P0638high severityPowertrain
Throttle Actuator Control Range/Performance (Bank 1)
on 2020 Honda Accord 1.5L I4 Turbo · FWD
What this code means
The PCM detected that the throttle actuator is not responding within the expected range. This can cause reduced power and limp mode.
Symptoms
- Reduced engine power
- Check engine light on
- Erratic or limited throttle response
Common causes
- Faulty throttle body/actuator
- Dirty throttle plate
- Damaged throttle control wiring
- Faulty PCM
Diagnostic steps
- Scan throttle position data
- Inspect and clean throttle body
- Test throttle actuator motor and wiring
- Perform throttle relearn or replace throttle body
🔌 Don't have a code reader?
Any of these will read and clear this code — pick by how deep you want to go.
Budget handheld~$40
ANCEL AD410 →
No-phone-needed handheld — reads, clears, live data, freeze frame.
✓ ANCEL official store
Serious DIY~$100
BlueDriver Pro →
Enhanced codes (ABS, airbag, TPMS) plus repair reports.
SHOP FAVORITEShop-grade tablet~$300
Autel MaxiCOM MK808S →
Bidirectional tests, service resets, all systems.
✓ Autel official store
Pro diagnostics$1,500+
Autel MaxiSys MS906 Pro →
Full-system pro platform — topology mapping, ECU coding, the works.
✓ Autel official store
As an Amazon Associate and Autel/ANCEL partner, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0005
Fuel Shutoff Valve A Control Circuit/Open
P0006
Fuel Shutoff Valve A Control Circuit Low
P0007
Fuel Shutoff Valve A Control Circuit High
P0008
Engine Position System Performance - Bank 1
P0009
Engine Position System Performance - Bank 2
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1