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2001 Ford Windstar ABS & Wheel Speed Sensor Codes: U1762, U1039, P1502, B1318 Explained | OBD-II Diagnosis Guide

Model: 2001 Windstar Fault Code: B1318 Posted: 2017-07-29 07:10

New member here — thanks in advance for any help! I own a 2001 Ford Windstar (4-door, 192K miles), original engine and transmission, well-maintained with no Check Engine Light (CEL) history. The van runs smoothly, shifts properly, stops safely, and passes safety inspections without issue. However, multiple warning lights are on — specifically the ABS and brake lights — despite normal operation. I’ve noticed a strange exhaust noise and some known Windstar-specific issues. While the vehicle functions fine, persistent diagnostic codes are frustrating. After using an OBD-II scanner (with plans to upgrade to a BlueDriver), I pulled several fault codes during an ABS system scan. The main codes include: - U1762: Oxygen Sensor Circuit Malfunction (sporadic readings between 0.800 and 0.835) - U1039: Invalid or Missing Data for Primary ID Vehicle Speed - P1502: Vehicle Speed Sensor Intermittent - B1318: Battery Voltage Low (battery replaced in August 2015, tested at 7/17/192K as functional) - C1155/C1233/C1145/C1234/C1236/C1237: Left and Right Front & Rear Wheel Speed Sensor Input Failures - C1198, C1194, C1254, C1246, C1250, C1242: ABS Valve Coil Circuit Failures (all related to inlet/outlet valves) - C1446: Brake Switch Circuit Failure (replaced in Feb 2016; still showing code) - C1185: Intelligent Cruise Control Unit — unclear origin I’ve replaced several components: - Front ABS sensors (both failed at knuckle, caused flashing OD light and intermittent speedometer issues) - Both lower control arms with ball joints - Front brake pads and hardware - Rear brake shoes - Brake booster, master cylinder, and fluid (due to ABS/brake lights) - Power steering pump and lines - Flex pipe (exhaust) - Spark plugs and wires - Air filter, fuel filter (K&N), PCV valve - Oxygen sensors (no service interval — last replaced at 2024) - Battery (650 CCA, replaced in 2015; tested as good) I’ve also performed regular maintenance: oil changes every 5K, fluid inspections monthly, and tire rotations. The rear suspension was replaced during a recall after snapping. Key questions: - Are these codes current or historical? (P1000 is pending — likely due to battery disconnect) - Do any of the codes indicate actual part failure or are they circuit/wiring issues? - Can clearing the codes via scanner or battery disconnect resolve them? - Is there a known fix for persistent ABS and wheel speed sensor faults in 2001 Windstar models? I’ve tried multiple battery disconnects and code clears, but the issue persists. The front sensors were replaced due to physical failure — they triggered the OD light and speedometer issues. I swapped out an ABS module (used) as recommended by many posts, but codes remain. My scanner reads OBD-II codes but lacks live input for wheel speed sensors. I’m wondering if a wiring issue or signal degradation is causing these persistent faults. Any guidance on testing sensor signals (e.g., spinning wheels with scanner or probing wires) would be greatly appreciated.

Related fault codes
B1318P1502U1039U1762
Comments (8)
Anonymous 2017-07-29 07:33

I'm trying to understand — what are the current codes showing right now? Can you confirm which ones are active versus historical?

Anonymous 2017-07-29 10:02

Apologies for the long post. All listed codes are currently present except P1000, which is likely due to a battery disconnect. Every component mentioned has been replaced — the only remaining issue is the rear wheel speed sensor. I reseated the plug, but it still shows errors.

Anonymous 2017-07-29 10:41

A diagnostic code does not always mean a part needs replacement — many are actually wiring or circuit faults. Replacing parts can be expensive. You should check wheel speed sensor circuits: remove the vehicle from the ground, spin each wheel while observing signals with a scanner or by probing wires. Specific codes to investigate: - C1198 (ABS Inlet Valve Coil LF Circuit Failure) - C1194 (ABS Outlet Valve Coil LF Circuit Failure) - C1254 (ABS Inlet Valve Coil RR Circuit Failure) - C1246 (ABS Outlet Valve Coil RR Circuit Failure) - C1250 (ABS Inlet Valve Coil LR Circuit Failure) - C1236 (Left Rear Wheel Speed Sensor Input Signal Missing) - C1237 (Rear Speed Wheel Input Signal Missing) - C1242 (ABS Outlet Valve Coil LR Circuit Failure) Note: Even rebuilt ABS modules may not clear these if underlying wiring or sensor issues remain.

Anonymous 2017-07-29 10:57

Thanks — I understand that. The front sensors were physically broken at the knuckle and caused the OD light and intermittent speedometer issues. All replacements were due to actual failure, not just code triggers. I replaced the ABS module with a used one as recommended by many posts. However, the Powertrain Control Module (PCM) appears to have retained all codes — it never cleared them. My scanner does not support live wheel sensor input.

Anonymous 2017-07-29 11:20

Agreed — without live signal monitoring, troubleshooting is very difficult. You need to verify if there's a signal at the wheel speed sensors when spinning wheels. Probing individual wires or using a wiring diagram (e.g., from revbase.com/BBBMotor/Wd) can help identify open circuits, shorts, or poor connections. One possibility: alternator diode failure could cause voltage spikes that interfere with ABS sensor AC signals — worth checking.

Anonymous 2017-07-29 11:28

I do have an OBD-II scanner that reads both engine and ABS codes. I can retrieve stored codes, but I'm unsure whether they are current or historical. Can you confirm which ones are active right now?

Anonymous 2017-07-29 11:36

"My scanner has no live input for wheel sensors." This means it cannot monitor real-time sensor signals — to properly diagnose, you’ll need either a scanner with live signal capability or direct wire probing.

Anonymous 2017-07-29 11:39

I'm not sure if the codes are current or historical — most scanners list separate files: current, history, pending. Try clearing all codes and then driving under normal conditions to see if they return. If they do, it may indicate a persistent circuit issue rather than a failed component.