E-03 on a diesel heater: glow plug fault
Updated
E-03 means the controller sees a fault in the glow plug circuit: the plug is open, shorted or badly connected. Owners most often fix it with a new glow plug. First check: the plug's connector, then the plug's resistance with a meter. If the plug tests good and E-03 appears at once, suspect the control board.
Which controller do you have?
The same number means different faults on different controllers. Match yours to a sketch first. This meaning applies to the 5-button LCD, the B2010 and the Vevor M-button panel; on the rotary-switch LCD of Heatport and T4 heaters and on the Hcalory HC-A01, the number 3 is a voltage fault.
- 5-button LCDE-01 … E-10 with two digits, on a black panel with five round buttonsThis page applies
- Vevor M-button panelE-xx flashing on a colour screen, four keys including M, voice promptsThis page applies
- Rotary knob, LEDsNo screen: an LED flashes a count, pauses, repeats
- LCD, E-2 … E-10E-2 … E-10, one digit after the dash, no E-1
- Rotary-switch LCD, E0 … E15E1, E2, E3 … with no dash, on an LCD switch you turn and press
- Knob LCD (Hcalory HC-A01)E-01 … E-10 on a colour LCD with one push-turn knob
At a glance
| Code | E-03 |
|---|---|
| Meaning | Glow plug circuit fault: plug open, shorted or badly connected |
| Most common cause | Failed glow plug. Less often the component on the control board that powers it |
| Check this first | Check the glow plug connector, then measure the plug's resistance |
| Evidence | Manuals and owner reports |
What E-03 means on each controller
| Code | Controller | Manual or brand | Meaning | Stated limit |
|---|---|---|---|---|
| E-03 | 5-button LCD | OnTrack Outdoor 5 kW Manual | Ignition plug (glow plug) failure Manual's remedy: Check whether the glow plug is open or short-circuited and whether connectors are loose/oxidised; run from a charged battery rather than a battery charger; check air inlet, outlet and exhaust for debris; leave at least 10 cm gap at the air inlet. | Glow plug should read 0.6-0.8 ohm; voltage across the plug should rise slowly to 8-9 V during start-up; battery should not drop below 12 V during start-up |
| E-03 | 5-button LCD | D2/D4 parking heater (generic manual) Manual | Glow plug fault Manual's remedy: Check whether the glow plug is open-circuit or short-circuit. | Not stated |
| E-03 | 5-button LCD | Hcalory M98 Manual | Glow plug short circuit / open circuit Manual's remedy: Glow plug short-circuited or connection wire reversed; insulation damage at the tail of the plug; glow plug leakage; poor contact at the connector; plug burned out - replace. | Not stated |
| E-03 | Vevor M-button panel | Vevor XMZ-D1 / XMZ-D2 Manual | Ignition plug abnormality Manual's remedy: Check the ignition plug is properly connected; plug faulty - replace; main board faulty - replace. | Not stated |
| E-3 | LCD, E-2 … E-10 | Vevor CY-5001/5002/5004, 5-key and 3-key LCD panels Manual | Ignition plug malfunction Manual's remedy: Check whether the ignition plug connector is loose or the wire is shorted to the casing; check whether the plug is damaged. | Not stated |
| E-3 | LCD, E-2 … E-10 | Gasmate DH203 Manual | Glow plug failure Manual's remedy: Contact service support for inspection or replacement of the glow plug. | Not stated |
| E-3 | LCD, E-2 … E-10 | Liwolf all-in-one Manual | Ignition plug failure Manual's remedy: Check for loose ignition plug connectors or wire shorted to the housing; check whether the plug is damaged. | Not stated |
| E3 | Rotary-switch LCD, E0 … E15 | Heatport H2 / H4 (EnControl) Manual | Undervoltage or overvoltage Manual's remedy: Verify battery voltage at the harness terminals (or at the ECU connector if the harness was extended); if below 12.6 V (flooded) / 12.8 V (AGM) charge the batteries first; overvoltage causes: charger in boost mode, alternator overcharging, solar controller overcharging; check ECU connector for dirt/corrosion; inspect harness; ECU. | Minimum 10.5 V (22.5 V for 24 V unit); maximum 15 V for 12 V version and 30 V for 24 V version |
| E3 | Rotary-switch LCD, E0 … E15 | T4 two-knob LCD switch Manual | Undervoltage or overvoltage Manual's remedy: Verify voltage matches the heater's requirements; check power cord installation and that no non-compliant cords are used; confirm the power converter gives adequate current and stable output. | Not stated |
| E-03 | Knob LCD (Hcalory HC-A01) | Hcalory HC-A01 Manual | Abnormal voltage Manual's remedy: Check the heater's supply voltage type matches the vehicle; check the voltage limits; check the main harness connector is not loose. | 24 V version: not higher than 32 V or lower than 18 V; 12 V version: not higher than 18 V or lower than 9 V |
| E-03 F1 | B2010 (spanner button) | B2010 controller Manual | Glow plug ('spark plug') short circuit | Not stated |
| E-03 F2 | B2010 (spanner button) | B2010 controller Manual | Glow plug ('spark plug') open circuit | Not stated |
| E-03 F3 | B2010 (spanner button) | B2010 controller Manual | Glow plug ('spark plug') abnormality | Not stated |
Why does my heater show E-03?
E-03 is raised by the glow plug circuit. Owners describe it appearing at switch-on or soon after the fan starts, before the heater tries to burn. Owners Causes, most common first:
- The glow plug has failed. The OnTrack, D2/D4, B2010 and Hcalory M98 manuals list a plug that is open circuit or short circuit; the Vevor XMZ manual says only that the plug is abnormal. Manual Three owners in three threads cleared E-03 with a new plug: one after two fault-free years, one on a new heater with under 3 hours of use. Owners
- The plug’s connector or wire. The Hcalory M98 manual lists poor contact at the connector, a reversed wire and damaged insulation at the tail of the plug. The Vevor XMZ manual says to check that the plug is properly connected. Manual
- The driver component on the control board. Two owners traced E-03 to the board. One measured the old and the new plug at 0.6 ohm each, got E-03 even before pressing On, and cured it by replacing the MOSFET that feeds the plug. The other found a burnt MOSFET had damaged the board, and a replacement board fixed it; no plug test is recorded in that report. Owners The Vevor XMZ manual also lists a faulty main board. Manual
- Low voltage during the start. The OnTrack guide says to run from a charged battery, not a battery charger, and that the battery should not drop below 12 V during start-up. Manual One owner in an E-3 thread fixed the start failure with heavier supply wire. Owners
The OnTrack guide adds two installation points under E-03: clear any debris from the air inlet, outlet and exhaust, and leave at least 10 cm (about 4 in) of space at the air inlet. Manual
On the B2010 a sub-code narrows it down: F1 is a short circuit, F2 an open circuit, F3 a plug “abnormality”. Manual See what F1, F2 and F3 mean.
How do I test the glow plug?
- Try one more start. One owner gets E-03 now and then and clears it by disconnecting power. Owners Let the heater finish its shutdown first: the Vevor manual says it needs 3-5 minutes to stop completely. Manual If E-03 comes straight back, go to step 2.
- Watch the supply voltage during the start. If it sags badly, fix that first: see E-01. If it holds, go to step 3.
- Check the glow plug connector. With power off, follow the plug’s lead to its connector. Look for a loose or oxidised connector and for damaged insulation on the wire. Manual Reseat it and try again. If E-03 remains, go to step 4.
- Measure the plug. Disconnect the plug’s lead and put a meter across its two wires. The OnTrack guide says the plug should read 0.6-0.8 ohm. Manual That is that guide’s figure only: one owner measured about 0.3 ohm on working plugs, and another measured 0.6 ohm on both an old and a new plug. Owners No continuity means the plug is open: go to step 5. A plausible low reading means the plug is probably good: go to step 6.
- Replace the glow plug. Removal is covered on cleaning the glow plug and its screen. One owner fitted a generic plug and had to move the old connector across because the connector styles differ. Owners
- Plug good, E-03 still there. The OnTrack guide says the voltage across the plug should rise slowly to 8-9 V during start-up. Manual If the plug tests good and the code appears at once, the two owner reports above point to the board.
If you are not sure, ask a technician. Repairing or replacing the control board goes beyond routine owner maintenance. A mistake here can cause a fuel or exhaust leak. Stop if anything is unclear.
How do I clear E-03 after the repair?
The manuals give no separate reset step for E-03. Start the heater again after the repair. If it will not respond, see how to reset a locked-out heater.
When should I stop?
Stop at the board. Owners replace glow plugs themselves; replacing a component soldered to the main board is a different job. Even a board swap can go wrong: one owner’s first replacement board arrived dead and showed E-06. Owners On a new heater, claim the part from the seller.
Is E-03 the same on other controllers?
Not always. Panels that show E-3 with no leading zero also use it for the ignition plug. But on the rotary-switch LCD of Heatport and T4 heaters E3 is undervoltage or overvoltage, and on the Hcalory HC-A01 knob LCD E-03 is abnormal voltage. Manual Check which controller you have before buying a plug.
Related questions
- Do I need a new glow plug if I get E-03?
- Often, but test first. Three owners cleared E-03 with a new plug. Two others traced it to the component on the control board that powers the plug, and one of them had measured the plug as good. A meter reading across the plug helps tell the two apart.
- What resistance should a diesel heater glow plug read?
- The OnTrack guide gives 0.6-0.8 ohm for its heater. That is one guide's figure. One owner measured about 0.3 ohm on working plugs and another measured 0.6 ohm on both an old and a new plug, so treat an open circuit as the clear failure.
- Why do I get E-03 with a new glow plug?
- Check the connector and the supply voltage during the start. If both are good, two owner reports point to the driver component on the main board, and the Vevor XMZ manual also lists a faulty main board as a cause of E-03.
- E-03 on a brand-new heater: is that normal?
- It happens. One owner's new Vevor showed E-03 with under 3 hours of use and a new glow plug fixed it the same day. On a new unit, ask the seller for the part first.
Where to go next
Sources
Everything on this page is compiled from the documents and discussions below. We summarise them in our own words; follow the links for the originals.
- OnTrack Outdoor: diesel heater troubleshooting guide (PDF) (cdn.shopify.com)
- D2/D4 parking heater 12 V/24 V user manual, Alza import (PDF) (dwn.alza.cz)
- B2010 controller operating manual V1.2 (PDF) (cdn.shopify.com)
- Vevor diesel heater manual, XMZ-D1 / XMZ-D2 (PDF copy) (tuitam.pl)
- Hcalory air heater user manual, M98 (PDF) (cdn.shopify.com)
- Heatport H2 / H4 EnControl user manual v1.00 (PDF) (cdn.shopify.com)
- Hcalory HC-A01 toolbox heater user manual (archived transcription) (web.archive.org)
- Owner report: E03 after two years fixed with a generic glow plug (wildcamping.co.uk forum) (wildcamping.co.uk)
- Owner report: E 03 gone after replacing the plug (drive2.ru) (drive2.ru)
- Owner report: E03 on a new Vevor fixed by a new glow plug (Reddit r/dieselheater) (reddit.com)
- Owner report: E-03 with a good plug traced to the MOSFET on the board (wildcamping.co.uk forum) (wildcamping.co.uk)
- Owner report: E03 from a burnt MOSFET, fixed with a replacement board (Reddit r/dieselheater) (reddit.com)
- Owner report: start failure in an E-3 thread fixed with heavier supply wire (Reddit r/dieselheater) (reddit.com)
- Owner report: occasional E-03 cleared by disconnecting power (Reddit r/dieselheater) (reddit.com)
- Owner report: working glow plugs measured at about 0.3 ohm (Reddit r/dieselheater) (reddit.com)