C1237 on Ford

Primary brake pressure sensor signal (Hyundai) or rear wheel speed sensor (Ford)

Severity: Inspect soon

Hyundai owners report C1237 with a failed brake hydraulic unit and in one case brake failure and towing; Ford owners report no ABS.

It gets more serious if:

Stop: Stop and have it checked if a red BRAKE warning or "check brake system" message appears, or the pedal feels hard, soft or different.

Safety-critical system: explanation only, no DIY steps. Source: how we rate severity

This page covers only what differs on Ford. For what C1237 means, the ranked causes and the test order, see the C1237 guide.

2000–2005 · F-150
Supported by vehicle data
Ford bulletins 15022 (2000-2001) and 18450 (2005) list C1237 with an ABS light and the C1229/C1230 codes. Only the NHTSA summaries were read; whether they are current is not verified.
2000–2001 · Expedition
Supported by vehicle data
Ford bulletin 15022 lists C1237 with an ABS lamp. Only the NHTSA summary was read.
2002–2004 · Explorer
Supported by vehicle data
Ford bulletins 03263 and 14900 group C1237 with rear wheel speed sensor codes. Only the NHTSA summary was read.

03263Status unverified
ABS lamp with C1235, C1236, C1237
2002–2004explorer · NHTSA 10008281
Covers vehicles with a differential-mounted rear wheel speed sensor. Summary only.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
14900Status unverified
ABS light on with C1230 and/or C1237
2002explorer · NHTSA 620216
Summary only; the repair is not stated.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
15022Status unverified
ABS lamp on with C1230, C1229 or C1237
2000–2001explorer, expedition, excursion, f-150, ranger · NHTSA 622841
Summary only; the repair is not stated.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
18450Status unverified
False ABS activation or ABS light with C1175, C1236, C1230 or C1237
2005f-150 · NHTSA 10014638
Summary only; the repair is not stated.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Ford 15022: ABS lamp on with C1230, C1229 or C1237 (2000-2001 Explorer, Expedition, Excursion, F-150, Ranger, Super Duty, E Series) — NHTSA manufacturer communications (flat file, NHTSA ID 622841)
Ford 18450: false ABS activation or ABS light with C1175 or C1236, or C1230 or C1237 (2005 F-150) — NHTSA manufacturer communications (flat file, NHTSA ID 10014638)
Ford 03263: ABS lamp with C1235, C1236, C1237 on vehicles with differential-mounted rear wheel speed sensor (2002-2004 Explorer, Mountaineer, Aviator) — NHTSA manufacturer communications (flat file, NHTSA ID 10008281)
Ford 14900: ABS light on with C1230 and/or C1237 (2002 Explorer, Mountaineer) — NHTSA manufacturer communications (flat file, NHTSA ID 620216)
NHTSA complaint ODI 10142417: 2002 Ford Explorer ABS light and C1237 — NHTSA Office of Defects Investigation
NHTSA complaint ODI 11435765: 2012 Hyundai Sonata C1237 hydraulic power unit — NHTSA Office of Defects Investigation

This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error