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C0902 Code Explained: Causes, Symptoms & Device Voltage Reference Circuit Fixes

An OBD-II scanner displaying C0902 next to a chassis control module, wiring harness, and multiple 5-volt reference sensors with illuminated ABS and StabiliTrak warning lights.

If your scan tool displays C0902, one of your vehicle’s electronic chassis control modules has detected a problem with its reference voltage circuit. Unlike C0899 (Device Voltage Low) or C0900 (Device Voltage High), which monitor the module’s incoming battery voltage, C0902 indicates a fault in the regulated voltage supplied to sensors that the module relies on for accurate operation.

On many GM vehicles, C0902 is commonly stored by the Electronic Brake Control Module (EBCM), Transfer Case Control Module (TCCM), or another chassis controller when the module detects that its 5-volt reference circuit is not operating correctly. This reference voltage powers critical sensors used by systems such as ABS, Traction Control, StabiliTrak, Electronic Suspension, and Four-Wheel Drive.

In most cases, C0902 is caused by a shorted sensor, damaged wiring, corrosion, poor electrical connections, or an open reference voltage circuit—not a failed control module.

For additional chassis diagnostic guides, visit our Complete OBD-II Trouble Code Library:

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Quick Facts

ItemInformation
OBD-II CodeC0902
DescriptionDevice Voltage Reference Circuit
CategoryChassis (C) Codes
SystemChassis Electronics / Sensor Reference Voltage
Severity★★★★☆ High
Safe to Drive?Usually, but electronic safety systems may be disabled
Common CausesShorted sensor, damaged wiring, open reference circuit, poor connections
Typical Repair Cost$75–800

What Does C0902 Mean?

The C0902 code indicates that a chassis control module has detected an abnormal condition within its reference voltage circuit.

Most electronic sensors do not operate directly from battery voltage. Instead, the control module generates a regulated 5-volt reference signal that powers multiple sensors throughout the vehicle.

The module continuously monitors this reference voltage to ensure it remains stable.

If the reference circuit experiences:

the module stores C0902.

Unlike charging system faults, C0902 specifically concerns the sensor reference voltage, not the vehicle’s primary battery supply.

Depending on the vehicle, the reference circuit may supply sensors including:

If the 5-volt reference becomes unstable, multiple sensors may immediately begin reporting incorrect information.

Symptoms of C0902

Common symptoms include:

Additional symptoms may include:

Since several sensors often share the same reference circuit, multiple diagnostic trouble codes frequently appear together.

Common Causes

Failed Sensor

One failed sensor can short the shared 5-volt reference circuit.

Common offenders include:

Disconnecting sensors one at a time often helps isolate the fault.

Open Reference Voltage Circuit

Broken wiring can interrupt the reference voltage supplied to multiple sensors.

Possible causes include:

Short to Ground

A damaged wire contacting the chassis can pull the reference voltage toward zero volts.

Common locations include:

Short to Battery Voltage

A damaged harness may allow battery voltage to contact the 5-volt reference circuit.

This condition can damage sensors and, in severe cases, the control module itself.

Corroded Connectors

Moisture intrusion can create high resistance or intermittent connections.

Inspect connectors for:

Poor Ground Connections

Control modules rely on clean ground connections to maintain a stable reference voltage.

Inspect:

Damaged Wiring Harness

Physical damage may include:

Harness damage is especially common near suspension and drivetrain components.

Internal Control Module Failure

Although uncommon, the module’s internal voltage regulator can fail.

Only consider module replacement after all external wiring and sensors have been thoroughly tested.

How Serious Is C0902?

High.

The vehicle may remain drivable, but several electronic safety systems depend on accurate sensor inputs.

Possible effects include:

Ignoring the problem may lead to additional sensor failures or damage to the control module.

Can You Drive With C0902?

Usually, yes—but with caution.

If the reference circuit fault disables:

vehicle handling during emergency situations may be affected.

Repairs should be completed as soon as practical.

How to Diagnose C0902

1. Scan All Control Modules

Look for additional sensor-related codes.

Multiple codes often identify which shared reference circuit has failed.

2. Verify the 5-Volt Reference

Using a digital multimeter:

If the voltage is missing or incorrect, continue circuit diagnosis.

3. Disconnect Sensors One at a Time

A shorted sensor can collapse the entire reference circuit.

Disconnect sensors individually while monitoring the reference voltage.

When voltage returns to normal, the faulty sensor has likely been identified.

4. Inspect Wiring Harnesses

Check for:

Repair damaged wiring as necessary.

5. Inspect Electrical Connectors

Look for:

Repair or replace damaged connectors.

6. Test Ground Circuits

Verify proper grounding using voltage-drop testing.

Poor grounds can affect reference voltage stability.

7. Verify Repairs

After repairs:

Common Repairs

RepairEstimated Cost
Replace faulty sensor$125–450
Repair damaged wiring$100–400
Replace electrical connector$75–250
Repair ground connection$75–200
Harness repair$150–600
Replace chassis control module (if necessary)$600–1,500

Common Diagnostic Mistakes

Technicians frequently:

Vehicles Commonly Affected

C0902 is commonly reported on:

Similar reference voltage circuit faults may also appear on Ford, Ram, Jeep, Toyota, Honda, Nissan, Hyundai, Kia, Subaru, Volkswagen, BMW, Mercedes-Benz, Audi, and many other vehicles equipped with electronically controlled chassis systems.

How to Prevent C0902

Reduce the likelihood of C0902 by:

Frequently Asked Questions

What causes C0902?

The most common causes include a shorted sensor, damaged wiring, open reference circuit, poor electrical connections, corroded connectors, or an internal control module voltage regulator failure.

Is C0902 serious?

Yes.

While the vehicle may remain drivable, important safety systems such as ABS and stability control may become disabled if the reference voltage is compromised.

Can a bad sensor cause C0902?

Absolutely.

A single internally shorted sensor can pull down the shared 5-volt reference circuit and trigger C0902 along with several additional sensor codes.

Can damaged wiring trigger C0902?

Yes.

Open circuits, shorts to ground, shorts to battery voltage, and excessive resistance are among the most common causes of this code.

Will replacing the control module fix C0902?

Not usually.

The vast majority of C0902 cases are caused by external wiring or sensor faults. The control module should only be replaced after the entire reference circuit has been thoroughly tested.

Final Thoughts

The C0902 code indicates that a chassis control module has detected a fault within its reference voltage circuit. Rather than pointing to a battery or charging system problem, this code focuses on the regulated voltage supplied to critical chassis sensors. A failed sensor, damaged wiring, corroded connector, or shorted reference circuit can quickly disable multiple electronic safety systems and trigger several diagnostic trouble codes at once.

A systematic diagnosis—including checking the 5-volt reference, disconnecting sensors individually, inspecting the wiring harness, and testing ground integrity—will usually identify the root cause. Once the faulty component is repaired, C0902 typically clears and normal operation is restored.

For additional chassis and drivetrain repair guides, browse our complete OBD-II Chassis Code Library:

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