P068A — ECM/PCM Power Relay De-Energized Performance – Too Early

**Overview**

The diagnostic trouble code P068A indicates that the vehicle’s Engine Control Module (ECM) or Powertrain Control Module (PCM) has detected that its power relay has de-energized prematurely. In simple terms, this means the electronic control unit’s power supply is turning off earlier than expected, which can affect vehicle operation.

Please note that **labels and code descriptions may vary between different vehicle manufacturers**. Dealers and repair guides often assign unique labels for similar conditions.

**Fast Facts**

  • System affected: Powertrain/Engine Control System
  • Severity: Medium — can cause drivability issues
  • Main symptoms: Engine stalling, starting problems, reduced power
  • Driveability: Limited — vehicle may operate intermittently or with issues

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Manufacturer variations for trouble code P068A

Different vehicle manufacturers may assign unique labels or slightly different descriptions for this trouble code, even though they point to the same underlying issue. It is essential to cross-reference vehicle-specific repair documents when diagnosing.

Some known label variations include:

  • Ford: P068A — PCM Power Relay De-Energized Too Early
  • Volkswagen: P068A — Engine Control Module Power Supply Loss
  • BMW: P068A — ECM Power Relay Cycling or Failing
  • Renault: P068A — Power Supply Issue in ECU

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What does trouble code P068A mean?

In simple terms, P068A is a code that indicates the vehicle’s electronic control system has detected that its power relay — which supplies electrical power to the ECM or PCM — has de-energized earlier than it should. This relay acts like a switch that controls power flow to critical engine management components.

The engine management system continuously monitors the status of its power supplies. When it detects that the relay controlling power to the ECM/PCM switches off too early, it triggers this code.

This situation can be caused by various issues, such as faulty relays, wiring problems, or an internal malfunction within the ECU.

Typically, this code appears during diagnosis when scanned with an OBD-II scanner during vehicle operation or post-road test. It often correlates with symptoms like engine stalling, failure to start, or inconsistent engine behaviour.

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Severity and risks of trouble code P068A

This trouble code generally indicates a **moderate risk**. If the power relay de-energizes prematurely, the vehicle’s engine management system can shut down unexpectedly or fail to function correctly, leading to operational issues.

Potential risks include:

– Loss of power during driving, which could be hazardous in certain situations
– Engine stalls or poor engine performance
– No-start conditions if the ECU loses power entirely
– Possible long-term damage if underlying electrical issues are not addressed

Given these risks, it is **not advisable to ignore** this trouble code. While the vehicle can often be driven temporarily, continued operation without repairs could lead to further damage.

**Conclusion:** – The vehicle’s driveability may be limited, so it is **recommended to have the vehicle inspected and repaired** promptly.

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Symptoms of trouble code P068A

This code is often accompanied by symptoms related to electrical and engine performance issues, such as:

  • Engine stalling or intermittent shutdowns — the vehicle stalls randomly or when idling
  • Fail to start or long cranking times — difficulty in igniting the engine
  • Loss of engine power — noticeable hesitation or reduced responsiveness
  • Warning lights — the MIL (Malfunction Indicator Lamp) or other warning lights appear on the dashboard
  • Electrical issues — flickering dashboard lights or erratic instrument cluster behaviour

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Most likely causes of trouble code P068A

This diagnostic trouble code is primarily associated with electrical and relay system issues within the vehicle. Several causes can trigger it, with some being more common than others.

Generally, the causes are ranked as follows:

1. Faulty or failing power relay — the relay that supplies power to the ECM/PCM may be defective or worn out, causing early de-energization.

2. Corroded or damaged wiring and connectors — poor connections, corrosion, or damaged wiring in the relay circuit can interrupt power supply, leading to the code.

3. Internal ECM/PCM malfunction — failure within the control module itself, such as a failed component or internal short circuit, can cause premature power loss.

4. Low or inconsistent battery voltage — insufficient voltage can result in relay operation issues or voltage drops, affecting power supply.

5. Bad grounds or electrical interference — inadequate grounding or electromagnetic interference (EMI) can disrupt relay operation.

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How to diagnose trouble code P068A

Diagnosing this code involves a methodical approach to verify the relay’s operation and the electrical system’s health. Always follow safety procedures and disconnect the battery if necessary to prevent electrical damage.

**Step-by-step diagnostics include:**

1. Visual inspection — examine relay and wiring harnesses for corrosion, damage, or loose connections, especially at the relay socket and ECU connector.

2. Check relay operation — swap the suspected relay with a known-good one or use a relay tester to verify proper switching.

3. Test the relay circuit — use a multimeter to check voltage at relay terminals, looking for voltage drops or irregularities during operation.

4. Inspect wiring and connectors — perform continuity tests and examine wiring for shorts, opens, or corrosion.

5. Check vehicle battery and charging system — ensure adequate and stable voltage (typically around 12.6V with engine off, 13.7–14.7V with engine running).

6. Use live data — scan the vehicle’s data stream to see when the power relay de-energizes and whether any other fault codes appear simultaneously.

7. Perform a workaround test — manually energize the relay circuit (if possible) to observe if the problem persists or goes away.

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Possible repairs for trouble code P068A

Based on the identified cause, repairs can range from simple relay replacements to more complex electrical repairs. The goal is to restore proper power supply to the ECM/PCM and eliminate the fault.

**Potential repairs include:**

– Replacing the faulty relay — a basic repair that often resolves the issue if the relay is defective.
– Repairing or replacing damaged wiring or connectors — a professional task that involves cleaning or soldering connections, or replacing wiring harnesses.
– Replacing the ECM/PCM — an advanced repair required if internal failure of the control module is confirmed.
– Restoring battery voltage and electrical system — ensuring the charging system is functioning correctly and replacing weak batteries.
– Improving grounding connections — cleaning and tightening ground points to reduce electrical noise and interference.

It is recommended to verify the root cause before replacing any components to avoid unnecessary repairs.

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Vehicles commonly associated with trouble code P068A in Europe

This fault can affect various makes and models, primarily those with electrical systems susceptible to relay or wiring issues. Without specific data, common brands include:

– Ford— particularly models with early-generation PowerShift transmission or eco-friendly systems
– Volkswagen— especially diesel variants with complex ECU wiring
– BMW — models with advanced control modules and electrical systems

Always consult manufacturer-specific databases or technical service bulletins when diagnosing.

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Frequent mistakes & best practices

Diagnosis of P068A can be hindered by common mistakes. Awareness of these pitfalls can save time and improve repair accuracy.

**Common mistakes include:**

– Replacing the relay without verifying its functionality — sometimes the relay appears faulty but the root cause lies elsewhere.
– Neglecting to check wiring and grounding connections — wiring issues are often overlooked but are frequent causes.
– Ignoring battery and charging system health — low voltage can produce false-positive codes.
– Assuming ECU replacement without thorough testing — an internal ECU fault is rare and should be confirmed before costly replacement.

**Best practices** involve thorough visual inspections, live data analysis, and confirming electrical integrity before component replacement.

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FAQ — trouble code P068A

**Can this code disappear on its own?**
Typically, no. This code usually persists until the underlying electrical issue is repaired. Temporary false triggers due to voltage dips may cause it to clear briefly but will often recur.

**Can I keep driving?**
Limited — while it might be possible to drive temporarily, ongoing issues like engine stalling or starting problems make this risky. It is advisable to schedule repairs promptly.

**Why does the code return after clearing?**
The root cause, such as a faulty relay, wiring issue, or electrical interference, remains unaddressed, causing the code to reappear once the system performs its self-tests.

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**In conclusion**, P068A is an electrical issue related to the control module’s power supply de-energizing prematurely. Correct diagnosis involves verifying relay function, wiring integrity, and electrical system health. Repairing the underlying cause is essential for restoring reliable vehicle operation and preventing further electrical problems.

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