Circuit Description
When you first turn the ignition switch to the RUN position, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. The SDM then measures the following circuits to ensure they are within their respective normal voltage ranges:
| • | Ignition positive voltage |
| • | 23 VLR |
| • | Deployment loop voltages |
The SDM then proceeds to CONTINUOUS MONITORING. The SDM contains a resistor network connected to 5 volts, ground, and to the SDM discriminating sensor signal input terminal A11. The SDM monitors two front end discriminating sensors that are wired in parallel. The 1.0 K ohm resistor located in the RH inflatable restraint front end discriminating sensor is parallel to the normally open switches in both sensors and provides a parallel path to ground. This causes a specified percentage of voltage to appear at the SDM discriminating sensor signal input. The SDM monitors this voltage to detect shorts to power or an open discriminating sensor.
Conditions for Setting the DTC
| • | The SDM is configured for inflatable restraint front end discriminating sensors. |
| • | The voltage at the discriminating sensor signal input terminal A11 is more than 3.65 volts for 5 consecutive samples. |
The CONTINUOUS MONITORING test checks for this DTC. This test occurs when ignition positive voltage is within the normal operating voltage range.
Action Taken When the DTC Sets
| • | The SDM sets DTC B0036. |
| • | The SDM commands ON the AIR BAG warning indicator via class 2 serial data. |
Conditions for Clearing the DTC
| • | Current DTC-The voltage at the discriminating sensor signal input terminal A11 is 3.65 volts or more for 5 consecutive samples. |
| • | History DTC |
| - | You issue a scan tool CLEAR CODES command. |
| - | After 255 malfunction free ignition cycles have occurred. |
Diagnostic Aids
A broken or chafed wire in the inflatable restraint front end discriminating sensor circuits may cause an intermittent condition. Inspect CKT 2160 and CKT 2151 carefully for cutting or chafing.
Test Description
The numbers below refer to the step numbers on the diagnostic table:
-
Tests for proper terminal contact of the yellow 2-way connector.
-
Tests for a malfunctioning discriminating sensor.
-
Tests for an open in the discriminating sensor ground circuit.
-
Test isolates an open in the discriminating sensor ground circuit to one side of in-line connector C101.
-
Tests for proper terminal contact of the inflatable restraint sensing and diagnostic module (SDM) connector.
-
Tests for an open in the discriminating sensor signal circuit.
-
Test isolates an open in the discriminating sensor signal circuit to one side of in-line connector C101.
-
Tests for a short to voltage in the discriminating sensor signal circuit.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the SIR Diagnostic System Check? | -- | Go to Step 2 | |
Do the terminals exhibit any signs of damage or corrosion? | -- | Go to Step 3 | Go to Step 5 | |
3 | Replace the discriminating sensor harness connector. Refer to Connector Repairs in wiring systems. Did you complete the replacement? | -- | Go to Step 4 | -- |
4 | Check for proper connection at the discriminating sensor connector terminals. Do the terminals exhibit any signs of damage or corrosion? | -- | Go to Step 7 | Go to Step 27 |
5 | Check for proper connection at the discriminating sensor connector terminals. Do the terminals exhibit any signs of damage or corrosion? | -- | Go to Step 7 | Go to Step 6 |
Does the resistance measure more than the specified value? | 1050 ohms | Go to Step 7 | Go to Step 8 | |
7 | Replace the inflatable restraint front end discriminating sensor. Refer to Inflatable Restraint Front End Discriminating Sensor Replacement . Did you complete the replacement? | -- | Go to Step 27 | -- |
Using a DMM measure the resistance from the discriminating sensor harness connector terminal B to ground. Refer to Circuit Testing in Wiring Systems. Does the resistance measure within the specified value? | 0-5 ohms | Go to Step 14 | Go to Step 9 | |
9 |
Do the terminals exhibit any signs of damage or corrosion? | -- | Go to Step 10 | Go to Step 11 |
10 | Replace the discriminating sensor in-line harness connector. Refer to Connector Repairs in Wiring Systems. Did you complete the replacement? | -- | Go to Step 27 | -- |
Using a DMM measure the resistance between the discriminating sensor harness connector terminal B and the discriminating sensor in-line harness connector terminal B. Refer to Circuit Testing in Wiring Systems. Does the resistance measure within the specified value? | 0-5 ohms | Go to Step 12 | Go to Step 13 | |
12 | Locate and repair an open in the discriminating sensor ground circuit between the in-line harness connector and the inflatable restraint sensing and diagnostic module (SDM). Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 27 | -- |
13 | Locate and repair an open in the discriminating sensor ground circuit between the discriminating sensor connector and the discriminating sensor in-line harness connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 27 | -- |
Does the connector exhibit any signs of damage or corrosion? | -- | Go to Step 15 | Go to Step 17 | |
15 | Replace the inflatable restraint sensing and diagnostic module (SDM) harness connector. Refer to Connector Repairs in Wiring Systems. Did you complete the replacement? | -- | Go to Step 16 | -- |
16 | Check for proper connection at the inflatable restraint sensing and diagnostic module (SDM) connector terminals. Do the terminals exhibit any signs of damage or corrosion? | -- | Go to Step 18 | Go to Step 27 |
17 | Check for proper connection at the inflatable restraint sensing and diagnostic module (SDM) connector terminals. Do the terminals exhibit any signs of damage or corrosion? | -- | Go to Step 18 | Go to Step 19 |
18 | Replace the inflatable restraint sensing and diagnostic module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Did you complete the replacement? | -- | Go to Step 27 | -- |
Does the resistance measure within the specified value? | 0-5 ohms | Go to Step 25 | Go to Step 20 | |
20 |
Do the terminals exhibit any signs of damage or corrosion? | -- | Go to Step 21 | Go to Step 22 |
21 | Replace the discriminating sensor in-line harness connector. Refer to Connector Repairs in Wiring Systems. Did you complete the replacement? | -- | Go to Step 27 | -- |
Using a DMM measure the resistance of the discriminating sensor input circuit between the discriminating sensor harness connector and the discriminating sensor in-line harness connector. Refer to Circuit Testing in Wiring Systems. Does the resistance measure within the specified value? | 0-5 ohms | Go to Step 23 | Go to Step 24 | |
23 | Locate and repair an open in the discriminating sensor input circuit between the discriminating sensor in-line harness connector and the inflatable restraint sensing and diagnostic module (SDM) harness connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 27 | -- |
24 | Locate and repair an open in the discriminating sensor input circuit between the discriminating sensor in-line harness connector and the discriminating sensor harness connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 27 | -- |
Does the voltage measure less than the specified value? | 1.0 V | Go to Step 26 | ||
26 |
Did you complete the repair? | -- | Go to Step 27 | -- |
27 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
