• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
Front End Sensor 1 High Signal | B0083 02 | B0083 04 | B0083 04 | B0083 01 | B0083 3A |
Front End Sensor 1 Low Reference | B0083 02 | B0083 04 | B0083 04 | B0083 01 | B0083 3A |
Front End Sensor 2 High Signal | B0084 02 | B0084 04 | B0084 04 | B0084 01 | B0084 3A |
Front End Sensor 2 Low Reference | B0084 02 | B0084 04 | B0084 04 | B0084 01 | B0084 3A |
Left Front Side Impact Sensor High Signal | B0085 02 | B0085 04 | B0085 04 | B0085 01 | B0085 3A |
Left Front Side Impact Low Reference | B0085 02 | B0085 04 | B0085 04 | B0085 01 | B0085 3A |
Right Front Side Impact Sensor High Signal | B0086 02 | B0086 04 | B0086 04 | B0086 01 | B0086 3A |
Right Front Side Impact Low Reference | B0086 02 | B0086 04 | B0086 04 | B0086 01 | B0086 3A |
The inflatable restraint front end sensor utilizes a unidirectional 2-wire circuit. The front end sensor modulates current on the interface to send ID, state of health, and deployment commands to the inflatable restraint sensing and diagnostic module (SDM). The SDM serves as a power source and a ground for the front end sensor. When the ignition is turned ON and input power from the SDM is first detected, the front end sensor responds by performing internal diagnostics and sending an ID to the SDM. The SDM considers the ID to be valid if the response time is less than 5 seconds. The front end sensor continually communicates status messages to the SDM, which determines if a fault is present in the front end sensor circuit. When a fault is detected, the SDM may reset the front end sensor up to 2 times by removing and reapplying power to it. If the fault is still present, the SDM will set a DTC.
Ignition voltage is between 9-16 volts.
All of the following conditions exist for 2 seconds:
• | The front end sensor has been shorted to voltage. |
• | The SDM has not received a message from the front end sensor for more than 5 milliseconds. |
• | The front end sensor has been shorted to ground. |
• | The front end sensor current has been above 23 mA for longer than 5 milliseconds. |
The front end sensor circuit is open.
• | The SDM has received a NOK message from the front end sensor. |
• | The SDM has not received a message. |
• | The SDM has received an ID message from the front end sensor, which does not match the ID stored in the SDM memory. |
• | The SDM has reset the front end sensor twice without detecting the correct ID message. |
The SDM has received invalid serial data from the front end sensor.
• | The SDM requests the instrument panel cluster (IPC) to illuminate the AIR BAG indicator. |
• | The SIR System is disabled and no deployments are allowed. |
• | The condition for setting the DTC is no longer present. |
• | A history DTC will clear after 250 fault-free ignition cycles. |
Control Module References for scan tool information
Important: Refer to SIR Service Precautions.
When removing connectors, inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector:• | Front end sensor |
• | SDM module |
• | Front end sensor wiring harness connector |
• | SDM wiring harness connector |
⇒ | If greater than the specified range, test the circuit for a short to voltage. |
⇒ | If greater than the specified range, test the circuit for a short to voltage. |
⇒ | If less than the specified value, test the circuit for a short to ground. |
• | With LHD left front end sensor terminal 2 and SDM terminal 19 X1. |
• | With RHD left front end sensor terminal 2 and SDM terminal 24 X2. |
• | With LHD right front end sensor terminal 2 and SDM terminal 24 X2. |
• | With RHD right front end sensor terminal 2 and SDM terminal 19 X1. |
⇒ | If greater than the specified range, test the circuit for an open/high resistance. |
• | With LHD left front end sensor terminal 1 and SDM terminal 20 X1. |
• | With RHD left front end sensor terminal 1 and SDM terminal 23 X2. |
• | With LHD right front end sensor terminal 1 and SDM terminal 23 X2. |
• | With RHD right front end sensor terminal 1 and SDM terminal 20 X1. |
⇒ | If greater than the specified range, test the circuit for an open/high resistance. |
⇒ | If the DTC resets, replace the SDM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for SDM replacement, setup, and programming |