AutoCodes – Cadillac – C0402 Cadillac

C0402 Cadillac Code - Transfer Case Solenoid Valve

Quick Answer

The rear drive clutch solenoid valve is internal to the torque transfer device housing. Common causes include Faulty Transfer Case Solenoid Valve, Transfer Case Solenoid Valve harness is open or shorted, Transfer Case Solenoid Valve circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: C0402 Cadillac indicates Transfer Case Solenoid Valve.
Common causes: Common causes include Faulty Transfer Case Solenoid Valve, Transfer Case Solenoid Valve harness is open or shorted, Transfer Case Solenoid Valve circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 5,079

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 04, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code C0402 Cadillac Description

The rear drive clutch solenoid valve is internal to the torque transfer device housing. The rear differential clutch control module supplies battery voltage to the control circuit and ground to the low reference circuit of the solenoid valve. The solenoid valve is controlled by a pulse width modulation (PWM) signal. The solenoid valve controls the hydraulic pressure to the clutch package of the torque transfer device. The locking level of the torque transfer device depends on the engagement of the clutch package.

OBDII Code C0402 Cadillac - Transfer Case Solenoid Valve - AutoCodes.com — C0402 Cadillac Code - Transfer Case Solenoid Valve

What does this mean?

What are the Possible Causes of the DTC C0402 Cadillac?

Faulty Transfer Case Solenoid Valve
Transfer Case Solenoid Valve harness is open or shorted
Transfer Case Solenoid Valve circuit poor electrical connection

How to Fix the DTC C0402 Cadillac?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

- C0402 02 Transfer Case Solenoid Valve Short to Ground
- C0402 04 Transfer Case Solenoid Valve Open
- C0402 42 Transfer Case Solenoid Valve Calibration Not Programmed
- C0402 43 Transfer Case Solenoid Valve EEPROM Incorrect Programming
- C0402 4B Transfer Case Solenoid Valve Calibration Not Learned
- C0402 61 Transfer Case Solenoid Valve Stuck

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the C0402 Cadillac code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about C0402 Cadillac Code

1. What are the common symptoms of OBDII code C0402 in a Cadillac related to the Transfer Case Solenoid Valve?

The common symptoms include difficulty shifting gears, erratic behavior of the transfer case, and a warning light on the dashboard.

2. What are the possible causes of OBDII code C0402 in a Cadillac?

Possible causes include a faulty transfer case solenoid valve, wiring issues, low transfer case fluid levels, or a malfunctioning transfer case control module.

3. How can I diagnose the cause of OBDII code C0402 in my Cadillac?

You can diagnose the issue by conducting a visual inspection of the transfer case components, testing the solenoid valve for proper functioning, checking the wiring for any damage, and scanning the transfer case control module for error codes.

4. Can I continue driving my Cadillac with OBDII code C0402 present?

It is not recommended to drive your vehicle with this code present, as it can lead to further damage to the transfer case components and affect the drivability of your Cadillac.

5. How can I repair OBDII code C0402 in my Cadillac related to the Transfer Case Solenoid Valve?

Repairing this code involves replacing the faulty transfer case solenoid valve, fixing any wiring issues, topping up transfer case fluid levels, and resetting the transfer case control module.

6. Is it possible to clear OBDII code C0402 in a Cadillac without fixing the underlying issue?

While you can clear the code temporarily, it is crucial to address the root cause to prevent the code from reappearing and causing potential damage to your Cadillac's transfer case system.

7. Can a DIY enthusiast repair OBDII code C0402 in a Cadillac?

Depending on your skill level and access to tools, some DIY enthusiasts may be able to replace the transfer case solenoid valve or address wiring issues. However, it is recommended to consult a professional mechanic for accurate diagnosis and repair.

8. How much does it typically cost to repair OBDII code C0402 in a Cadillac at a dealership or repair shop?

The cost of repairing this code can vary depending on the exact cause, labor rates, and the price of parts. On average, you can expect to pay a few hundred dollars for parts and labor.

9. Are there any preventive maintenance tips to avoid OBDII code C0402 in a Cadillac?

To prevent this code, it is advisable to regularly check transfer case fluid levels, have the transfer case system inspected during routine maintenance, and address any warning signs promptly to avoid potential issues.

10. What is the importance of addressing OBDII code C0402 promptly in a Cadillac?

Addressing this code promptly is crucial to ensure the proper functioning of the transfer case system, maintain the drivability of your Cadillac, and prevent more extensive and costly repairs in the future.