DTC B1018 Passenger Deployment Loop Short to GND. Chevrolet Metro 2001

For 1990-2009 cars
SIR Components
SIR Schematics
SIR Handling Caution
Handling ESD Sensitive Parts Notice
SIR Handling Caution

### Circuit Description

When you turn the ignition switch to the ON position, the inflatable restraint Sensing and Diagnostic Module (SDM) performs tests in order to diagnose critical malfunctions. Upon passing these tests, the system measures IGNITION 1 voltage, the 23-volt loop reserve, and deployment loop voltages in order to verify normal voltage ranges. The SDM monitors the voltage at DRIVER SIDE LOW terminal 10 and at the Passenger Side Low terminal 3 in order to detect shorts to ground in the inflator module circuits.

### Conditions for Setting the DTC

• | The driver deployment loop is not open.

• | The passenger deployment loop is not open.

• | The driver deployment loop is not shorted to voltage.

• | The voltage at Driver Side Low terminal 10 is more than 1.5 volts.

• | The voltage at the Passenger Side Low terminal 3 is less than 1.5 volts for 500 milliseconds.

The following tests check for this DTC. These tests occur when IGNITION 1 is within the normal operating voltage range.

• | The POWER ON test.If the malfunction is detected in this test, the resistance measurement test will not be performed.

• | The Continuous Monitoring Test.

### Action Taken When the DTC Sets

• | The SDM sets a diagnostic trouble code.

• | The SDM turns ON the AIR BAG warning lamp.

### Conditions for Clearing the DTC

• | Clear the Current DTC when the voltage at the Passenger Side Low terminal 3 is more than 1.5 volts for 500 milliseconds.

• | Clear the History DTC under the following conditions:

- | You use the scan tool in order to clear the DTC.

- | 250 malfunction-free ignition cycles have occurred.

### Diagnostic Aids

A short to ground in the inflatable restraint IP module's circuit can cause an intermittent condition. Move the wires, and monitor the PASSENGER SENSELO in order to locate the fault. Carefully inspect the YEL/RED wire and the YEL wire for broken wires or for chafed wires. Wiring pigtail damage requires replacement of the inflatable restraint IP module.

The diagnostic table directs the technician to note the entry value of the PASSENGER SENSELO. Comparing the value of the PASSENGER SENSELO can help determine if an intermittent condition exists.

If measurements are requested in this table, use the J 39200 Digital Multimeter with the correct terminal adapter from the J 35616 Connector Test Adapter Kit. If a check for correct connection is requested, refer to Testing for Intermittent Conditions and Poor Connections . If a wire repair, a connector repair, or a terminal repair is requested, use the J-38125 Terminal Repair Kit, and refer to Wiring Repair .

### Test Description

Numbers below refer to step numbers on the diagnostic table.

1. This test determines the Passenger Side Low voltage measured by inflatable restraint Sensing Diagnostic Module (SDM).

2. This test isolates the malfunction to one side of the inflatable restraint IP module yellow connector located behind the IP compartment.

3. This test determines whether the malfunction is in the YEL/RED wire.

4. This test determines whether the malfunction is in the YEL wire.

#### DTC B1018 Passenger Deployment Loop Short to GND

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the SIR Diagnostic System Check performed? | -- | Go to Step 2 | Go to SIR Diagnostic System Check

2

1. Turn the ignition switch to the LOCK position.
2. Connect a scan tool to the data link connector. Follow the directions in the instruction manual of the scan tool.
3. Turn the ignition switch to the ON position.
4. Request the SIR data list display.
5. Read and record on the repair order the Passenger Side Low voltage PASSENGER SENSELO.

Is the PASSENGER SENSELO less than the specified value?

1.5 V

Go to Step 3

Refer to Diagnostic Aids

3

1. Turn the ignition switch to the LOCK position.
2. Disconnect the inflatable restraint (SIR) steering wheel and inflatable restraint IP modules yellow connectors. These are located under the steering wheel side cap and behind the IP compartment.
3. Connect the J 38715-A to the inflatable restraint steering wheel and inflatable restraint IP module harness connectors.
4. Turn the ignition switch to the ON position.
5. Using the scan tool, request the SIR data list display. Read the Passenger Side Low voltage PASSENGER SENSELO.

Is the PASSENGER SENSELO less than specified value?

1.5 V

Go to Step 5

Go to Step 4

4

1. Turn the ignition switch to the LOCK position.
2. Inspect the inflatable restraint IP module pigtail for damage. Verify that the pigtail and the nearby wiring are routed correctly.
3. Replace the inflatable restraint IP module. Refer to Inflatable Restraint Instrument Panel Module Replacement in this section.

Did you replace the inflatable restraint IP module?

--

Go to Step 9

--

5

1. Turn the ignition switch to the LOCK position.
2. Disconnect the inflatable restraint Sensing and Diagnostic Module (SDM).
3. Disconnect the J 38715-A .
4. Measure the resistance on the SDM harness connector from terminal 4 to terminal 6 (ground).

Is the resistance reading less than the specified value?

OL

(Infinite)

Go to Step 6

Go to Step 7

6 | Repair a short to ground condition in the YEL/RED wire. Is the circuit repair complete? | -- | Go to Step 9 | --
7 | Measure the resistance on the SDM harness connector from terminal 3 to terminal 6 (ground). Is the resistance reading less than the specified value? | OL (Infinite) | Go to Step 8 | Go to Sensing and Diagnostic Module Integrity Check
8 | Repair a short to ground condition in the YEL wire. Is the circuit repair complete? | -- | Go to Step 9 | --

9

1. Reconnect all the SIR system components.
2. Verify that all the components are properly mounted.

Did you reconnect and mount all the SIR components?

--

Go to Step 10

--

10 | Clear the SIR diagnostic trouble codes. Did you clear the SIR diagnostic trouble codes? | -- | Go to SIR Diagnostic System Check | --