Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / P068A — ECM/PCM Power Relay De-Energized Performance - Too Early

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

Detailed page for trouble code P068A.

34,405codes
59brands
11,914generic
22,491specific
All codes P-codes (Powertrain) B-codes (Body) C-codes (Chassis) U-codes (Network/User) Tesla Alerts
Reset
Code

P068A

Generic P — Powertrain

ECM/PCM Power Relay De-Energized Performance - Too Early

Brand: Generic
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Weak or discharged battery
  • Faulty PCM/ECM power relay (sticking or intermittent)
  • Poor battery positive feed or fuse to the relay/PCM (corrosion, loose connector)
  • Open or intermittent relay control/wiring to the PCM
  • Poor PCM ground(s)
  • Parasitic load or short drawing relay coil power down

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Intermittent stalling or engine shuts off unexpectedly
  • No-crank or no-start conditions when PCM loses power
  • Intermittent loss of electrical systems controlled by PCM
  • Stored or intermittent communication faults to scan tool

What to check

  • Read freeze frame and full DTC list; note conditions when P068A set (key position, engine running, cranking).
  • Check battery state-of-charge and terminal condition; perform battery load test.
  • Visually inspect battery positive cable, fuses, fusible links, and wiring to PCM power relay.
  • Inspect and wiggle the power relay and its socket for loose/corroded terminals; test/replace relay with known good unit.
  • Backprobe relay coil/control and contacts with key ON and during crank; record voltages.
  • Measure battery voltage at PCM power pin(s) with key ON and during the event (expect near battery voltage).

Signal parameters

  • Battery voltage at battery terminals: ~12.4–12.8 V (resting), 13.5–14.8 V (engine running/charging).
  • PCM B+ power pin with key ON: near battery voltage (within ~0.5 V).
  • Relay coil control circuit: ~0 V when de-energized, ~12 V (or switched ground depending on design) when energized.
  • Relay contact continuity: near 0 Ω when energized; voltage drop across closed contact
  • Ground resistance from PCM ground to chassis:

Diagnostic algorithm

  1. Confirm the code: read freeze frame data and other stored codes; clear codes and attempt to reproduce under same conditions.
  2. Check battery health and terminals: measure resting voltage and perform a load/cranking test. Repair/replace battery or terminals if weak or corroded.
  3. Visual inspection: inspect fuses, fusible links, relay socket, connector pins and wiring for corrosion, melting, or loose pins.
  4. Verify relay operation: with key ON, backprobe relay coil and contact circuits. Confirm coil gets proper supply and control signal and contacts close to supply PCM B+.
  5. Measure PCM supply: backprobe PCM power input(s) with key ON, during crank and while running (if safe). Confirm voltage remains stable and near battery voltage. Watch for voltage drop or sudden loss.
  6. Check grounds: clean and tighten PCM ground(s). Measure voltage drop on ground while energizing circuits to detect high resistance.
  7. Swap test: exchange the power relay with an identical known-good relay (or bench-test the suspect relay) and retest for code recurrence.
  8. Inspect ignition/power control: if relay coil control is lost, check ignition switch, body control module or immobilizer outputs that control relay coil.
  9. Parasitic/short test: if relay is being de-energized unexpectedly, perform parasitic current test or inspect downstream circuits for shorts that could trigger shutdown.
  10. If wiring, relay, battery and grounds are good and the fault persists, consider PCM internal fault. Consult manufacturer bulletins and consider PCM reprogramming or replacement as a last step.

Likely causes

  • Battery voltage falls below operating threshold (bad battery or poor connections)
  • Corroded/loose relay terminals or blown/loose fuse feeding PCM
  • Relay coil losing supply or control signal (wiring or ignition switch issue)
  • Intermittent PCM ground causing false de-energize detection
  • Defective power relay

Fault status

⚠️ Status
PCM power relay de-energized earlier than expected; PCM detected loss or drop of its power feed and set P068A.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours

Similar codes

P0680 P0685 P0601 P0606
8,055

The library contains 8,055 repair and diagnostic manuals. Choose a brand to open the full manual tree by year, model and trim.

ALFA ROMEO
89
AUDI
1,160
BMW
479
CHEVROLET
373
DAEWOO
75
FIAT
26
GENESIS
207
HUMMER
138
HYUNDAI
371
ISUZU
86
LAND ROVER
320
LEXUS
280
LINCOLN
166
MERCEDES-BENZ
856
MERCURY
296
MITSUBISHI
406
PORSCHE
136
TESLA
58
TOYOTA
2,042
TRIUMPH
131
VOLKSWAGEN
139
VOLVO
221
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P068A

LAND ROVER P — Powertrain

Engine control module / powertrain control module - relay de-energized very early

Brand: LAND ROVER
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Weak or discharged battery
  • Faulty PCM/ECM power relay (sticking or intermittent)
  • Poor battery positive feed or fuse to the relay/PCM (corrosion, loose connector)
  • Open or intermittent relay control/wiring to the PCM
  • Poor PCM ground(s)
  • Parasitic load or short drawing relay coil power down

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Intermittent stalling or engine shuts off unexpectedly
  • No-crank or no-start conditions when PCM loses power
  • Intermittent loss of electrical systems controlled by PCM
  • Stored or intermittent communication faults to scan tool

What to check

  • Read freeze frame and full DTC list; note conditions when P068A set (key position, engine running, cranking).
  • Check battery state-of-charge and terminal condition; perform battery load test.
  • Visually inspect battery positive cable, fuses, fusible links, and wiring to PCM power relay.
  • Inspect and wiggle the power relay and its socket for loose/corroded terminals; test/replace relay with known good unit.
  • Backprobe relay coil/control and contacts with key ON and during crank; record voltages.
  • Measure battery voltage at PCM power pin(s) with key ON and during the event (expect near battery voltage).

Signal parameters

  • Battery voltage at battery terminals: ~12.4–12.8 V (resting), 13.5–14.8 V (engine running/charging).
  • PCM B+ power pin with key ON: near battery voltage (within ~0.5 V).
  • Relay coil control circuit: ~0 V when de-energized, ~12 V (or switched ground depending on design) when energized.
  • Relay contact continuity: near 0 Ω when energized; voltage drop across closed contact
  • Ground resistance from PCM ground to chassis:

Diagnostic algorithm

  1. Confirm the code: read freeze frame data and other stored codes; clear codes and attempt to reproduce under same conditions.
  2. Check battery health and terminals: measure resting voltage and perform a load/cranking test. Repair/replace battery or terminals if weak or corroded.
  3. Visual inspection: inspect fuses, fusible links, relay socket, connector pins and wiring for corrosion, melting, or loose pins.
  4. Verify relay operation: with key ON, backprobe relay coil and contact circuits. Confirm coil gets proper supply and control signal and contacts close to supply PCM B+.
  5. Measure PCM supply: backprobe PCM power input(s) with key ON, during crank and while running (if safe). Confirm voltage remains stable and near battery voltage. Watch for voltage drop or sudden loss.
  6. Check grounds: clean and tighten PCM ground(s). Measure voltage drop on ground while energizing circuits to detect high resistance.
  7. Swap test: exchange the power relay with an identical known-good relay (or bench-test the suspect relay) and retest for code recurrence.
  8. Inspect ignition/power control: if relay coil control is lost, check ignition switch, body control module or immobilizer outputs that control relay coil.
  9. Parasitic/short test: if relay is being de-energized unexpectedly, perform parasitic current test or inspect downstream circuits for shorts that could trigger shutdown.
  10. If wiring, relay, battery and grounds are good and the fault persists, consider PCM internal fault. Consult manufacturer bulletins and consider PCM reprogramming or replacement as a last step.

Likely causes

  • Battery voltage falls below operating threshold (bad battery or poor connections)
  • Corroded/loose relay terminals or blown/loose fuse feeding PCM
  • Relay coil losing supply or control signal (wiring or ignition switch issue)
  • Intermittent PCM ground causing false de-energize detection
  • Defective power relay

Fault status

⚠️ Status
PCM power relay de-energized earlier than expected; PCM detected loss or drop of its power feed and set P068A.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours

Similar codes

P0680 P0685 P0601 P0606
320

Browse 320 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LAND ROVER

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email

Report

Harassment or bullying behavior
Contains mature or sensitive content
Contains misleading or false information
Contains abusive or derogatory content
Contains spam, fake content or potential malware

Block Member?

Please confirm you want to block this member.

You will no longer be able to:

  • See blocked member's posts
  • Mention this member in posts
  • Invite this member to groups
  • Message this member
  • Add this member as a connection

Please note: This action will also remove this member from your connections and send a report to the site admin. Please allow a few minutes for this process to complete.

Report

You have already reported this .