When your EV stops charging and you’ve already checked the obvious (the car’s charge port, the wallbox, the circuit breaker), the cable itself is often the culprit. EV charging cables fail in predictable ways, and most of those failures have clear symptoms. We’ve mapped the five most common fault modes we see across warranty returns: latch and lock failures, thermal trips and overheat protection, contact wear, pilot-signal errors and physical cable damage. For each one, we’ll tell you what the symptom looks like, what’s causing it, and whether it can be fixed or needs replacing.
Before you blame the cable: a 60-second pre-check
EV charging failures are rarely just the cable. Before you conclude it is the cable at fault, run through this quick check to rule out the more common culprits:
1. Try a different socket or charger. If the cable works at a public charger but not at your home wallbox (or vice versa), the fault is likely in the installation, not the cable. The IET Code of Practice for EV Charging Equipment Installation, 5th edition (2023) recommends that any persistent charging failure with a specific installation should trigger a review of the circuit, including the RCD and any Smart charging firmware.
2. Try a different cable. If you have access to another cable (a borrowed one, a public tethered charger), and your car charges normally with it, that strongly indicates the cable is the problem.
3. Check the car’s charging log. Most modern EVs log charging sessions and error codes. Your car may have recorded a specific fault code, such as “communication error,” “connector not locked,” or “overcurrent detected,” that points directly at a fault mode.
4. Check the circuit breaker and RCD. A tripped RCD or MCB is a separate issue, but it is quick to rule out. If the RCD has tripped, investigate why before resetting. A persistent RCD trip can indicate a genuine earth-fault that should be looked at by an electrician.
If the cable is the only variable that correlates with the fault, continue to the fault modes below.
Fault 1: Latch and lock failure
Symptoms
The connector does not click firmly into the vehicle inlet, or clicks in initially but pops out during the charging session. The car may not register a connection at all, or may stop charging mid-session showing a “connector not locked” or similar error. In some cases the latch button is sticky, requiring more force than normal to press or failing to spring back cleanly.
Cause
Three things cause latch failures: debris in the latch mechanism (mud, grit, ice or road film blocking the latch arm), a worn or fatigued latch spring (the internal spring that holds the latch in the locked position loses tension over time), or damage to the corresponding latch recess on the vehicle inlet (if the inlet socket is damaged, no cable latch will seat correctly, and the car is the problem, not the cable).
Fix or replace?
Clean the latch area first with a dry soft brush, or compressed air if available. If the connector now latches firmly, the cause was debris. If the latch is still unreliable after cleaning, the spring is likely the issue: this is not user-serviceable in a certified connector. The cable must be replaced. Do not use a cable with an unreliable latch. An unsecured connector means the contact pair may not be fully seated, generating heat at the contact interface, and the safety handshake defined by IEC 61851-1 may not complete correctly.
Fault 2: Overheat protection / thermal trip
Symptoms
Charging starts normally, then stops after 10-40 minutes. The cable or connector feels warm to the touch, sometimes hot. The car may show an “interrupted charging” notification. Restarting the charging session after the cable cools down allows it to start again, but it trips again after a similar interval.
Cause
EV cables have internal thermal protection that cuts current if the cable temperature exceeds a safe threshold. The threshold exists because an overheating cable indicates a problem elsewhere. Three distinct causes:
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Tightly coiled cable during charging. The internal conductors dissipate heat through the outer jacket; if the cable is coiled into a small heap during a long, high-current session, heat builds up in the bundle. Always uncoil the cable fully before starting a charge.
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Current mismatch. A 16A cable used on a 32A wallbox may overheat because it is being asked to carry more current than it was designed for. Check the cable’s rated current against the wallbox’s maximum output. A 16A cable (rated approximately 3.7kW single-phase) should not be used on a 32A (7.4kW) circuit.
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Dirty or partially-worn contact pins. As described above, increased contact resistance means more heat at the contact point. A slightly corroded pin pair may pass enough current for charging to begin, but generate heat that trips the thermal protection before the session completes. Clean the pins (dry cloth only); if the fault persists, the connector needs replacing.
Fix or replace?
Uncoil the cable fully during every charge (step one). Check the current rating matches the wallbox (step two). Clean the connector pins (step three). If the thermal trip persists after all three steps, the thermal protection element in the cable may itself be degraded or the contact pins are worn beyond cleaning. Replace the cable.
Fault 3: Contact wear and pin damage
Symptoms
Charging runs at a lower power level than expected: the car reports 3kW when the cable and wallbox support 7.4kW. Charging is intermittent or drops in and out. You may see visible discolouration (greening, blackening or brown deposits) on one or more pins. The connector feels slightly warm at the pin end even at lower charge rates.
Cause
IEC 62196-2 specifies a minimum mechanical endurance of 3,000 mating cycles for Type 2 connectors. At one charge per day, that is over eight years of daily plugging, so contact wear in a well-maintained cable is rarely a problem within the warranty period. What accelerates wear is: forcing a misaligned connector (which drags pins across the contact surface on an angle), contaminated pins (grit particles act as abrasives during mating), or moisture that is left to sit on the pin surfaces, causing oxidation. Once oxidation forms, it increases resistance, generates heat, and the heat accelerates further oxidation in a self-reinforcing cycle.
Fix or replace?
Light surface oxidation, a slight dulling of the pin surface with no visible deposits, may respond to the mechanical self-cleaning action of a few careful plug-unplug cycles on a clean socket. Visible deposits (green, brown, black), pitted pin surfaces or any bent pin cannot be cleaned. The connector must be replaced. Contact EV Cable Hub to claim your EV cable warranty if the cable is within its warranty period.
Fault 4: Pilot-signal error (no charge initialisation)
Symptoms
The cable seats correctly, the latch clicks, but the car does not begin charging. The car’s display may show “connected” without starting, or may show “communication error” or “cable error.” The wallbox LED may remain amber or flash an error pattern rather than showing a charging green. Unplugging and re-plugging the cable sometimes resolves the issue temporarily.
Cause
The Control Pilot (CP) pin, the signal wire that enables the digital handshake between car and charger as defined by IEC 61851-1, is not completing the circuit correctly. This can be caused by: contamination or corrosion on the CP pin specifically (it is the smallest pin in the connector and the most sensitive to deposits); a bent CP pin that does not make clean contact with the vehicle inlet socket; or an intermittent break in the CP wire within the cable body (a knock or tight bend that has damaged the pilot signal wire without visibly affecting the outer jacket).
Fix or replace?
Inspect the CP pin specifically (it is the smallest pin, and in the UK Type 2 layout it sits in the upper right position when looking at the connector face). A dry cotton bud can clean the CP pin. If the connection is still intermittent after cleaning, and the cable shows no external damage, the CP wire inside the cable body may be intermittently broken. This is not visible from outside and is not repairable. Replace the cable. If the fault occurs with multiple cables on the same car, the issue is the vehicle inlet, so consult your car dealer.
Fault 5: Physical cable damage
Symptoms
Visible cuts, gouges, abrasions or crush marks on the outer jacket. A bulge in the jacket at any point along the cable. Any section where the inner insulation layers are visible. A section of cable that feels rigid or stiff in a way that is different from the rest of the cable (this can indicate a crushed internal conductor).
Cause
The most common cause is a vehicle tyre rolling over the cable, by far the most frequent mechanical damage we see in our returns. Other causes: sharp objects (tools, stones) causing cuts, cable doors on car-park pillars closing on the cable, and cables caught under items in a garage.
Fix or replace?
Replace immediately. Do not use the cable. Physical damage to the outer jacket may compromise the insulation layers beneath, even if the inner conductors appear intact. A cable with a damaged jacket is no longer IP55-rated at that point, and moisture can track into the insulation even if the outer breach appears small. A cable with a visible bulge has internal damage to the insulation layer beneath. The risk of using a cable with any physical damage is not theoretical. It is a genuine fire and electric shock risk.
Symptom-to-fault quick-reference table
- Symptom | Fault mode | Most likely cause | Fix / action
- Connector won't click/latch into car | Latch failure | Debris in latch mechanism | Clean latch; if spring broken, replace cable
- Connector clicks in but releases during charge | Latch failure | Worn latch spring | Replace cable
- Charging stops 10-40 min; cable/connector warm | Thermal trip | Coiled cable; current mismatch; dirty pins | Uncoil; check rating; clean pins. If it persists, replace
- Car shows not connected with cable seated | Pilot-signal error | Dirty or damaged CP pin | Clean CP pin (dry cotton bud). If it persists, replace
- Charging speed lower than expected; intermittent | Contact wear | Oxidised or pitted pins | Clean minor oxidation; if pitted/bent, replace
- Outer jacket cut, split or crushed | Physical damage | Mechanical impact / run-over | Replace immediately; do not use
- Burning smell or hot connector | Contact overload / resistance fault | Worn/corroded pins or current mismatch | Stop charging immediately; replace cable
When to claim your warranty
If your cable has developed a fault that points to a manufacturing defect (latch spring failure within the warranty period, a CP pin that has failed without physical damage, a jacket that has separated from the plug body without mechanical cause), this is a warranty claim, not something you need to live with or buy around.
Every cable we sell carries a minimum two-year warranty. If your cable is within this period and the fault mode matches a manufacturing defect rather than misuse, contact us with your order number and a description of the symptom. We handle the claim process with the manufacturer on your behalf.
- START: Cable fault identified
- → Is there any physical damage to jacket, pins or connector body? → YES → Replace now, do not use it
- → Is there a burning smell or very hot connector? → YES → Stop charging; replace now
- → NO to both above → Can fault be cleared by cleaning and correct cable management? → YES → Use cable but monitor closely
- → NO → Is the cable within its warranty period? → YES → Contact EV Cable Hub; we handle the claim
- → NO → Choose a replacement cable
If the fault is caused by misuse (physical damage, cable used at a current above its rating, or evidence of modification), warranty cover does not apply, but a replacement EV charging cable from our range is quick to find and order.
Frequently asked questions
My EV shows “charging paused”. Is it the cable?
Not always. “Charging paused” can come from the vehicle’s battery management system (thermal protection, battery full), from the wallbox (SMART scheduling, grid signal) or from the cable. Try a different cable. If the issue persists, it is not the cable.
Can I repair an EV charging cable myself?
No. EV charging cables are sealed electrical products certified as a complete unit under IEC 62196-2. Cutting, splicing or opening the connector voids the safety certification and creates a hazard. Any cable with damaged conductors, cracked jacket or damaged connector must be replaced, not repaired.
Why does my cable only charge at 7.4kW instead of 22kW?
Almost certainly the cable spec, not a fault. A single-phase (3-conductor) Type 2 cable delivers up to 7.4kW (32A single-phase) even on a 22kW three-phase post. For 22kW you need a five-pin three-phase Type 2 cable and a vehicle with a three-phase onboard charger.
How many times can I plug in before the connector wears out?
IEC 62196-2 specifies a minimum mechanical endurance of 3,000 mating cycles. At one charge per day that is over eight years of cycles. Real-world life depends on keeping pins clean and avoiding forcing a misaligned connector.
My cable feels warm during charging. Is that normal?
Mild warmth at the connector during 32A charging is normal, because any conductor under load generates some heat. The connector should feel warm, not hot. If it is uncomfortably hot, or if there is any burning smell, stop charging immediately. That indicates a fault, most likely worn contacts, a current mismatch or a coiled cable overheating.
The latch is sticking. Can I force it?
Never force a sticking latch. A connector that will not seat or release properly is not making a fully sealed contact. Forcing it risks pin damage on both cable and vehicle inlet. Clean the latch area, try gently, and if the problem persists, arrange a replacement.
