Toyota CH-R Service Manual: Diagnosis System

DIAGNOSIS SYSTEM

CHECK DLC3

(a) Check the DLC3.

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FUNCTION OF SRS WARNING LIGHT

(a) Primary check

(1) Turn the ignition switch off. Wait for at least 2 seconds, then turn the ignition switch ON. The SRS warning light comes on for approximately 6 seconds and diagnosis of the airbag system is performed.

HINT:

If malfunctions are detected during the primary check, the SRS warning light remains on even after the primary check period of approximately 6 seconds.

(b) Constant check

(1) After the primary check, the airbag sensor assembly constantly monitors the airbag system for malfunctions.

(c) Review

(1) When the airbag system is normal:

The SRS warning light comes on only during the primary check period of approximately 6 seconds after the ignition switch is turned ON.

(2) When the airbag system is malfunctioning:

HINT:

The SRS warning light will remain illuminated if any airbag or pretensioner has been deployed.

SRS WARNING LIGHT CHECK

(a) Turn the ignition switch ON, and check that the SRS warning light comes on for approximately 6 seconds (primary check).

(b) Check that the SRS warning light goes off approximately 6 seconds after the ignition switch is turned ON (constant check).

HINT:

When any of the following symptoms occur, refer to Problem Symptoms Table.

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FUNCTION OF PASSENGER AIRBAG ON/OFF INDICATOR

(a) Initial check

(1) Turn the ignition switch ON.

(2) The passenger airbag ON/OFF indicator comes on for approximately 4 seconds, then goes off for approximately 2 seconds.

(3) Approximately 6 seconds after the ignition switch is turned ON, the passenger airbag ON/OFF indicator will indicate ON/OFF depending on the following conditions.

PASSENGER AIRBAG ON/OFF INDICATOR CHECK

(a) Turn the ignition switch ON.

(b) Check that the passenger airbag ON/OFF indicator ("ON" and "OFF") comes on for approximately 4 seconds, then goes off for approximately 2 seconds.

HINT:

Refer to the indicator operation table in Function of Passenger Airbag ON/OFF Indicator for the passenger airbag ON/OFF indicator operation when the ignition switch is turned ON and approximately 6 seconds elapse.

FUNCTION OF SRS CONNECTORS

(a) The SRS connectors are located as shown in the illustration.

(b) Terminal twin-lock mechanism

(1) This mechanism is designed to increase the ability of the terminal to remain connected and prevent it from accidentally being disconnected.

(2) The connector has a two-piece construction consisting of the housing and spacer to securely lock the terminal using both the lance (primary lock) and spacer (secondary lock).

(c) Half connection prevention mechanism

(1) This mechanism is designed to prevent the connector from being connected only halfway.

(2) If the connector is not completely connected, the connector is disconnected due to the spring force so that no continuity exists.

(d) Activation prevention mechanism

(1) This mechanism is designed to create a short circuit automatically between the positive and negative terminals of an airbag power source connector when disconnected.

(2) The short spring plate contained in the connector creates a closed circuit on the airbag side (no potential difference can occur between both terminals), preventing accidental airbag deployment when servicing.

(e) Connector lock mechanism (1)

(1) This mechanism is designed to prevent the connector from accidentally being disconnected.

(2) Locking the connector locking button engages the locking button claws in the grooves on the other side of the connector to connect the connector securely.

(f) Connector Position Assurance (CPA) mechanism

(1) This mechanism is designed to detect when the connector is connected only halfway.

(2) The CPA and female connector slide to the male connector side at the same time and the primary lock is completed when the female connector is engaged with the male connector. From this point, only the CPA slides to the male connector side and secondary lock is completed when the CPA retainer is engaged with the female connector. When the CPA and female connector ends are aligned, they are completely engaged.

(g) Connector lock mechanism (2)

(1) This mechanism is designed to prevent the connector from accidentally being disconnected.

(2) Sliding the connector all the way into the holder and locking the lance completes the primary lock.

(3) Engaging the retainer to the holder as shown in the illustration completes the secondary lock, preventing the connector from accidentally being disconnected.

(h) Improper connection prevention lock mechanism

(1) This mechanism is designed to prevent the connector from being connected only halfway.

(2) When the holder is connected to the airbag sensor assembly, the unlock rib unlocks the temporary hold lock, allowing the lever to be pushed in by rotating around axis A.

(3) Locking the lever to the holder locks the holder securely.

ACTIVATION PREVENTION MECHANISM

(a) Function of activation prevention mechanism

(1) An activation prevention mechanism is built into the connector of the airbag system squib circuit to prevent accidental airbag and pretensioner deployment.

(2) This mechanism closes the circuit when the connector is disconnected by bringing the short spring into contact with the terminals and insulating the circuit from external power sources to prevent accidental airbag and pretensioner deployment.

(b) Releasing of activation prevention mechanism

(1) To release the activation prevention mechanism, insert a piece of paper with the same thickness as the male terminal (approximately 0.5 mm (0.0197 in.)) between the terminals and short spring to break the connection.

(2) Refer to the following illustrations concerning connectors utilizing the activation prevention mechanism and its release method.

CAUTION:

Never release the activation prevention mechanism on the squib connector even when inspecting with the squib disconnected.