B1435 — Wiper Hi/Low Speed Relay Coil Circuit Open

B1435 — Wiper Hi/Low Speed Relay Coil Circuit Open. A fault in the ignition system. Short, gentle driving to a shop is usually possible. Typical causes: failed ignition coil or coil pack, moisture or oil in the spark plug wells, worn spark plugs or wrong plug gap.

body electrical

Is it safe to drive?

Drive with caution Drive with caution and avoid load. Ignition faults cause misfires that quickly overheat and destroy the catalytic converter; if the Check Engine Light flashes, stop and fix it first.

How to diagnose with an OBD scanner

  1. Read the code and freeze frame Connect an OBD2 scanner, confirm B1435 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many B0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the ignition system for damage, corrosion, chafing or poor contact.
  4. Subsystem check Do a continuity test end-to-end on the wiper hi/low speed relay coil circuit and wiggle the harness while measuring — intermittent opens show up as fluctuating readings.
  5. Subsystem check Swap the coil to another cylinder and see if the fault code follows it.
  6. Subsystem check Inspect spark plugs for wear, oil or carbon tracks and check plug gaps.
  7. Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm B1435 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for B1435 (parts and labor, USD, independent shop rates): Repair coil wiring or connector: $80–$250; Replace spark plugs: $90–$250; Replace an ignition coil: $150–$380. Overall, fixing B1435 usually costs between $80 and $380. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

Will B1435 clear itself?

Sometimes B1435 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

What is the most common cause of B1435?

The most common causes are: failed ignition coil or coil pack, moisture or oil in the spark plug wells, worn spark plugs or wrong plug gap.

How much does it cost to fix B1435?

Repair coil wiring or connector — $80–$250; Replace spark plugs — $90–$250; Replace an ignition coil — $150–$380. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

Is it safe to drive with B1435?

Drive with caution and avoid load. Ignition faults cause misfires that quickly overheat and destroy the catalytic converter; if the Check Engine Light flashes, stop and fix it first.

What does OBD2 code B1435 mean?

B1435 — Wiper Hi/Low Speed Relay Coil Circuit Open. A fault in the ignition system. Short, gentle driving to a shop is usually possible. Typical causes: failed ignition coil or coil pack, moisture or oil in the spark plug wells, worn spark plugs or wrong plug gap.

When your OBD2 scanner pulls code B1435, the module is reporting that it cannot complete an electrical circuit through the wiper hi/low speed relay coil. The official definition reads "Wiper Hi/Low Speed Relay Coil Circuit Open," placing this fault squarely in the body electrical category. In plain terms, something is preventing current from reaching the relay coil that controls your wiper motor's two-speed operation. The ECU expects to see a complete path to ground through that coil; when it finds a break instead, it logs B1435 and lights the Check Engine or body control warning light.

Modern vehicles use the body control module (BCM) or a dedicated wiper relay to manage wiper speed. When you switch between low and high, the module energizes different relay coils or applies voltage through different circuit paths to give the motor more or less current. B1435 triggers specifically when the module attempts to activate either speed circuit and finds no response — an open in the coil supply, ground, or the wiring between them. The fault must repeat under the module's defined test conditions before it stores the code, so a single glitch usually will not set it. Any freeze frame data saved with B1435 shows vehicle speed, engine temperature, and other conditions at the moment of failure, giving you a starting point for recreation during testing.

Symptoms of B1435

  • Only one wiper speed works, or wipers do not operate at all
  • Wiper motor runs continuously at a single speed regardless of switch position
  • High-speed wiper function completely inoperative
  • Wiper indicator or warning light stays illuminated on the dash
  • No clicking sound from the wiper relay area when switching speeds
  • Intermittent wiper operation that worsens in wet or humid conditions

What causes B1435?

  • Internally open wiper hi/low speed relay coil
  • Blown fuse feeding the wiper speed control circuit
  • Broken or severed wire in the wiper relay coil harness
  • Connector unplugged, backing out, or corroded at the relay or BCM
  • Wiper switch failure sending incorrect or no signal
  • Faulty BCM or PCM output driver for the wiper speed circuit
  • Water intrusion causing corrosion inside the wiper motor connector
  • Short to ground elsewhere on the circuit triggering fuse failure

How to diagnose B1435

  1. Connect an OBD2 scanner, confirm B1435 is stored, and record the freeze frame data. Note the conditions recorded — load, temperature, speed — because you will need to reproduce them to trigger the fault during live testing.
  2. Check for any related diagnostic trouble codes. Codes in the B14xx range or body system codes pointing to the BCM or instrument cluster often appear alongside B1435 and can direct you to the root cause faster.
  3. Locate the wiper relay and its associated connectors. Visually inspect every wire and terminal in the circuit — from the BCM output through the relay coil to ground. Look for chafing, melted insulation, corrosion, or pins that are bent, pushed back, or missing.
  4. Perform a continuity test on the suspected open section of the circuit. For intermittent opens, wiggle the harness while monitoring the multimeter — a fluctuating reading points to a broken strand inside the insulation.
  5. Test the relay coil resistance with a multimeter if accessible, or swap the relay with a known good unit. If the fault follows the relay, the coil inside is open.
  6. Inspect the wiper switch and its wiring for damage, particularly if only one speed works or if the fault is intermittent. Use a wiring diagram to verify switch operation at each speed position.
  7. Clear the code, operate the wipers through all speed modes, and complete a drive cycle that replicates the freeze frame conditions. If B1435 returns, the circuit remains open and the repair is not complete.

How to fix B1435

Address the cheapest and most common failures before spending on major components:

  • Repair coil wiring or connector — $80–$250
  • Replace spark plugs — $90–$250
  • Replace an ignition coil — $150–$380

How much does it cost to fix B1435?

The total bill depends on which part of the circuit is actually failed. Typical parts-and-labor costs at an independent shop for B1435-related repairs:

  • Repair coil wiring or connector: $80–$250
  • Replace spark plugs: $90–$250
  • Replace an ignition coil: $150–$380

In most cases, fixing B1435 costs between $80 and $380. Spending time on a solid diagnosis before purchasing parts almost always saves money — the most expensive scenario is rarely the first one to investigate.

Can you drive with B1435?

Drive with caution. While the wipers themselves do not affect engine operation, reduced or lost wiper function in rain or snow creates a serious visibility hazard. If only one speed works, plan your route and avoid driving in conditions that demand full wiper performance. Get the circuit diagnosed and repaired promptly to restore full operation.

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