Mechanics

ENGINE COLLING TEMPERATURE

1998 Cadillac Deville

Engine Cooling problem
1998 Cadillac Deville V8 Front Wheel Drive Automatic 45995 miles

Engine cooling temperatured is running from 220- 238 degrees. Water pump and thermostat appear to be working. There is no cooland loss, however engine smells hot when you turn it off. Acouple of times I have noticed the cooling fans a running after engine was turned off. What should the normal operating temperature be for this vehicle. I live in S. Florida where daytime temperatures are in the low 90's.
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Jleejr7
July 22, 2008.



ENGINE COOLING FAN -1998 Cadillac DeVille
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1999 4.0L: AURORA, & 1998-99 4.6L: DEVILLE, ELDORADO & SEVILLE

NOTE: Check for, and repair any A/C-related DTCs before proceeding with COOLING FAN FUNCTIONAL CHECK. See ACM SELF-DIAGNOSTICS in appropriate AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING. If DTC P1660 is set or sets during COOLING FAN FUNCTIONAL CHECK, DTC must be diagnosed before proceeding. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
Description
When PCM commands low speed cooling fan operation, low speed cooling fan relay is grounded, allowing current to flow through both cooling fans in a series circuit to ground. If PCM commands high speed cooling fan operation, all 3 cooling fan relays are grounded, changing circuit to a parallel circuit to ground. If a fault occurs, certain symptoms will occur due to series/parallel circuit design.
The PCM will command low speed cooling fan operation under the following conditions:  Engine coolant temperature exceeds 229 °F (109 °C).
 Transmission fluid temperature exceeds 302 °F (150 °C).
 A/C operation is requested.
 If coolant temperature at key-off is greater than 304 °F (151 °C), with system voltage greater than 12 volts, cooling fans will remain on for about 3 minutes.
The PCM will command high speed cooling fan operation under the following conditions:  Engine coolant temperature reaches 234 °F (112 °C).
 Transmission fluid temperature is greater than 304 °F (151 °C).
 When certain DTCs set.
Cooling fans will switch from high speed to low speed, except when DTCs are set, when coolant temperature drops to less than 229 °F (109 °C). Cooling fans will switch from low speed to off when coolant temperature drops to less than 216 °F (102 °C).
Cooling Fan Functional Check
1. If On-Board Diagnostic (OBD) System Check has not been performed, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If OBD System Check has been performed, go to next step. 2. Ensure engine coolant temperature is between 41-212 °F (5-100 °C). Turn A/C controls off. Start engine and let idle. Using scan tool, select RELAY CONTROL function. Monitor DRIVER 1 display on scan tool. Command all relays off for 15 seconds, then on for 15 seconds. If DRIVER 1 display indicates a fault, go to DTC P1660. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If no fault is indicated, go to next step. 3. With engine idling, turn A/C on to maximum cooling. If any other DTCs set, diagnose DTCs before continuing this procedure. See appropriate SELF-DIAGNOSTICS article in ENGINE

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ENGINE COOLING FAN -1998 Cadillac DeVille
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PERFORMANCE. If no DTCs are set, go to next step. 4. Turn ignition off. Disconnect PCM connector C2. With a test light connected to ground, probe PCM connector C2 terminals No. 32 (Dark Green wire) and No. 33 (Dark Blue wire). If test light illuminates at both terminals, go to next step. If test light does not illuminate, go to step 14. 5. Reconnect PCM connector C2 (if disconnected). Ensure engine coolant temperature is less than 212 °F (100 °C). Observe cooling fan operation while individually commanding fan relay No. 1 on, then all relays on, then all relays off. With fan relay No. 1 on, both cooling fans should operate at low speed. With all relays commanded on, both cooling fans should operate at high speed. With all relays commanded off, both cooling fans should not operate (unless PCM detects a fault or high temperature condition). If both cooling fans operate as commanded, system is operating normally at this time. If both cooling fans do not operate as commanded, go to next step. 6. If only cooling fan No. 1 (left) runs with fan relay No. 1 commanded on, and then both cooling fans operate when all relays are commanded on, go to next step. If operation is not as specified, go to step 8. 7. Repair White wire for a short to ground between cooling fan No. 1 and series/parallel cooling fan relay. Go to step 5. 8. If neither cooling fan operates with fan relay No. 1 commanded on, and only cooling fan No. 2 (right) operates with all relays commanded on, go to COOLING FAN SYMPTOM TEST NO. 1. If system does not operate as specified, go to next step. 9. If neither cooling fan operates with fan relay No. 1 commanded on, and only cooling fan No. 1 operates with all relays commanded on, go to COOLING FAN SYMPTOM TEST NO. 2. If system operated other than as specified, go to next step. 10. If both cooling fans operate with fan relay No. 1 commanded on, and only cooling fan No. 2 operates with all relays commanded on, go to COOLING FAN SYMPTOM TEST NO. 3. If system operated other than as specified, go to next step. 11. If both cooling fans operate with fan relay No. 1 commanded on, and only cooling fan No. 1 operates with all relays commanded on, go to COOLING FAN SYMPTOM TEST NO. 4. If system operated other than as specified, go to next step. 12. If neither cooling fan operates with either fan relay No. 1 or all relays commanded on, go to COOLING FAN SYMPTOM TEST NO. 5. If system does not operate as specified, go to next
step. 13. If either cooling fan operates when all relays are commanded off, go to DIAGNOSTIC AIDS. If system does not operate as specified, go to step 5. 14. Check for cause of no power. Possible causes for no power are:  Blown cooling fan relay battery feed fuse.
 Open in cooling fan relay coil.
 Open in cooling fan relay control circuit.
After repairs, go to step 5.

NOTE: Cooling fan symptom test No. 1 is to be used if neither cooling fan operates when low speed operation is requested, and only right cooling fan operates with high speed request. DTC P1660 is not set.
Cooling Fan Symptom Test No. 1

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1. Perform COOLING FAN FUNCTIONAL CHECK. Go to next step. 2. Disconnect cooling fan No. 1 (left) connector. Turn ignition on. Using scan tool, select RELAY CONTROL function. Command relay No. 1 on. Using a DVOM, measure voltage between ground and cooling fan No. 1 connector terminal " B" (Black wire). See WIRING DIAGRAMS. If reading is 10 volts or greater, go to next step. If reading is not as specified, go to step 6. 3. Using a fused jumper wire, jumper cooling fan No. 1 connector terminals together. If cooling fan No. 2 (right) operates, go to step 8. If cooling fan No. 2 does not operate, go to next step. 4. With cooling fan No. 1 connector terminals still jumpered, remove fan relay No. 2 (series/parallel) from engine compartment junction block. Use a DVOM to measure voltage between ground and fan relay No. 2 connector terminal No. 30 (White wire). If reading is 10 volts or greater, go to next step. If reading is not as specified, go to step 9. 5. Connect a fused jumper wire between fan relay No. 2 (series/parallel) connector terminals No. 30 (White wire) and No. 87A (Light Blue wire). If cooling fan No. 2 operates, go to step 10. If cooling fan No. 2 does not operate, go to step 11. 6. Using scan tool, exit RELAY CONTROL function. Remove fan relay No. 1 (low speed). Use a DVOM to measure voltage between ground and fan relay No. 1 connector terminal No. 30 (Red wire). If reading is 10 volts or greater, go to next step. If reading is not as specified, go to step 12. 7. Connect a fused jumper wire between fan relay No. 1 (low speed) connector terminals No. 30 (Red wire) and No. 87 (Black wires). Use DVOM to measure voltage between ground and Black wire at cooling fan No. 1 connector terminal " B". If reading is 10 volts or greater, go to step 13. If reading is not as specified, go to step 14. 8. Replace cooling fan No. 1 (left). Go to COOLING FAN FUNCTIONAL CHECK. 9. Repair open in White wire between cooling fan No. 1 and fan relay No. 2 (series/parallel). Go to COOLING FAN FUNCTIONAL CHECK.
10. Replace fan relay No. 2 (series/parallel). Go to COOLING FAN FUNCTIONAL CHECK. 11. Repair open in Light Blue wire between series/parallel cooling fan relay, and splice between high speed cooling fan relay and secondary cooling fan motor. Go to COOLING FAN FUNCTIONAL CHECK. 12. Repair open in Red wire between fan relay No. 1 (low speed) and COOLING FAN fuse (60-amp). Go to COOLING FAN FUNCTIONAL CHECK. 13. Replace fan relay No. 1 (low speed). Go to COOLING FAN FUNCTIONAL CHECK. 14. Repair open in Black wire between fan relay No. 1 (low speed) and cooling fan No. 1 (left). Go to COOLING FAN FUNCTIONAL CHECK.

NOTE: Cooling fan symptom test No. 2 is to be used if neither cooling fan operates when low speed operation is requested, and only cooling fan No. 1 (left) operates with high speed request. DTC P1660 is not set.
Cooling Fan Symptom Test No. 2
1. Perform COOLING FAN FUNCTIONAL CHECK. Go to next step. 2. Disconnect cooling fan No. 2 (right) connector. Turn ignition on. Using scan tool, select RELAY CONTROL function. Command fan relay No. 1 on. Connect a fused jumper wire between cooling fan No. 2 connector terminals. See WIRING DIAGRAMS. If cooling fan No. 1 (left) operates, go to step 5). If cooling fan No. 1 does not operate, go to next step.

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3. With fan relay No. 1 still commanded on, remove fan relay No. 2 (series/parallel). Connect a fused jumper wire between fan relay No. 2 connector terminals No. 30 (White wire) and No. 87A (Light Blue wire). If cooling fan No. 1 (left) operates, go to step 6). If cooling fan No. 1 does not operate, go to next step. 4. With fan relay No. 2 (series/parallel) terminals still jumpered, use a DVOM to measure voltage between ground and cooling fan No. 2 connector terminal " B" (Light Blue wire). If reading is 10 volts or greater, go to step 7). If reading is not as specified, go to step 8). 5. Replace cooling fan No. 2. Go to COOLING FAN FUNCTIONAL CHECK. 6. Replace fan relay No. 2 (series/parallel). Go to COOLING FAN FUNCTIONAL CHECK. 7. Repair open in Black wire between cooling fan No. 2 and splice. Go to COOLING FAN FUNCTIONAL CHECK. 8. Repair open in Light Blue wire between fan relay No. 2 (series/parallel) and splice. Go to COOLING FAN FUNCTIONAL CHECK.

NOTE: Cooling fan symptom test No. 3 is to be used if both cooling fans operate when low speed operation is requested, and only cooling fan No. 2 (right) operates with high speed request. DTC P1660 is not set.
Cooling Fan Symptom Test No. 3
1. Perform COOLING FAN FUNCTIONAL CHECK. Go to next step. 2. Turn ignition on. Using scan tool, select RELAY CONTROL function. Command all relays on. Remove fan relay No. 2 (series/parallel). Use a DVOM to measure voltage between ground and fan relay No. 2 connector terminal No. 85 (Orange wire). See WIRING DIAGRAMS. If reading is 10 volts or greater, go to next step. If reading is not as specified, go to step 5. 3. Remove fan relay No. 3 (high speed). Use a DVOM to measure resistance of Dark Blue wire between fan relay No. 2 connector terminal No. 86 and fan relay No. 3 connector terminal No. 86. If resistance is 5 ohms or less, go to next step. If resistance is not as specified, go to step 6. 4. Reconnect fan relay No. 3. With all 3 relays still commanded on, connect a fused jumper wire between fan relay No. 2 connector terminals No. 30 (White wire) and No. 87 (Black wire). If both cooling fans operate, go to step 8. If both cooling fans do not operate, go to step 7. 5. Repair open in Orange wire between fan relay No. 2 (series/parallel) and splice. Go to COOLING FAN FUNCTIONAL CHECK. 6. Repair open in Dark Blue wire between fan relay No. 2 (series/parallel) and splice. Go to COOLING FAN FUNCTIONAL CHECK. 7. Repair open in Black wire between fan relay No. 2 (series/parallel) and splice. Go to COOLING FAN FUNCTIONAL CHECK. 8. Replace fan relay No. 2 (series/parallel). Go to COOLING FAN FUNCTIONAL CHECK.

NOTE: Cooling fan symptom test No. 4 is to be used if both cooling fans operate when low speed operation is requested, and only cooling fan No. 1 (left) operates with high speed request. DTC P1660 is not set.
Cooling Fan Symptom Test No. 4

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1. Perform COOLING FAN FUNCTIONAL CHECK. Go to next step. 2. Turn ignition on. Using scan tool, select RELAY CONTROL function. Command all 3 relays on. Remove fan relay No. 3 (high speed). Use a DVOM to measure voltage between ground and fan relay No. 3 connector terminal No. 85 (Orange wire). See WIRING DIAGRAMS. If reading is 10 volts or greater, go to next step. If reading is not as specified, go to step 6. 3. Use a DVOM to measure voltage between ground and fan relay No. 3 connector terminal No. 30 (Light Blue wire). If reading is 10 volts or greater, go to next step. If reading is not as specified, go to step 7. 4. Remove fan relay No. 2 (series/parallel). Use a DVOM to measure resistance of Dark Blue wire between fan relay No. 3 connector terminal No. 86 and fan relay No. 2 connector terminal No. 86. If resistance is 5 ohms or less, go to next step. If resistance is not as specified, go to step 8. 5. Reconnect fan relay No. 2. With all 3 relays still commanded on, connect a fused jumper wire between fan relay No. 3 connector terminals No. 30 (Red wire) and No. 87 (Light Blue wire). If cooling fan No. 2 operates, go to step 10. If cooling fan No. 2 does not operate, go to step 9. 6. Repair open in Red wire or circuit between fan relay No. 3 and COOLING FAN fuse (60-amp) or COOL FANS fuse (50-amp). Go to COOLING FAN FUNCTIONAL CHECK. 7. Repair open in Orange wire between fan relay No. 3 and splice. Go to COOLING FAN FUNCTIONAL CHECK. 8. Repair open in Dark Blue wire between fan relay No. 3 and splice. Go to COOLING FAN FUNCTIONAL CHECK. 9. Repair open in Light Blue wire between fan relay No. 3 and splice. Go to COOLING FAN FUNCTIONAL CHECK. 10. Replace fan relay No. 3 (high speed). Go to COOLING FAN FUNCTIONAL CHECK.

NOTE: Cooling fan symptom test No. 5 is to be used if neither cooling fan operates when low or high speed operation is requested and DTC P1660 is not set.
Cooling Fan Symptom Test No. 5
1. Perform COOLING FAN FUNCTIONAL CHECK. Go to next step. 2. Check COOLING FAN fuse (60-amp) or COOL FANS fuse (50-amp). If fuse is okay, go to next step. If fuse is blown, go to step 4. 3. Remove fan relay No. 1 (low speed). Use a DVOM to measure voltage between ground and fan relay No. 1 connector terminal No. 30 (Red wire). See WIRING DIAGRAMS. If reading is 10 volts or greater, go to step 8. If reading is not as specified, go to step 9. 4. Turn ignition switch to LOCK position. Replace COOLING FAN fuse (60-amp) or COOL FANS fuse (50-amp). If fuse blows, go to step 10. If fuse does not blow, go to next step. 5. Turn ignition on. Using scan tool, select RELAY CONTROL function. Command fan relay No. 1 on. If fuse blows, go to step 11. If fuse does not blow, go to next step. 6. Command all 3 relays on. If fuse blows, go to next step. If fuse does not blow, system is operating normally at this time. 7. Exit RELAY CONTROL function. Replace COOLING FAN fuse (60-amp) or COOL FANS fuse (50-amp). Using scan tool, select RELAY CONTROL function. Command fan relay No. 1 on. If cooling fan No. 1 operates, go to step 12. If cooling fan No. 1 does not operate, go to step 13.

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8. Repair open in Black wire between fan relay No. 2 (series/parallel) and ground, or between cooling fan No. 2 and ground. Go to COOLING FAN FUNCTIONAL CHECK. 9. Repair open in Red wire between COOLING FAN fuse (60-amp) or COOL FANS fuse (50-amp) and either fan relay No. 1 (low speed) or fan relay No. 3 (high speed). Go to COOLING FAN FUNCTIONAL CHECK. 10. Repair short to ground in Red wire between COOLING FAN fuse (60-amp) or COOL FANS fuse (50-amp) and either fan relay No. 1 (low speed) or fan relay No. 3 (high speed). Go to COOLING FAN FUNCTIONAL CHECK. 11. Repair short to ground in Black wire between fan relay No. 1 and cooling fan No. 1. Go to COOLING FAN FUNCTIONAL CHECK. 12. Replace cooling fan No. 1. Go to COOLING FAN FUNCTIONAL CHECK. 13. Replace cooling fan No. 2. Go to COOLING FAN FUNCTIONAL CHECK.
Diagnostic Aids
If cooling fans run when all cooling fan relays are 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 COOLING FAN FUNCTIONAL CHECK. This will help diagnose possible multiple failures.

7/22/2008
No matter where you live!

Merlin2021
Jul 22, 2008.
195-210 would be the range. Has the thermostat been replaced? Also a radiator that has lost 10 to20% of it's cooling efficency can bump temp up 30 degrees. Check for debris on condensor and rad.

Docfixit
Jul 22, 2008.
Thanks Docfixit.I guess there wasn't enough info here?

Merlin2021
Jul 22, 2008.