The steering wheel module deployment loop consists of a dual stage inflatable restraint steering wheel module, an inflatable restraint steering wheel module coil, the steering wheel module - high and steering wheel module - low circuits. There are 2 shorting bar used in the inflatable restraint steering wheel module and the inflatable restraint steering wheel module coil connectors which will short together the steering wheel module - high and steering wheel module - low circuits when the connector is disconnected, this will help to prevent unwanted deployment of the inflator module during servicing. During a frontal crash of sufficient force the sensing and diagnostic module (SDM) will allow current to flow through the deployment loop in order to deploy the inflatable restraint steering wheel module. The SDM performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity and for shorts to ground or voltage. If a malfunction is detected, a DTC will be stored.
This diagnostic procedure supports the following DTCs:
• | DTC B1800 Driver Air Bag Deployment Loop Resistance Too Low |
• | DTC B1801 Driver Air Bag Deployment Loop Resistance Too High |
• | DTC B1802 Driver Air Bag Deployment Loop Short To Ground |
• | DTC B1803 Driver Air Bag Deployment Loop Short To Voltage |
Ignition 1 voltage is within the normal operating voltage range.
This DTC will set when the SDM detects a low resistance condition in the steering wheel module deployment loop.
This DTC will set when the SDM detects a high resistance condition in the steering wheel module deployment loop.
This DTC will set when the SDM detects a short to ground in the steering wheel module deployment loop.
This DTC will set when the SDM detects a short to voltage in the steering wheel module deployment loop.
The SDM commands the AIR BAG indicator ON.
The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.
The following are possible causes of the malfunction:
• | A short between the steering wheel module - high and the steering wheel module - low circuits |
• | An open or high resistance in the steering wheel module - high or the steering wheel module - low circuits |
• | A short to ground in the steering wheel module - high or the steering wheel module - low circuits |
• | A short to voltage in the steering wheel module - high or the steering wheel module - low circuits |
• | A malfunctioning inflatable restraint steering wheel module |
• | A malfunctioning inflatable restraint steering wheel module coil |
• | An internal SDM malfunction |
If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections .
The numbers below refer to the step numbers on the diagnostic table.
This step tests to see if the malfunction is caused by the inflatable restraint steering wheel module.
This step tests to see if the malfunction is caused by the inflatable restraint steering wheel module coil.
This step tests to see if the malfunction is caused by the inflatable restraint steering wheel module.
This step tests to see if the malfunction is caused by the inflatable restraint steering wheel module coil.
If DTC B1800 is present, test for a short between the steering wheel module - high and the steering wheel module - low circuits.
If DTC B1801 is present, test the steering wheel module - high and the steering wheel module - low circuits for an open or high resistance.
If DTC B1802 is present, test the steering wheel module - high and the steering wheel module - low circuits for a short to ground.
If DTC B1803 is present, test the steering wheel module - high and the steering wheel module - low circuits for a short to voltage.
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: SIR Schematics Connector End View Reference: SIR Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 | Is DTC B1800, B1801, B1802 or B1803 set as a current DTC? | Go to Step 3 | Go to Diagnostic Aids |
3 |
Does the connector exhibit any signs of damage or corrosion? | Go to Step 4 | Go to Step 5 |
4 |
Did you complete the replacement? | Go to Step 16 | -- |
5 | Is DTC B1801, B1802 or B1803 set as a current DTC? | Go to Step 7 | Go to Step 6 |
6 | Is DTC B1800 set as a current DTC? | Go to Step 9 | -- |
Does the scan tool indicate that DTC B1801, DTC B1802, DTC B1803 is current? | Go to Step 8 | Go to Step 13 | |
Does the scan tool indicate that DTC B1801, DTC B1802, DTC B1803 is current? | Go to Step 11 | Go to Step 14 | |
Does the scan tool indicate that DTC B1800 is current? | Go to Step 10 | Go to Step 13 | |
Does the scan tool indicate that DTC B1800 is current? | Go to Step 11 | Go to Step 14 | |
11 |
Did you find and correct the condition? | Go to Step 16 | Go to Step 12 |
Did you find and correct the condition? | Go to Step 16 | Go to Step 15 | |
13 |
Did you complete the replacement? | Go to Step 16 | -- |
14 |
Did you complete the replacement? | Go to Step 16 | -- |
15 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Did you complete the replacement? | Go to Step 16 | -- |
16 |
Does the DTC reset? | Go to Step 2 | System OK |