DTC 41
DTC 41 - IG1 Power Circuit System fuse No.13 circuitDTC 41, 42 - IG1 Power Circuit (fuse No.13 Or No.5 Circuit):
Connector - C-72, C-101, C-107:
CIRCUIT OPERATION
The SRS-ECU is powered from the ignition switch (IG1).
The SRS-ECU power is supplied from two circuits. Even if one circuit is shut off, the air bag can inflate.
The SRS-ECU judges how severe a collision is by detecting signals from the left and right side impact sensors and the analog G-sensor. If the impact is over a predetermined level, the SRS-ECU outputs an ignition signal. At this time, if the safing G-sensor is on, the SRS air bag will inflate.
DTC SET CONDITIONS
These diagnostic trouble codes are output if the voltage between the IG1 terminals (fuse No.13 or No.5 circuit) and ground is lower than a predetermined value for a continuous period of five seconds or more. However, if the vehicle condition returns to normal, diagnostic trouble code numbers 41 or 42 will be automatically erased, and the SRS warning light will switch off.
TROUBLESHOOTING HINTS
- Damaged wiring harnesses or connectors
- Malfunction of the SRS-ECU
DIAGNOSIS
Required Special Tool:
MB991223 (MB991222): Harness set (Probe)
STEP 1. Check the ignition switch (IG1) line at the SRS-ECU connector C-72.
1. Disconnect SRS-ECU connector C-72 and measure at the harness side.
2. Turn the ignition switch to "ON" position.
3. Use special tool MB991223 (MB991222) measure the voltage between terminal 12 (for DTC 41) or 9 (for DTC 42) and the ground. Voltage should be 9 volts or more.
If less than 9 volts, go to Step 2.
If 9 volts or more, go to Step 3.
STEP 2. Check the harness wires between the ignition switch (IG1) and SRS-ECU connector C-72.
Connector - C-101, C-107:
NOTE: After inspecting intermediate connectors C-101, C-107; inspect the wiring harness. If intermediate connectors are damaged, repair or replace them. Refer to General Information, Harness Connector Inspection.
Then go to Step 5.
If harness wires are in good condition, go to Step 5. If any harness wires between the ignition switch (IG1) and SRS-ECU connector C-72 are damaged, repair them. Then go to Step 5.
STEP 3. Check the ground line at the SRS-ECU connector C-72.
Measure the resistance between terminal 3 and ground.
Should be less than 2 ohms. If open circuit, go to Step 4.
If less than 2 ohms, replace the SRS-ECU. Then go to Step 5.
STEP 4. Check the harness wires between SRS-ECU connector C-72 and ground.
If harness wires are in good condition, go to Step 5. If any harness wires between SRS-ECU connector C-72 and ground are damaged, repair them. Then go to Step 5.
STEP 5. Check the diagnostic trouble codes.
Confirm that diagnostic trouble codes 41 and 42 are not output.