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Home/Cars/Toyota/Camry/Seventh Generation (2012-2017)/how to resolve B1242 code in Toyota Camry Seventh Generation (2012-2017)

how to resolve B1242 code in Toyota Camry Seventh Generation (2012-2017)

Toyota Camry Seventh Generation (2012-2017)

Error Codes
Severity: mediumDifficulty: mediumError Code: B12421-2 hours
3 min read
507 words

Problem Statement

Learn how to diagnose and fix B1242 electrical issues in Toyota Camry (2012-2017). Step-by-step guide with diagnostic procedures and repair instructions.

Error Code
B1242
Component
Electrical
Repair Time
1-2 hours

Safety Warnings

  • ⚠Disconnect the battery before working on electrical systems.
  • ⚠Wear safety goggles and gloves when handling the battery.

Symptoms

  • •Check engine light illuminated
  • •Battery warning light on the dashboard
  • •Poor electrical performance (e.g., dimming lights)
  • •Difficulty starting the engine
  • •Intermittent electrical issues with accessories

Diagnostic Steps

  1. 1Scan the vehicle’s OBD-II system to confirm the B1242 code and check for additional codes.
  2. 2Inspect the battery terminals for corrosion and ensure they are securely connected.
  3. 3Measure the battery voltage with a multimeter; it should be around 12.6 volts when fully charged.
  4. 4Check the battery condition using a load tester to ensure it can hold a charge under load.
  5. 5Inspect the battery sensor wiring for damage or disconnection.
  6. 6Verify the alternator output to ensure it is charging the battery correctly while the engine is running.

Solution

Solution

1. Preparation

  • Tools Required: OBD-II scanner, multimeter, socket set, battery terminal cleaner, load tester.
  • Disconnect the negative battery terminal to ensure safety while working on the electrical system.

2. Clean Battery Terminals

  • Use a battery terminal cleaner to remove any corrosion from the battery terminals.
  • After cleaning, reconnect the terminals securely, starting with the positive terminal followed by the negative terminal.

3. Replace Battery (if necessary)

  • If the battery fails the load test, remove the battery:
    • Use a socket set to remove the battery hold-down bracket.
    • Carefully lift the battery out of the tray.
  • Install the new battery:
    • Place the new battery in the tray.
    • Reattach the hold-down bracket and tighten to manufacturer specifications (usually around 8-10 ft-lbs).

4. Replace Battery Sensor (if necessary)

  • If the wiring to the battery sensor is damaged or the sensor is faulty:
    • Disconnect the battery again.
    • Locate the battery sensor (usually connected to the battery terminal).
    • Disconnect the sensor and replace it with a new one.
    • Reconnect the sensor ensuring all connections are secure.

5. Reset the Codes

  • Reconnect the battery and use the OBD-II scanner to clear the B1242 code.
  • Start the engine and check the dashboard for warning lights.

Verification

After completing the repair, verify that the issue has been resolved:

  • Test the affected component to ensure it functions correctly
  • Check for any error codes or warning lights
  • Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

  • •Follow the manufacturer's recommended maintenance schedule
  • •Address warning signs early before they develop into major issues
  • •Use quality parts and fluids recommended for your vehicle
  • •Keep detailed records of all repairs and maintenance

Tools & Equipment Required

  • OBD-II scanner
  • Multimeter
  • Socket set
  • Battery terminal cleaner
  • Load tester

Parts Required

  • New battery (if necessary)
  • Battery sensor (if necessary)

Additional Information

Error CodeB1242
Component

Electrical

Repair Time

1-2 hours

Difficulty

medium

Severity

medium

Tools

5 items

Parts

2 items

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