Possible Causes

NOTE: The listed causes may not be a complete list of all potential issues and there may be other causes.

• Faulty ignition control module
• Ignition control module harness is open or shorted
• Poor electrical connection in ignition control module circuit

Description

The ignition control module (ICM) has independent power and ground circuits.

The circuits between the ICM and the powertrain control module (PCM) consist of the following circuits:

– Ignition control (IC) timing signal

– IC timing control

– Low resolution engine speed signal

– Medium resolution engine signal

– Camshaft position signal

– Low reference

The ICM sends 3X signals to the PCM and controls ignition timing during engine starting.

Timing advance switches to PCM control after the following actions occur:

The PCM receives the second 3X signal. The PCM applies 5 volts to the ignition control (IC) timing signal circuit.

The ICM monitors the CKP timing signal when the engine starts. The CKP timing signal is transmitted from the CKP sensor to the ICM on the CKP sensor signal 2 circuit.

The CKP timing signal is used to determine the correct cylinder pair and initiate the ignition coil firing sequence.

The 18X reference pulses are transmitted from the CKP sensor to the ICM on the CKP sensor 1 circuit.

The 18X reference pulses are used for fuel injection and ignition control.

Once the ICM has received both signals, the ICM transmits the 18X and 3X reference signals to the PCM.

The CMP and CKP sensors share a 12-volt reference circuit and a low reference circuit.

The CKP sensor consists of the following circuits:

– 12-volt reference

– Low reference

– CKP sensor signal 1

– CKP sensor signal 2

How to Repair

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

• Illuminated engine light (or service engine soon warning light)

Possible Causes

NOTE: The listed causes may not be a complete list of all potential problems and there may be other causes.

• Dirty or low engine oil
• Valve timing
• Oil control valve
• Variable valve timing control assembly
• Engine control module (ECM)

Description

The Variable Valve Timing (VVT) system controls the intake valve timing according to driving conditions. The Engine Control Module (ECM) controls the Oil Control Valve (OCV) to perform correct valve timing. The oil pressure controlled by the OCV is supplied to the VVT controller, then the VVT controller changes the relative position between the camshaft and the crankshaft.

How to Repair

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

• Check engine light illuminated (or service engine soon warning light)

Possible Causes

NOTE: The listed causes may not be a complete list of all potential problems and there may be other causes.

• Faulty ignition coil “C”
• Ignition coil “C” harness is open or shorted
• Poor electrical connection in ignition coil “C” circuit

Description

The ignition coil “C” primary circuit is the generic description for Mazda code P1354, but the manufacturer may have a different description for your vehicle model and year. Currently, we do not have additional information about Mazda OBDII code P1354.

How to Repair

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

• Engine Light On (or Service Engine Soon Warning Light)

Possible Causes

NOTE: The listed causes may not be a complete list of all potential issues and there may be other causes.

• Faulty spark plug
• Faulty ignition coil
• Intake vacuum leak
• Faulty camshaft position sensor
• Ignition coil harness is open or shorted
• Poor electrical connection in ignition coil circuit

Description

Under CARB/OBD regulations, the Engine Control Module (ECM) must determine if a misfire is occurring and also identify the specific cylinder(s) and severity of the misfire event, and whether it is relevant for emissions or damaging to the catalyst.

To accomplish these tasks, the control module monitors the crankshaft for acceleration losses during the firing segments of each cylinder based on the firing order.
The misfire/engine roughness calculation is derived from differences in period duration (T) of individual increment gear segments. Each segment period consists of a 120° angular range of crankshaft angle that begins 78° before top dead center (TDC).

If the expected period duration exceeds the allowed value, a misfire fault for that particular cylinder is recorded in the ECM’s fault memory.

Depending on the measured misfire rate level, the control unit illuminates the Service Engine Soon light, may cut fuel to the particular cylinder, and may switch lambda operation to open loop. All misfire faults are weighted to determine whether the misfire is relevant for emissions or damaging to the catalyst.

How to Repair

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

• Engine Light On (or Service Engine Soon Warning Light)

Possible Causes

NOTE: The listed causes may not be a complete list of all potential issues and there may be other causes.

• Dirty or low engine oil
• Valve timing
• Oil control valve
• Variable valve timing control assembly
• Engine control module (ECM)

Technical Notes

Description

The Variable Valve Timing (VVT) system controls the intake valve timing according to driving conditions. The Engine Control Module (ECM) controls the Oil Control Valve (OCV) to perform correct intake valve timing. The oil pressure controlled by the OCV is supplied to the VVT controller, then the VVT controller changes the relative position between the camshaft and the crankshaft.

How to Repair

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

• Check engine light illuminated (or service engine soon warning light illuminated)

Possible Causes

NOTE: The listed causes may not be a complete list of all potential issues and there may be other causes.

• Injection pump failure
• Check the modulating piston displacement sensor
• Check the quantity regulator

Description

The malfunction of the modulating piston displacement sensor electrical circuit is the generic description for Volkswagen code P1354, but the manufacturer may have a different description for your vehicle model and year. Currently, we do not have additional information about Volkswagen OBDII code P1354.

How to Repair

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

• Check engine light on (or service engine soon warning light illuminated)

Possible Causes

NOTE: The listed causes may not be a complete list of all potential problems and there may be other causes.

• Faulty ignition coil
• Ignition coil harness is open or shorted
• Poor electrical connection in ignition coil circuit

Description

Under CARB/OBD regulations, the Engine Control Module (ECM) must determine if a misfire is occurring and also identify the specific cylinder(s) and severity of the misfire event and whether it is emissions relevant or damaging to the catalyst. To accomplish these tasks, the control module monitors the crankshaft for acceleration losses during the firing segments of each cylinder according to the firing order.
The misfire/engine roughness calculation is derived from the period time (T) differences of individual increment gear segments. Each segment period consists of a 120° crankshaft angle range that begins 78° before top dead center (TDC).
If the expected period time is greater than the allowed value, a misfire fault for the particular cylinder is recorded in the ECM fault memory. Depending on the measured misfire rate level, the control unit illuminates the “Service Engine Soon” light, may cut fuel to the particular cylinder, and may switch lambda operation to open loop. All misfire faults are weighted to determine whether the misfire is emissions relevant or damaging to the catalyst.

How to Repair

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

• Engine Light On (or Service Engine Soon Warning Light On)

Possible Causes

NOTE: The listed causes may not be a complete list of all potential problems and there may be other causes.

• Faulty cylinder 1 ignition coil
• Cylinder 1 ignition coil harness is open or shorted
• Poor electrical connection in cylinder 1 ignition coil circuit
• Faulty Engine Control Module (ECM)

Description

The Engine Control Module (ECM) must determine if a misfire is occurring and identify the specific cylinder(s) and severity of the misfire event and whether it is relevant for emissions or damaging to the catalyst. To accomplish these tasks, the control module monitors the crankshaft for acceleration losses during the firing segments of each cylinder based on the firing order.
The misfire/engine roughness calculation is derived from differences in period duration (T) of individual increment gear segments. Each segment period consists of an angular range of 120° of crankshaft angle that begins 78° before Top Dead Center (TDC).
If the expected period duration exceeds the allowed value, a misfire fault for the particular cylinder is recorded in the ECM fault memory. Depending on the measured misfire rate level, the control unit illuminates the “Service Engine Soon” light, may cut fuel to the particular cylinder, and may switch lambda operation to open loop. All misfire faults are weighted to determine whether the misfire is relevant for emissions or damaging to the catalyst.

How to Repair

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

• Engine Light On (or Service Engine Soon Warning Light On)

Possible Causes

NOTE: The listed causes may not be a complete list of all potential problems and there may be other causes.

• Faulty spark plug
• Faulty ignition coil
• Intake vacuum leak
• Faulty camshaft position sensor
• Ignition coil harness is open or shorted
• Poor electrical connection in ignition coil circuit

Description

Under CARB/OBD regulations, the Engine Control Module (ECM) must determine if a misfire is occurring and also identify the specific cylinder(s) and severity of the misfire event, and whether it is emissions-relevant or damaging to the catalyst. To accomplish these tasks, the control module monitors the crankshaft for acceleration losses during the firing segments of each cylinder based on the firing order.
The misfire/engine roughness calculation is derived from differences in period duration (T) of individual increment gear segments. Each segment period consists of an angular range of 120° of crankshaft angle that begins 78° before Top Dead Center (TDC).
If the expected period duration exceeds the allowed value, a misfire fault for that particular cylinder is recorded in the ECM’s fault memory. Depending on the measured misfire rate level, the control unit illuminates the Service Engine Soon light, may cut fuel to the particular cylinder, and may switch lambda operation to open loop. All misfire faults are weighted to determine whether the misfire is emissions-relevant or damaging to the catalyst.

How to Repair

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

• Engine Light On (or Service Engine Soon Warning Light On)

Possible Causes

NOTE: The listed causes may not be a complete list of all potential problems and there may be other causes.

• Faulty ignition coil “D”
• Ignition coil “D” harness is open or shorted
• Ignition coil “D” circuit poor electrical connection

Description

The ignition coil “D” primary circuit is the generic description for Ford code P1355, but the manufacturer may have a different description for your vehicle model and year. Currently, we have no additional information about Ford OBDII code P1355.

How to Repair

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

• Engine light on (or service engine soon light on)