GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Vivant 🢒 DTC 🢒 DTC 066

Circuit Description

When the ignition switch is turned to ON, the sensing and diagnostic module (SDM) will perform tests to diagnose critical malfunctions within itself. Upon passing these tests, Ignition 1 and deployment loop voltages are measured to ensure that they are within their respective normal voltage ranges. The SDM monitors the voltages at the right side belt pretensioner low terminal, terminal B3, and the left side belt pretensioner low terminal, terminal B2, to detect shorts to ground or voltage in the deployment loops.

Conditions for Setting the DTC
    • Voltage at the left side belt pretensioner high terminal is higher than 6 volts for 500 milliseconds.
    • Voltage at the left side belt pretensioner high terminal is less than 2 volts and the resistance of the left side belt pretensioner deployment loop is less than 4.5 ohms for 500 milliseconds.
    • Ignition voltage is within the normal operation range.

Action Taken When the DTC Sets
    • The SDM will turn on the AIRBAG indicator and set a DTC 66.
    • The SDM will disable the left side belt pretensioner resistance test.

Conditions for Clearing the DTC
    •  Voltage at the left side belt pretensioner high terminal is less than equal to 6 volts for 500 milliseconds.
    • Voltage at the left side belt pretensioner high terminal is higher than or equal to 2 volts and the resistance of the left side belt pretensioner deployment loop is less than 4.5 ohms for 500 milliseconds.
    • The ignition switch is turned to OFF.
    • The scan tool CLEAR CODES command is received.

Diagnostic Aids

Diagnostic Aids Carefully inspect the wires in the left side belt pretensioner loop for cutting or chafing. If the wiring pigtail of the left side belt pretensioner is damaged, the left side belt pretensioner module must be replaced.

Caution: Refer to Sensing and Diagnostic Module Voltage after Ignition is Turned Off Caution in the Preface section.

Caution: Refer to Sensing and Diagnostic Module Handling Caution in the Preface section.

Step

Action

Values

Yes

No

1

Perform the Diagnostic System Check - SIR.

Is the SIR Diagnostic System Check complete?

--

Go to Step 2

Go to Diagnostic System Check - SIR

2

Visually inspect the wires to the left side belt pretensioner including the pigtail to the left side belt pretensioner.

Is there any evidence of rubbing, damage, or chafing?

--

Go to Step 3

Go to Step 4

3
  1. Turn OFF the ignition and remove the key.
  2. Temporarily disconnect the passenger airbag, the yellow clock spring connector on the steering column and connector C221.
  3. Replace any damaged wiring, terminals, or harnesses. The left side belt pretensioner will require replacement if the pigtail wire harness has been damaged. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  4. Replace the SDM. The arrow must be pointing to the front of the vehicle.

Did you complete the repair?

--

Go to Diagnostic System Check - SIR

--

4
  1. Turn the ignition OFF.
  2. Disconnect the passenger airbag, the yellow clock spring connector on the steering column and connector C221.
  3. Disconnect the SDM.
  4. Using a digital multimeter, measure resistance between terminal A and/or B of the belt pretensioner and ground.

Refer to Diagnostic Illustration 19 in SIR Diagnostic Illustrations .

Is the resistance equal to the specified value?

∞

Go to Step 6

Go to Step 5

5
  1. Repair the short to ground between the belt pretensioner circuit and ground or replace the wiring harness.
  2. Replace the SDM. The arrow must be pointing to the front of the vehicle.

Did you complete the repair?

--

Go to Diagnostic System Check - SIR

--

6
  1. Disconnect the SDM.
  2. Turn ON the ignition.
  3. Measure the voltage between terminal A and/or B of the belt pretensioner and ground.

Refer to Diagnostic Illustration 20 in SIR Diagnostic Illustrations .

Is the voltage equal to the specified value?

--

Go to Step 5

Go to Step 7

7
  1. Replace the SDM. The arrow must be pointing to the front of the vehicle.
  2. Install the scan tool to the data link connector (DLC).
  3. Clear the trouble code.
  4. Perform the Diagnostic System Check - SIR.

Is DTC 66 still current?

--

Go to Step 8

System OK

8
  1. Replace the left side belt pretensioner.
  2. Replace the SDM. The arrow must be pointing to the front of the vehicle.

Did you complete the repair?

--

Go to Diagnostic System Check - SIR

--