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SPN 974 FMI 7 — ATC (automatic traction control) diff brake — not responding

What it means: ATC (automatic traction control) diff brake — not responding.

How serious / can you keep driving: Serious. Power derate likely — plan to stop soon.

Check first: Check ATC solenoid

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Listed providers nearest Albuquerque, NM

Closest first. Tell them SPN 974 FMI 7 and what the truck is doing. RoadService.app lists these providers and does not employ them or carry out the repair.

Commercial Tire Co☎ Call
0.0 mi away — based in Albuquerque, NM · (505) 226-2125
Dugger Services, Inc.☎ Call
0.0 mi away — based in Albuquerque, NM · (505) 823-9696
Back2road truck repair☎ Call
0.0 mi away — based in Albuquerque, NM · (505) 220-3541

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SeriousBrakes, ABS & StabilityPower derate likely — plan to stop soon

Applies to: Bendix · Wabco

What SPN 974 FMI 7 means

ATC (automatic traction control) diff brake — not responding.

How serious is it?

Serious. Power derate likely — plan to stop soon.

Most likely causes

Diff brake solenoid
Air
Wiring
Solenoid

First moves (roadside)

Check ATC solenoid
Check ATC

FAQ

What does SPN 974 FMI 7 mean?

ATC (automatic traction control) diff brake — not responding.

How serious is SPN 974 FMI 7?

Serious — Power derate likely — plan to stop soon.

What's the most likely cause of SPN 974 FMI 7?

The most common cause is: Diff brake solenoid. Other possibilities include Air; Wiring; Solenoid.

Can I keep driving with SPN 974 FMI 7?

Power derate likely — plan to stop soon. When in doubt, get a qualified mobile diesel tech on the truck before continuing.

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Related codes

Codes that commonly appear alongside SPN 974 FMI 7, or share the same subsystem.

Same symptom: ABS or stability lamp

Other codes behind a lit ABS or stability lamp — the ones that turn an inspection into an out-of-service order.

Right rear wheel speed erratic (SPN 792 FMI 2) · Brakes, ABS & Stability
Right rear wheel speed abnormal (SPN 792 FMI 8) · Brakes, ABS & Stability
Left tag/pusher wheel speed erratic (SPN 793 FMI 2) · Brakes, ABS & Stability
Right tag/pusher wheel speed erratic (SPN 794 FMI 2) · Brakes, ABS & Stability
Left Front Wheel Speed Sensor Circuit Low (C0031) · Brakes, ABS & Stability
Left Front Wheel Speed Sensor Performance (C0034) · Brakes, ABS & Stability

All Brakes, ABS & Stability codes

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