor LH.

The front airbag sensor RH or front airbag sensor LH detects impacts to the vehicle and sends signals to the center airbag sensor assembly to determine if the airbag should be deployed.

DTC B161A/8A is stored when a malfunction is detected in the front collision sensor circuit (front airbag sensor RH circuit and front airbag sensor LH circuit).

Scheme 156

1. The rear airbag sensor consists of the safing sensor, diagnostic circuit, lateral deceleration sensor, etc.
2. If the center airbag sensor receives signals from the lateral deceleration sensor, it determines whether the SRS should be activated.
3. DTC B1630 or B1635 is stored when a malfunction is detected in the rear airbag sensor circuit.

Scheme 157

Scheme 158

The circuit for the side collision sensor LH or RH (to determine deployment of the front seat side airbag LH or RH and curtain shield airbag LH or RH) is composed of the center airbag sensor, side airbag sensor LH or RH and rear airbag sensor LH or RH.

The rear airbag sensor LH or RH detect impacts to the vehicle and send signals to the center airbag sensor to determine if the airbag should be deployed.

DTC B1633 or B1638 is stored when a malfunction is detected in the circuit for the rear collision sensor LH or RH (to determine deployment of the curtain shield airbag LH or RH).

The circuit for the side collision sensor LH or RH (to determine deployment of the front seat side airbag LH or RH and curtain shield airbag LH or RH) is composed of the center airbag sensor, rear airbag sensor LH or RH and side airbag sensor LH or RH.

The side airbag sensor LH or RH and rear airbag sensor LH or RH detect impacts to the vehicle and send signals to the center airbag sensor to determine if the airbag should be deployed.

DTC B1642/81 or B1647/82 is stored when a malfunction is detected in the circuit for the side collision sensor LH or RH (to determine deployment of the front seat side airbag LH or RH and curtain shield airbag LH or RH).

The occupant classification system circuit consists of the center airbag sensor and occupant classification ECU.

If the center airbag sensor receives signals from the occupant classification ECU, it determines whether the instrument panel passenger airbag, lower No. 2 instrument panel airbag, front seat side airbag RH and front seat outer belt should be operated.

DTC B1650/32 is stored when a malfunction is detected in the occupant classification system circuit.

Scheme 159

The seat belt buckle switch LH circuit consists of the center airbag sensor and front seat inner belt LH.

DTC B1656/37 is stored when a malfunction is detected in the seat belt buckle switch LH circuit.

Scheme 160

The passenger airbag ON/OFF indicator circuit consists of the center airbag sensor and passenger airbag ON/OFF indicator.

The passenger airbag ON/OFF indicator indicates the operation condition of the instrument panel passenger airbag, lower No. 2 instrument panel airbag, front seat side airbag RH and front seat outer belt RH.

DTC B1660/43 is stored when a malfunction is detected in the passenger airbag ON/OFF indicator circuit.

Scheme 161

The curtain airbag cutoff switch is a mechanism that operates both the right and left sides of the curtain shield airbag and the front seat outer belt when the center airbag sensor detects a roll-over.

The RSCA OFF indicator is installed in the combination meter.

If the curtain airbag cutoff switch is operated, the indicator comes on to inform the driver that the roll-over detection system is not operating.

The initial setting of the roll-over detection system is on. This system automatically operates every time the ignition switch is turned to ON.

Scheme 162

The rear floor side airbag sensor consists of the diagnostic circuit, rear floor deceleration sensor, etc.

If the center airbag sensor receives signals from the rear floor deceleration sensor, it determines whether the SRS should be activated.

DTC B1675/82 is stored when a malfunction is detected in the rear floor side airbag sensor circuit.

Scheme 163

HINT

"Rear floor airbag sensor RH" refers to the rear floor side airbag sensor.

1. The rear floor side airbag sensor circuit consists of the center airbag sensor and rear floor side airbag sensor.
2. The rear floor side airbag sensor detects impacts to the vehicle and sends signals to the center airbag sensor to determine if the airbag should be deployed.
3. DTC B1676/85 or B1677/85 is stored when a malfunction is detected in the rear floor side airbag sensor circuit.

The side airbag sensor LH or RH consists of the safing sensor, diagnostic circuit, lateral deceleration sensor, etc.

If the center airbag sensor receives signals from the lateral deceleration sensor, it determines whether the SRS should be activated.

DTC B1690/15 or B1695/16 is stored when a malfunction is detected in the side airbag sensor LH or RH circuit.

Scheme 164

Scheme 165

The circuit for the side collision sensor LH or RH (to determine deployment of the front seat side airbag LH or RH and curtain shield airbag LH or RH) is composed of the center airbag sensor, rear airbag sensor LH or RH and side airbag sensor LH or RH.

The rear airbag sensor LH or RH and side airbag sensor LH or RH detect impacts to the vehicle and send signals to the center airbag sensor to determine if the airbag should be deployed.

DTC B1692/81 or B1697/82 is stored when a malfunction is detected in the circuit for the side collision sensor LH or RH (to determine deployment of the front seat side airbag LH or RH and curtain shield airbag LH or RH).

The circuit for the side collision sensor LH or RH (to determine deployment of the front seat side airbag LH or RH and curtain shield airbag LH or RH) is composed of the center airbag sensor, rear airbag sensor LH or RH and side airbag sensor LH or RH.

The rear airbag sensor LH or RH and side airbag sensor LH or RH detect impacts to the vehicle and send signals to the center airbag sensor to determine if the airbag should be deployed.

DTC B1693/81 or B1698/82 is stored when a malfunction is detected in the circuit for the side collision sensor LH or RH (to determine deployment of the front seat side airbag LH or RH and curtain shield airbag LH or RH).

1. The driver side squib circuit consists of the center airbag sensor, spiral cable and steering pad.
2. The circuit instructs the SRS to deploy when deployment conditions are met.
3. These DTCs are stored when a malfunction is detected in the driver side squib circuit.

Scheme 166

The front passenger side squib circuit consists of the center airbag sensor and instrument panel passenger airbag.

The circuit instructs the SRS to deploy when deployment conditions are met.

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

Scheme 167

The driver side squib 2nd step circuit consists of the center airbag sensor, spiral cable and steering pad.

The circuit instructs the SRS to deploy when deployment conditions are met.

These DTCs are stored when a malfunction is detected in the driver side squib 2nd step circuit.

Scheme 168

The front passenger side squib 2nd step circuit consists of the center airbag sensor and instrument panel passenger airbag.

The circuit instructs the SRS to deploy when deployment conditions are met.

These DTCs are stored when a malfunction is detected in the front passenger side squib 2nd step circuit.

Scheme 169

The side squib RH circuit consists of the center airbag sensor and front seat side airbag RH.

This circuit instructs the SRS to deploy when deployment conditions are met.

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

Scheme 170

The side squib LH circuit consists of the center airbag sensor and front seat side airbag LH.

The circuit instructs the SRS to deploy when deployment conditions are met.

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

Scheme 171

The curtain shield squib RH circuit consists of the center airbag sensor and curtain shield airbag RH.

The circuit instructs the SRS to deploy when deployment conditions are met.

These DTCs are stored when a malfunction is detected in the curtain shield squib RH circuit.

Scheme 172

The curtain shield squib LH circuit consists of the center airbag sensor and curtain shield airbag LH.

The circuit instructs the SRS to deploy when deployment conditions are met.

These DTCs are stored when a malfunction is detected in the curtain shield squib LH circuit.

Scheme 173

The driver side knee squib circuit consists of the center airbag sensor and lower No. 1 instrument panel airbag.

This circuit instructs the SRS to deploy when deployment conditions are met.

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

Scheme 174

The front passenger side knee squib circuit consists of the center airbag sensor and lower No. 2 instrument panel airbag.

The circuit instructs the SRS to deploy when deployment conditions are met.

These DTCs are stored when a malfunction is detected in the front passenger side knee squib circuit.

Scheme 175

The front pretensioner squib RH circuit consists of the center airbag sensor and front seat outer belt RH.

This circuit instructs the SRS to deploy when deployment conditions are met.

These DTCs are stored when a malfunction is detected in the front pretensioner squib RH circuit.

Scheme 176

The front pretensioner squib LH circuit consists of the center airbag sensor and front seat outer belt LH.

This circuit instructs the SRS to deploy when deployment conditions are met.

These DTCs are stored when a malfunction is detected in the front pretensioner squib LH circuit.

Scheme 177

The SRS warning light is located in the combination meter.

When the SRS is normal, the SRS warning light comes on for approximately 6 seconds after the ignition switch is turned from off to ON, and then goes off automatically.

If there is a malfunction in the SRS, the SRS warning light comes on to inform the driver of a problem.

When terminals TC and CG of the DLC3 are connected, DTCs are output by the blinking of the SRS warning light.

The SRS is equipped with a voltage-increase circuit (DC-DC converter) in the center airbag sensor in case the source voltage drops.

When the battery voltage drops, the voltage-increase circuit (DC-DC converter) functions to increase the voltage of the SRS to normal voltage.

A malfunction in this circuit is not recorded in the center airbag sensor. The SRS warning light automatically goes off when the source voltage returns to normal.

The signal to illuminate the SRS warning light is transmitted from the center airbag sensor to the combination meter through the CAN communication system.

Scheme 178

Refer to SRS Warning Light Remains ON .

DTC output mode is set by connecting terminals TC and CG of the DLC3.

DTCs are output by the blinking of the SRS warning light.

HINT

1. When each warning light continues blinking, a ground short in the wiring of terminal TC of the DLC3 or an internal ground short in each ECU is suspected.
2. A DTC output mode signal is transmitted through the CAN communication system to each ECU including the center airbag sensor. Thus, when all systems do not enter DTC output mode, there may be an ECM malfunction.

Scheme 179