What Does C1198 Mean?
The ABS control module has detected a general circuit failure in the left front (LF) inlet valve solenoid coil. The inlet valve controls brake pressure application during ABS events on the left front wheel. With this fault, the ABS system is disabled and the warning lamp will illuminate. The driver retains normal braking but loses anti-lock protection.
Common Causes
35%
Open or high-resistance connection in the LF inlet valve solenoid coil winding due to internal coil failure
30%
Damaged wiring harness between the ABS module and the hydraulic modulator with intermittent open or short
20%
Corroded or backed-out pins at the ABS modulator electrical connector
15%
ABS electronic control module internal driver circuit fault
Diagnostic Steps
1
Check for additional ABS codes. If multiple valve codes are present on the same corner, suspect a wiring or connector issue rather than individual valve failures.
2
Disconnect the ABS modulator connector and measure the LF inlet valve solenoid coil resistance. Expected specification is 3-6 ohms. An open reading or significantly high resistance confirms coil failure.
3
Inspect the modulator connector for corrosion, bent pins, water intrusion, or terminal push-back. Clean contacts with electrical contact cleaner and verify terminal tension.
4
With the modulator disconnected, perform a continuity check on each wire in the harness from the ABS module connector to the modulator connector pins. Repair any open circuits found.
5
If harness and connector check good but solenoid resistance is out of spec, the ABS hydraulic modulator assembly requires replacement as the solenoid is not individually serviceable.
Estimated Repair Cost
$150 - $1,200
Parts + labor, varies by vehicle and location
The ABS control module has detected a general circuit failure in the left front (LF) inlet valve solenoid coil. The inlet valve controls brake pressure application during ABS events on the left front wheel. With this fault, the ABS system is disabled and the warning lamp will illuminate. The driver ...
The most common cause of C1198 (ABS Inlet Valve Coil LF Circuit Failure) is: Open or high-resistance connection in the LF inlet valve solenoid coil winding due to internal coil failure
Typical repair costs for C1198 range from $150 to $1,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Normal braking is unaffected but the ABS system is fully disabled. The left front wheel can lock under hard braking, particularly on wet or icy roads. Drive with increased following distance and avoid sudden stops until the repair is completed.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C1198 to identify the root cause.
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Quick Info
Category
Chassis
System
ABS / Traction Control
Difficulty
Type
Manufacturer
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