28 - DTC-Based Diagnostics / MODULE, Powertrain Control (PCM), 2.4L / Diagnosis and Testing
P0128-THERMOSTAT RATIONALITY
For a complete wiring diagram, refer to the Wiring Information.
When Monitored and Set Conditions
When Monitored: This diagnostic runs when the following conditions are met:
•With the engine running.
•Start up coolant temperature less than 65°C (149°F).
•Ambient temperature between -8°C (17.6°F) and 50°C (122°F).
•Average vehicle speed greater than 16 km/h (10 mph) until coolant temperature reaches 85°C.
•Engine speed does not go above 5400 rpm for more than 32 seconds.
•The pass/fail determination point is reached when the coolant temp model reaches 88°C (190.4°F).
Set Conditions:
•The predicted coolant temperature reaches the target threshold before the actual coolant temperature and the PCM detects that the actual engine coolant temperature is too far below the what is acceptable for a good thermostat.
Default Actions:
•MIL light will illuminate.
Possible Causes
LOW COOLANT LEVEL
COOLING SYSTEM ISSUES
THERMOSTAT OPERATION
Cooling / Engine / THERMOSTAT / Removal
2.0L/2.4L
CAUTION:
Do not loosen radiator draincock with system hot and pressurized. Serious burns from coolant can occur.
CAUTION:
The Thermostat and housing is serviced as an assembly. Do not remove the thermostat from the housing, damage to the thermostat may occur.
1.Disconnect and isolate the negative battery cable. If equipped with an Intelligent Battery Sensor (IBS), disconnect the IBS connector first before disconnecting the negative battery cable.
2.Remove the engine cover.
3.Remove the battery (Refer to 08 - Electrical/Battery System/BATTERY/Removal) .
4.Remove the battery tray assembly (Refer to 08 - Electrical/Battery System/TRAY, Battery/Removal) .
5.Remove the belly pan (Refer to 13 - Frame and Bumpers/Under Body Protection/BELLY PAN/Removal) .
6.Drain the cooling system.
7.Lower vehicle.
8.Remove the brake vacuum pump (Refer to 09 - Engine/Cylinder Head/PUMP, Vacuum/Removal) .
9.Remove the three bolts that attach the PDC to the body.
10.Position the PDC to the side to allow for thermostat housing removal.
11.Remove the intake manifold upper support bracket (1) bolts (3).
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12.Loosen but do not remove the bracket nuts (2).
NOTE: The bracket can not be removed at this time, loosening the nuts allow the necessary movement for the thermostat housing to be removed.
13.Remove the coolant recovery bottle return hose (1).
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14.Disconnect the engine coolant temperature sensor harness connector (2).
15.Disconnect the forward most shift cable from the transmission lever.
16.Disconnect the quick-coupling and remove the heater core supply hose (4) . Pliers, Hose Clamp 10288
17.Using Special Tool 10288, release the clamps at the heater core return (5) and thermostat outlet (7).
18.Remove the heater core return hose (5).
19.Remove the thermostat outlet hose (7).
20.Remove the thermostat housing bolts (3).
21.Remove the thermostat housing (6) from the engine.
07 - Cooling / Engine / THERMOSTAT / Installation
2.0L/2.4L
CAUTION:
The Thermostat and housing is serviced as an assembly. Do not remove the thermostat from the housing, damage to the thermostat may occur.
1.Clean the mating surfaces on the engine block and thermostat housing.
2.Install new gasket seal onto the thermostat housing.
3.Pull the manifold bracket (1) slightly away from the engine to allow the housing to be installed.
4.Position the thermostat housing (6) in place.
5.Install the four housing bolts. Tighten bolts to 9 N·m (80 in. lbs.).
NOTE: Make sue the left lower bolt passes through the Adele clamp that secures the lower tube assembly to the housing.
6.Connect the cable to the transmission lever .
7.Install the thermostat outlet hose (7).
8.Install the heater core supply (4) and return hoses (5). Pliers, Hose Clamp 10288
9. Use Special Tool 10288 to secure the clamp at the heater core return hose (5) and the thermostat outlet (7).
10.Install the engine coolant temperature sensor (2). Plug in the connector.
11.Install the coolant recovery bottle return hose (1).
12.Tighten the bracket bolts (3) and nuts (2) to 9 N·m (80 in. lbs.).
13.Install the three PDC bolts. Tighten to 9 N·m (80 in. lbs.)
14.Install the battery tray (Refer to 08 - Electrical/Battery System/TRAY, Battery/Installation) .
15.Install the battery. Tighten the nut to 5 N·m (44 in. lbs.).
16.Install the brake vacuum pump (Refer to 09 - Engine/Cylinder Head/PUMP, Vacuum/Installation) .
17.Fill the cooling system (Refer to 07 - Cooling - Standard Procedure) .
18.Install the engine cover.
The procedure for refilling the cooling system has been posted and requires a special tool, UView Airlift, or similar. See this link:
http://www.dodge-dart.org/forum/dodge-dart-mechanical-problems/37402-cylinder-2-real-trouble-14.html
