P0800

Transfer Case Control System (MIL Request)

Q: Is it safe to drive with P0800?

For normal two-wheel-drive road use, usually yes. But the four-wheel-drive system may not work when you need it, so don't count on 4WD off-road or in bad weather until it's fixed.

Q: Can I just clear P0800?

It returns until the underlying transfer case fault is repaired. Because P0800 is a MIL request, always read the transfer case module for the specific code driving it.

Transmission / transfer case Generic OBD-II Medium

What it means

P0800 means the transfer case control module has requested the check-engine light because it detected a fault in the four-wheel-drive transfer case system. The engine and normal driving aren't affected, but 4WD may not engage or disengage as it should. Because this code is a request flag, the real fault is usually stored as a separate transfer-case code — read that module to pinpoint it.

Medium

Can I keep driving? Normal on-road driving is usually fine, but four-wheel-drive may not engage or disengage correctly — avoid relying on 4WD until it's diagnosed.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Four-wheel-drive won't engage or disengage properly
4WD/AWD warning light on the dash
Transfer case stuck in one range (high or low)
Grinding or binding when turning in 4WD

Common causes

Most likely first

Fault in the transfer case control module requesting the MILLikely
Malfunctioning transfer case shift motor or actuatorCommon
Failed transfer case mode/range selector switchCommon
Damaged wiring or connectors in the transfer case circuitLess often
Low or contaminated transfer case fluidLess often

How to diagnose & fix

Work through it in order

Scan the transfer case control module for its own stored codes — P0800 is a request flag, so the real fault is usually a companion code.
Inspect the transfer case wiring, connectors, and the shift motor for damage or corrosion.
Check the mode/range selector switch operation.
Check transfer case fluid level and condition.
Test the shift motor and control module; replace the faulty component identified.

FAQ

Quick answers

Is it safe to drive with P0800?+

For normal two-wheel-drive road use, usually yes. But the four-wheel-drive system may not work when you need it, so don't count on 4WD off-road or in bad weather until it's fixed.

Can I just clear P0800?+

It returns until the underlying transfer case fault is repaired. Because P0800 is a MIL request, always read the transfer case module for the specific code driving it.

Read & clear P0800 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX