TP sensor circuit high voltage
The throttle position sensor read too high, as if its circuit is open or shorted to the reference. This is the standard Honda meaning for the code.
- Manufacturer
- Honda
- Platform
- PGM-FI (Keihin, Renesas M32R)
- Models
- CBR600RR
- Years
- 2003-2022
- Subsystem
- TP (throttle position) sensor
- FI-light blink
- 8 short
- Hex
- 0x0802
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 throttle sensor check as 08-01, but the signal sat too high, the pattern of an open circuit or a short to the reference voltage.
Conditions
Detection conditions
- The ECU reads the throttle position sensor against a normal range.
Sets the fault when
- The signal stays above the high limit long enough to rule out brief noise.
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
- Throttle position (TP) sensor
- Its signal, ground, and reference wiring
Symptoms & likely causes
Possible symptoms
- FI (check-engine) light on
- Poor throttle response, since a default throttle value is used
Likely causes
- Open TP signal or ground wire
- TP signal shorted to the reference voltage
- Failed TP sensor
Diagnostic guidance
Diagnose as a high-voltage throttle-sensor circuit fault: check for an open or a short to reference.
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.
The ECU checks each sensor against a normal high and a normal low value. A brief spike is ignored; only a reading that stays out of range long enough counts as a real fault. Too low sets the "-01" (low) code, too high sets the "-02" (high) code.
// A sensor reading outside its normal band, held long enough to be real.
if (reading < low_limit || reading > high_limit) {
bad_count++; // ignore brief electrical noise
if (bad_count >= limit)
set_fault(); // low -> "-01", high -> "-02"
} else {
bad_count = 0; // back in range: no fault
}
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.
// Once a fault is confirmed, remember it and warn the rider.
if (fault_confirmed) {
store_code(code); // kept until the codes are cleared
fi_light = ON;
if (fault_is_serious)
limp_home = ON; // safe defaults so you can ride home
}
Related codes
Questions about code 08-02
- What does Honda code 08-02 mean?
- The throttle position sensor read too high, as if its circuit is open or shorted to the reference. This is the standard Honda meaning for the code.
- Which motorcycles does code 08-02 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 08-02?
- It depends on the fault. Code 08-02 relates to the TP (throttle position) sensor. 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 08-02?
- Diagnose as a high-voltage throttle-sensor circuit fault: check for an open or a short to reference.
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.