P0358 Toyota Code - Ignition Coil 8 Primary/Secondary Circuit Malfunction
Quick Answer
A Direct Ignition System (DIS) is a 1-cylinder ignition system in which each cylinder is ignited by one ignition coil assembly and one spark plug is connected to the end of each secondary wiring. Common causes include Faulty Ignition Coil 8, Ignition Coil 8 harness is open or shorted, Ignition Coil 8 circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P0358 Toyota indicates Ignition Coil 8 Primary/Secondary Circuit Malfunction.
- Common causes
- Common causes include Faulty Ignition Coil 8, Ignition Coil 8 harness is open or shorted, Ignition Coil 8 circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P0358 Toyota Description
The Engine Control Module (ECM) determines the ignition timing and transmits the ignition (IGT) signals to each cylinder. Using the IGT signal, the ECM turns the power transistor inside the igniter on and off. The power transistor, in turn, switches the current supplied to the primary coil on and off. When the current to the primary coil is cut off, a powerful voltage is generated in the secondary coil. This voltage is applied to the spark plugs, causing them to spark inside the cylinders. As the ECM cuts the current to the primary coil, the igniter sends back an ignition confirmation (IGF) signal to the ECM for each cylinder ignition.
If the ECM does not receive any IGF signals despite transmitting the IGT signal, it interprets this as a fault in the igniter and stores a Diagnostic Trouble Code (DTC).
What are the Possible Causes of the DTC P0358 Toyota?
- Faulty Ignition Coil 8
- Ignition Coil 8 harness is open or shorted
- Ignition Coil 8 circuit poor electrical connection
- Faulty Engine Control Module (ECM)
How to Fix the DTC P0358 Toyota?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0358 Toyota code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P0358 Toyota Code
What does the OBDII code P0358 mean for a Toyota?
The P0358 code indicates a malfunction in the ignition coil circuit for cylinder 8, either in the primary or secondary circuit.
What are the common symptoms of the P0358 code in a Toyota?
Symptoms may include engine misfires, rough idling, reduced fuel efficiency, poor acceleration, or the Check Engine Light illuminating.
What causes the P0358 code to appear in a Toyota vehicle?
Potential causes include a faulty ignition coil, damaged wiring or connectors in the coil circuit, a malfunctioning powertrain control module (PCM), or a bad spark plug in cylinder 8.
Can I drive my Toyota with the P0358 code active?
Driving with the P0358 code is not recommended, as it can lead to further engine damage, reduced performance, and increased emissions.
How do I diagnose the P0358 code on my Toyota?
Start by checking the ignition coil and its wiring for cylinder 8, inspecting for damage or loose connections, and testing the coil’s resistance with a multimeter.
What tools are required to fix the P0358 code on a Toyota?
You may need an OBDII scanner, a multimeter, basic hand tools, and potentially a replacement ignition coil or spark plug for cylinder 8.
Does the P0358 code always mean the ignition coil is bad?
No, the issue could also be caused by damaged wiring, a faulty PCM, or a worn-out spark plug in cylinder 8.
How much does it cost to fix the P0358 code on a Toyota?
Repair costs can range from $50 to $200 for parts like ignition coils or spark plugs, while labor costs depend on the mechanic’s rates.
How can I prevent the P0358 code from recurring in my Toyota?
Regular maintenance, such as replacing spark plugs and ignition coils as recommended, and inspecting wiring for damage, can help prevent this issue.
Can a faulty PCM cause the P0358 code on a Toyota?
Yes, a malfunctioning PCM can occasionally cause the P0358 code, though this is less common compared to ignition coil or wiring issues.
Discuss the causes and fixes for P0358 Toyota OBDII Code
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Hi there. I see the diagnostic refers coil 8 but this car is a 4 cylinder.
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