Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSVOLVO1991240 L4-2.3L SOHC VIN 88 B230FREPAIR AND DIAGNOSISPOWERTRAIN MANAGEMENTCOMPUTERS AND CONTROL SYSTEMSCOOLANT TEMPERATURE SENSOR/SWITCH (FOR COMPUTER)TESTING AND INSPECTIONFUEL INJECTION
1991 Volvo 240 L4-2.3L SOHC VIN 88 B230F
Fuel Injection
1991 Volvo 240 L4-2.3L SOHC VIN 88 B230FSECTION Fuel Injection
TESTING PROCEDURE:
NOTE: While trouble shooting, always check the wiring, fuses and connectors for good condition and routing. Use the wiring diagrams found in CHASSIS ELECTRICAL DIAGRAMS to supplement your testing efforts.
1. Turn ignition OFF.
2. Access fuel injection ECU by removing the passenger side kick panel and glove compartment.
3. Check fuel injection ECU ground connections. They should make good contact and fit tight.
4. Remove ECU connector by pressing up the latch and folding out the wire cluster.
5. Remove connector protective sleeve.
IMPORTANT: ^ Never check connections from the front. Connectors can get damaged and worsen the problem.
^ Check connections through the holes in the connector.
^ Connection pin numbers are printed on the connector side.
6. Check temperature sensor by connecting an ohm meter between ground and ECU connector pin 13.
7. Resistance depending on coolant temperature should be (also see chart):
-10°C (14°F) 8,260 - 10,560 ohms
+20°C (68°F) 2,280 - 2,720 ohms
+80°C (176°F) 290 - 364 ohms
8. If a fault occurs, measure at coolant temperature sensor to see if the sensor or the wiring is the problem.
a. If reading is the same at the sensor, replace sensor and retest.
b. If reading at sensor is correct, check wiring and ground connection at intake manifold.
9. After testing, disconnect all test equipment, reconnect all connectors (including the ECU connector) and remount all panels.
NOTE: While trouble shooting, always check the wiring, fuses and connectors for good condition and routing. Use the wiring diagrams found in CHASSIS ELECTRICAL DIAGRAMS to supplement your testing efforts.
Fuel Injection, Ignition Control Unit (ECU) And System Relay:
1. Turn ignition OFF.
2. Access fuel injection ECU by removing the passenger side kick panel and glove compartment.
3. Check fuel injection ECU ground connections. They should make good contact and fit tight.
Disconnecting ECU Connector:
4. Remove ECU connector by pressing up the latch and folding out the wire cluster.
Removing Protective Sleeve:
5. Remove connector protective sleeve.
IMPORTANT: ^ Never check connections from the front. Connectors can get damaged and worsen the problem.
^ Check connections through the holes in the connector.
^ Connection pin numbers are printed on the connector side.
Testing ECU Pin 13:
6. Check temperature sensor by connecting an ohm meter between ground and ECU connector pin 13.
Coolant Temperature Resistance Chart:
7. Resistance depending on coolant temperature should be (also see chart):
-10°C (14°F) 8,260 - 10,560 ohms
+20°C (68°F) 2,280 - 2,720 ohms
+80°C (176°F) 290 - 364 ohms
8. If a fault occurs, measure at coolant temperature sensor to see if the sensor or the wiring is the problem.
a. If reading is the same at the sensor, replace sensor and retest.
b. If reading at sensor is correct, check wiring and ground connection at intake manifold.
9. After testing, disconnect all test equipment, reconnect all connectors (including the ECU connector) and remount all panels.
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.