Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer is having trouble with the power relay, which is like a switch that helps turn the computer on and off. It's like when a light switch gets stuck and the light won't turn on or off properly.
The ECM/PCM power relay is responsible for supplying power to the engine control module (ECM) or powertrain control module (PCM). A 'high' circuit condition means the voltage is higher than expected, which could indicate a problem with the relay or its wiring.
The P0687 code is triggered when the ECM/PCM detects a high voltage condition in the power relay control circuit. This could be due to a malfunctioning relay, a short circuit, or a wiring issue that causes excessive voltage to be present in the circuit.
• Check Engine Light is on
• Engine may not start
• Intermittent stalling
• Poor engine performance
• Faulty ECM/PCM power relay
• Short circuit in the wiring
• Faulty ECM/PCM
• Corroded or damaged connectors
ECM: Engine Control Module
PCM: Powertrain Control Module
Relay: An electrically operated switch
• Inspect the ECM/PCM power relay for damage
• Check the wiring and connectors for shorts or corrosion
• Test the relay with a multimeter
• Verify ECM/PCM operation
• Replace the ECM/PCM power relay
• Repair or replace damaged wiring
• Clean or replace corroded connectors
• Replace the ECM/PCM if necessary
• Multimeter
• Screwdriver set
• Relay puller tool
$100 - $300
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regularly inspect and clean electrical connectors
• Ensure proper battery maintenance
• Avoid exposure of electrical components to moisture
Electrical Issue
• Avoid driving the vehicle until the issue is resolved
• Consult a professional mechanic for diagnosis
• Regularly check for any new warning lights or symptoms
Check with your vehicle manufacturer for warranty coverage on electrical components.
P0687 is not a commonly reported code but can occur in vehicles with electrical system issues.
High – This issue can prevent the vehicle from starting or cause it to stall unexpectedly.
Driving with this code can lead to unexpected stalling, which may be dangerous. Address the issue promptly.
• Engine off
• Battery connected
The ECM/PCM power relay is typically located in the engine compartment fuse box.
Q: Can I drive my car with a P0687 code?
A: It's not recommended, as the vehicle may stall or not start.
Q: How can I reset the P0687 code?
A: Fix the underlying issue first, then use an OBD-II scanner to clear the code.
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