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Engine Cooling Fan - Deville, Eldorado & Seville Cadillac Eldorado X

Cooling Fan 24 illustrations ~2545 words

DESCRIPTION & OPERATION

WARNINGTo avoid the danger of being burned, do not remove the coolant recovery reservoir cap while the engine and radiator is still hot. Scalding fluid and steam may be blown out under pressure. Check the engine coolant level visually in the "see-through"reservoir. The level should be at or above the "FULL COLD" mark on the tank when the engine is cold. At normal operating temperatures the engine coolant level should be above the "FULL COLD" mark on the tank.
WARNINGVehicles are equipped with air bag supplemental restraint system. Before attempting any repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in appropriate AIR BAG RESTRAINT SYSTEMS article.
CAUTIONWhen battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.

The cooling system utilizes 2 plastic fans. The fans are driven by individual electric motors which are controlled electrically by the Powertrain Control Module (PCM). Fan speed is variable and is controlled based on engine coolant, transmission and A/C high-pressure refrigerant temperature.

CIRCUIT DESCRIPTION

When the PCM commands low speed fan operation it grounds Cooling Fan Relay 1 which allows current to flow through both cooling fans in a series circuit to ground. If the PCM commands high speed fan operation it grounds all the cooling fan relays, including Fan Relay 1, which changes the circuit to a parallel circuit to ground. If a fault occurs, certain symptoms will occur due to the series/parallel circuit design.

The PCM will command low speed fan operation when engine coolant temperature exceeds approximately 106°C (229°F), transmission fluid temperature exceeds 150°C (302°F) or A/C operation is requested.

The PCM will command High Speed Fan Operation when engine coolant temperature reaches 112°C (234°F), transmission temperature is more than 151°C (304°F) or when certain DTCs set.

The fans will switch from high to low (except DTCs set) when the coolant drops below 106°C (229°F). The fans will switch from low to OFF when the coolant drops below 102°C (216°F).

The fans will stay ON for approximately 3 minutes after the vehicle is shut OFF when the coolant temperature at key-off is more than 151°C (304°F) and system voltage was more than 12 volts.

ENGINE COOLANT TEMPERATURE SENSOR

The Engine Coolant Temperature sensor is a thermistor, a sensor whose resistance varies with temperature. The ECT sensor signal is on CKT 410 and sensor ground on CKT 808. As the temperature of the sensor increases, resistance decreases. For a list of resistance values at a given temperature, see ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE TEST table under COMPONENT TESTS.

The Engine Coolant Temperature sensor circuit uses two pull-up resistors for temperature sensing. When sensor resistance is high indicating low temperatures the PCM uses a 3.65 k/ohms resistor and a 348 ohms resistor in series. As temperature increases to 50°C (122°F), the sensor resistance will decrease to 973 ohms. This resistance corresponds to 0.97 volt at the PCM. At this point the PCM shifts to the single 348 ohms pull-up resistor to measure temperature above 50°C (122°F).

DTCs will set if the PCM detects a failure in the ECT circuit. See TESTS W/CODES article in ENGINE PERFORMANCE.

COMPONENT LOCATIONS

ComponentLocation
Engine Compartment Fuse/Relay CenterLeft Of Engine Compartment, Near The Front Strut Tower. (Scheme 1)
Cooling Fan Motor, (Left)Behind Left Side Of Radiator. (Scheme 2)
Cooling Fan Motor, (Right)Behind Right Side Of Radiator. (Scheme 2)
Cooling Fan 1 RelayIn Center Front Of engine Compartment, On The Lower Radiator Support, Near The Cooling Fans. (Scheme 2)
Cooling Fan 2 RelayIn Center Front Of engine Compartment, On The Lower Radiator Support, Near The Cooling Fans. (Scheme 2)
Cooling Fan 3 RelayIn Center Front Of engine Compartment, On The Lower Radiator Support, Near The Cooling Fans. (Scheme 2)
Engine Compartment Fuse/Relay CenterForward Of Left Front Strut Tower. (Scheme 1)
Engine Coolant Temperature SensorAt Left Rear Corner Of Engine, Below The EGR Valve. (Scheme 3)
Powertrain Control Module (PCM)In Left Front Corner Of Engine Compartment, Under Air Filter Housing.
Right Maxi(R) Fuse BlockForward Of Left Front Strut Tower, Near engine Compartment Fuse/Relay Center. (Scheme 1)
G107At Lower Left Front Of Engine, Below Thermostat Housing. (Scheme 4)
S117In Engine Harness, Approximately 34 cm From Right Engine Cooling Fan Connector. (Scheme 2)
S118In Engine Harness Approximately 16.5 cm From PCM Connector Breakout. (Scheme 4)
S129In engine Harness Approximately 4 cm from C129 Connector Breakout. (Scheme 2)
S130In Engine Harness, Approximately 6.5 cm From Electronic Brake Traction Control Module (EBTCM) Connector Breakout. (Scheme 2)

COMPONENT LOCATIONS

Scheme 1

Scheme 1
Scheme 1

Scheme 2

Scheme 2
Scheme 2

Scheme 3

Scheme 3
Scheme 3

Locating Ground G107 & Splice S118. Scheme 4

Scheme 4: Locating Ground G107 & Splice S118
Scheme 4: Locating Ground G107 & Splice S118

COOLING FAN DIAGNOSIS (FUNCTIONAL CHECK)

If DTC P1660 is set, or sets during the functional check, it must be diagnosed before proceeding with any of the symptom tables. See DTC P1660 - COOLING FAN CONTROL CIRCUITS under DIAGNOSTIC TESTS.

If the cooling fans operate when commanded OFF and DTC P1660 is not set, either a cooling fan relay is stuck ON or a cooling fan circuit is shorted to power.

Whenever a repair is completed, repeat the COOLING FAN DIAGNOSIS (FUNCTIONAL CHECK). This will help diagnose possible multiple failures, an example would be 2 relays contaminated by water.

Diagnostic Aids

A DTC that has been cleared will not reset if the conditions that were present when the DTC set, no longer exist. Sometimes with the help of a snapshot on DTC set data or information from the driver, the problem may still be identified or at least narrowed down to a short list of possible intermittent failures. This may explain what to look for and which direction to head in looking for an intermittent failure.

Test step(s) below refer to number(s) on ELECTRIC COOLING FAN DIAGNOSIS (FUNCTIONAL CHECK). (Scheme 5)and (Scheme 6). For COOLING FAN SYMPTOM TABLES 1-5 (Scheme 7)- (Scheme 13).

Test Step No. 1

Perform the ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See BASIC TESTING article in ENGINE PERFORMANCE. System check must be performed first so that any mis-diagnosis is avoided, due to the PCM commanding the fans on due to a present DTC, etc. (Scheme 5)

Test Step No. 2

Test step is checking to see if there is a fault on the cooling fan relay control circuits. (Scheme 5)

Test Step No. 3

Test step checks if any A/C DTCs will set. If A/C DTCs set they must be diagnosed before proceeding with the SYSTEM OPERATION CHECK. See appropriate AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING or TESTS W/CODES article in ENGINE PERFORMANCE.

Test Step No. 4

Test step commands fans on in sequence to determine the symptom (fault-if any) is present. (Scheme 5)

Scheme 5

Scheme 5: Test Step No. 4
Scheme 5: Test Step No. 4

Scheme 6

Scheme 6
Scheme 6

Scheme 7

Scheme 7
Scheme 7

Scheme 8

Scheme 8
Scheme 8

Scheme 9

Scheme 9
Scheme 9

Scheme 10

Scheme 10
Scheme 10

Scheme 11

Scheme 11
Scheme 11

Scheme 12

Scheme 12
Scheme 12

Scheme 13

Scheme 13
Scheme 13

SELF-DIAGNOSTIC SYSTEM

Note. Use of Tech 1 scan tool is required to retrieve DTCs. Refer to user reference manuals supplied with scan tool.

RETRIEVING DIAGNOSTIC TROUBLE CODES

Note. Before connecting scan tool to vehicle, diagnostic system should be checked to determine if system is operating properly and if information received will be accurate. This is done by performing ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See BASIC TESTING article in ENGINE PERFORMANCE. If vehicle does not pass OBD system check, information received may be invalid.

CLEARING DIAGNOSTIC TROUBLE CODES

To clear DTCs from memory, either to determine if malfunction will occur again or after making necessary repairs, disconnect power supply to PCM/VCM for at least 30 seconds or clear codes using a scan tool.

DIAGNOSTIC TROUBLE CODE DEFINITIONS

DTC (1)Description
P1660Cooling Fan Control Circuits
(1) Perform appropriate test under DIAGNOSTIC TESTS . Codes listed in this table are only for testing covered in this article. For a complete list of codes, see SELF-DIAGNOSTICS, TESTS W/CODES under ENGINE PERFORMANCE.
(1)Perform appropriate test under DIAGNOSTIC TESTS . Codes listed in this table are only for testing covered in this article. For a complete list of codes, see SELF-DIAGNOSTICS, TESTS W/CODES under ENGINE PERFORMANCE.

DIAGNOSTIC TROUBLE CODE DEFINITIONS

DTC P1660: COOLING FAN CONTROL CIRCUITS

Note. For circuit reference, see appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

PCM Quad Driver Module (QDM) provides 4 switchable ground outputs for operating solenoids, relays, warning lights, and other devices. Each of these ground outputs has an internal fault line that feed back to the PCM. When the output is off, the QDM should receive 12 volts fed to the solenoids, relays, etc. When the output is switched on the QDM should receive zero volts, since it is grounding the output. If the QDM receives zero volts when the output is off or 12 volts when the output is on, it sets the fault line low. The fault line of the cooling fan control relay output is monitored by DTCs.

Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) System Check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See «BASIC TESTING»(/cadillac/eldorado/x-1992-2002/remont/testing-diagnostics/#engine-controls-basic-engine-testing-46l) article in ENGINE PERFORMANCE. After OBD system check is performed, go to next step.
  2. Turn ignition on. Turn A/C controls off. Using scan tool in MISC TESTS select OUTPUT TESTS, then select FAN RELAYS. Note QUAD DRIVER 1 display and command ALL RELAYS off. If scan tool display indicates OK, go to next step. If scan tool display does not indicate OK, go to step 8.
  3. In MISC TESTS, select OUTPUT TESTS, then select FAN RELAYS. Note QUAD DRIVER 1 display and ALL RELAYS on. If scan tool display indicates OK, go to next step. If scan tool display does not indicate OK, go to step 5.
  4. If a cooling fan is inoperative or if a fault is suspected, perform COOLING FAN DIAGNOSIS (FUNCTIONAL CHECK). See «COOLING FAN DIAGNOSIS (FUNCTIONAL CHECK)»(/cadillac/eldorado/x-1992-2002/remont/cooling-fan/#engine-cooling-fan-deville-eldorado-seville__cooling-fan-diagnosis-functional-check) under TROUBLE SHOOTING. If cooling fans operate, fault is not present.
  5. While noting QUAD DRIVER 1 display, command FAN RELAY 1 on. If scan tool display indicates OK, go to step 7. If scan tool display does not indicate OK, go to next step.
  6. Store fluid life index as indicated on scan tool. Turn ignition to LOCK position and wait 30 seconds, then disconnect PCM harness connector C2. (Scheme 14) Remove fan relay 1 (low speed). Using DVOM, check voltage between ground and cooling fan low speed control circuit at PCM harness connector terminal No. 32 (Dark Green wire). If voltage reading is.5 volt or less, go to step 18. If voltage is more than.5 volt, go to step 16.
  7. Store fluid life index as indicated on scan tool. Turn ignition switch to LOCK position and wait 30 seconds, then disconnect PCM harness connector C2. Remove fan relays 2 and 3. Using DVOM, check voltage between ground and cooling fan high speed control circuit at PCM harness connector terminal No. 33 (Dark Blue wire). If voltage reading is.5 volt or less, go to step 18. If voltage is more than.5 volt, go to step 17.
  8. With ALL RELAYS still commanded off, observe operation of both cooling fans. If either fan is operating, go to next step. If neither fan is operating, go to step 10.
  9. Store fluid life index as indicated on scan tool. Turn ignition switch to LOCK position. Wait 30 seconds, then disconnect PCM harness connector C2. (Scheme 14) Turn ignition on. Using DVOM, check voltage between ground and cooling fan low speed control circuits at PCM harness connector terminal No. 32 (Dark Green wire). If voltage reading is less than 10 volts, go to step 15. If voltage is 10 volts or more, go to step 14.
  10. Store fluid life index as indicated on scan tool. Turn ignition to LOCK position and wait 30 seconds, then disconnect PCM harness connector C2. Turn ignition on. Using DVOM, check voltage between ground and cooling fan high (terminal No. 33 Dark Blue Wire) and low speed (terminal No. 32 Dark Green wire) control circuits at PCM harness connector. If voltage reading is 10 volts or more, go to step 18. If voltage is less than 10 volts, go to next step.
  11. If voltage reading from step 9 is low for both terminals, go to step 13. If voltage reading from step 9 is only low for one of the terminals, go to next step.
  12. Repair open in circuit or replace fan relay for the circuit that measured low.
  13. Repair cause of no voltage to both circuits. Replace fuse if blown.
  14. Repair short to ground in cooling fan high speed control circuit.
  15. Repair short to ground in cooling fan low speed control circuit.
  16. Repair short to voltage in cooling fan low speed control circuit.
  17. Repair short to voltage in cooling fan high speed control circuit.
  18. Check terminal contact at PCM. Repair as necessary. If terminal contact is okay, go to next step.
  19. Replace PCM. Program replacement PCM using required equipment.

Scheme 14

Scheme 14
Scheme 14

If a coolant sensor-related diagnostic trouble code is present, see TESTS W/CODES article in ENGINE PERFORMANCE.. An out-of-calibration sensor may not set a diagnostic trouble code. To test sensor calibration, disconnect ECT sensor connector. Measure resistance between sensor terminals. Resistance should be high when engine is cold and drop as engine warms. See ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE table. If resistance is not as specified, replace sensor.

Temperature °F (°C)Ohms
212 (100)177
194 (90)241
176 (80)332
158 (70)467
140 (60)667
122 (50)973
113 (45)1188
104 (40)1459
95 (35)1802
86 (30)2238
77 (25)2796
68 (20)3520
59 (15)4450
50 (10)5670
41 (5)7280
32 (0)9420
23 (-5)12,300
14 (-10)16,180
5 (-15)21,450
4 (-20)28,680
22 (-30)52,700
40 (-40)100,700
(1) Measure resistance across sensor terminals.
(1)Measure resistance across sensor terminals.

ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE (1)

COOLING FAN RELAY OPERATION

To check relay operation, see COOLING FAN RELAY OPERATION .

Operational ModeOFFLOW FANSHIGH FANS
Low Speed Cooling Fan Relay (#1)De-EnergizedEnergizedEnergized
Series/Parallel Cooling Fan Relay #2 (1)De-EnergizedDe-EnergizedEnergized
High Speed Cooling Fan Relay #3De-EnergizedDe-EnergizedEnergized
(1) The series/parallel cooling fan relay is a dual position switch and while de-energized, supplied a ground path for the low speed fan circuit.
(1)The series/parallel cooling fan relay is a dual position switch and while de-energized, supplied a ground path for the low speed fan circuit.

COOLING FAN RELAY OPERATION

REMOVAL & INSTALLATION

WARNINGVehicles are equipped with air bag supplemental restraint system. Before attempting any repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in appropriate AIR BAG RESTRAINT SYSTEMS article.
CAUTIONWhen battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.

Note. Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener.

Note. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

Note. The numbers in parenthesis () refer to the numbers shown in the illustrations.

Removal

  1. Remove the intake air duct (1) clamp (5) from the MAF sensor (4). (Scheme 15)
  2. Lift the air cleaner element assembly (1) off of the air inlet assembly (2) locating pins. (Scheme 16)
  3. Slide the air cleaner element assembly (1) toward the fender to unseat the locating tab of the air cleaner element assembly (1) from the slot of the air inlet assembly (2).
  4. Remove or disconnect the Intake Air Temperature (IAT) sensor. (Scheme 17)
  5. Remove the air cleaner element.
  6. Remove the air cleaner element assembly.

Installation

  1. Install the air cleaner element.
  2. Ensure the rubber locating grommets are secure in the bottom of the air cleaner element assembly (1). (Scheme 16)
  3. Slide locating tab on bottom of the air cleaner element assembly (1) down into the slot on the top of air inlet assembly (2).
  4. Press the air cleaner element assembly (1) down onto the locating pins ensuring the locating grommets are secure in the bottom of the air cleaner element assembly (1).
  5. Install or connect the Intake Air Temperature sensor. (Scheme 17)
  6. Install the intake air duct (1) to the MAF sensor (4). Tighten the clamp (5) assembly to specification. See «TORQUE SPECIFICATIONS»(/cadillac/eldorado/x-1992-2002/remont/cooling-fan/#engine-cooling-fan-deville-eldorado-seville__torque-specifications). (Scheme 15)

Scheme 15

Scheme 15
Scheme 15

Scheme 16

Scheme 16
Scheme 16

Scheme 17

Scheme 17
Scheme 17

ENGINE COOLANT FAN

WARNINGKeep hands, tools and clothing away from engine coolant fan to help prevent personal injury. This engine coolant fan is electric and can come on weather or not the engine is running. The engine coolant fan can start automatically in response to a temperature sensor with the ignition in the on position.
WARNINGTo help avoid personal injury or damage to the vehicle, a bent, cracked or damaged fan blade or housing should always be replaced.
  1. Remove upper filler panel. See «UPPER FILLER PANEL»(/cadillac/eldorado/x-1992-2002/remont/cooling-fan/#engine-cooling-fan-deville-eldorado-seville).
  2. Remove air filter assembly. See «AIR FILTER ASSEMBLY»(/cadillac/eldorado/x-1992-2002/remont/cooling-fan/#engine-cooling-fan-deville-eldorado-seville).
  3. Remove left engine torque strut. See «ENGINE TORQUE STRUT»(/cadillac/eldorado/x-1992-2002/remont/cooling-fan/#engine-cooling-fan-deville-eldorado-seville__engine-torque-strut).
  4. Drain engine coolant sufficiently to allow removal of the upper radiator hose.
  5. Remove upper radiator hose.
  6. Disconnect the upper oil cooler line from the radiator.
  7. Disconnect the cooling fan electrical connectors. (Scheme 18)
  8. Remove the cooling fans. (Scheme 19)
  1. Install cooling fans. (Scheme 19)
  2. Tighten cooling fan bolts to specification. See «TORQUE SPECIFICATIONS»(/cadillac/eldorado/x-1992-2002/remont/cooling-fan/#engine-cooling-fan-deville-eldorado-seville__torque-specifications).
  3. Connect the cooling fan electrical connectors. (Scheme 18)
  4. Connect upper oil cooler line to the radiator.
  5. Install the upper radiator hose.
  6. Install the left engine torque strut. See «ENGINE TORQUE STRUT»(/cadillac/eldorado/x-1992-2002/remont/cooling-fan/#engine-cooling-fan-deville-eldorado-seville__engine-torque-strut).
  7. Install air filter assembly. See «AIR FILTER ASSEMBLY»(/cadillac/eldorado/x-1992-2002/remont/cooling-fan/#engine-cooling-fan-deville-eldorado-seville).
  8. Install the upper filler panel. See «UPPER FILLER PANEL»(/cadillac/eldorado/x-1992-2002/remont/cooling-fan/#engine-cooling-fan-deville-eldorado-seville).

Scheme 18

Scheme 18
Scheme 18

Scheme 19

Scheme 19
Scheme 19
WARNINGAllow sufficient time for the engine to cool before removing the ECT sensor. Personal injury or excessive coolant loss may result if the engine is hot.
CAUTIONUse care when handling the coolant sensor. Damage to the coolant sensor will effect the operation of the fuel control system.

Note. A non-hardening sealer should be applied to the sensor threads prior to installation to prevent coolant leaks. Use P/N 1050805 or equivalent.

  1. Partially drain the cooling system.
  2. Disconnect the ECT sensor electrical connector.
  3. Unscrew and remove the ECT sensor. (Scheme 3)
  1. Install the ECT sensor and tighten to specification. See «TORQUE SPECIFICATIONS»(/cadillac/eldorado/x-1992-2002/remont/cooling-fan/#engine-cooling-fan-deville-eldorado-seville__torque-specifications). (Scheme 3)
  2. Connect the ECT sensor electrical connector.
  3. Refill cooling system.

ENGINE TORQUE STRUT

Note. Engine torque struts can be removed in order to provide access for various other service operations.

  1. Remove any fasteners which seem logical for the service being performed. Ensure that the torque struts are not preloaded in their installed position. (Scheme 20)
  2. Adjustment is provided at the point the strut fastens to the core support bracket.
  3. Ensure that this bolt is loose during assembly. Tighten to specification as the final step of the assembly. See «TORQUE SPECIFICATIONS»(/cadillac/eldorado/x-1992-2002/remont/cooling-fan/#engine-cooling-fan-deville-eldorado-seville__torque-specifications).

Scheme 20

Scheme 20
Scheme 20

Removal (Deville/Concours)

  1. Remove plastic rivets retaining upper filler panel to radiator support. (Scheme 21)
  2. Lift outer ends of upper filler panel to disengage clips.
  3. Remove filler panel.
  1. Set upper filler panel in place. Verify outer forward edge of filler panel is tucked under headlamp bezel. (Scheme 21)
  2. Install plastic rivets.
  3. Press down on filler panel to engage clips.

Scheme 21

Scheme 21
Scheme 21

Removal & Installation (Eldorado)

  1. Rotate 2 fasteners a quarter turn. (Scheme 22)
  2. Lift filler panel.
  3. To install, position filler panel and secure by rotating fasteners.

Scheme 22

Scheme 22
Scheme 22

Removal (SLS/STS)

  1. Remove fasteners retaining upper filler panel. (Scheme 23)
  2. Lift outer edges of filler panel to disengage retainers.
  1. Position filler panel and press to engage retainers. (Scheme 23)
  2. Install fasteners to retain filler panel.

Scheme 23

Scheme 23
Scheme 23

TORQUE SPECIFICATIONS

ApplicationFt. Lbs. (N.m)
Engine Coolant Temperature Sensor15 (20)
Engine Strut Bolt44 (60)
INCH Lbs. (N.m)
Electric Cooling Fan Mounting Bolts/Screws89 (10)
MAF Sensor Clamps31 (3.5)

TORQUE SPECIFICATIONS

Scheme 24

Scheme 24: WIRING DIAGRAMS
Scheme 24: WIRING DIAGRAMS