6.(F855) 5-VOLT SUPPLY CIRCUIT OPEN
Turn the ignition off.
Disconnect the C1 PCM harness connector.
Measure the resistance of the (F855) 5-volt Supply circuit from the Sen-
sor harness connector to the PCM harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 7
No>>
Repair the open in the (F855) 5-volt Supply circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
7.(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (F855) 5-volt Supply
circuit in the Oil Pressure Sensor harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (F855) 5-volt Supply cir-
cuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 8
8.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion,damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
P0523-OIL PRESSURE CIRCUIT HIGH
For a complete wiring diagramRefer to Section 8W.
When Monitored:
With the ignition on and battery voltage above 10.4 volts.
Set Condition:
The oil pressure sensor signal at PCM goes above 4.9 volts. One Trip Fault.
Possible Causes
OIL PRESSURE SENSOR
(G6) OIL PRESSURE SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
(G6) OIL PRESSURE SIGNAL CIRCUIT OPEN
(K900) SENSOR GROUND CIRCUIT OPEN
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.OIL PRESSURE SENSOR VOLTAGE ABOVE 4.8 VOLTS
Ignition on, engine not running.
With the scan tool in Sensors, read the Oil Pressure Sensor voltage.
Is the Oil Pressure Sensor voltage above 4.8 volts?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.OIL PRESSURE SENSOR
Turn the ignition off.
Disconnect the Oil Pressure Sensor harness connector.
Ignition on, engine not running.
Connect a jumper wire between the (G60) Oil Pressure Signal circuit and (K900) Sensor ground circuit at the Sen-
sor harness connector.
With the scan tool in Sensors, read the Oil Pressure Sensor voltage.
Is the voltage below 1.0 volt?
Ye s>>
Replace the Oil Pressure Sensor.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
NOTE: Remove the jumper wire before continuing.
3.(G6) OIL PRESSURE SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
Turn the ignition off.
Disconnect the PCM harness connectors.
Ignition on, engine not running.
Using a 12-volt test light connected to ground, probe the (G6) Oil PressureSignal circuit.
Is the test light brightly illuminated?
Ye s>>
Repair the short to voltage in the (G6) Oil Pressure Signal circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
4.(G6) OIL PRESSURE SIGNAL CIRCUIT OPEN
Turn the ignition off.
Measure the resistance of the (G6) Oil Pressure Signal circuit from the OilPressure Sensor harness connector to
the PCM harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 5
No>>
Repair the open in the (G6) Oil Pressure Signal circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE) Per-
form POWERTRAIN VERIFICATION TEST.
5.(K900) SENSOR GROUND CIRCUIT OPEN
Measure the resistance of the (K900) Sensor ground circuit from the Oil Pressure Sensor harness connector to the
PCM harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 6
No>>
Repair the open in the (K900) Sensor ground circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
6.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Possible Causes
A/C SELECT CIRCUIT OPEN
A/C SELECT IN HVAC
PCM
A/C REQUEST CIRCUIT OPEN
REFRIGERATION SYSTEM NOT PROPERLY CHARGED
HIGH PRESS CUT-OFF SWITCH
LOW PRESSURE SWITCH
A/CCLUTCHCOIL
A/C COMPRESSOR CLUTCH GROUND CIRCUIT OPEN
(C3) A/C CLUTCH RELAY OUTPUT CIRCUIT OPEN
FUSED B+ CIRCUIT OPEN
A/CCLUTCHRELAY
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.DTC AND COMMUNICATION PRESENT
Ignition on, engine not running.
Verify that communication with the HVAC and PCM is available over the BUS.
With the scan tool, check for DTCs in the PCM and HVAC module.
Are any A/C DTC’s or communication failures present?
Ye s>>
Diagnose the related DTC(s) or BUS failure before continuing.
Perform BODY VERIFICATION TEST - VER 1.
No>>
Go To 2
2.A/C SELECT CIRCUIT OPEN
Engine running.
With the scan tool, read the A/C Select status in the PCM.
Turn the A/C Switch on and off a few times.
Does the A/C Select state change?
Ye s>>
Go To 3
No>>
Go To 12
3.A/C REQUEST CIRCUIT OPEN
Engine Running.
Turn the A/C system on and the fan on high.
With the scan tool in Inputs/Outputs, read the A/C request state.
Does the A/C request state change?
Ye s>>
Go To 4
No>>
Repair the open in the A/C Request circuit.
Perform BODY VERIFICATION TEST - VER 1.
4.REFRIGERATION SYSTEM NOT PROPERLY CHARGED
Turn the ignition off.
Verify that the Refrigerant System is properly charged per Service Procedure.
Is the Refrigerant System properly charged?
Ye s>>
Go To 5
No>>
Properly charge the Refrigerant System per Service Information.
Perform BODY VERIFICATION TEST - VER 1.
5.HIGH PRESSURE CUT-OFF SWITCH
Turn the ignition off.
Verify the High Pressure Cut-Off Switch operation per Service Information.
Is the High Pressure Cut-Off Switch OK?
Ye s>>
Go To 6
No>>
Replace the High Pressure Cut-Off Switch.
Perform BODY VERIFICATION TEST - VER 1.
6.LOW PRESSURE SWITCH
Turn the ignition off.
Verify the Low Pressure Switch operation per Service Information.
Is the Low Pressure Switch OK?
Ye s>>
Go To 7
No>>
Replace the Low Pressure Switch.
Perform BODY VERIFICATION TEST - VER 1.
7.A/C CLUTCH COIL
Ignition on, engine not running.
Disconnect the A/C Compressor Clutch harness connector.
Connect a test light between the ground circuit and the A/C Clutch Relay Output circuit.
With the scan tool, actuate the A/C Clutch Relay.
Does the test light illuminate brightly on and off with the relay actuation?
Ye s>>
Replace the A/C Clutch Coil.
Perform BODY VERIFICATION TEST - VER 1.
No>>
Go To 8
8.A/C COMPRESSOR CLUTCH GROUND CIRCUIT OPEN
Turn the ignition off.
Disconnect the A/C Clutch harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance between ground and the A/C Compressor Clutch ground circuit in the A/C Clutch harness
connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 9
No>>
Repair the open in the A/C Compressor Clutch ground circuit.
Perform BODY VERIFICATION TEST - VER 1.
page page
ENGINE - 3.7L - SERVICE INFORMATION
DESCRIPTION ............................. 2180
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - INTRODUCTION............. 2180
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - PERFORMANCE............. 2181
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - MECHANICAL............... 2183
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - LUBRICATION............... 2183
DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION PRESSURE............... 2185
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE...... 2185
STANDARD PROCEDURE
STANDARD PROCEDURE - REPAIR
DAMAGED OR WORN THREADS.......... 2186
STANDARD PROCEDURE - FORM-IN-
PLACE GASKETS AND SEALERS.......... 2186
STANDARD PROCEDURE - ENGINE
GASKET SURFACE PREPARATION........ 2187
REMOVAL ................................. 2188
INSTALLATION ............................. 2192
SPECIFICATIONS
SPECIFICATIONS - 3.7L ENGINE .......... 2195
TORQUE ................................. 2199
SPECIAL TOOLS ........................... 2202
ELEMENT - AIR CLEANER
REMOVAL ................................. 2206
INSTALLATION ............................. 2207
HEAD-CYLINDER-LEFT
DIAGNOSIS AND TESTING - CYLINDER HEAD
GASKET . . ............................... 2208
REMOVAL ................................. 2208
INSTALLATION ............................. 2211
CAMSHAFT
DESCRIPTION ............................. 2214
REMOVAL ................................. 2214
INSTALLATION ............................. 2215
COVER-CYLINDER HEAD
DESCRIPTION ............................. 2217
REMOVAL ................................. 2217
INSTALLATION ............................. 2218
VALVES & SEATS - INTAKE/EXHAUST
DESCRIPTION ............................. 2219
STANDARD PROCEDURE - REFACING ....... 2219
REMOVAL ................................. 2220
INSTALLATION ............................. 2221
ARM-VALVE ROCKER
DESCRIPTION ............................. 2222REMOVAL ................................. 2222
INSTALLATION ............................. 2222
SEALS-VALVE GUIDE
DESCRIPTION ............................. 2224
SPRINGS-VALVE
DESCRIPTION ............................. 2225
REMOVAL ................................. 2225
INSTALLATION ............................. 2225
HEAD-CYLINDER-RIGHT
DIAGNOSIS AND TESTING - HYDRAULIC
LASH ADJUSTER ......................... 2227
REMOVAL
REMOVAL RIGHT CYLINDER HEAD ........ 2227
INSTALLATION
INSTALLATION RIGHT CYLINDER HEAD . . . 2230
CAMSHAFT
DESCRIPTION ............................. 2234
REMOVAL ................................. 2234
INSTALLATION ............................. 2237
COVER - CYLINDER HEAD
REMOVAL ................................. 2239
INSTALLATION ............................. 2239
ROCKER ARM - VALVE
DESCRIPTION ............................. 2240
REMOVAL ................................. 2240
SEALS - VALVE GUIDE
DESCRIPTION ............................. 2241
SPRINGS - VALVE
DESCRIPTION ............................. 2242
REMOVAL ................................. 2242
INSTALLATION ............................. 2242
BLOCK-ENGINE
DESCRIPTION ............................. 2244
STANDARD PROCEDURE - CYLINDER BORE
HONING ................................. 2244
CLEANING ................................. 2244
INSPECTION............................... 2245
CRANKSHAFT
DESCRIPTION ............................. 2246
REMOVAL ................................. 2247
INSPECTION............................... 2248
INSTALLATION ............................. 2248
BEARINGS-CRANKSHAFT MAIN
STANDARD PROCEDURE
MAIN BEARING FITTING.................. 2251
SEAL-CRANKSHAFT OIL-FRONT
REMOVAL ................................. 2253
INSTALLATION ............................. 2254
SEAL-CRANKSHAFT OIL-REAR
DIAGNOSIS AND TESTING - REAR SEAL
AREA LEAKS ............................. 2255
REMOVAL ................................. 2255
INSTALLATION ............................. 2256
PLATE-FLEX
REMOVAL ................................. 2257
INSTALLATION ............................. 2257
ROD-PISTON AND CONNECTING
DESCRIPTION ............................. 2258
STANDARD PROCEDURE
CONNECTING ROD BEARING FITTING .... 2258
STANDARD PROCEDURE - PISTON
FITTING.................................. 2261
REMOVAL ................................. 2262
CLEANING ................................. 2262
INSPECTION ............................... 2262
INSTALLATION ............................. 2263
RINGS-PISTON
STANDARD PROCEDURE - PISTON RING
FITTING .................................. 2265
DAMPER-CRANKSHAFT
REMOVAL ................................. 2268
INSTALLATION ............................. 2269
COVER-STRUCTURAL
DESCRIPTION ............................. 2270
OPERATION ............................... 2270
REMOVAL ................................. 2270
INSTALLATION ............................. 2270
MOUNT-FRONT
REMOVAL ................................. 2271
INSTALLATION ............................. 2273
MOUNT-REAR
REMOVAL ................................. 2275
INSTALLATION ............................. 2275
LUBRICATION
DESCRIPTION ............................. 2276
OPERATION ............................... 2276
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE OIL
LEAK.................................... 2278
DIAGNOSIS AND TESTING - CHECKING
ENGINE OIL PRESSURE.................. 2279
DIAGNOSIS AND TESTING - REAR SEAL
AREA LEAKS............................. 2279
PAN-ENGINE OIL
DESCRIPTION ............................. 2280
REMOVAL ................................. 2281
CLEANING ................................. 2282
INSPECTION ............................... 2282
INSTALLATION ............................. 2282SWITCH-OIL PRESSURE
DESCRIPTION ............................. 2284
OPERATION ............................... 2284
REMOVAL ................................. 2284
INSTALLATION ............................. 2284
PUMP-ENGINE OIL
REMOVAL ................................. 2285
DISASSEMBLY . ............................ 2285
INSPECTION............................... 2285
ASSEMBLY................................ 2287
INSTALLATION ............................. 2287
FILTER-ENGINE OIL
REMOVAL ................................. 2288
INSTALLATION ............................. 2288
OIL
STANDARD PROCEDURE - ENGINE OIL
SERVICE ................................. 2289
MANIFOLD-INTAKE
DESCRIPTION ............................. 2291
DIAGNOSIS AND TESTING - INTAKE
MANIFOLD LEAKS ........................ 2291
REMOVAL ................................. 2291
INSTALLATION ............................. 2292
MANIFOLD-EXHAUST
DESCRIPTION ............................. 2294
REMOVAL ................................. 2294
INSTALLATION ............................. 2295
VALVE TIMING
DESCRIPTION ............................. 2297
OPERATION ............................... 2297
STANDARD PROCEDURE
MEASURING TIMING CHAIN WEAR ........ 2298
SERVICE PROCEDURE - TIMING
VERIFICATION........................... 2298
SHAFT-BALANCE
REMOVAL ................................. 2302
INSTALLATION ............................. 2303
SHAFT-IDLER
REMOVAL ................................. 2304
INSTALLATION ............................. 2304
COVER-TIMING
REMOVAL ................................. 2305
INSTALLATION ............................. 2306
CHAIN AND SPROCKETS-TIMING
REMOVAL ................................. 2307
INSPECTION............................... 2309
INSTALLATION ............................. 2310