Which motorcycles does code 15-01 apply to?

It is documented here for the Honda CBR600RR (2003-2022). Other Honda models may use the same display code with a different meaning, so confirm against your model.

Can I still ride with code 15-01?

It depends on the fault. Code 15-01 relates to the No.4 primary injector circuit. If the bike runs poorly or a safety-related system is affected, avoid riding until it is checked. The FI light stays on until the fault is fixed and the codes are cleared.

Bonk DTC docs

15-01 Strongly inferred

No.4 primary injector circuit malfunction

The No.4 primary injector circuit did not respond as commanded (open or short). Standard Honda meaning.

Manufacturer: Honda
Platform: PGM-FI (Keihin, Renesas M32R)
Models: CBR600RR
Years: 2003-2022
Subsystem: No.4 primary injector circuit
FI-light blink: 1 long, 5 short
Hex: 0x1501

Saw 15-01 as 1 long, 5 short on the FI light? Decode a blink pattern →

All major 15 codes How blink codes work

Strongly inferred. Strongly inferred: the standard Honda meaning is well established, but exactly how this ECU handles it internally is inferred rather than fully confirmed.

What it means

Same injector-circuit check as 12-01, applied to the No.4 primary injector.

Conditions

Detection conditions

The ECU drives the No.4 injector and checks the circuit responds.

Sets the fault when

The circuit stays open or shorted long enough to count.

Clears the fault when

Fix the underlying problem, then clear the stored codes with a diagnostic tool or the manufacturer’s reset procedure. If the fault is still present, the code returns the next time the ECU detects it.

Parts involved

No.4 primary fuel injector and its wiring

Symptoms & likely causes

Possible symptoms

FI (check-engine) light on
Misfire on that cylinder

Likely causes

Open or shorted injector
Wiring or connector fault

Diagnostic guidance

Test the injector coil and its wiring for opens and shorts.

How the ECU decides

A simplified view of the logic behind this code: a short C snippet with a plain-English summary. It shows the real decision the ECU makes without the low-level detail.

For an output like an injector, coil, or sensor heater, the ECU switches the circuit on and checks that it actually responded. If the circuit is open or shorted for long enough, it sets the code and stops driving that output.

C How an injector / coil / heater circuit sets a code

1// Command the output on, then confirm the circuit responded.
2turn_on(output);
3if (circuit_response(output) == BAD) {   // open or short
4    bad_count++;
5    if (bad_count >= limit)
6        set_fault();
7}

Reverse-engineered interpretation · CBR600RR ECU reverse-engineering analysis

When the ECU confirms a fault, it saves the code and turns on the FI (check-engine) light. For a serious fault it also runs the engine on safe default values (limp-home) so you can still ride, with the light on.

C How a confirmed fault is stored

1// Once a fault is confirmed, remember it and warn the rider.
2if (fault_confirmed) {
3    store_code(code);      // kept until the codes are cleared
4    fi_light = ON;
5    if (fault_is_serious)
6        limp_home = ON;    // safe defaults so you can ride home
7}

Reverse-engineered interpretation · CBR600RR ECU reverse-engineering analysis

Related codes

Questions about code 15-01

What does Honda code 15-01 mean?: The No.4 primary injector circuit did not respond as commanded (open or short). Standard Honda meaning.
Which motorcycles does code 15-01 apply to?: It is documented here for the Honda CBR600RR (2003-2022). Other Honda models may use the same display code with a different meaning, so confirm against your model.
Can I still ride with code 15-01?: It depends on the fault. Code 15-01 relates to the No.4 primary injector circuit. If the bike runs poorly or a safety-related system is affected, avoid riding until it is checked. The FI light stays on until the fault is fixed and the codes are cleared.
What should I check first for code 15-01?: Test the injector coil and its wiring for opens and shorts.

Sources

Every technical claim on this page traces to the research below. Source labels are sanitized; no local research paths are exposed.

firmware

2005-2006 Honda CBR600RR ECU firmware

Factory PGM-FI firmware for the 2005-2006 CBR600RR. Primary source of truth.
analysis

Firmware fault-code table extraction

Reads the list of codes the ECU can store directly out of each firmware.
reference

HondaECU project (open-source Honda ECU tool)

Community reference mapping Honda PGM-FI codes to their meanings.
analysis

CBR600RR ECU reverse-engineering analysis

Independent analysis of how the ECU detects, stores, and reports faults.

Content version 1.0.0 · last reviewed 2026-07-14

Decode a blink pattern All major 15 codes Full DTC index