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P0354 on Subaru Crosstrek

Ignition Coil D Primary/Secondary Circuit Malfunction

Factory diagnostic protocol and troubleshooting wire for fault code P0354 specifically for the Subaru Crosstrek (2021–2026, 2.0L Boxer-4 (152HP) / 2.5L (182HP) / 2.0L PHEV Plug-In Hybrid (149HP)).

Verified OEM Telemetry & Field Repair Tree
Subaru Crosstrek2021–2026
Subaru Crosstrek
SUV2.0L Boxer-4 (152HP) / 2.5L (182HP) / 2.0L PHEV Plug-In Hybrid (149HP)
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
Crosstrek SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Not Recommended
Critical urgency level
Est. Repair Cost
$100 - $350 (DIY: $30 - $90)
Parts & Labor DIY
Check P0354 On Another Subaru Model:
Diagnose P0354 on Specific Crosstrek Model Year:

1. Symptoms of P0354 on Subaru Crosstrek

When the Engine Control Module (ECM/PCM) on your Subaru Crosstrek (2.0L Boxer-4 (152HP) / 2.5L (182HP) / 2.0L PHEV Plug-In Hybrid (149HP)) logs fault code P0354, drivers commonly observe:

Flashing CEL on Subaru Crosstrek (2.0L Boxer-4 (152HP) / 2.5L (182HP) / 2.0L PHEV Plug-In Hybrid (149HP))
Rough running on Subaru Crosstrek (2.0L Boxer-4 (152HP) / 2.5L (182HP) / 2.0L PHEV Plug-In Hybrid (149HP))
Loss of power on Subaru Crosstrek (2.0L Boxer-4 (152HP) / 2.5L (182HP) / 2.0L PHEV Plug-In Hybrid (149HP))
P0304 code on Subaru Crosstrek (2.0L Boxer-4 (152HP) / 2.5L (182HP) / 2.0L PHEV Plug-In Hybrid (149HP))
Subaru Crosstrek OBD-II Port Location
The 16-pin diagnostic connector is located Under driver side steering column. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Subaru Crosstrek

Historical warranty claims and technical repair bulletins for Subaru Crosstrek point to the following failure distribution:

55%
Dead Cylinder 4 ignition coil (Subaru OEM Part)
25%
Wiring damage (Subaru OEM Part)
12%
Corroded connector (Subaru OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Subaru Crosstrek.

3. Step-by-Step DIY Repair Guide for Subaru Crosstrek

01
Test Coil with Swap Method

Swap Coil 4 to Cylinder 1. on the Subaru Crosstrek equipped with 2.0L Boxer-4 (152HP) / 2.5L (182HP) / 2.0L PHEV Plug-In Hybrid (149HP).

Required Tool: 10mm Socket
02
Replace Coil 4

Install new OEM coil pack. on the Subaru Crosstrek equipped with 2.0L Boxer-4 (152HP) / 2.5L (182HP) / 2.0L PHEV Plug-In Hybrid (149HP).

Required Tool: Socket Set
03
Clear DTCs

Clear memory and road test. on the Subaru Crosstrek equipped with 2.0L Boxer-4 (152HP) / 2.5L (182HP) / 2.0L PHEV Plug-In Hybrid (149HP).

Required Tool: OBD-II Scanner
Recommended Parts & Testing Tools

Equipment for Diagnosing Subaru Crosstrek (P0354)

Prime Fast Delivery & Verified Fitment
OEM Ignition Component

Direct-Fit Laser Iridium Spark Plugs (Set of 4/6)

4.8 / 5.0 (Top Rated)

Pre-gapped iridium spark plugs engineered to restore smooth combustion on Subaru Crosstrek.

$36 – $68 Prime
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Ignition Service Tool

Magnetic Swivel Spark Plug Socket Set

4.8 / 5.0 (Amazon Choice)

360-degree magnetic swivel socket prevents ceramic plug cracks inside deep engine spark wells.

$16.99 Prime
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Top Mobile OBD-II Scanner

BlueDriver Bluetooth Pro OBDII Scan Tool

4.7 / 5.0 (50,000+ Reviews)

Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.

Compare OEM & Aftermarket Replacement Sensors for Subaru CrosstrekVerified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
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Other Common Fault Codes on Subaru Crosstrek

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Subaru Crosstrek:

4. Subaru Crosstrek P0354 FAQs

What causes code P0354 to trigger on a Subaru Crosstrek?

On the Subaru Crosstrek (2.0L Boxer-4 (152HP) / 2.5L (182HP) / 2.0L PHEV Plug-In Hybrid (149HP)), P0354 is most frequently caused by Dead Cylinder 4 ignition coil or Wiring damage.

Where is the OBD-II port located on my Subaru Crosstrek?

On the Subaru Crosstrek, the 16-pin DLC diagnostic connector is located Under driver side steering column. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Subaru Crosstrek with code P0354?

No. Cylinder 4 ignition coil has failed. Given that P0354 carries a Critical severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.