Fix B0090: Mechanic’s Solutions That WORKED!

The B0090: Active Switch Voltage Out of Range OBD2 code is related to the airbag system, specifically indicating an issue with the “active switch voltage being out of range.”

This code typically arises in vehicles equipped with a manual airbag on/off switch, which allows the passenger airbag to be disabled. It suggests a problem in the electrical circuit that controls this switch, such as incorrect voltage levels, which can prevent the airbag system from operating as designed.

B0090 quick overview

Meaning	B0090: Active Switch Voltage Out of Range
Is it serious?	Yes, this code is serious as it directly impacts the functionality of the airbag system, potentially affecting passenger safety.
Possible causes	– Faulty airbag on/off switch – Wiring or connector issues – Fault in the airbag diagnostic module – Corrosion or damage to wires
How to diagnose?	Check voltage levels at the airbag on/off switch and the diagnostic module. Inspect wiring and connectors for damage, corrosion, or loose connections. Replace faulty components such as the airbag on/off switch if necessary. Reprogram or replace the airbag diagnostic module if issues persist after other fixes. Ensure proper setup and programming with a compatible diagnostic tool.

How to fix B0090 – learn from mechanics

I looked into B0090 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

Case #1: GMC B0090

Vehicle information 2009 GMC Savana 1500 5.3L

Issue + repair history

• Error codes B1019, B1001, B0098, B0090, B0088, B0087, B0086, B0085, B0084, B0083, B0081, B0080, B007, B0040, B0033, B0024, B0023, B0022, B0017, B0016, B0015 were pending.
• Vehicle previously involved in a crash and repaired.
• Airbag diagnostic module (part no. 20778832) installed, but looking for equipment (rollower sensor, side curtains, seat weight sensors) not present in the vehicle according to VIN.

Other OBD2 Codes + Test Results

• No other OBD2 codes mentioned.
• Replaced airbag diagnostic module with new part no. 225928058 and then with another new module with part no. 20778832, but pending codes persisted.

Mechanic suggestions

• Module setup requires a Tech 2 diagnostic tool.
• The B1001 code may need special attention; requires programming with GM scantool and software access.
• Recommend taking the installed SDM to a dealer for programming.

Final fix

• Utilized Tech 2 diagnostic tool for module setup and programming.
• Reprogramming the module did not work, but replacing and programming the module resolved the issue.

Case #2: Chevrolet B0090

Vehicle information 2005 Chevrolet Silverado 2500 HD 6.0L

Issue + repair history

• Snap-on scanner indicates “active switch voltage out of range”.
• No related repair history mentioned.

Other OBD2 Codes + Test Results

• Code B0090: Ignition voltage 11.80V with key on, engine running 13.59V; driver belt a/p voltage 0.0V with key on, 12.2V with engine running.

Mechanic suggestions

• Pin test the Tan/Black wire for voltage at the Supplemental Inflatable Restraint Diagnostic Module (SDM) with the passenger’s switch in the on position.
• Check for continuity from the switch Tan/Black wire to the SDM Tan/Black wire.
• If no voltage on the Tan/Black wire with the switch On, check for voltage at the Yellow wire at the switch.
• Check the Tan/Black wire for a short to ground.
• If switch is not putting out voltage in the ON position, replace the switch. If voltage is at the Tan/Black wire at the SDM and the connector is OK, replace the SDM.
• If voltage is on the Pink wire with the switch on, check the Pink wire for a short to voltage or a switch leaking voltage to the Pink wire.
• Verify the position of the inflatable restraint instrument panel (I/P) module disable switch.
• Check for shorts between the I/P module disable switch signal and I/P module suppression indicator control circuits.
• Consider replacing the (PDS) Passenger Disable Switch if testing indicates failure.

Final fix

• Replaced the airbag switch in the dash.

Case #3: GMC B0090

Vehicle information 2006 GMC Sierra 3500 SL 6.0L

Issue + repair history

• SERVICE AIR BAG message displayed on the instrument panel.
• Turning off the passenger side airbag removes the message.
• Code B0090 (ACTIVE SWITCH VOLTAGE OUT OF RANGE) present.
• Replaced the (I.P. module disable switch), but problem persisted.
• Checked all connectors and wires for open and grounds.

Other OBD2 Codes + Test Results

• No other codes mentioned.
• No additional test results provided.

Mechanic suggestions

• Have the airbag system relearned at the dealer after replacing an airbag part.
• Check connector C223 for corrosion or clean connection by unplugging and plugging it back in.
• Verify voltage into the switch, as the problem seems to be around the new switch.
• Backprobe circuits 353 (pink) and 371 (tan/blk) with a voltmeter with the switch in both the “ON” and “OFF” positions to check for voltage changes.
• Check circuits 1139 (yellow) and 1050 (black) for faults by connecting a test light between them.

Final fix

• Discovered a break inside the tan and black wire caused by salt exposure.
• Salt accumulation under the sill plate led to wire corrosion.
• Replaced the damaged wire to resolve the issue.

Diagnostic Step	Explanation
Check voltage at the airbag on/off switch	Measure the voltage to ensure it falls within the specified range for both the “ON” and “OFF” positions.
Inspect wiring and connectors	Look for any signs of damage, corrosion, or loose connections that could affect voltage levels.
Replace the airbag on/off switch	If the switch is faulty and not maintaining correct voltage levels, it should be replaced.
Reprogram or replace the airbag diagnostic module	If problems persist, the module may need reprogramming or replacement to correct the issue.
Repair damaged wiring	Address any found issues with the wiring, especially if caused by external factors like salt corrosion.