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 calculation of engine misfire/roughness 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 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 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 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 powertrain control module (PCM) consist of the following circuits:

– Ignition control (IC) synchronization signal

– IC synchronization 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) synchronization signal circuit.

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

The CKP synchronization 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:

– A 12-volt reference

– A low reference

– A CKP sensor signal 1

– A 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 MIL (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 sensor coil or crankshaft position sensor
• Faulty ignition control module

Description

The undefined ignition diagnostic monitor pulse width is the generic description for Ford code P1357, but the manufacturer may have a different description for your vehicle model and year. Currently, we do not have additional information about Ford OBDII code P1357.

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 on)

Identified Problem

Is your Volkswagen displaying the fault code P1357? This error code indicates a malfunction in the ignition coil circuit for cylinder 1, a common issue in Golf, Passat, Tiguan, and other VW group models.

Common Symptoms

• 🚨 Engine light on (check engine)
• 🌀 Rough idle and vibrations
• ⚠ Noticeable power loss
• ⛽ Increased fuel consumption
• 🔥 Misfires in cylinder 1

Probable Causes (VW Specific)

1. Faulty ignition coil (common internal failure)
2. Connector issue (oxidized connectors)
3. Damaged wiring (cut or chafed wires)
4. Worn or defective spark plug
5. ECU failure (less common)

Diagnosis in 5 Steps

1. Visual inspection
   • Check the cylinder 1 ignition coil (located on the timing belt side)
   • Inspect the condition of the connector and wires
2. Substitution test
   • Swap the coil with another cylinder
   • If the code follows → Replace the coil
3. Electrical test
   • Measure resistance:
     • Primary: 0.5-1.0 Ω
     • Secondary: 5000-10000 Ω
4. Spark plug check
   • Check gap and wear
5. Complete ECU scan
   • Use VCDS for in-depth analysis

Recommended Solutions

• ✅ Replace the ignition coil (prefer Bosch or Beru)
• ✅ Clean or replace the connector if oxidized
• ✅ Replace spark plugs if necessary (NGK recommended)
• ✅ Check wiring along its entire length

What to Absolutely Avoid

• ❌ Using low-quality parts
• ❌ Neglecting engine cover sealing
• ❌ Forgetting to reset the ECU after repair

Consequences if Ignored

• 🔧 Accelerated catalyst deterioration
• ⛽ 20% increase in fuel consumption
• 💥 Risk of long-term engine damage

Conclusion

The P1357 code on Volkswagen is usually resolved easily by replacing the faulty ignition coil. For a lasting repair:

1. Use quality OEM parts
2. Check all circuit components
3. Perform a complete diagnosis if the problem persists

🔧 Need help? Consult a Volkswagen specialist equipped with VCDS for an accurate diagnosis.

Possible Causes

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

• Faulty cylinder 2 ignition coil
• Cylinder 2 ignition coil harness is open or shorted
• Poor electrical connection in cylinder 2 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 ignition segments of each cylinder based on the firing order.
The calculation of engine misfires/roughness 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 starting 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 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 according to 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 starting 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 control module
• Ignition control module harness is open or shorted
• Poor electrical connection in the 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 transitions 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:

– A 12-volt reference

– A low reference

– A CKP sensor signal 1

– A 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

• Malfunction Indicator Lamp illuminated (or Service Engine Soon warning lamp illuminated)

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 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:

– A 12-volt reference

– A low reference

– A CKP sensor signal 1

– A 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 MIL (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 sensor coil or crankshaft position sensor
• Faulty ignition control module

Description

The ignition diagnostic monitor signal out of self-test range is the generic description for Ford code P1358, but the manufacturer may have a different description for your vehicle model and year. Currently, we do not have additional information about Ford OBDII code P1358.

How to Fix

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)