Frayed or chafed injector harness wire shorting to the engine block or chassis; Failed cylinder 5 fuel injector with an internally shorted solenoid coil; Corroded or water-intruded injector connector pins causing a short; Damaged engine wiring harness near the intake manifold or cylinder head; ECM driver circuit failure for cylinder 5 injector (less common); Aftermarket alarm or remote start wiring tapped into the injector circuit

DTC codes / Volkswagen codes / P1229

P1229 · VolkswagenCylinder 5 Injector Circuit Short To Ground

Q: What does code P1229 mean?

Cylinder 5 Injector Circuit Short To Ground. P1229 on a Volkswagen means the engine control module (ECM) has detected a short to ground on the electrical circuit that fires cylinder 5's fuel injector. The ECM commands the injector on and monitors the circuit, and it sees the voltage stay at or near zero volts when it should pulse, indicating the control wire is touching ground or the injector's internal coil has shorted.

P1229 on a Volkswagen means the engine control module (ECM) has detected a short to ground on the electrical circuit that fires cylinder 5's fuel injector. The ECM commands the injector on and monitors the circuit, and it sees the voltage stay at or near zero volts when it should pulse, indicating the control wire is touching ground or the injector's internal coil has shorted.

SystemPowertrain

Code typeVolkswagen specific

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Check engine light illuminated, often with no other noticeable symptoms
Rough idle or misfire that is most pronounced at idle and low engine speeds
Noticeable loss of power and sluggish acceleration under load
Shaking or vibration from the engine bay, especially when cold
Fuel smell from the exhaust or black smoke if the injector is stuck open
In rare cases, the engine may stall or be hard to start

Common causes, most likely first

Frayed or chafed injector harness wire shorting to the engine block or chassis
Failed cylinder 5 fuel injector with an internally shorted solenoid coil
Corroded or water-intruded injector connector pins causing a short
Damaged engine wiring harness near the intake manifold or cylinder head
ECM driver circuit failure for cylinder 5 injector (less common)
Aftermarket alarm or remote start wiring tapped into the injector circuit

How to diagnose and fix it

Scan all modules and record freeze-frame data to confirm the fault is active and not intermittent
Visually inspect the cylinder 5 injector connector and harness for chafing, corrosion, or loose pins
Disconnect the injector and measure resistance across its terminals; compare to the other injectors
With the injector unplugged and key on, measure voltage on the control wire to ground; a near-zero reading confirms a short
Isolate the harness by wiggling and flexing sections while watching a multimeter or scope on the control wire
Repair or replace the damaged section of harness, then clear the code and verify the injector pulses with a noid light or scope
If the harness and injector test good, check the ECM driver circuit for a short to ground before condemning the ECM

Why cylinder 5 injector shorts are often misdiagnosed

A shorted injector coil can test fine on a basic resistance check when cold, so always compare hot and cold readings against the other injectors.
The harness often rubs through on the metal bracket near the intake manifold, and the short only appears when the engine moves under load.
A short to ground on the injector control wire can be caused by a failed ignition coil or spark plug wire arcing nearby, so inspect the secondary ignition system first.
Some technicians replace the injector only to find the code returns because the ECM driver was damaged by the original short, so always check driver resistance after repair.
P1229 can be set by a low battery or poor ground connection that causes the ECM to see a false short, so verify battery and ground integrity before condemning parts.

Can I keep driving with P1229?

You can drive short distances to a repair shop, but avoid heavy acceleration and long trips because a shorted injector can dump raw fuel into the exhaust and overheat the catalytic converter. If the engine is misfiring badly or you smell fuel, stop driving and have it towed.

Tools that help

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Guidance is general and written for Volkswagen vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.