Diagnosis code 62: Driver’s Air Bag Module (Squib) System Fault for Earth Circuit (Short-Circuited to Earth)

OPERATION

The SRS-ECU judges how severe a collision is by detecting signals from the front impact sensors and the front air bag analog G-sensor. If the impact is over a predetermined level, the SRS-ECU outputs an ignition signal. At this time, if the front air bag safing G-sensor is on, the SRS air bag will inflate.

The ignition signal is input to the air bag module via the clock spring to inflate the air bag.

DIAGNOSIS CODE SET CONDITIONS

This diagnosis code is set if there is abnormal resistance between the input terminals of the driver's air bag module (squib). However, if no diagnosis code resets, the SRS warning lamp will be switched off (diagnosis code will be retained).

PROBABLE CAUSES

Malfunction of the clock spring

Damaged harness wires and connectors

Short to the earth in the driver's air bag module (squib) harness

Malfunction of the SRS-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check the driver's air bag module (Check whether the diagnosis code is reset).

Disconnect the negative battery terminal.

By sliding the A section (in the figure) of air bag module connector C-306 in arrow direction, disconnect the connector.

Connect special tool dummy resistor (MB991865) to special tool resistor harness (MB991866).

CAUTION

Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.

Insert special tool (MB991866) into clock spring side air bag module connector C-306 by backprobing.

Connect the negative battery terminal.

Erase the diagnosis code memory, and check the diagnosis code.

Q: Is diagnosis code 62 set?

YES: Go to Step 2

.
NO: Replace the driver's air bag module (Refer to

). Then go to Step 5

STEP 2. Check the clock spring (Check whether the diagnosis code is reset).

Disconnect the negative battery terminal.

Disconnect the clock spring connector C-307.

Connect special tool dummy resistor (MB991865) to special tool resistor harness (MB991866).

CAUTION

Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.

Insert special tool (MB991866) into clock spring harness side connector C-307 (terminal No.3 and 4) by backprobing.

Connect the negative battery terminal.

Erase the diagnosis code memory, and check the diagnosis code.

Q: Is diagnosis code 62 set?

YES: Go to Step 3

.
NO: Replace the clock spring (Refer to

). Then go to Step 5

STEP 3. Check the driver’s air bag module circuit at the SRS-ECU connector C-115.

Disconnect SRS-ECU connector C-115.

DANGER

To prevents the air bag from deploying unintentionally, disconnect the clock spring connector C-307 to short the squib circuit.

Disconnect the clock spring connector C-307.

CAUTION

Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.

Check for continuity between C-115 harness side connector terminals 11, 12 and body earth.

OK: Open circuit

Q: Is the check result normal?

YES: Erase the diagnosis code memory, and check the diagnosis code. If diagnosis code 62 sets, replace the SRS-ECU (Refer to

). Then go to Step 5

.
NO: Go to Step 5

STEP 4. Check the harness for short circuit to earth between SRS-ECU connector C-115 (terminal No.11 and 12) and clock spring connector C-307 (terminal No.3 and 4).

Q: Are the harness wires between SRS-ECU connector C-115 (terminal No.11 and 12) and clock spring connector C-307 (terminal No.3 and 4) in good condition?

YES: Go to Step 5

.
NO: Repair the harness wires between SRS-ECU connector C-115 and clock spring connector C-307. Then go to Step 5

STEP 5. Check whether the diagnosis code is reset.

Q: Is diagnosis code 62 set?

YES: Return to Step 1

.
NO: The procedure is complete (If no malfunctions are found in all steps, an intermittent malfunction is suspected). Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points


Diagnosis code 62: Driver’s Air Bag Module (Squib) System Fault for Earth Circuit (Short-Circuited to Earth)

OPERATION The SRS-ECU judges how severe a collision is by detecting signals from the front impact sensors and the front air bag analog G-sensor. If the impact is over a predetermined level, the SRS-ECU outputs an ignition signal. At this time, if the front air bag safing G-sensor is on, the SRS air bag will inflate. The ignition signal is input to the air bag module via the clock spring to inflate the air bag.
DIAGNOSIS CODE SET CONDITIONS This diagnosis code is set if there is abnormal resistance between the input terminals of the driver's air bag module (squib). However, if no diagnosis code resets, the SRS warning lamp will be switched off (diagnosis code will be retained).
PROBABLE CAUSES Malfunction of the clock spring Damaged harness wires and connectors Short to the earth in the driver's air bag module (squib) harness Malfunction of the SRS-ECU
	DIAGNOSIS PROCEDURE

	STEP 1. Check the driver's air bag module (Check whether the diagnosis code is reset). Disconnect the negative battery terminal.
	By sliding the A section (in the figure) of air bag module connector C-306 in arrow direction, disconnect the connector. Connect special tool dummy resistor (MB991865) to special tool resistor harness (MB991866).
	CAUTION Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened. Insert special tool (MB991866) into clock spring side air bag module connector C-306 by backprobing. Connect the negative battery terminal. Erase the diagnosis code memory, and check the diagnosis code. Q: Is diagnosis code 62 set? YES: Go to Step 2. NO: Replace the driver's air bag module (Refer to ). Then go to Step 5.
	STEP 2. Check the clock spring (Check whether the diagnosis code is reset). Disconnect the negative battery terminal.
	Disconnect the clock spring connector C-307. Connect special tool dummy resistor (MB991865) to special tool resistor harness (MB991866). CAUTION Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened. Insert special tool (MB991866) into clock spring harness side connector C-307 (terminal No.3 and 4) by backprobing. Connect the negative battery terminal. Erase the diagnosis code memory, and check the diagnosis code. Q: Is diagnosis code 62 set? YES: Go to Step 3. NO: Replace the clock spring (Refer to ). Then go to Step 5.
	STEP 3. Check the driver’s air bag module circuit at the SRS-ECU connector C-115. Disconnect SRS-ECU connector C-115. DANGER To prevents the air bag from deploying unintentionally, disconnect the clock spring connector C-307 to short the squib circuit. Disconnect the clock spring connector C-307.
	CAUTION Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened. Check for continuity between C-115 harness side connector terminals 11, 12 and body earth. OK: Open circuit Q: Is the check result normal? YES: Erase the diagnosis code memory, and check the diagnosis code. If diagnosis code 62 sets, replace the SRS-ECU (Refer to ). Then go to Step 5 . NO: Go to Step 5.
	STEP 4. Check the harness for short circuit to earth between SRS-ECU connector C-115 (terminal No.11 and 12) and clock spring connector C-307 (terminal No.3 and 4). Q: Are the harness wires between SRS-ECU connector C-115 (terminal No.11 and 12) and clock spring connector C-307 (terminal No.3 and 4) in good condition? YES: Go to Step 5 . NO: Repair the harness wires between SRS-ECU connector C-115 and clock spring connector C-307. Then go to Step 5.
	STEP 5. Check whether the diagnosis code is reset. Q: Is diagnosis code 62 set? YES: Return to Step 1 . NO: The procedure is complete (If no malfunctions are found in all steps, an intermittent malfunction is suspected). Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points .