2001 Chevrolet Corvette ENGINE COOLING Electric Cooling Fans - Cars

Please download to get full document.

View again

of 22
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Information Report
Category:

Internet

Published:

Views: 0 | Pages: 22

Extension: PDF | Download: 0

Share
Related documents
Description
MODEL IDENTIFICATION ENGINE COOLING Electric Cooling Fans - Cars NOTE: For electric cooling fan diagnosis on 2000 Prizm, see appropriate MANUAL A/C-HEATER SYSTEMS article. MODEL IDENTIFICATION
Transcript
MODEL IDENTIFICATION ENGINE COOLING Electric Cooling Fans - Cars NOTE: For electric cooling fan diagnosis on 2000 Prizm, see appropriate MANUAL A/C-HEATER SYSTEMS article. MODEL IDENTIFICATION - CARS Body Code (1) Model C Park Avenue E Eldorado F Camaro & Firebird G Aurora H Bonneville & LeSabre J Cavalier & Sunfire K DeVille & Seville M Metro N Alero, Grand Am & Malibu S Prizm V Catera W Century, Grand Prix, Intrigue, Lumina, Monte Carlo & Regal Y Corvette J Saturn L Series Z Saturn S Series (1) Vehicle body code is fourth character of VIN. DESCRIPTION & OPERATION ELECTRIC COOLING FAN CONTROL All Models Except Catera All FWD and some RWD vehicles use an electric cooling fan. The electric cooling fan is used for radiator and A/C condenser cooling. Cooling fan operates when A/C is on and when engine coolant temperature exceeds a specific value. One or more cooling fan relays may be used. For cooling fan relay location, see COOLING FAN RELAY LOCATION table. COOLING FAN RELAY LOCATION Application C Body E Body K Body F Body G Body H Body J Body N Body W Body Except Lumina Lumina V Body Y Body Metro Prizm Fuse/Relay Block No. 1 Location Right Front Of Engine Compartment, In Fuse/Relay Block Mounted On Lower Radiator Support In Underhood Fuse Block On Right Side Of Engine Compartment In Underhood Electrical Center, On Left Inner Fender Panel In Underhood Fuse Block, On Right Side Of Engine Compartment In Underhood Fuse Block, On Right Side Of Engine Compartment In Underhood Fuse/Relay Block At Left Front Corner Of Engine Compartment In Underhood Junction Block, At Left Side Of Engine Compartment Inside Electrical Center At Right Side Of Engine Compartment Inside Electrical Centers At Right & Left Front Of Engine Compartment In ECM Housing, In Left Front Of Engine Compartment In Underhood Electrical Center In Front Of Battery In Engine Compartment Relay Box Near Battery Left Front Of Engine Compartment, To Left Of Air Cleaner Fuse/Relay Block No. 2 Saturn L Series Saturn S Serires Left Front Of Engine Compartment, To Left Of Battery In Cooling Fan Control Module, Next To Battery In Underhood Fuse Block, In Left Front Of Engine Compartment SCAN TOOL A variety of information is transmitted through Data Link Connector (DLC). This data is transmitted at a high frequency which requires the use of Tech 2 Scan Tool. Other types of scan tools are available and may function and provide adequate information for diagnostic work. Always refer to scan tool manufacturer's instructions. TROUBLE SHOOTING PRELIMINARY INFORMATION This article contains only the text required to test electric cooling fans. Other diagnostic information may be referenced while performing electric cooling fan diagnosis. See appropriate ENGINE PERFORMANCE articles for complete information on engine control systems. Trouble shoot cooling fan using appropriate diagnostic information provided. For cooling fan relay location, see COOLING FAN RELAY LOCATION table. To help save diagnostic time, always check for blown fuses or fusible links before proceeding with any testing. If fuses are blown, locate and repair short circuit before replacing fuses. Ensure all related relay and wire harness connections are clean and tight. Repair as necessary. See WIRING DIAGRAMS for component, terminal and wire color identification. NOTE: Vehicles may be equipped with a PCM/ECM using an Electronically Erasable Programmable Read Only Memory (EEPROM). When replacing PCM/ECM, the new PCM/ECM must be programmed. ELECTRIC COOLING FAN CIRCUIT DIAGNOSIS To help save diagnostic time, check cooling system fluid level, water pump belt condition and tension. Always check for blown fuses or fusible links before proceeding with any testing. If fuses are blown, locate and repair short circuit before replacing fuses. Ensure all related relay and wire harness connections are clean and tight. Repair as necessary. See WIRING DIAGRAMS. 1.0L & 1.3L METRO Description Cooling fan is controlled by Powertrain Control Module (PCM) through cooling fan relay based on inputs from engine coolant temperature sensor. PCM turns on the cooling fan when coolant temperature sensor rises above 208 F (97.5 C) and turns off cooling fan when coolant temperature sensor drops less than 199 F (92.5 C). PCM controls cooling fan motor by grounding cooling fan relay control circuit which closes fan relay contacts. Diagnosis WARNING: Vehicles may be equipped with a PCM using an Electronically Erasable Programmable Read Only Memory (EEPROM). When replacing PCM, new PCM must be programmed. 1. Install scan tool. Turn ignition on, engine off. Verify ECT sensor reading is less than 194 F (90 C). If cooling fan is not operating, go to next step. If cooling fan is operating, go to step Turn ignition on, engine off. Using scan tool, clear DTCs. Command fan on and then off. If cooling fan operated when commanded on and shut off when commanded off, go to DIAGNOSTIC AIDS. If fan did not operate when commanded on and shut off when commanded off, go to step 7 3. Ensure ECT is less than 194 F (90 C). Disconnect cooling fan relay located in relay box near battery. If cooling fan is not operating, go to next step. If cooling fan is operating, go to step Using test light connected to battery voltage, probe cooling fan relay connector cavity No. 2 (Blue wire). If test light illuminates, go to step 6. If test light does not illuminate, go to step Repair short to power in Blue or Blue/Red wire between cooling fan relay and cooling fan motor. See WIRING DIAGRAMS. After repairs, go to step Check for short to ground in Blue wire between PCM and cooling fan relay. repair as necessary. After repairs, go to step 19. If repair was not necessary, go to step Turn ignition on. Using test light connected to ground, probe cooling fan relay cavity No. 1 (Black/White wire). If test light illuminates, go to next step. If test light does not illuminate, go to step Using test light connected to ground, probe cooling fan relay cavity No. 4 (Black/Blue wire). If test light illuminates, go to next step. If test light does not illuminate, go to step Connect a fused jumper between cooling fan relay connector cavities No. 3 (Blue/Red wire) and No. 4 (Black/White wire). If cooling fan operates, go to next step. If cooling fan does not operate, go to step Using test light connected to battery voltage, probe cooling fan connector cavity No. 2 (Blue wire). Using scan tool, command cooling fan on. If test light illuminates, go to step 16. If test light does not illuminate, go to next step. 11. Check for open in Blue wire between PCM and cooling fan relay. Repair as necessary. After repairs, go to step 19. If repair was not necessary, go to step Check for open in Blue or Blue/Red wire between cooling fan relay and cooling fan motor. Repair as necessary. See WIRING DIAGRAMS. After repairs, go to step 19. If repair was not necessary, go to next step. 13. Check for open or poor terminal contact in Black wire between cooling fan motor and ground. Repair as necessary. After repairs, go to step 19. If repair was not necessary, go to step Repair open in Black/White wire between cooling fan relay terminal No. 1 and junction block. After repairs, go to step Repair open in Black/Blue wire between cooling fan relay terminal No. 4 and fuse box. After repairs, go to step Replace cooling fan relay. After repairs, go to step Replace PCM. After repairs, go to step Replace cooling fan motor. After repairs, go to next step. 19. Using scan tool, clear any DTCs and road test vehicle within freeze frame conditions that caused DTC to set. If any DTCs set, go to appropriate DTC. See appropriate SELF- DIAGNOSTICS article in ENGINE PERFORMANCE. If no DTCs are stored, system is okay at this time. Diagnostic Aids Whenever vehicle owner complains of an overheating problem, determine if complaint was due to an actual boilover, or TEMP light or gauge indicated overheating. Whenever gauge or light indicates overheating, but no boilover is detected, gauge or light circuit should be checked. Gauge accuracy can also be checked by comparing engine coolant temperature sensor reading with gauge reading. If engine is actually overheating, and gauge indicates overheating, but cooling fan is not coming on, ECT sensor has probably shifted out of calibration and should be replaced. Whenever engine is overheating and cooling fan is on, cooling system should be checked. 1.8L PRIZM NOTE: For electric cooling fan diagnosis on 2000 Prizm, see appropriate MANUAL A/C-HEATER SYSTEMS article. Description Engine cooling fan system consists of 2 electric cooling fans and 3 fan relays. Relays are arranged in a series/parallel configuration that allows Powertrain Control Module (PCM) to operate both fans together at low or high speeds. Cooling fans and fan relays receive battery voltage on 2 individual power circuits, from fuse and relay block 1 and from junction block 2. During high speed operation, which is when ECT reaches 199 F (93 C) or A/C system pressure exceeds 220 psi, PCM removes ground for fan 1 and fan 2 relays through cooling fan relay control circuit. This de-energizes fan 2 relay which switches relay contacts and provides a ground path for auxiliary fan motor. At the same time, fan 1 relay is de-energized, closing relay contacts and providing battery voltage on main fan motor supply voltage circuit to main fan motor. During low speed operation, which is when A/C is operating and Engine Coolant Temperature (ECT) is less than 181 F (83 C), PCM supplies ground path for fan 1 and fan 2 relays through cooling fan relay control circuit. This energizes both relays, opens fan 1 relay contacts and switches contacts in fan 2 relay. Engine main relay supplies battery voltage through cooling fan motor supply voltage circuit to auxiliary fan motor. When A/C is operating, compressor clutch (MG) relay energizes fan 3 relay. Ground path for auxiliary fan motor is through switched contacts in fan 2 relay, through closed contacts of fan 3 relay and through main fan motor to ground. Result is a series circuit with both fans running at low speed. During high speed fan operation, both engine cooling fans have their own power and ground path. Result is a parallel circuit with both fans running at high speed. A/C high pressure switch is in series with PCM controlled ground for coils of fan 1 and fan 2 relays. If A/C system pressure exceeds 220 psi, pressure switch opens ground circuit to coils of fan 1 and 2 relays. This has same effect as if PCM had removed ground for relays. PCM will control ground for fan relays based on input from ECT sensor in order to maintain cooling system at normal operating temperature. Main and auxiliary fan motors run at half speed in series configuration when all of the following conditions occur: A/C system is operating. A/C system pressure is less than 178 psi. ECT is less than 181 F (83 C). Main and auxiliary fan motors run at full speed in parallel configuration when either of the following conditions occur: ECT reaches 199 F (93 C). A/C system pressure exceeds 220 psi. Main Cooling Fan Inoperative 1. Review DESCRIPTION, and then go to next step. 2. Run engine until operating temperature is reached and thermostat opens. If cooling fans operate, problem is intermittent. If cooling fans do not operate, go to next step. 3. Exchange fan 1 relay with known good relay (fan 3 relay, A/C MG relay, or horn relay). If problem was found, repair as necessary. After repairs, go to step 14. If problem was not found, go to next step. 4. Stop engine. Disconnect main fan motor connector. Connect test light across main fan motor connector. Start engine. If test light illuminates, go to step 12. If test light does not illuminate, go to next step. 5. Check main fan motor ground circuit (White/Black wire) for open. If problem was found, repair as necessary. After repairs, go to step 14. If problem was not found, go to next step. 6. Check main fan motor supply voltage circuit (Black/Red wire) for open. If problem was found, repair as necessary. After repairs, go to step 14. If problem was not found, go to next step. 7. Check supply voltage circuit to fuse and relay block 1 for open. If problem was found, repair as necessary. After repairs, go to step 14. If problem was not found, go to next step. 8. Check fan 1 relay switch supply voltage circuit for open. If problem was found, repair as necessary. After repairs, go to step 14. If problem was not found, go to next step. 9. Check engine main relay switch supply voltage circuit for open. If problem was found, repair as necessary. After repairs, go to step 14. If problem was not found, go to next step. 10. Check engine main relay control circuit (Black/Yellow wire) for open. If problem was found, repair as necessary. After repairs, go to step 14. If problem was not found, go to next step. 11. Remove fuse and relay block 1 from inner fender. Repair poor connections or high resistance in fuse and relay block 1 connectors. After repairs, go to step Check main fan motor connector for poor connections. If problem was found, repair as necessary. After repairs, go to step 14. If problem was not found, go to next step. 13. Replace main fan motor. After repairs, go to next step. 14. Operate system to verify repair. 1. Review DESCRIPTION, and then go to next step. 2. Connect scan tool. Ensure engine is less than operating temperature. Move blower speed switch to any position except OFF. Depress A/C switch to ON position. Using scan tool, command A/C compressor clutch (MG) relay on. When MG relay is energized, cooling fans will also turn on at low speed. If cooling fans operate at low speed, problem is intermittent. If cooling fans do not operate at low speed, go to next step. 3. Exchange fan 3 relay with a known good relay (fan 1 relay, A/C MG relay or horn relay). If cooling fans operate at low speed, go to step 8. If cooling fans do not operate at low speed, go to next step. 4. Check fan 3 relay coil supply voltage circuit (Black/White wire) for open. If problem was found, repair as necessary. After repairs, go to step 9. If problem was not found, go to next step. 5. Check fan 3 relay coil ground circuit (White/Black wire) for open. If problem was found, repair as necessary. After repairs, go to step 9. If problem was not found, go to next step. 6. Check White/Red wire between fan 3 relay and fan 2 relay for open. If problem was found, repair as necessary. After repairs, go to step 9. If problem was not found, go to next step Chevrolet Corvette Auxiliary Cooling Fan Inoperative 1. Review DESCRIPTION, and then go to next step. 2. Run engine until operating temperature is reached and thermostat opens. If cooling fans operate, problem is intermittent. If cooling fans do not operate, go to next step. 3. Stop engine. Disconnect auxiliary fan motor connector. Connect test light across auxiliary fan motor connector. Start engine. If test light illuminates, go to step 7. If test light does not illuminate, go to next step. 4. Check auxiliary fan motor supply voltage circuit (Blue/Red wire) for open. If problem was found, repair as necessary. After repairs, go to step 9. If problem was not found, go to next step. 5. Remove fan 2 relay from fuse and relay block 2. Check White wire between auxiliary fan motor and fan 2 relay for open. If problem was found, repair as necessary. After repairs, go to step 9. If problem was not found, go to next step. 6. Replace fan 2 relay. After repairs, go to step Check auxiliary fan motor connector for poor connections. If problem was found, repair as necessary. After repairs, go to step 9. If problem was not found, go to next step. 8. Replace auxiliary fan motor. After repairs, go to next step. 9. Operate system to verify repair. Cooling Fan Inoperative At Low Speed 1. Review DESCRIPTION, and then go to next step. 2. Ensure Engine Coolant Temperature ECT is less than 199 F (93 C). Depress A/C switch to OFF position. Turn blower switch to OFF position. Turn ignition switch on. If only main fan motor is running continuously, go to step 4. If not only main fan motor is running continuously, go to next step. 3. If only auxiliary fan motor is running continuously, go to step 8. If both fans are running continuously, go to step Remove fan 1 relay from fuse and relay block 1. If main fan motor runs, go to next step. If main fan motor does not run, go to step Repair short to voltage in main fan motor supply voltage circuit (Black/Red wire). After repairs, go to step Check fan 1 relay control circuit (Blue/Black wire) for open. If problem was found, repair as necessary. After repairs, go to step 17. If problem was not found, go to next step. 7. Replace fan 1 relay. After repairs, go to step Remove fan 2 relay from fuse and relay block 2. If auxiliary fan motor runs, go to next step. If auxiliary fan motor does not run, go to step Repair short to ground in White wire between auxiliary fan motor and fuse and relay block 2. After repairs, go to step Replace fan 2 relay. After repairs, go to step Remove fan 3 relay from fuse and relay block 2. If both fan motors run, go to next step. If both fan motors do not run, go to step Check fan 2 relay control circuit (Blue/Black wire), including A/C refrigerant pressure switch, for open. If problem was found, repair as necessary. After repairs, go to step 17. If problem was not found, go to next step. 13. Check ECT sensor for incorrect performance or for incorrect input to PCM. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If ECT sensor is operating correctly, replace PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to step Check A/C MG relay for continuity between terminals No. 3 (Black/White wire) and No. 5 (Blue/Red wire). Check fan 3 relay for continuity between terminals No. 3 (White/Red 2001 Chevrolet Corvette 7. Repair open in fan 3 relay switch supply voltage circuit (White wire). After repairs, go to step Replace fan 3 relay. After repairs, go to next step. 9. Operate system to verify repair. Cooling Fan Operates Continuously 1. Connect scan tool. Turn ignition on, engine off. Using scan tool, command cooling fan relay on and off. If cooling fan motor follows command, problem is intermittent. If cooling fan motor does not follow command, go to next step. 2. Remove cooling fan relay from underhood fuse block. Connect jumper wire between left rear and right front terminals of relay connector or install known good relay. If cooling fan runs, check relay connector. If connector is good, replace relay. If cooling fan does not run, go to next step. 3. Reinstall cooling fan relay. Disconnect cooling fan motor. Connect test light between terminals of cooling fan motor harness connector. Using scan tool, command cooling fan relay on. If test light is on, check cooling fan motor connector. If connector is good, replace cooling fan motor. If test light is not on, go to next step. 4. Connect test light between cooling fan connector terminal B (Light Blue wire) and 2001 Chevrolet Corvette wire) and No. 5 (White wire). If continuity exists in either relay, go to next step. If continuity does not exist in either relay, go to step Replace faulty relay. After repairs, go to step Repair short to voltage in fan 3 relay coil supply voltage circuit (Black/White wire). After repairs, go to next step. 17. Operate system to verify repair. 1.9L SATURN S SERIES Description A fan control relay is used by Powertrain Control Module (PCM) to control engine cooling fan operation. Engine cooling fan is turned on or off by PCM dependent upon engine coolant temperature, vehicle speed or A/C request. Under high ambient temperatures, fan may run up to 4 minutes with key off. Under normal operating conditions, cooling fan motor operates whenever Engine Coolant Temperature (ECT) is greater than 222 F (106 C) or A/C relay is comm
Recommended
Engine Cooling

Engine Cooling

16 pages

View more...
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks