Subaru 1983 – 1988 Carbureted models DTC 21 – Ignition pulse system (1983 only)/coolant temperature sensor or circuit (1983 to 1985 carbureted)
DTC 21 meaning on Subaru 1983 – 1988 Carbureted models
DTC 21 refers to the Ignition Pulse System (1983 only) or Coolant Temperature Sensor or Circuit (1983 to 1985 carbureted) on Subaru vehicles manufactured between 1983 and 1988. This diagnostic trouble code indicates a fault related to the ignition pulse system or the coolant temperature sensor/circuit.
Subaru 1983 – 1988 Carbureted models DTC 21 symptoms
Common symptoms of DTC 21 on Subaru 1983 – 1988 Carbureted models may include:
- Engine misfires or rough idling
- Poor fuel efficiency
- Difficulty starting the engine
- Engine overheating
Subaru 1983 – 1988 Carbureted models DTC 21 causes
The potential causes of DTC 21 on Subaru 1983 – 1988 Carbureted models include:
- Faulty ignition pulse system components
- Malfunctioning coolant temperature sensor
- Wiring or connection issues in the circuit
Subaru 1983 – 1988 Carbureted models DTC 21 seriousness
DTC 21 can lead to poor engine performance, reduced fuel efficiency, and potential overheating issues if left unresolved. It is important to address this code promptly to prevent further damage to the vehicle.
How to diagnose DTC 21 on Subaru 1983 – 1988 Carbureted models
Diagnosing DTC 21 on Subaru 1983 – 1988 Carbureted models involves:
- Using a scan tool to retrieve the trouble codes
- Inspecting the ignition pulse system components
- Testing the coolant temperature sensor and circuit for proper operation
- Checking the wiring and connections for any signs of damage
How to fix DTC 21 on Subaru 1983 – 1988 Carbureted models
To fix DTC 21 on Subaru 1983 – 1988 Carbureted models, you may need to:
- Replace faulty ignition pulse system components
- Replace the malfunctioning coolant temperature sensor
- Repair any wiring or connection issues in the circuit
- Clear the trouble codes after the repairs have been completed
How to erase DTC 21 on Subaru 1983 – 1988 Carbureted models
To erase DTC 21 on Subaru 1983 – 1988 Carbureted models, you can clear the trouble codes using a scan tool or by disconnecting the battery for a few minutes. Once the codes are cleared, ensure that the underlying issue has been addressed to prevent the code from reappearing.
Recommended tools for Subaru 1983 – 1988 Carbureted models diagnostics
Explore our expert picks: The Best OBD2 Scanners for 2025
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.