Temperature vs Resistance - Engine Coolant Temperature (ECT) Sensor
| Temperature C°/F° | Resistance Minimum Ohms | Resistance Maximum Ohms |
|---|---|---|
| Engine Coolant Temperature (ECT) | ||
| 40/-40 | 40,490 | 50,136 |
| 20/-4 | 14,096 | 16,827 |
| 10/14 | 8,642 | 10,152 |
| 0/32 | 5,466 | 6,326 |
| 20/68 | 2,351 | 2,649 |
| 25/77 | 1,941 | 2,173 |
| 40/104 | 1,118 | 1,231 |
| 60/140 | 573 | 618 |
| 80/176 | 313 | 332 |
| 100/212 | 182 | 191 |
| 120/248 | 109 | 116 |
| 140/284 | 068 | 074 |
Temperature vs Resistance - Engine Coolant Temperature (ECT) Sensor
Temperature vs Resistance - Intake Air Temperature (IAT) Sensor
| Temperature C°/F° | Resistance Minimum Ohms | Resistance Maximum Ohms |
|---|---|---|
| Intake Air Temperature (IAT) Sensor | ||
| 40/-40 | 35,140 | 43,760 |
| 20/-4 | 12,660 | 15,120 |
| 10/14 | 7,943 | 9,307 |
| 0/32 | 5,119 | 5,892 |
| 20/68 | 2,290 | 2,551 |
| 25/77 | 1,900 | 2,100 |
| 40/104 | 1,096 | 1,238 |
| 60/140 | 565 | 654 |
| 80/176 | 312 | 370 |
| 100/212 | 184 | 222 |
| 120/248 | 114 | 141 |
| 140/284 | 74 | 93 |
Temperature vs Resistance - Intake Air Temperature (IAT) Sensor
Ignition System Specifications
| Application | Specification | |
|---|---|---|
| Metric | English | |
| Firing Order | 1-2-3-4-5-6 | |
| Spark Plug Gap (non-adjustable) | 1.10 mm | 0.044 in |
| Spark Plug Torque | 20 N.m | 15 lb ft |
| Spark Plug Type | AC 41-988 | |
Ignition System Specifications
Fastener Tightening Specifications
| Application | Specification | |
|---|---|---|
| Metric | English | |
| Accelerator Pedal Position (APP) Sensor Bolt | 9 N.m | 80 lb in |
| Air Cleaner Bolt | 9 N.m | 80 lb in |
| Air Cleaner Cover Screw | 8 N.m | 71 lb in |
| Air Cleaner Duct Clamps | 4 N.m | 35 lb in |
| Barometric Pressure Sensor Bolt | 10 N.m | 89 lb in |
| Camshaft Position Actuator Solenoid Valve | 10 N.m | 89 lb in |
| Camshaft Position (CMP) Sensor Bolt | 10 N.m | 89 lb in |
| Crankshaft Position (CKP) Sensor Bolt | 10 N.m | 89 lb in |
| Engine Control Module (ECM) Bolts | 10 N.m | 89 lb in |
| Engine Control Module (ECM) Bracket Electrical Connector Bracket Bolt | 10 N.m | 89 lb in |
| Engine Control Module (ECM) Bracket to Cylinder Head Bolt | 10 N.m | 89 lb in |
| Engine Control Module (ECM) Bracket to Engine Front Cover Bolt | 23 N.m | 17 lb ft |
| Engine Control Module (ECM) Bracket Wire Harness Retainer Bolt | 23 N.m | 17 lb ft |
| Engine Control Module (ECM) Wiring Harness Ground Wire Bolt | 10 N.m | 89 lb in |
| Engine Control Module (ECM) Redundant Ground Wire Bolt | 5 N.m | 44 lb in |
| Engine Coolant Temperature (ECT) Sensor | 22 N.m | 16 lb ft |
| Evaporative Emission (EVAP) Canister Nut | 6 N.m | 53 lb in |
| Fuel Filler Tube Bolt | 3.5 N.m | 31 lb in |
| Fuel Filler Tube Brace Bolt | 9 N.m | 80 lb in |
| Fuel Filler Tube Hose Clamp | 3.5 N.m | 31 lb in |
| Fuel Filter Bracket Bolt | 9 N.m | 80 lb in |
| Fuel Filter Outlet Fitting | 30 N.m | 22 lb ft |
| Fuel Rail Bolt | 10 N.m | 89 lb in |
| Fuel Tank Strap Bolt | 50 N.m | 37 lb ft |
| Heated Oxygen Sensor (HO2S) | 40 N.m | 30 lb ft |
| Ignition Coil Bolt | 10 N.m | 89 lb in |
| Intake Manifold Runner Control Solenoid Bolt | 10 N.m | 89 lb in |
| Knock Sensor Bolt | 23 N.m | 17 lb ft |
| MAF Sensor Screw | 4 N.m | 35 lb in |
| Rear Frame Bolt | 200 N.m | 148 lb ft |
| Shock Bolt - Lower | 90 N.m | 66 lb ft |
| Spark Plug | 20 N.m | 15 lb ft |
| Throttle Body Bolt | 10 N.m | 89 lb in |
Fastener Tightening Specifications
Action Taken When the DTC Sets - Type A
The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
Action Taken When the DTC Sets - Type B
The control module illuminates the MIL on the second consecutive ignition cycle that the diagnostic runs and fails.
Action Taken When the DTC Sets - Type B1
- The following applies to misfire DTCs: If the control module detects a low level or an emission level misfire condition during 2 consecutive trips, the control module illuminates the MIL. If the control module detects a high level or catalyst damaging misfire, the control module flashes the MIL at a rate of once per second. If the control module detects a misfire during 2 non-consecutive trips, the stored conditions are compared with the current conditions. The control module illuminates the MIL when the following conditions occur: The engine load is within 10 percent of the previous test that failed. The engine speed is within 375 RPM of the previous test that failed. The engine coolant temperature is in the same range of the previous test that failed.
- The following applies to fuel trim DTCs: If the control module detects a fuel trim condition during 2 consecutive trips, the control module illuminates the MIL. If the control module detects a fuel trim condition during 2 non-consecutive trips, the stored conditions are compared with the current conditions. The control module illuminates the MIL when the following conditions occur: The engine load is within 10 percent of the previous test that failed. The engine speed is within 375 RPM of the previous test that failed. The engine coolant temperature is in the same range of the previous test that failed.
Conditions for Clearing the MIL/DTC - Type A or Type B
- The control module turns OFF the MIL after 3 or 4 consecutive ignition cycles depending on the DTC, when the diagnostic runs and does not fail.
- An active DTC clears when the diagnostic runs and passes.
- Use a scan tool in order to clear the MIL and the DTC.
Action Taken When the DTC Sets - Type C
- The control module stores the DTC information into memory when the diagnostic runs and fails.
- The MIL will not illuminate.
- The driver information center, if equipped, may display a message.
Conditions for Clearing the DTC - Type C
- A last test failed, or active DTC, clears when the diagnostic runs and passes.
- Use a scan tool in order to clear the DTC.
Diagnostic Trouble Code (DTC) Type(s)
| DTC | United States, Canada, and Mexico | Unleaded Export - RPO NA3, NT4, NT7 | Unleaded Export - RPO NF9 |
|---|---|---|---|
| P0008 | B | B | C |
| P0009 | B | B | C |
| P0010 | B | B | B |
| P0011 | B | B | B |
| P0013 | B | B | B |
| P0014 | B | B | B |
| P0016 | B | B | C |
| P0017 | B | B | C |
| P0018 | B | B | C |
| P0019 | B | B | C |
| P0020 | B | B | B |
| P0021 | B | B | B |
| P0023 | B | B | B |
| P0024 | B | B | B |
| P0030 | B | B | B |
| P0031 | B | B | B |
| P0032 | B | B | B |
| P0036 | B | B | B |
| P0037 | B | B | B |
| P0038 | B | B | B |
| P0050 | B | B | B |
| P0051 | B | B | B |
| P0052 | B | B | B |
| P0053 | B | B | C |
| P0056 | B | B | B |
| P0057 | B | B | B |
| P0058 | B | B | B |
| P0059 | B | B | C |
| P0101 | B | B | C |
| P0102 | B | B | B |
| P0103 | B | B | B |
| P0112 | B | B | B |
| P0113 | B | B | B |
| P0117 | B | B | B |
| P0118 | B | B | B |
| P0121 | B | B | B |
| P0122 | B | B | B |
| P0123 | B | B | B |
| P0125 | B | B | C |
| P0128 | B | C | C |
| P0130 | B | B | B |
| P0131 | B | B | B |
| P0132 | B | B | B |
| P0133 | B | B | C |
| P0135 | B | B | C |
| P0137 | B | B | B |
| P0138 | B | B | B |
| P0140 | B | B | B |
| P0141 | B | B | C |
| P0150 | B | B | B |
| P0151 | B | B | B |
| P0152 | B | B | B |
| P0153 | B | B | C |
| P0155 | B | B | C |
| P0157 | B | B | B |
| P0158 | B | B | B |
| P0160 | B | B | B |
| P0161 | B | B | C |
| P0201 | B | B | B |
| P0202 | B | B | B |
| P0203 | B | B | B |
| P0204 | B | B | B |
| P0205 | B | B | B |
| P0206 | B | B | B |
| P0221 | B | B | B |
| P0222 | B | B | B |
| P0223 | B | B | B |
| P0261 | B | B | B |
| P0262 | B | B | B |
| P0264 | B | B | B |
| P0265 | B | B | B |
| P0267 | B | B | B |
| P0268 | B | B | B |
| P0270 | B | B | B |
| P0271 | B | B | B |
| P0273 | B | B | B |
| P0274 | B | B | B |
| P0276 | B | B | B |
| P0277 | B | B | B |
| P0300 | B1 | B1 | C |
| P0301 | B1 | B1 | C |
| P0302 | B1 | B1 | C |
| P0303 | B1 | B1 | C |
| P0304 | B1 | B1 | C |
| P0305 | B1 | B1 | C |
| P0306 | B1 | B1 | C |
| P0318 | C | C | C |
| P0324 | B | B | B |
| P0327 | B | B | C |
| P0328 | B | B | C |
| P0332 | B | B | C |
| P0333 | B | B | C |
| P0335 | A | A | A |
| P0336 | A | A | A |
| P0338 | A | A | A |
| P0341 | B | B | B |
| P0342 | B | B | B |
| P0343 | B | B | B |
| P0346 | B | B | B |
| P0347 | B | B | B |
| P0348 | B | B | B |
| P0351 | B | B | B |
| P0352 | B | B | B |
| P0353 | B | B | B |
| P0354 | B | B | B |
| P0355 | B | B | B |
| P0356 | B | B | B |
| P0366 | B | B | B |
| P0367 | B | B | B |
| P0368 | B | B | B |
| P0391 | B | B | B |
| P0392 | B | B | B |
| P0393 | B | B | B |
| P0420 | B | B | C |
| P0430 | B | B | C |
| P0442 | A | X | X |
| P0443 | B | B | B |
| P0446 | B | B | C |
| P0449 | B | B | B |
| P0451 | B | B | C |
| P0452 | B | B | B |
| P0453 | B | B | B |
| P0455 | B | B | C |
| P0458 | B | B | B |
| P0459 | B | B | B |
| P0461 | C | C | C |
| P0462 | C | C | C |
| P0463 | C | C | C |
| P0480 | B | B | B |
| P0481 | B | B | B |
| P0496 | B | B | C |
| P0498 | B | B | B |
| P0499 | B | B | B |
| P0506 | B | C | C |
| P0507 | B | C | C |
| P0521 | C | C | C |
| P0522 | C | C | C |
| P0523 | C | C | C |
| P0532 | C | C | C |
| P0533 | C | C | C |
| P0560 | C | C | C |
| P0562 | C | C | C |
| P0563 | C | C | C |
| P0564 | C | C | C |
| P0571 | C | C | C |
| P0581 | C | C | C |
| P0601 | A | A | A |
| P0602 | A | A | A |
| P0604 | A | A | A |
| P0606 | A | A | A |
| P0608 | C | C | C |
| P0615 | C | C | C |
| P0616 | C | C | C |
| P0617 | C | C | C |
| P0625 | C | C | C |
| P0626 | C | C | C |
| P0627 | B | B | B |
| P0628 | B | B | B |
| P0629 | B | B | B |
| P0638 | A | A | A |
| P0645 | C | C | C |
| P0646 | C | C | C |
| P0647 | C | C | C |
| P0650 | B - No MIL | B - No MIL | B - No MIL |
| P0654 | C | C | C |
| P0691 | B | B | B |
| P0692 | B | B | B |
| P0693 | B | B | B |
| P0694 | B | B | B |
| P0700 | A | A | A |
| P0721 | B | B | C |
| P0722 | B | B | C |
| P0850 | C | C | C |
| P0856 | C | C | C |
| P0864 | C | C | C |
| P1011 | C | C | C |
| P1012 | C | C | C |
| P1013 | C | C | C |
| P1014 | C | C | C |
| P1258 | A | A | A |
| P1551 | A | A | A |
| P1629 | C | C | C |
| P1630 | C | C | C |
| P1631 | C | C | C |
| P1668 | C | C | C |
| P167A | B | B | B |
| P167B | B | B | B |
| P1689 | C | C | C |
| P1845 | C | C | C |
| P2008 | C | C | C |
| P2009 | C | C | C |
| P2010 | C | C | C |
| P2066 | C | C | C |
| P2067 | C | C | C |
| P2068 | C | C | C |
| P2088 | B | B | B |
| P2089 | B | B | B |
| P2090 | B | B | B |
| P2091 | B | B | B |
| P2092 | B | B | B |
| P2093 | B | B | B |
| P2094 | B | B | B |
| P2095 | B | B | B |
| P2096 | B | B | C |
| P2097 | B | B | C |
| P2098 | B | B | C |
| P2099 | B | B | C |
| P2100 | A | A | A |
| P2101 | A | A | A |
| P2105 | A | A | A |
| P2107 | C | C | C |
| P2119 | A | A | A |
| P2122 | A | A | A |
| P2123 | A | A | A |
| P2127 | A | A | A |
| P2128 | A | A | A |
| P2138 | A | A | A |
| P2176 | A | A | A |
| P2177 | B1 | B1 | C |
| P2178 | B1 | B1 | C |
| P2179 | B1 | B1 | C |
| P2180 | B1 | B1 | C |
| P2187 | B1 | B1 | C |
| P2188 | B1 | B1 | C |
| P2189 | B1 | B1 | C |
| P2190 | B1 | B1 | C |
| P2195 | B | B | C |
| P2196 | B | B | C |
| P2197 | B | B | C |
| P2198 | B | B | C |
| P2227 | B | B | C |
| P2228 | B | B | B |
| P2229 | B | B | B |
| P2231 | B | B | C |
| P2232 | B | B | B |
| P2234 | B | B | C |
| P2235 | B | B | B |
| P2237 | B | B | C |
| P2240 | B | B | C |
| P2243 | B | B | C |
| P2247 | B | B | C |
| P2251 | B | B | C |
| P2254 | B | B | C |
| P2270 | B | B | C |
| P2271 | B | B | C |
| P2272 | B | B | C |
| P2273 | B | B | C |
| P2297 | B | B | C |
| P2298 | B | B | C |
| P2300 | B | B | B |
| P2301 | B | B | B |
| P2303 | B | B | B |
| P2304 | B | B | B |
| P2306 | B | B | B |
| P2307 | B | B | B |
| P2309 | B | B | B |
| P2310 | B | B | B |
| P2312 | B | B | B |
| P2313 | B | B | B |
| P2315 | B | B | B |
| P2316 | B | B | B |
| P2626 | B | B | C |
| P2629 | B | B | C |
| P2636 | C | C | C |
| U0001 | A | A | A |
| U0101 | A | A | A |
| U0121 | C | C | C |
| U0155 | C | C | C |
| U0415 | C | C | C |
| U0423 | C | C | C |
Diagnostic Trouble Code (DTC) Type(s)
Scheme 1
| Callout | Component Name |
|---|---|
| 1 | Positive Crankcase Ventilation (PCV) Hose to Cam Cover |
| 2 | Upper Intake Manifold |
| 3 | PCV Hose to Intake Manifold |
| 4 | Throttle Body Assembly |
| 5 | Evaporative Emissions (EVAP) Canister Purge Solenoid |
| 6 | Emissions Hose to EVAP Canister |
Scheme 2
| Callout | Component Name |
|---|---|
| 1 | EVAP Service Port Connection |
| 2 | Fuel Filler Pipe Vapor Recirculation Hose |
| 3 | Fuel Tank Pressure (FTP) Sensor |
| 4 | EVAP Purge Canister |
| 5 | EVAP Vent Valve |
| 6 | Fill Limit Vent Valve (FLVV) |
| 7 | Fuel Tank Vent/Rollover Valve |
| 8 | EVAP Purge Solenoid |
Scheme 3
| Callout | Component Name |
|---|---|
| 1 | Secondary Fuel Sender Assembly - Left |
| 2 | Primary Fuel Sender Assembly - Right |
| 3 | Fuel Feed Hose |
| 4 | Fuel Feed Pipe |
| 5 | Fuel Pressure Test Connection |
| 6 | Fuel Rail and Injectors |
| 7 | Fuel Filter |
| 8 | Fuel Return Hose |
| 9 | Fuel Filler Tube |
| 10 | Fill Limit Vent Valve (FLVV) |
| 11 | Fuel Tank |
Engine Controls Schematic Icons
Engine Controls Schematic Icons Icon Icon Definition NOTE: The OBD II symbol is used on the circuit diagrams in order to alert the technician that the circuit is essential for proper OBD II emission control circuit operation. Any circuit which fails and causes the malfunction indicator lamp (MIL) to turn ON, or causes emissions-related component damage, is identified as an OBD II circuit. IMPORTANT: Twisted-pair wires provide an effective shield that helps protect sensitive electronic components from electrical interference. If the wires were covered with shielding, install new shielding. In order to prevent electrical interference from degrading the performance of the connected components, you must maintain the proper specification when making any repairs to the twisted-pair wires shown : The wires must be twisted a minimum of 9 turns per 31 cm (12 in) as measured anywhere along the length of the wires The outside diameter of the twisted wires must not exceed 6.0 mm (0.25 in)
Scheme 4
Scheme 5
Scheme 6
Scheme 7
Scheme 8
Scheme 9
Scheme 10
Scheme 11
Scheme 12
Scheme 13
Scheme 14
Scheme 15
Scheme 16
Scheme 17
Scheme 18
Scheme 19
| Callout | Component Name |
|---|---|
| 1 | Intake Manifold Runner Control (IMRC) Solenoid |
| 2 | Ignition Coil 5 |
| 3 | Evaporative Emission (EVAP) Canister Purge Solenoid Valve |
| 4 | Ignition Coil 3 |
| 5 | Ignition Coil 1 |
| 6 | Throttle Body Assembly |
| 7 | Knock Sensor (KS) - Bank 1 |
| 8 | Crankshaft Position (CKP) Sensor |
| 9 | Engine Block Heater Assembly |
Scheme 20
| Callout | Component Name |
|---|---|
| 1 | Ignition Coil 2 |
| 2 | Ignition Coil 4 |
| 3 | Ignition Coil 6 |
| 4 | Barometric Pressure (BARO) Sensor |
| 5 | Intake Manifold Runner Control (IMRC) Solenoid |
| 6 | Engine Coolant Temperature (ECT) Sensor |
| 7 | Knock Sensor (KS) - Bank 2 |
| 8 | Engine Oil Level/Temperature Sensor |
| 9 | Engine Oil Pressure (EOP) Sensor |
Scheme 21
| Callout | Component Name |
|---|---|
| 1 | Camshaft Position (CMP) Sensor - Exhaust Bank 1 |
| 2 | Camshaft Position (CMP) Actuator Solenoid - Exhaust Bank 1 |
| 3 | Camshaft Position (CMP) Actuator Solenoid - Intake Bank 1 |
| 4 | Camshaft Position (CMP) Sensor - Intake Bank 1 |
| 5 | Camshaft Position (CMP) Sensor - Intake Bank 2 |
| 6 | Camshaft Position (CMP) Actuator Solenoid - Intake Bank 2 |
| 7 | Camshaft Position (CMP) Actuator Solenoid - Exhaust Bank 2 |
| 8 | Camshaft Position (CMP) Sensor - Exhaust Bank 2 |
Scheme 22
| Callout | Component Name |
|---|---|
| 1 | Mass Air Flow (MAF) Sensor |
| 2 | Radiator |
| 3 | Throttle Body Assembly |
Scheme 23
| Callout | Component Name |
|---|---|
| 1 | Park Brake Switch |
| 2 | Brake Pedal Position Sensor |
| 3 | Accelerator Pedal Position (APP) Sensor |
| 4 | Left Front Floor Panel |
Scheme 24
| Callout | Component Name |
|---|---|
| 1 | HO2S - Bank 2 Sensor 1 |
| 2 | HO2S - Bank 1 Sensor 1 |
| 3 | HO2S - Bank 1 Sensor 2 |
| 4 | HO2S - Bank 2 Sensor 2 |
Scheme 25
| Callout | Component Name |
|---|---|
| 1 | EVAP Canister |
| 2 | Evaporative Emissions (EVAP) Canister Vent Solenoid (LY7/LH2) |
| 3 | Fuel Tank |
| 4 | Secondary Fuel Sender Assembly |
| 5 | Fuel Pump and Sender Assembly (LY7/LH2) |
| 6 | C420 |
| 7 | Fuel Tank Pressure (FTP) Sensor (LY7/LH2) |
Scheme 26
| Callout | Component Name |
|---|---|
| 1 | Valve Cover - Right |
| 2 | Fuel Injector 5 |
| 3 | Intake Manifold |
| 4 | Fuel Injector 6 |
| 5 | Fuel Injector 4 |
| 6 | Fuel Injector 2 |
| 7 | Valve Cover - Left |
| 8 | Fuel Injector 1 |
| 9 | Fuel Injector 3 |
Scheme 27
| Callout | Component Name |
|---|---|
| 1 | Evaporative Emission (EVAP) Canister Purge Solenoid Valve |
| 2 | Intake Manifold |
| 3 | Throttle Actuator Control (TAC) Motor |
| 4 | Engine Control Module (ECM) |
| 5 | G103 |
Engine Control Module (ECM) Connector End Views
Engine Control Module (ECM) C1 Connector End Connector Part Information OEM: 1928403513 Service: 64-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 TN 407 KS Low Reference Bank 2 2 OG 5278 Heated Oxygen Sensor Input Pump Current Bank 1 Sensor (1) 3 L-GN 5280 Heated Oxygen Sensor Input Pump Current Bank 2 Sensor (1) 4 OG 5275 Camshaft Position Intake Sensor (1) 5 GY 605 Reference Voltage Feed - 5-Volt Reference 6 YE 7017 Variable Intake Manifold Position Signal 7 TN 470 Low Reference 8 PU 486 Throttle Position Sensor Signal 2 9 D-GN/WH 2124 Electronic Spark Timing Signal Cylinder 4 10 WH/BK 5039 Engine Speed Sensor High 11 - - Not Used 12 OG/BK 5272 Camshaft Phaser Intake Solenoid (2) 13 L-GN 5282 Camshaft Phaser Exhaust Solenoid (1) 14 - - Not Used 15 BN 582 Throttle Motor Feed - Close 16 GY/WH 5037 Heated Oxygen Sensor Heater High Control Bank 2 Sensor (2) 17 GY 1716 Knock Sensor Return 18 TN 1653 Oxygen Sensor Return - Left - Forward of Catalytic Converter 19 PU/WH 1666 Oxygen Sensor Signal - Right - Forward of Catalytic Converter 20 D-GN 5273 Camshaft Position Exhaust Sensor (1) 21 GY 23 Alternator Field Duty Cycle Signal 22 - - Not Used 23 YE 410 Coolant Temperature Sensor Signal 24 - - Not Used 25 L-BU/WH 2126 Electronic Spark Timing Signal Cylinder 6 26 OG/WH 2122 Electronic Spark Timing Signal Cylinder 2 27-28 - - Not Used 29 PU 5284 Camshaft Phaser Intake Solenoid (1) 30 WH/BK 5283 Camshaft Phaser Exhaust Solenoid (2) 31 YE 581 Throttle Motor Feed - Open 32 L-GN 5038 Heated Oxygen Sensor Heater High Control Bank 1 Sensor (3) 33 D-BU 496 Knock Sensor Signal 1 34 PU 1665 Oxygen Sensor Signal - Left - Forward of Catalytic Converter 35 WH 5281 Heated Oxygen Sensor Pump Current Bank 2 Sensor (1) 36 PU 5274 Camshaft Position Exhaust Sensor (2) 37 BN 1174 Oil Level Sensor Signal 38 D-GN/WH 357 Oil Temperature Sensor Signal 39 TN 2752 Sensor Return - Throttle Position Sensor 40 TN/BK 231 Oil Pressure Switch Signal 41 D-GN 2125 Electronic Spark Timing Signal Cylinder 5 42 PU 2121 Electronic Spark Timing Signal Cylinder 1 43 OG 225 Alternator Output - Regulator Reference Voltage 44 L-BU/BK 5041 Intake Manifold Control (1) 45 L-BU/BK 844 Fuel Injector 4 Output 46 PK/BK 1746 Fuel Injector 3 Output 47 TN/WH 845 Fuel Injector 5 Output 48 L-GN/WH 428 Canister Purge Solenoid Output 49 GY/BK 1798 Return 50 L-BU 1876 Knock Sensor Signal 2 51 PU/WH 5279 Heated Oxygen Sensor Pump Current Bank 1 Sensor (1) 52 TN 1667 Oxygen Sensor Return - Right - Forward of Catalytic Converter 53 YE 5276 Camshaft Position Intake Sensor (2) 54 GY 2701 Reference Voltage Feed - 5-Volt Ref - Throttle Position Sensor 55 D-GN 485 Throttle Position Sensor Signal 1 56 OG/BK 5266 Baro Sensor Signal 57 GY 705 Reference Voltage Feed - 5-Volt Reference 58 L-BU 2123 Electronic Spark Timing Signal Cylinder 3 59 PU/WH 5024 Engine Speed Sensor Low 60-61 - - Not Used 62 L-GN/BK 1745 Fuel Injector 2 Output 63 TN 1744 Fuel Injector 1 Output 64 YE/BK 846 Fuel Injector 6 Output
Engine Control Module (ECM) C2 Connector End Connector Part Information OEM: 1928403386 Service: 64-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 PK/BK 5290 Engine Main Relay Fused Control (1) 2 BK/WH 3122 Oxygen Sensor Heater Control Low - Front 3 PK 239 Run/Crank Ignition 1 Voltage 4 D-BU 473 High Speed Cooling Fan Relay Control 5-6 - - Not Used 7 WH/BK 1164 Electronic Throttle - Pedal Position 5-Volt Ref 1 8 PU 1272 Electronic Throttle - Pedal Position 2 9 RD/BK 380 Air Conditioning Refrigerant Pressure Sensor Signal 10 WH 17 Stop Lamp Switch Signal 11 TN 472 Manifold Absolute Temperature Sensor Signal 12 D-GN 890 Fuel Tank Pressure Sensor Signal 13-16 - - Not Used 17 PK/BK 5290 Engine Main Relay Fused Control (1) 18 RD/WH 3223 Oxygen Sensor Signal - Bank 2 Sensor 2 Heater Control Low 19 D-GN/WH 465 Fuel Pump Primary Relay Control 20 D-GN 335 Low Speed Cooling Fan Relay Control 21 - - Not Used 22 BN 818 Vehicle Speed Signal 23 TN/BK 2500 High Speed GMLAN Serial Data (+) (1) 24 BN 5069 Engine Main Relay Coil Control 25 BK 452 Sensor Return 26 BK 2760 Sensor Return - Induction Air Temperature 27 L-BU 1937 Fuel Gage Sensor Signal - Right 28 - - Not Used 29 PU/WH 1668 Heated Oxygen Sensor High Signal Bank 1 Sensor (2) 30-31 - - Not Used 32 OG/BK 1786 Transmission Park/Neutral Signal 33 WH 1310 Canister Vent Valve Solenoid Output 34 - - Not Used 35 YE 447 Starter Relay Coil Control 36 RD/WH 1440 Battery Positive Voltage 37-38 - - Not Used 39 GY 596 Reference Voltage Feed - 5-Volt Reference 40 BN 1271 Electronic Throttle - Pedal Position Return 1 41 TN 1671 Heated Oxygen Sensor Low Signal Bank 2 Sensor (2) 42 D-BU 1936 Fuel Gage Sensor Signal - Left 43 YE 492 Mass Air Flow Signal 44 L-BU 1162 Electronic Throttle - Pedal Position Signal 2 45-48 - - Not Used 49 D-GN/WH 459 A/C Compressor Clutch Relay Control 50 BN/WH 419 Check Engine Indicator Lamp Output 51-54 - - Not Used 55 TN 2501 High Speed GMLAN Serial Data (-) (1) 56 TN 1274 Electronic Throttle - Pedal Position 5-Volt Ref 2 57 TN/WH 1669 Oxygen Sensor Return - Left - Rear of Catalytic Converter 58 YE/BK 5728 ECM/TCM Serial Data Wake Up 59 - - Not Used 60 D-BU 1161 Electronic Throttle - Pedal Position Signal 1 61 PU 1670 Heated Oxygen Sensor High Signal Bank 2 Sensor (2) 62-64 - - Not Used
Engine Controls Connector End Views
Accelerator Pedal Position (APP) Sensor Connector End Connector Part Information OEM: 15326829 Service: 88953153 6-Way F 150 Series Sealed (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A PU 1272 Accelerator Pedal Position Low Reference (2) B L-BU 1162 Accelerator Pedal Position Signal (2) C TN 1274 Accelerator Pedal Position 5-Volt Reference (2) D BN 1271 Accelerator Pedal Position Low Reference (1) E D-BU 1161 Accelerator Pedal Position Signal (1) F WH/BK 1164 Accelerator Pedal Position 5-Volt Reference (1)
Barometric Pressure (BARO) Sensor Connector End Connector Part Information OEM: 1928403966 Service: 3-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 GY 605 Reference Voltage Feed 5-Volt Reference 2 TN 470 Sensor Return 3 L-GN 432 Manifold Absolute Pressure Sensor Signal
Camshaft Position (CMP) Actuator Solenoid Exhaust Bank 1 Connector End Connector Part Information OEM: 7283-7526-30 Service: 2-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 PK/BK 5293 Engine Main Relay Fused Control (4) 2 L-GN 5282 Camshaft Phaser Exhaust Solenoid (1)
Camshaft Position (CMP) Actuator Solenoid Exhaust Bank 2 Connector End Connector Part Information OEM: 7283-7526-30 Service: 2-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 PK/BK 5293 Engine Main Relay Fused Control (4) 2 WH/BK 5283 Camshaft Phaser Exhaust Solenoid (2)
Camshaft Position (CMP) Actuator Solenoid Intake Bank 1 Connector End Connector Part Information OEM: 7283-7526-30 Service: 2-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 PK/BK 5293 Engine Main Relay Fused Control (4) 2 PU 5284 Camshaft Phaser Intake Solenoid (1)
Camshaft Position (CMP) Actuator Solenoid Intake Bank 2 Connector End Connector Part Information OEM: 7283-7526-30 Service: 2-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 PK/BK 5293 Engine Main Relay Fused Control (4) 2 OG/BK 5272 Camshaft Phaser Intake Solenoid (2)
Camshaft Position (CMP) Sensor Exhaust Bank 1 Connector End Connector Part Information OEM: 1928403966 Service: 3-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 TN 470 Sensor Return 2 D-GN 5273 Camshaft Position Exhaust Sensor (1) 3 GY 705 Reference Voltage Feed 5-Volt Reference
Camshaft Position (CMP) Sensor Exhaust Bank 2 Connector End Connector Part Information OEM: 1928403966 Service: 3-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 TN 470 Sensor Return 2 PU 5274 Camshaft Position Exhaust Sensor (2) 3 GY 705 Reference Voltage 5-Volt Reference
Camshaft Position (CMP) Sensor Intake Bank 1 Connector End Connector Part Information OEM: 1928403966 Service: 3-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 TN 470 Sensor Return 2 OG 5275 Camshaft Position Intake Sensor (1) 3 GY 705 Reference Voltage Feed 5-Volt Reference
Camshaft Position (CMP) Sensor Intake Bank 2 Connector End Connector Part Information OEM: 1928403966 Service: 3-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 TN 470 Sensor Return 2 YE 5276 Camshaft Position Intake Sensor (2) 3 GY 705 Reference Voltage Feed 5-Volt Reference
Crankshaft Position (CKP) Sensor Connector End Connector Part Information OEM: 1928403874 Service: 2-Way F ? (?) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 PU/WH 5024 Engine Speed Sensor Low 2 WH/BK 5039 Engine Speed Sensor High
Engine Coolant Temperature (ECT) Sensor Connector End Connector Part Information OEM: 1928403874 Service: 2-Way F ? (?) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 YE 410 Coolant Temperature Sensor Signal 2 TN 470 Sensor Return
Evaporative Emission (EVAP) Canister Purge Solenoid Valve Connector End Connector Part Information OEM: 1928404072 Service: 2-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 PK/BK 5293 Engine Main Relay Fused Control (4) 2 L-GN/WH 428 Canister Purge Solenoid Output
Evaporative Emission (EVAP) Canister Vent Solenoid Connector End Connector Part Information OEM: 12052643 Service: 12101858 2-Way F Metri-Pack 150 Series Sealed (RD) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A OG 1540 Fuse Output - Battery - Type III Fuse B WH 1310 Canister Vent Valve Solenoid Output
Fuel Injector 1 Connector End Connector Part Information OEM: 15305086 Service: 15306318 2-Way F Metri-Pack 150 Series (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A PK/BK 5291 Engine Main Relay Fused Control (2) B TN 1744 Fuel Injector 1 Output
Fuel Injector 2 Connector End Connector Part Information OEM: 15305086 Service: 15306318 2-Way F Metri-Pack 150 Series (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A PK/BK 5292 Engine Main Relay Fused Control (3) B L-GN/BK 1745 Fuel Injector 2 Output
Fuel Injector 3 Connector End Connector Part Information OEM: 15305086 Service: 15306318 2-Way F Metri-Pack 150 Series (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A PK/BK 5291 Engine Main Relay Fused Control (2) B WH 1746 Fuel Injector 3 Output
Fuel Injector 4 Connector End Connector Part Information OEM: 15305086 Service: 15306318 2-Way F Metri-Pack 150 Series (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A PK/BK 5292 Engine Main Relay Fused Control (3) B L-BU/BK 844 Fuel Injector 4 Output
Fuel Injector 5 Connector End Connector Part Information OEM: 15305086 Service: 15306318 2-Way F Metri-Pack 150 Series (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A PK/BK 5291 Engine Main Relay Fused Control (2) B TN/WH 845 Fuel Injector 5 Output
Fuel Injector 6 Connector End Connector Part Information OEM: 15305086 Service: 15306318 2-Way F Metri-Pack 150 Series (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A PK/BK 5292 Engine Main Relay Fused Control (3) B YE/BK 846 Fuel Injector 6 Output
Fuel Pump and Sender Assembly Connector End Connector Part Information OEM: 12160482 Service: 12167154 4-Way F (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A D-BU 1936 Primary Fuel Level Sensor Signal B GY 120 Fuel Pump Motor Feed C BK 1050 Ground D BK 2759 Fuel Tank Pressure Sensor Low Reference
Fuel Tank Pressure (FTP) Sensor Connector End Connector Part Information OEM: 12059595 Service: 88986451 3-Way F Metri-Pack 150 Series Sealed (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A TN 2759 Sensor Return - Fuel Tank Press 1 Sensor B D-GN 890 Fuel Tank Pressure Sensor Signal C GY/BK 2709 Reference Voltage Feed 5-Volt Reference - Fuel Tank Press 1 Sensor
Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1 Connector End Connector Part Information OEM: 1475104-1 Service: 6 Way F Unknown (?) (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 PU/WH 1665 Oxygen Sensor Signal - Left - Forward Of Catalytic Converter 2 WH 5279 Heated Oxygen Sensor Pump Current Bank 1 Sensor (1) 3 PK/BK 5293 Engine Main Relay Fused Control (4) 4 L-BU 5038 Heated Oxygen Sensor Heater High Control Bank 1 Sensor (3) 5 TN/WH 1653 Oxygen Sensor Return - Left - Forward Of Catalytic Converter 6 L-GN 5278 Heated Oxygen Sensor Input Pump Current Bank 1 Sensor (1)
Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2 Connector End Connector Part Information OEM: 12092839 Service: 4-Way M Metri-Pack 150 Series Sealed (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A TN/WH 1669 Oxygen Sensor Return - Left - Rear Of Catalytic Converter B PU/WH 1668 Oxygen Sensor Signal - Left - Rear Of Catalytic Converter C BK/WH 3122 Oxygen Sensor Heater Control Low - Front D PK/BK 5294 Engine Main Relay Fused Control (5)
Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 Connector End Connector Part Information OEM: 1475104-1 Service: 6-Way F Unknown (?) (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 PU 1666 Oxygen Sensor Signal - Right - Forward Of Catalytic Converter 2 PU/WH 5281 Heated Oxygen Sensor Pump Current Bank 2 Sensor (1) 3 PK/BK 5293 Engine Main Relay Fused Control (4) 4 PU/WH 5037 Heated Oxygen Sensor Heater High Control Bank 2 Sensor (2) 5 TN 1667 Oxygen Sensor Return - Right - Forward Of Catalytic Converter 6 OG 5280 Heated Oxygen Sensor Input Pump Current Bank 2 Sensor (1)
Heated Oxygen Sensor (HO2S) Bank 2 Sensor 2 Connector End Connector Part Information OEM: 12092839 Service: 4-Way M Metri-Pack 150 Series (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A TN 1671 Oxygen Sensor Return - Right - Rear Of Catalytic Converter B PU 1670 Oxygen Sensor Signal - Right - Rear Of Catalytic Converter C RD/WH 3223 Oxygen Sensor Signal - Bank 2 Sensor 2 Heater Control Low D PK/BK 5294 Engine Main Relay Fused Control (5)
Ignition Coil 1 Connector End Connector Part Information OEM: 1928403441 Service: 4-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 PU 2121 Electronic Spark Timing Signal Cylinder 1 2 PK/BK 5291 Engine Main Relay Fused Control (2) 3 BK/WH 1551 Ground - Clean 4 BK 1550 Ground
Ignition Coil 2 Connector End Connector Part Information OEM: 1928403441 Service: 4-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 OG/WH 2122 Electronic Spark Timing Signal Cylinder 2 2 PK/BK 5292 Engine Main Relay Fused Control (3) 3 BK/WH 151 Ground - Clean 4 BK 150 Ground
Ignition Coil 3 Connector End Connector Part Information OEM: 1928403441 Service: 4-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 L-BU 2123 Electronic Spark Timing Signal Cylinder 3 2 PK/BK 5291 Engine Main Relay Fused Control (2) 3 BK/WH 1551 Ground - Clean 4 BK 1550 Ground
Ignition Coil 4 Connector End Connector Part Information OEM: 1928403441 Service: 4-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 D-GN/WH 2124 Electronic Spark Timing Signal Cylinder 4 2 PK/BK 5292 Engine Main Relay Fused Control (3) 3 BK/WH 151 Ground - Clean 4 BK 150 Ground
Ignition Coil 5 Connector End Connector Part Information OEM: 1928403441 Service: 4-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 D-GN 2125 Electronic Spark Timing Signal Cylinder 5 2 PK/BK 5291 Engine Main Relay Fused Control (2) 3 BK/WH 1551 Ground - Clean 4 BK 1550 Ground
Ignition Coil 6 Connector End Connector Part Information OEM: 1928403441 Service: 4-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 L-BU/WH 2126 Electronic Spark timing Signal Cylinder 6 2 PK/BK 5292 Engine Main Relay Fused Control (3) 3 BK/WH 151 Ground - Clean 4 BK 150 Ground
Intake Manifold Runner Control (IMRC) Solenoid Connector End Connector Part Information OEM: 15326389 Service: 5-Way F Metri-Pack 150 Series (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A TN 470 Sensor Low Reference B YE 7017 Variable Intake Manifold Position Signal C L-BU/WH 5041 Intake Manifold Control D BK 1450 Ground E PK/BK 5293 Engine Main Relay Fused Control (4)
Knock Sensor (KS) Bank 1 Connector End Connector Part Information OEM: 1928403874 Service: 2-Way F (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 D-BU 496 Knock Sensor Signal 1 2 GY 1716 Knock Sensor Return
Knock Sensor (KS) Bank 2 Connector End Connector Part Information OEM: 1928403874 Service: 2-Way F (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 L-BU 1876 Knock Sensor Signal 2 2 TN 407 Sensor Return
MAF/IAT Sensor Connector End Connector Part Information OEM: 1928403200 Service: 5-Way F Unknown (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 TN 472 Manifold Absolute Temperature Sensor Signal 2 PK 439 Run/Crank Ignition 1 Voltage 3 BK 2760 Sensor Return - Induction Air Temperature 4 GY 596 Reference Voltage Feed - 5-Volt Reference 5 YE 492 Mass Air Flow Sensor Signal
Secondary Fuel Sender Assembly Connector End Connector Part Information OEM: 12160482 Service: 12167154 4-Way F Metri-Pack 150 Series Sealed (WH) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A L-BU 1937 Secondary Fuel Level Sensor Signal B-C - - Not Used D BK 2759 Fuel Tank Pressure Sensor Low Reference
Throttle Body Assembly Connector End Connector Part Information OEM: 1928404900 Service: 6-Way F Bosch (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 D-GN 581 Throttle Actuator Control Open 2 GY 2752 Throttle Position Sensor Low Reference 3 TN 2701 Throttle Position Sensor 5-Volt Reference 4 PU 582 Throttle Actuator Control Close 5 YE 486 Throttle Position Sensor Signal 2 6 TN 485 Throttle Position Sensor Signal 1
Removal Procedure
- Turn the ignition OFF.
- Remove the front compartment sight shields as necessary. Refer to «Sight Shields, Hood Adjuster, Hood Bumper, Hood Latch Replacement»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
- Using a scan tool, retrieve the percentage of remaining engine oil and the remaining automatic transmission fluid life. Record the remaining engine oil and the remaining automatic transmission fluid life.
- Use a DMM in order to measure the main relay circuit voltage at the ECM fuse in the underhood fuse block. Refer to «Electrical Center Identification Views»(/cadillac/sts/i-2004-2007/remont/electrical-component-locations/#wiring-systems-electrical-power-management-component-locator) in Wiring Systems.
- Disconnect the battery negative cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/cadillac/sts/i-2004-2007/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
- Remove the ECM fuse in the underhood fuse block. Refer to «Electrical Center Identification Views»(/cadillac/sts/i-2004-2007/remont/electrical-component-locations/#wiring-systems-electrical-power-management-component-locator) in Wiring Systems.
- Remove the TCM/IPC fuse in the underhood fuse block. Refer to «Electrical Center Identification Views»(/cadillac/sts/i-2004-2007/remont/electrical-component-locations/#wiring-systems-electrical-power-management-component-locator) in Wiring Systems.
- Remove the ECM/TCM fuse in the underhood fuse block. Refer to «Electrical Center Identification Views»(/cadillac/sts/i-2004-2007/remont/electrical-component-locations/#wiring-systems-electrical-power-management-component-locator) in Wiring Systems.
- Unlock the chassis side (upper) engine control module (ECM) electrical connector. Depress the ECM electrical connector lever lock (1). Simultaneously rotate the ECM connector clamp lever and depress the lock slide (2).
- Remove the body side (upper) ECM connector.
- Unlock and remove the engine side (lower) ECM connector.
- Remove the ECM redundant ground wire and bolt (2) from the ECM.
- Remove the ECM bolts.
- Remove the ECM.
- If you are replacing the ECM bracket, perform the following steps
- Remove the electrical connector bracket and bolt from the ECM bracket.
- Remove the ground wire and bolt from the ECM bracket.
- Remove the wire harness retainer and bolt from the side of the ECM bracket.
- Remove the ECM bracket bolts (2 and 3).
- Remove the ECM bracket (1).
Installation Procedure
- Install the ECM bracket (1).
- Install the ECM bracket bolts (2 and 3). Tighten: Tighten the ECM bracket bolt (2) to 10 N.m (89 lb in). Tighten the ECM bracket bolts (3) to 23 N.m (17 lb ft).
- Install the wire harness retainer and bolt to the side of the ECM bracket. Tighten: Tighten the wire harness retainer bolt to 23 N.m (17 lb ft).
- Install the electrical connector bracket and bolt to the ECM bracket. Tighten: Tighten the electrical connector bracket bolt to 10 N.m (89 lb in).
- Install the wiring harness ground wire and bolt (2) to the ECM bracket. Tighten: Tighten the wiring harness ground wire bolt 10 N.m (89 lb in).
- Install the ECM.
- Install the ECM bolts. Tighten: Tighten the ECM bolts to 10 N.m (89 lb in).
- Install the ECM redundant ground and bolt (2) to the ECM. Tighten: Tighten the ECM redundant ground wire bolt to 5 N.m (44 lb in).
- Install the engine side (lower) ECM connector.
- Install the body side (upper) ECM connector.
- Install the ECM/TCM fuse in the underhood fuse block. Refer to «Electrical Center Identification Views»(/cadillac/sts/i-2004-2007/remont/electrical-component-locations/#wiring-systems-electrical-power-management-component-locator) in Wiring Systems.
- Install the TCM/IPC fuse in the underhood fuse block. Refer to «Electrical Center Identification Views»(/cadillac/sts/i-2004-2007/remont/electrical-component-locations/#wiring-systems-electrical-power-management-component-locator) in Wiring Systems.
- Install the ECM fuse in the underhood fuse block. Refer to «Electrical Center Identification Views»(/cadillac/sts/i-2004-2007/remont/electrical-component-locations/#wiring-systems-electrical-power-management-component-locator) in Wiring Systems.
- Connect the battery negative cable to the battery. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/cadillac/sts/i-2004-2007/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
- Program the ECM. Refer to «Control Module References»(/cadillac/sts/i-2004-2007/remont/communication-devices/#computerintegrating-systems__control-module-references) in Computer/Integrating Systems.
- Turn OFF the ignition for at least 5 seconds after the programming event is complete.
- Install the front compartment sight shields as necessary. Refer to «Sight Shields, Hood Adjuster, Hood Bumper, Hood Latch Replacement»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
Description
The engine control module (ECM) learns the idle position of the throttle body to ensure the correct idle operation. Anytime the ECM or the throttle body is replaced, the ECM must learn the idle position. The engine idle may be unstable or a DTC may set if the idle position is not learned.
Conditions for Running the Idle Learn Procedure
- DTCs P0121, P0122, P0123, P0221, P0222, P0223, P0638, P2100, P2101, P2105, P2107, and P2119 are not set.
- The engine speed is less than 40 RPM.
- The vehicle speed is 0 km/h (0 mph).
- The accelerator pedal position is less than 14.9 percent.
- The ignition 1 voltage is more than 10 volts.
- The engine coolant temperature is between 5-85°C (41-185°F).
- The intake air temperature is between 5-60°C (41-140°F).
Idle Learn Procedure
- Turn OFF the ignition for 30 seconds.
- Turn ON the ignition, with the engine OFF for 60 seconds.
- Turn OFF the ignition.
- Turn ON the ignition, with the engine OFF.
- Clear the DTCs with a scan tool.
| CAUTION | Allow sufficient time for the engine to cool before removing the ECT sensor. A hot engine may cause an excessive coolant loss or a personal injury. |
- Turn the ignition OFF.
- Remove the front compartment sight shields as necessary. Refer «Sight Shields, Hood Adjuster, Hood Bumper, Hood Latch Replacement»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
- Disconnect the engine coolant temperature (ECT) sensor electrical connector.
- Remove the coolant temperature sensor.
- Install the coolant temperature sensor. Tighten: Tighten the coolant temperature sensor to 22 N.m (16 lb ft).
- Install the coolant temperature sensor electrical connector.
- Inspect and fill the cooling system as necessary. Refer to «Draining and Filling Cooling System»(/cadillac/sts/i-2004-2007/remont/cooling-system-mechanical/#engine-cooling-system) in Engine Cooling.
- Install the front compartment sight shields as necessary. Refer «Sight Shields, Hood Adjuster, Hood Bumper, Hood Latch Replacement»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
- Turn the ignition OFF.
- Remove the mass air flow (MAF) electrical connector.
- Remove the air cleaner intake duct. Refer to «Air Cleaner Intake Duct Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Remove the MAF sensor fasteners.
- Remove the MAF sensor and the MAF sensor seal.
- Discard the MAF sensor seal.
- Install the new MAF sensor seal and the MAF sensor.
- Install the MAF sensor screws. Tighten: Tighten the MAF sensor screws to 4 N.m (35 lb in).
- Install the air cleaner intake duct. Refer to «Air Cleaner Intake Duct Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Install the MAF electrical connector.
- Turn the ignition OFF.
- Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
- Disconnect the barometric pressure (BARO) sensor electrical connector.
- Remove the BARO sensor bolt.
- Remove the BARO sensor.
- Install the BARO sensor.
- Install the BARO sensor bolt. Tighten: Tighten the sensor bolt to 10 N.m (89 lb in).
- Connect the BARO sensor electrical connector.
- Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
- Turn the ignition OFF.
- Remove the fuel injector sight shield, if necessary. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
- Disconnect the heated oxygen sensor (HO2S) electrical connector.
- Remove the HO2S electrical connector from the wiring harness bracket.
- Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) in General Information.
- Remove the HO2S from the catalytic converter.
- Install the HO2S to the catalytic converter. Tighten: Tighten the HO2S to 40 N.m (30 lb ft).
- Lower the vehicle.
- Install the HO2S electrical connector to the wiring harness bracket.
- Connect the HO2S electrical connector.
- Install the fuel injector sight shield, if necessary. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
- Turn the ignition OFF.
- Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) in General Information.
- Disconnect the heated oxygen sensor (HO2S) electrical connector.
- Remove the HO2S wiring harness from the transmission case.
- Remove the HO2S.
- Install the HO2S. Tighten: Tighten the HO2S to 40 N.m (30 lb ft).
- Connect the HO2S electrical connector.
- Install the HO2S wiring harness to the transmission case.
- Lower the vehicle.
- Turn the ignition OFF.
- Remove the fuel injector sight shield, if necessary. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
- Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) in General Information.
- Disconnect the heated oxygen sensor (HO2S) electrical connector.
- Remove the HO2S electrical connector from the wiring harness bracket.
- Remove the HO2S.
- Install the HO2S. Tighten: Tighten the HO2S to 40 N.m (30 lb ft).
- Install the HO2S electrical connector to the wiring harness bracket.
- Connect the HO2S electrical connector.
- Lower the vehicle.
- Install the fuel injector sight shield, if necessary. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
- Turn the ignition OFF.
- Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) in General Information.
- Disconnect the heated oxygen sensor (HO2S) electrical connector (bank 1 shown, bank 2 similar).
- Remove the HO2S wiring harness from the transmission case.
- Remove the HO2S.
- Install the HO2S. Tighten: Tighten the HO2S to 40 N.m (30 lb ft).
- Connect the HO2S electrical connector (bank 1 shown, bank 2 similar).
- Install the HO2S wiring harness to the transmission case.
- Lower the vehicle.
- Remove the closeout/insulator panel from under the dashboard on the drivers side. Refer to «Closeout/Insulator Panel Replacement - Left»(/cadillac/sts/i-2004-2007/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges-and-console) in Instrument Panel, Gages and Console.
- Disconnect the accelerator pedal position (APP) sensor electrical connector from the accelerator pedal module.
- Remove the APP sensor mounting bolts.
- Remove the APP sensor from the vehicle.
- Position the APP sensor to the mounting plate.
- Install the APP sensor mounting bolts. Tighten: Tighten the APP sensor mounting bolts to 9 N.m (80 lb in).
- Connect the APP sensor electrical connector.
- Operate the accelerator pedal and observe the APP angles using a scan tool. The accelerator pedal should operate freely, without binding between closed throttle and wide open throttle.
- Install the closeout/insulator panel. Refer to «Closeout/Insulator Panel Replacement - Left»(/cadillac/sts/i-2004-2007/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges-and-console) in Instrument Panel, Gages and Console.
- Turn the ignition OFF.
- Remove the air cleaner intake duct. Refer to «Air Cleaner Intake Duct Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Remove the throttle body electrical connector.
- Unlock and reposition the wiring harness conduit.
- Remove the throttle body bolts.
- Remove the throttle body and gasket.
- Carefully clean the throttle body mounting surfaces of any gasket and/or seal material.
- Install the throttle body and NEW gasket.
- Install the throttle body bolts. Tighten: Tighten the throttle body bolts to 10 N.m (89 lb in).
- Install the wiring harness conduit.
- Install the throttle body electrical connector.
- Install the air cleaner intake duct. Refer to «Air Cleaner Intake Duct Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Perform the idle learn procedure. Refer to «Idle Learn Procedure»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__idle-learn-procedure) .
- Use the scan tool to clear all DTCs.
Throttle Body Service
- Remove the air cleaner intake duct. Refer to «Air Cleaner Intake Duct Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Fully open the throttle valve in order to Inspect the throttle body bore and the throttle valve plate for any deposits.
- Use a clean shop towel and Top Engine Cleaner GM P/N 1052626 or equivalent product in order to clean the throttle body bore and the throttle valve plate. If necessary, use a parts cleaning brush in order to remove heavy deposits.
- Install the air cleaner duct. Refer to «Air Cleaner Intake Duct Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
Fuel Pressure Relief Procedure
| CAUTION | Gasoline or gasoline vapors are highly flammable. A fire could occur if an ignition source is present. Never drain or store gasoline or diesel fuel in an open container, due to the possibility of fire or explosion. Have a dry chemical (Class B) fire extinguisher nearby. |
| CAUTION | Relieve the fuel system pressure before servicing fuel system components in order to reduce the risk of fire and personal injury. After relieving the system pressure, a small amount of fuel may be released when servicing the fuel lines or connections. In order to reduce the chance of personal injury, cover the regulator and the fuel line fittings with a shop towel before disconnecting. This will catch any fuel that may leak out. Place the towel in an approved container when the disconnection is complete. |
Tools Required
J 34730-1A Fuel Pressure Gage. See Special Tools .
- Turn the ignition OFF.
- Disconnect the negative battery cable in order to avoid possible fuel discharge if an accidental attempt is made to start the engine. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/cadillac/sts/i-2004-2007/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
- Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
- Connect the J 34730-1A to the fuel pressure valve. See «Special Tools»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__special-tools) . Wrap a shop towel around the fitting while connecting the gage in order to avoid spillage.
- Install the bleed hose into an approved container.
- Open the valve in order to bleed the system pressure. Fuel connections are now safe for servicing.
- Drain any fuel remaining in the gage into an approved container.
- Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
- Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/cadillac/sts/i-2004-2007/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
- Relieve the fuel pressure. Refer to «Fuel Pressure Relief Procedure»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__fuel-pressure-relief-procedure) .
- Remove the fuel pressure test port cap.
- Install the fuel pressure gage to the fuel pressure test port.
- Place the shop towel in an approved container.
- Perform any tests and/or diagnostics as needed.
- Relieve the fuel pressure. Refer to «Fuel Pressure Relief Procedure»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__fuel-pressure-relief-procedure) .
- Remove the fuel pressure gage.
- Place the shop towel in an approved container.
- Install the fuel pressure test port cap.
Quick Connect Fitting(s) Service (Metal Collar)
Tools Required
- J 37088-A Fuel Line Disconnect Tool Set. See «Special Tools»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__special-tools) .
- J 44581 Fuel Line Disconnect Tool
- Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__fuel-pressure-relief-procedure) .
- Remove the retainer from the quick-connect fitting.
- Blow dirt out of the fitting using compressed air.
- Depending on the fuel line size and ability to access the fitting, choose the appropriate tool: J 37088-A or. See «Special Tools»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__special-tools) . J 44581 . Insert the J 37088-A or. See «Special Tools»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__special-tools) . J 44581 into the female connector, then push inward to release the locking tabs.
- Pull the connection apart.
- Using a clean shop towel, wipe off the male pipe end.
- Inspect both ends of the fitting for dirt and burrs.
- Clean or replace the components as required.
- Apply a few drops of clean engine oil to the male pipe end.
- Push both sides of the quick-connect fitting together to cause the retaining tabs to snap into place.
- Pull on both sides of the quick-connect fitting to make sure the connection is secure.
- Install the retainer to the quick-connect fitting.
- Inspect for leaks using the following procedure: Turn the ignition ON, with the engine OFF for 2 seconds. Turn the ignition OFF, for 10 seconds. Turn the ignition ON, with the engine OFF for 2 seconds. Turn the ignition OFF. Inspect for leaks.
Quick Connect Fitting(s) Service (Plastic Collar)
| CAUTION | Refer to Gasoline/Gasoline Vapors Caution in Cautions and Notices. |
- Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__fuel-pressure-relief-procedure) .
- Blow dirt out of the fitting using compressed air.
- Squeeze the plastic tabs of the male end connector.
- Pull the connection apart.
- Using a clean shop towel, wipe off the male pipe end
- Inspect both ends of the fitting for dirt and burrs.
- Clean or replace the components as required.
- Apply a few drops of clean engine oil to the male pipe end.
- Push both sides of the quick-connect fitting together to cause the retaining tabs/fingers to snap into place.
- Pull on both sides of the quick-connect fitting to make sure the connection is secure.
- Inspect for leaks using the following procedure: Turn the ignition ON, with the engine OFF for 2 seconds. Turn the ignition OFF, for 10 seconds. Turn the ignition ON, with the engine OFF for 2 seconds. Turn the ignition OFF. Inspect for leaks.
| CAUTION | Refer to Gasoline/Gasoline Vapors Caution in Cautions and Notices. |
- Keep a shop cloth and a container ready to capture any spilled fuel.
- Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__fuel-pressure-relief-procedure) .
- Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) in General Information.
- Disconnect the quick-connect fitting at the fuel filter inlet. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__quick-connect-fittings-service-metal-collar) .
- Using a primary and back-up wrench, remove the threaded fitting at the fuel filter outlet.
- Slide the fuel filter rearward from the fuel filter bracket.
- Remove the fuel pipe O-ring seal. Discard the O-ring seal if damaged.
- Drain any remaining fuel into an approved gasoline container.
- Discard the fuel filter into an approved container.
- Lubricate the fuel pipe O-ring seal with clean engine oil.
- Install the fuel pipe O-ring seal to the fuel pipe.
- Remove the protective caps from the new fuel filter.
- Slide the fuel filter forward into the fuel filter bracket.
- Install the threaded fitting to the fuel filter outlet. Use a back-up wrench in order to prevent the fuel filter from turning. Tighten: Tighten the fuel filter outlet fitting to 30 N.m (22 lb ft).
- Connect the quick-connect fitting at the fuel filter inlet. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__quick-connect-fittings-service-metal-collar) .
- Lower the vehicle.
Fuel Tank Draining Procedure
Tools Required
- J 36850 Transjel Lubricant. See «Special Tools»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__special-tools) .
- J 42960-2 Fuel Flapper Door Holder. See «Special Tools»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__special-tools) .
- J 45004 Fuel Drain Hose. See «Special Tools»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__special-tools) .
| CAUTION | Refer to Gasoline/Gasoline Vapors Caution in Cautions and Notices. |
| CAUTION | Never drain or store fuel in an open container. Always use an approved fuel storage container in order to reduce the chance of fire or explosion. |
| CAUTION | Place a dry chemical (Class B) fire extinguisher nearby before performing any on-vehicle service procedures. Failure to follow these precautions may result in personal injury. |
- Remove the fuel filler cap.
- Install the J 42960-2 into the fuel fill pipe in order to hold the door open. See «Special Tools»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__special-tools) .
- Insert the J 45004 into the fuel tank until the hose reaches the bottom of the fuel tank. See «Special Tools»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__special-tools) .
- Use an air operated pump device in order to drain the fuel into an approved gasoline container. Up to 26 liters (7 gallons) of residual fuel may remain in the secondary side of the fuel tank.
- Simultaneously twist and pull in order to remove the J 45004 from the fuel tank. See «Special Tools»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__special-tools) .
| CAUTION | Refer to Gasoline/Gasoline Vapors Caution in Cautions and Notices. |
- Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__fuel-tank-draining-procedure) .
- Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__fuel-pressure-relief-procedure) .
- Remove the exhaust system. Refer to «Exhaust System Replacement»(/cadillac/sts/i-2004-2007/remont/exhaust/#engine-exhaust-system__exhaust-system-replacement) in Engine Exhaust.
- Remove the propeller shaft. Refer to «Propeller Shaft Replacement - Rear (AWD)»(/cadillac/sts/i-2004-2007/remont/driveshaft-universal-joints/#propeller-shaft-and-universal-joints__propeller-shaft-replacement-rear-awd) or «Propeller Shaft Replacement - Rear (RWD)»(/cadillac/sts/i-2004-2007/remont/driveshaft-universal-joints/#propeller-shaft-and-universal-joints__propeller-shaft-replacement-rear-rwd) in Propeller Shaft.
- Disconnect the filler hose (1) from the fuel tank.
- Disconnect the filler vent tube (2) from the evaporative emission (EVAP) hose. Refer to «Quick Connect Fitting(s) Service (Plastic Collar)»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__quick-connect-fittings-service-plastic-collar) .
- Refer to «Quick Connect Fitting(s) Service (Plastic Collar)»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__quick-connect-fittings-service-plastic-collar) in order to disconnect the following from the chassis bundle: The fuel feed hose The fuel return hose The fuel EVAP hose
- Disconnect the fuel tank electrical connector.
- Disconnect the EVAP hoses from the EVAP canister.
- Pull outward on the retainer tab in order to disengage the retainer from the chassis.
- Disconnect the electrical connector from the EVAP canister.
- Raise the lower control arms using a suitable screw jack (3) in order to remove the load from the lower shock bolts (2).
- Remove the lower shock bolts (2).
- Remove the screw jack (3).
- Position the screw jack under the rear frame near the adjuster tie bar, in order to support the front of the rear frame.
- Remove the 2 front bolts from the rear frame.
- Lower the screw jack until there is approximately 50 mm (2 in) (a) between the front mounting surface of the rear frame and the chassis. This will allow clearance to access the fuel tank strap bolts.
- Remove the fuel tank strap bolts.
- Position the fuel tank straps downward around the rear frame.
- Carefully bend the fuel tank straps ONLY enough to allow the fuel tank to be removed.
- With the aid of an assistant, carefully lower the fuel tank from the vehicle.
- Remove the following components if replacing just the fuel tank: The primary fuel tank module-Refer to «Fuel Tank Module Replacement - Primary»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) . The secondary fuel tank module-Refer to «Fuel Tank Module Replacement - Secondary»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) . The fuel tank pressure sensor-Refer to «Fuel Tank Pressure Sensor Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Install the following components if fuel tank replacement was necessary: The primary fuel tank module-Refer to «Fuel Tank Module Replacement - Primary»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) . The secondary fuel tank module-Refer to «Fuel Tank Module Replacement - Secondary»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) . The fuel tank pressure sensor-Refer to «Fuel Tank Pressure Sensor Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Pressure test the fuel tank. Refer to «Fuel Tank Leak Test»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-troubleshooting) .
- With the aid of an assistant, carefully raise the fuel tank to the vehicle, aligning the filler neck with the filler hose.
- Carefully bend the fuel tank straps back to their original form.
- Position the fuel tank straps around the rear frame and upward into position, aligning the holes in the straps with the threaded holes in the chassis.
- Install the fuel tank strap bolts. Tighten: Tighten the fuel tank strap bolts to 50 N.m (37 lb ft).
- Connect the filler hose (1) to the fuel tank. Tighten: Tighten the fuel filler tube hose clamp (3) to 3.5 N.m (31 lb in).
- Connect the filler vent tube (2) to the EVAP hose. Refer to «Quick Connect Fitting(s) Service (Plastic Collar)»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__quick-connect-fittings-service-plastic-collar) .
- Connect the EVAP hoses to the EVAP canister.
- Insert the retainer into the chassis and press inward on the tab to engage.
- Connect the electrical connector to the EVAP canister.
- Connect the fuel tank electrical connector.
- Refer to «Quick Connect Fitting(s) Service (Plastic Collar)»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__quick-connect-fittings-service-plastic-collar) in order to connect the following to the chassis bundle: The fuel feed hose The fuel return hose The fuel EVAP hose
- Raise the rear frame using the screw jack.
- Install the 2 front bolts to the rear frame. Tighten: Tighten the rear frame bolts to 200 N.m (148 lb ft).
- Remove the screw jack.
- Position the screw jack (3) under the lower control arm in order to raise the lower control arms (2).
- Install the lower shock bolts (2). Tighten: Tighten the lower shock bolts to 90 N.m (66 lb ft).
- Remove the screw jack (3).
- Install the propeller shaft. Refer to «Propeller Shaft Replacement - Rear (AWD)»(/cadillac/sts/i-2004-2007/remont/driveshaft-universal-joints/#propeller-shaft-and-universal-joints__propeller-shaft-replacement-rear-awd) or «Propeller Shaft Replacement - Rear (RWD)»(/cadillac/sts/i-2004-2007/remont/driveshaft-universal-joints/#propeller-shaft-and-universal-joints__propeller-shaft-replacement-rear-rwd) in Propeller Shaft.
- Install the exhaust system. Refer to «Exhaust System Replacement»(/cadillac/sts/i-2004-2007/remont/exhaust/#engine-exhaust-system__exhaust-system-replacement) in Engine Exhaust.
- Refill the fuel tank.
- Inspect for fuel leaks.
- Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) .
- Disconnect the fuel tank pressure sensor electrical connector (1).
- Remove the fuel tank pressure sensor from the evaporative emission (EVAP) canister.
- Install the fuel tank pressure sensor to the EVAP canister until fully seated.
- Connect the fuel tank pressure sensor electrical connector (1).
- Lower the vehicle.
- Remove the fuel filler cap.
- Drain the fuel tank below the level of the fuel filler hose. Refer to «Fuel Tank Draining Procedure»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__fuel-tank-draining-procedure) .
- Remove the bolts securing the fuel filler tube to the body.
- Remove the right rear wheel. Refer to «Tire and Wheel Removal and Installation»(/cadillac/sts/i-2004-2007/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
- Remove the right rear wheelhouse liner. Refer to «Wheelhouse Liner Panel Replacement - Rear»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-rear-end) in Body Rear End.
- Remove the fuel filler tube brace bolt.
- Disconnect the fuel filler hose (1) from the fuel tank.
- Disconnect the filler vent tube (2) from the evaporative emission (EVAP) hose. Refer to «Quick Connect Fitting(s) Service (Plastic Collar)»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__quick-connect-fittings-service-plastic-collar) .
- Remove the fuel filler tube from the vehicle.
- Position the fuel filler tube to the vehicle.
- Connect the filler hose (1) to the fuel tank. Tighten: Tighten the fuel filler tube hose clamp (3) to 3.5 N.m (31 lb in).
- Connect the filler vent tube (2) to the EVAP hose. Refer to «Quick Connect Fitting(s) Service (Plastic Collar)»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__quick-connect-fittings-service-plastic-collar) .
- Install the fuel filler tube brace bolt. Tighten: Tighten the fuel filler tube brace bolt to 9 N.m (80 lb in).
- Install the bolts securing the fuel filler tube to the body. Tighten: Tighten the fuel filler tube bolts to 3.5 N.m (31 lb in).
- Install the right rear wheelhouse liner. Refer to «Wheelhouse Liner Panel Replacement - Rear»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-rear-end) in Body Rear End.
- Install the right rear wheel. Refer to «Tire and Wheel Removal and Installation»(/cadillac/sts/i-2004-2007/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
- Add fuel to the fuel tank.
- Inspect for fuel leaks.
- Install the fuel filler cap.
Tools Required
J 45747 Fuel Tank Sender Wrench. See Special Tools .
- Remove the fuel tank hoses. Refer to «Fuel Hoses/Pipes Replacement - Filter to Tank»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Disconnect the electrical connector from the primary fuel tank module.
- Rotate the cam lock ring counterclockwise using the J 45747 . See «Special Tools»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__special-tools) .
- Remove the cam lock ring from the fuel tank.
- Carefully lift the primary fuel tank module (1) from the fuel tank only enough to access the transfer tube (2).
- Complete the following in order to disconnect the transfer tube from the primary fuel tank module: Pull the locking mechanism away from the module. Remove the transfer tube from the module.
- Remove the primary fuel tank module from the fuel tank.
- Remove the primary fuel tank module seal from the module. Do not reuse the seal.
- Place the new primary fuel tank module seal (1) over the module (2).
- Complete the following in order to connect the transfer tube (2) to the primary fuel tank module (1). Grasp the transfer tube (2) from inside the fuel tank. Position the module (1) near the module opening. Connect the transfer tube (2) to the module (1).
- Carefully insert the primary fuel tank module (1) into the fuel tank.
- Press the primary fuel tank module (1) downward, aligning the module to the encapsulated ring.
- Position the cam lock ring to the fuel tank.
- Rotate the cam lock ring clockwise using the J 45747 until fully seated. See «Special Tools»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__special-tools) .
- Connect the electrical connector to the primary fuel tank module.
- Install the fuel tank hoses. Refer to «Fuel Hoses/Pipes Replacement - Filter to Tank»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
J 45747 Fuel Tank Sender Wrench. See Special Tools .
- Remove the fuel tank. Refer to «Fuel Tank Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Disconnect the electrical connector from the secondary fuel tank module.
- Rotate the cam lock ring counterclockwise using the J 45747 . See «Special Tools»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__special-tools) .
- Remove the cam lock ring from the fuel tank.
- Carefully lift the secondary fuel tank module (2) from the fuel tank only enough to access the transfer tube (1).
- Complete the following in order to disconnect the transfer tube from the secondary fuel tank module. Pull the locking mechanism away from the module. Remove the transfer tube from the module.
- Remove the secondary fuel tank module from the fuel tank.
- Remove the secondary fuel tank module seal from the module. Do not reuse the seal.
- Place the new secondary fuel tank module seal (1) over the module (2).
- Complete the following in order to connect the transfer tube (1) to the secondary fuel tank module (2). Grasp the transfer tube (1) from inside the fuel tank. Position the module (2) near the module opening. Connect the transfer tube (1) to the module (2).
- Carefully insert the secondary fuel tank module (2) into the fuel tank.
- Press the secondary fuel tank module (2) downward, aligning the module to the encapsulated ring.
- Position the cam lock ring to the fuel tank.
- Rotate the cam lock ring clockwise using the J 45747 until fully seated. See «Special Tools»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__special-tools) .
- Connect the electrical connector to the secondary fuel tank module.
- Install the fuel tank. Refer to «Fuel Tank Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
| CAUTION | Refer to Gasoline/Gasoline Vapors Caution in Cautions and Notices. |
- Remove the primary fuel tank module. Refer to «Fuel Tank Module Replacement - Primary»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Disconnect the fuel level sensor electrical connector (1) from the module.
- Complete the following in order to remove the fuel level sensor (1) from the module assembly: Pull the locking tab (2) away from the sensor (1). Slide the sensor (1) away from the module assembly.
- Complete the following in order to install the fuel level sensor (1) to the module assembly: Align the tabs of the sensor (1) with the slots in the module assembly. Slide the sensor (1) fully into position, ensure the locking tab (2) is engaged.
- Connect the fuel level sensor electrical connector (1) to the module.
- Install the primary fuel tank module. Refer to «Fuel Tank Module Replacement - Primary»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Remove the fuel tank. Refer to «Fuel Tank Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Disconnect the following from the primary fuel tank module: The pressure hose The return hose
- Disconnect the hoses from the retaining feature at the fuel tank.
- Clean any contamination from the male pipe ends of the primary fuel tank module.
- Connect the hoses to the retaining feature at the fuel tank.
- Connect the following to the primary fuel tank module: The pressure hose The return hose
- Install the fuel tank. Refer to «Fuel Tank Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
The fuel system hose/pipes are serviceable individually or as a complete fuel/brake bundle assembly, the following procedure is servicing the fuel hose/pipes individually.
- Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__fuel-pressure-relief-procedure) .
- Remove the fuel pipe retaining clip from the fuel pipe. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__quick-connect-fittings-service-metal-collar) .
- Disconnect the fuel pipe (2) from the fuel rail. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__quick-connect-fittings-service-metal-collar) .
- Disconnect the evaporative emission (EVAP) purge line (3) from the purge solenoid.
- Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) in General Information.
- Disconnect the fuel pipes from the fuel filter and the fuel tank bundle
- Pull the locking mechanism (1) outward in order to disengage the fuel/brake bundle chassis pipe retainers from the rail.
- Open the retainers (1) located at the forward portion of the rail in order to remove the chassis hose/pipes.
- Complete the following in order to remove the chassis hose/pipes from the retainers (2) located at the rearward portion of the rail. Pull the retainers (2) free from the rail. Open the retainers (2) at the top. Remove the chassis hose/pipes from the retainers (2).
- Pull downward in order to disconnect the fuel/brake bundle chassis pipe retainer from the underbody.
- Remove the bolt securing the fuel filter bracket to the body.
- Remove the EVAP hose from the fuel filter bracket.
- Remove the bolts securing the transmission support to the underbody, from the right side only.
- Pull the right side transmission support down only enough to allow removal of the chassis fuel hose/pipes.
- Partially lower the hoist only enough to simultaneously gain access to both the front and rear portions of the chassis fuel hose/pipes.
- With the aid of an assistant, carefully guide the chassis fuel hose/pipes down through the engine compartment, removing from the bottom.
- Clean any of the contamination from the male line ends and apply a few drops of clean engine oil.
- With the aid of an assistant, carefully guide the chassis fuel hose/pipes up through the engine compartment into position.
- Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) in General Information.
- Pull the right side transmission support down only enough to allow installation of the chassis fuel hose/pipes.
- Install the transmission support right side bolts. Refer to «Transmission Support Replacement»(/cadillac/sts/i-2004-2007/remont/frames-subframes-crossmembers/#frame-underbody) in Frame and Underbody.
- Install the EVAP hose to the fuel filter bracket
- Install the fuel filter bracket bolt. Tighten: Tighten the fuel filter bracket bolt to 9 N.m (80 lb in).
- Install the fuel/brake bundle to the underbody.
- Complete the following in order to install the chassis hose/pipes to the retainers (2) located at the rearward portion of the rail: Install the chassis hose/pipes into the retainers (2). Close the retainers (2) at the top. Insert the retainers (2) into the rail.
- Install the chassis hose/pipes into the retainers (1) located at the forward portion of the rail.
- Close the retainers.
- Push the locking mechanism (1) inward in order to engage the fuel/brake bundle chassis pipe retainers to the rail.
- Connect the fuel feed pipe and the EVAP hose to the fuel bundle.
- Lower the vehicle.
- Connect the evaporative emission (EVAP) purge line (3) to the purge solenoid.
- Connect the fuel feed pipe (1) to the fuel rail. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__quick-connect-fittings-service-metal-collar) .
- Install the fuel pipe retaining clip.
Fuel System Cleaning
| CAUTION | Refer to Gasoline/Gasoline Vapors Caution in Cautions and Notices. |
The following procedure covers the disassembly and the inspection of the complete fuel supply system. If the fuel system is contaminated, the fuel system can be cleaned. You can usually determine the extent of the fuel system contamination during the disassembly.
- Remove the fuel filter. Refer to «Fuel Filter Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Inspect the fuel system for contamination of the in-line fuel filter. Replace the filter after cleaning the fuel lines if the filter is plugged or contaminated.
- Remove the fuel module assemblies. Refer to «Fuel Tank Module Replacement - Primary»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) and «Fuel Tank Module Replacement - Secondary»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Locate the tank in a suitable work area away from any heat, any flame, or any other source of ignition.
- Perform the following procedures: Inspect the fuel sender strainer. Replace the primary fuel tank module if the strainer is contaminated. Inspect the secondary fuel tank module for debris. Clean the secondary fuel tank module if debris is found. CAUTION: Wear safety glasses when using compressed air, as flying dirt particles may cause eye injury. Use compressed air in order to apply air pressure to the transfer tube.
- Flush the fuel tank with running hot water for at least five minutes. Pour the water out of the fuel sender assembly opening. Rock the tank in order to ensure that the removal of the water from the tank is complete.
- Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__quick-connect-fittings-service-metal-collar) in order to disconnect the following quick connect fittings from the fuel rail: The feed hose/pipe The return hose/pipe
- Use compressed air in order to apply air pressure to the fuel lines in the opposite direction from the normal fuel flow.
- Remove the fuel injectors and fuel rail. Refer to «Fuel Injectors and Fuel Rail Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Clean and inspect the fuel injectors and fuel rail.
Assemble the fuel system as follows
- Install the fuel injectors and fuel rail. Refer to «Fuel Injectors and Fuel Rail Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Install the fuel module assemblies. Refer to «Fuel Tank Module Replacement - Primary»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) and «Fuel Tank Module Replacement - Secondary»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Install the fuel filter. Refer to «Fuel Filter Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__quick-connect-fittings-service-metal-collar) in order to connect the following quick connect fittings to the fuel rail: The feed hose/pipe The return hose/pipe
| CAUTION | Refer to Gasoline/Gasoline Vapors Caution in Cautions and Notices. |
- Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__fuel-pressure-relief-procedure) .
- Remove the upper intake manifold with the lower intake manifold. Refer to «Intake Manifold Replacement - Upper»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
- Remove the fuel pipe retaining clip.
- Disconnect the fuel feed pipe (2) from the fuel injector rail. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__quick-connect-fittings-service-metal-collar) .
- Use compressed air in order to remove debris from the area where the fuel injectors enter the intake manifold.
- Remove the fuel rail bolts.
- Remove the fuel rail with the fuel injectors.
- Disengage the fuel injector electrical connector lock.
- Disconnect the fuel injector electrical connector.
- Remove the fuel injector retainer clip.
- Remove the fuel injector.
- Remove and discard the fuel injector seals.
- Install NEW fuel injector seals.
- Install the fuel injector.
- Install the fuel injector retainer clip.
- Install the fuel injector electrical connector.
- Engage the fuel injector electrical connector lock.
- Install the fuel rail with the fuel injectors.
- Install the fuel rail bolts. Tighten: Tighten the fuel rail bolts to 10 N.m (89 lb in).
- Connect the fuel feed pipe (2) to the fuel rail. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__quick-connect-fittings-service-metal-collar) .
- Install the fuel pipe retaining clip.
- Install the upper intake manifold. Refer to «Intake Manifold Replacement - Upper»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical -3.6L (LY7).
- Turn the ignition OFF.
- Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
- Disconnect the purge line (3) from the purge valve solenoid.
- Disconnect the purge valve solenoid electrical connector.
- Disconnect the purge line from the manifold side of the purge valve solenoid.
- Remove the purge valve solenoid from the bracket.
- Install the purge valve solenoid to the bracket.
- Disconnect the purge line from the manifold side of the purge valve solenoid.
- Disconnect the purge valve solenoid electrical connector.
- Connect the purge line (3) to the purge valve solenoid.
- Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
- Remove the evaporative emission (EVAP) canister. Refer to «Evaporative Emission (EVAP) Canister Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Clean away any debris that may be present around the EVAP canister vent valve.
- Twist the EVAP canister vent valve counterclockwise.
- Pull the EVAP canister vent valve from the EVAP canister.
- Insert the EVAP canister vent valve into the EVAP canister.
- Twist the EVAP canister vent valve clockwise into the locked position.
- Install the EVAP canister. Refer to «Evaporative Emission (EVAP) Canister Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
Note. Do not attempt to straighten kinked nylon pipes. Replace any kinked nylon pipes in order to prevent damage to the vehicle. Do not attempt to repair sections of nylon pipes. Replace damaged nylon pipes. Replace the vapor hoses/pipes with original equipment or parts that meet GM specifications.
- Remove the fuel tank. Refer to «Fuel Tank Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Remove the chassis to canister evaporative emission (EVAP) hose from the following: The body retainer (1) The 3 retaining features (2) on the fuel tank The retainer clip (3)
- Remove the EVAP hose from the fuel tank.
- Position the EVAP hose to the fuel tank.
- Install the chassis to canister EVAP hose to the following: The body retainer (1) The 3 retaining features (2) on the fuel tank The retainer clip (3)
- Install the fuel tank. Refer to «Fuel Tank Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Remove the rear frame. Refer to «Frame Replacement - Rear»(/cadillac/sts/i-2004-2007/remont/frames-subframes-crossmembers/#frame-underbody) in Frame and Underbody.
- Disconnect the evaporative emission (EVAP) hoses from the EVAP canister.
- Disconnect the electrical connector from the EVAP canister.
- Remove the EVAP canister retaining nuts.
- Complete the following in order to remove the EVAP canister: Lower the rear of the canister enough to clear the 2 weld studs. Slide the canister rearward from the body brace.
- Complete the following in order to install the EVAP canister: Insert the fresh air tube and tab on the canister forward into the body brace. Rotate the rear of the canister up over the 2 weld studs on the floor pan.
- Install the EVAP canister retaining nuts. Tighten: Tighten the EVAP canister retaining nuts to 6 N.m (53 lb in).
- Connect the EVAP hoses to the EVAP canister.
- Connect the electrical connector to the EVAP canister.
- Install the rear frame. Refer to «Frame Replacement - Rear»(/cadillac/sts/i-2004-2007/remont/frames-subframes-crossmembers/#frame-underbody) in Frame and Underbody.
- Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) in General Information.
- Using a 90 degree pick, disengage the lower filter cover clips.
- Insert a flat-bladed tool between the filter cover and canister, and push up to disengage the upper clips.
- Remove and discard the evaporative emission (EVAP) canister filter cover.
- Remove and discard the EVAP canister filter.
- Clean the inside of the EVAP canister filter housing with a clean shop towel.
- Insert a NEW EVAP canister filter into the EVAP canister.
- Install a NEW EVAP canister filter cover seal to a EVAP NEW canister cover.
- Snap the EVAP canister filter cover onto the EVAP canister.
- Lower the vehicle.
Scheme 28
- Turn the ignition OFF.
- Remove the engine cover. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
- If you are replacing the ignition coil for cylinder 1 or 3, remove and reposition the intake manifold. Perform the following steps: Disconnect the air cleaner duct from the throttle body. Disconnect the positive crankcase ventilation (PCV) hose from the right bank camshaft cover. IMPORTANT: Do NOT separate the upper intake manifold from the lower intake manifold. Remove the intake manifold bolts. Remove the intake manifold brace bolts (1 and 2) and the brace. Remove and reposition the upper intake manifold with the lower intake manifold in order to gain sufficient clearance for ignition coil removal.
- Remove the ignition coil electrical connector(s).
- Remove the ignition coil bolt(s).
- Remove the ignition coil(s).
- Install the ignition coil(s).
- Install the ignition coil bolt(s). Tighten: Tighten the ignition coil bolt(s) to 10 N.m (89 lb in).
- Install the ignition coil electrical connector(s).
- If necessary, install the intake manifold. Refer to «Intake Manifold Replacement - Lower»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
- Install the engine cover. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
- Turn the ignition OFF.
- Remove the engine cover. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
- If you are replacing the ignition coil for cylinder 2, remove and reposition the intake manifold. Perform the following steps: Disconnect the air cleaner duct from the throttle body. Disconnect the positive crankcase ventilation (PCV) hose from the right bank camshaft cover. IMPORTANT: Do NOT separate the upper intake manifold from the lower intake manifold. Remove the intake manifold bolts. Remove the intake manifold brace bolts (1 and 2) and the brace. Remove and reposition the upper intake manifold with the lower intake manifold in order to gain sufficient clearance for ignition coil removal.
- Remove the ignition coil electrical connector(s).
- Remove the ignition coil bolt(s).
- Remove the ignition coil(s).
- Install the ignition coil(s).
- Install the ignition coil bolt(s). Tighten: Tighten the ignition coil bolt(s) to 10 N.m (89 lb in).
- Install the ignition coil electrical connector(s).
- If necessary, install the upper intake manifold. Refer to «Intake Manifold Replacement - Upper»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
Spark Plug Operation
Worn or dirty spark plugs may operate well at idle speeds, but frequently fail at higher load. Bad spark plugs are often responsible for the following conditions
- Power loss
- Poor fuel economy
- Loss of speed
- Hard starting
- Poor engine performance
Normal spark plug operation results in brown to grayish tan deposits on the area of the spark plug that enters the cylinder. A small amount of reddish brown, yellow, and white powdery residue may also be present on the insulator tip around the center electrode. These deposits are normal combustion by-products of fuels and lubricating oils which contain additives.
Misfiring is a general term that applies to a poor running engine. With misfiring, the ignition spark is not igniting the air/fuel mixture at the proper time. While other possible causes must be investigated, the spark plugs should be inspected first. Spark voltage should not reach ground before jumping across the gap at the tip of the spark plug. This leaves the air/fuel mixture unburned, causing misfiring. Pre-ignition misfiring occurs when the spark plug tip overheats, igniting the mixture before the spark jumps.
Carbon fouling of the spark plug is indicated by dry carbon deposits on the portion of the spark plug inside of the cylinder. Excess idling and driving at slower speeds under light engine loads can keep the spark plug temperatures so low that these deposits are not burned off. Rich fuels or poor ignition system output may also cause carbon fouling.
Oil fouling of the spark plug appears as wet oily deposits on the portion of the spark plug inside of the cylinder. This may be caused by the following conditions
- Oil getting past worn piston rings
- Breaking in a new or recently overhauled engine
Deposit fouling of the spark plug occurs when the normal reddish brown, yellow, or white deposits of combustion by-products become sufficient enough to cause misfiring. In some cases, these deposits melt and form a shiny glaze on the insulator around the center electrode. If the fouling is found only in one or two of the cylinders, valve stem clearances or the intake valve seals may be allowing excess lubricating oil to enter the cylinder, particularly if the deposits are heavier on the intake valve side of the spark plug.
Excess gap means that the air space between the center and side electrodes at the bottom of the spark plug is too wide for consistent firing. This may be due to improper gap adjustment or to excess wear of the electrodes during use. A gap that is too small may cause idling instability. Excess gap wear might indicate vehicle operation at continual high speeds or with high engine loads. This causes the spark plugs to run too hot. Excessively lean fuel may also cause the wear.
Improper torque or seating can cause a spark plug to run hot, eventually leading to excess gap wear. In extreme cases, an overtightened or under-tightened spark plug can cause exhaust blow-by. The cylinder head seats must make good contact for sufficient heat transfer and spark plug cooling. Dirty or damaged threads in the head or on the spark plug can keep the spark plug from seating even though the proper torque is applied. Once the spark plugs are properly seated, tighten the spark plugs properly.
Cracked or broken insulators and insulator tips may be the result of improper installation or heat shock. Heat shock is a rapid increase in the insulator tip temperature which causes the insulator material to crack. The upper insulators can be broken when a poorly-fitting tool is used during servicing, or when the spark plug is hit from the outside. Cracks in the upper insulator may be inside the shell or invisible. The breakage may not cause problems until oil or water penetrates the crack later. Heat shock breakage in the lower insulator tip generally occurs during severe engine operating conditions such as higher RPM or heavy loading. Over advanced timing or low grade fuels may also cause heat shock breakage. Always replace spark plugs with broken or cracked insulators.
Damage during gapping can occur when the tool is pushed against the center electrode or the surrounding insulator, causing the insulator to crack. When gapping a spark plug, bend only the outside electrode. Keep tools free of any other parts.
Spark plugs with less than the recommended amount of service can sometimes be cleaned and re-gapped, then returned to service. If there is any doubt about the serviceability of a spark plug, replace the spark plug.
- Turn the ignition OFF.
- Remove the ignition coil. Refer to «Ignition Coil(s) Replacement - Bank 1»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) and/or «Ignition Coil(s) Replacement - Bank 2»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Use compressed air in order to remove debris from the spark plug cavity.
- Remove the spark plug.
- Ensure that the spark plug gap is equivalent to the spark plug gap specification. Refer to «Ignition System Specifications»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction__ignition-system-specifications) .
- Install the spark plug. Tighten: Tighten the spark plug to 20 N.m (15 lb ft).
- Install the ignition coil. Refer to «Ignition Coil(s) Replacement - Bank 1»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) and/or «Ignition Coil(s) Replacement - Bank 2»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Turn the ignition OFF.
- Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) in General Information.
- Reposition the wiring harness heat shield to obtain access.
- Disconnect the crankshaft position (CKP) electrical connector (3).
- Remove the crankshaft sensor bolt.
- Remove the crankshaft sensor.
- Install the crankshaft position sensor.
- Install the crankshaft position sensor bolt. Tighten: Tighten the crankshaft position sensor bolt to 10 N.m (89 lb in).
- Connect the CKP electrical connector (3).
- Install the wiring harness heat shield to the oil level indicator tube.
- Lower the vehicle.
- Turn the ignition OFF.
- Remove the power steering fluid reservoir bolts and reposition the power steering fluid reservoir in order to provide access. Refer to «Remote Power Steering Fluid Reservoir Replacement (LH2)»(/cadillac/sts/i-2004-2007/remont/manual-power-steering/#power-steering-system) or «Remote Power Steering Fluid Reservoir Replacement (LY7)»(/cadillac/sts/i-2004-2007/remont/manual-power-steering/#power-steering-system) in Power Steering System.
- Remove the camshaft position (CMP) sensor electrical connector.
- Remove the CMP sensor bolt.
- Remove the CMP sensor.
- Install the CMP sensor.
- Install the CMP sensor bolt. Tighten: Tighten the CMP sensor bolt to 10 N.m (89 lb in).
- Install the CMP sensor electrical connector.
- Install the power steering fluid reservoir. Refer to «Remote Power Steering Fluid Reservoir Replacement (LH2)»(/cadillac/sts/i-2004-2007/remont/manual-power-steering/#power-steering-system) or «Remote Power Steering Fluid Reservoir Replacement (LY7)»(/cadillac/sts/i-2004-2007/remont/manual-power-steering/#power-steering-system) in Power Steering System.
- Turn the ignition OFF.
- Remove the power steering fluid reservoir bolts and reposition the power steering fluid reservoir in order to provide access. Refer to «Remote Power Steering Fluid Reservoir Replacement (LH2)»(/cadillac/sts/i-2004-2007/remont/manual-power-steering/#power-steering-system) or «Remote Power Steering Fluid Reservoir Replacement (LY7)»(/cadillac/sts/i-2004-2007/remont/manual-power-steering/#power-steering-system) in Power Steering System.
- Remove the camshaft position (CMP) sensor electrical connector.
- Remove the CMP sensor bolt.
- Remove the CMP sensor.
- Install the CMP sensor.
- Install the CMP sensor bolt. Tighten: Tighten the CMP sensor bolt to 10 N.m (89 lb in).
- Install the CMP sensor electrical connector.
- Install the power steering fluid reservoir. Refer to «Remote Power Steering Fluid Reservoir Replacement (LH2)»(/cadillac/sts/i-2004-2007/remont/manual-power-steering/#power-steering-system) or «Remote Power Steering Fluid Reservoir Replacement (LY7)»(/cadillac/sts/i-2004-2007/remont/manual-power-steering/#power-steering-system) in Power Steering System.
- Turn the ignition OFF.
- Remove the front compartment sight shields as necessary. Refer to «Sight Shields, Hood Adjuster, Hood Bumper, Hood Latch Replacement»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
- Remove the ECM bracket bolts and reposition the ECM bracket in order to provide access.
- Disconnect the camshaft position (CMP) sensor electrical connector.
- Remove the CMP sensor bolt.
- Remove the CMP sensor.
- Install the CMP sensor.
- Install the CMP sensor bolt. Tighten: Tighten the CMP sensor bolt to 10 N.m (89 lb in).
- Connect the CMP sensor electrical connector.
- Install the ECM bracket with the ECM. Refer to «Engine Control Module (ECM) Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Install the front compartment sight shields as necessary. Refer to «Sight Shields, Hood Adjuster, Hood Bumper, Hood Latch Replacement»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
- Turn the ignition OFF.
- Remove the front compartment sight shields as necessary. Refer to «Sight Shields, Hood Adjuster, Hood Bumper, Hood Latch Replacement»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
- Disconnect the camshaft position (CMP) sensor electrical connector.
- Remove the CMP sensor bolt.
- Remove the CMP sensor.
- Install the CMP sensor.
- Install the CMP sensor bolt. Tighten: Tighten the bolt to 10 N.m (89 lb in).
- Connect the CMP sensor electrical connector.
- Install the front compartment sight shields as necessary. Refer to «Sight Shields, Hood Adjuster, Hood Bumper, Hood Latch Replacement»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
- Turn the ignition OFF.
- Remove the front compartment sight shields as necessary. Refer to «Sight Shields, Hood Adjuster, Hood Bumper, Hood Latch Replacement»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
- Remove the ECM bracket bolts and reposition the ECM bracket in order to provide access.
- Disconnect the camshaft position (CMP) actuator valve electrical connector.
- Remove the CMP actuator valve bolt.
- Remove the CMP actuator valve.
- Install the CMP actuator valve.
- Install the CMP actuator valve bolt. Tighten: Tighten the CMP actuator valve bolt to 10 N.m (89 lb in).
- Connect the CMP actuator valve electrical connector.
- Install the ECM bracket with the ECM. Refer to «Engine Control Module (ECM) Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Install the front compartment sight shields as necessary. Refer to «Sight Shields, Hood Adjuster, Hood Bumper, Hood Latch Replacement»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
- Turn the ignition OFF.
- Remove the front compartment sight shields as necessary. Refer to «Sight Shields, Hood Adjuster, Hood Bumper, Hood Latch Replacement»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
- Disconnect the camshaft position (CMP) actuator valve electrical connector.
- Remove the CMP actuator valve bolt.
- Remove the CMP actuator valve.
- Install the CMP actuator valve.
- Install the CMP actuator valve bolt. Tighten: Tighten the bolt to 10 N.m (89 lb in).
- Connect the CMP valve electrical connector.
- Install the front compartment sight shields as necessary. Refer to «Sight Shields, Hood Adjuster, Hood Bumper, Hood Latch Replacement»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
- Turn the ignition OFF.
- Remove the power steering fluid reservoir bolts and reposition the power steering fluid reservoir in order to provide access. Refer to «Remote Power Steering Fluid Reservoir Replacement (LH2)»(/cadillac/sts/i-2004-2007/remont/manual-power-steering/#power-steering-system) or «Remote Power Steering Fluid Reservoir Replacement (LY7)»(/cadillac/sts/i-2004-2007/remont/manual-power-steering/#power-steering-system) in Power Steering System.
- Remove the camshaft position (CMP) actuator valve electrical connector.
- Remove the CMP actuator valve bolt.
- Remove the CMP actuator valve.
- Install the CMP actuator valve.
- Install the CMP actuator valve bolt. Tighten: Tighten the CMP actuator valve bolt to 10 N.m (89 lb in).
- Install the CMP actuator valve electrical connector.
- Install the power steering fluid reservoir. Refer to «Remote Power Steering Fluid Reservoir Replacement (LH2)»(/cadillac/sts/i-2004-2007/remont/manual-power-steering/#power-steering-system) or «Remote Power Steering Fluid Reservoir Replacement (LY7)»(/cadillac/sts/i-2004-2007/remont/manual-power-steering/#power-steering-system) in Power Steering System.
- Turn the ignition OFF.
- Remove the power steering fluid reservoir bolts and reposition the power steering fluid reservoir in order to provide access. Refer to «Remote Power Steering Fluid Reservoir Replacement (LH2)»(/cadillac/sts/i-2004-2007/remont/manual-power-steering/#power-steering-system) or «Remote Power Steering Fluid Reservoir Replacement (LY7)»(/cadillac/sts/i-2004-2007/remont/manual-power-steering/#power-steering-system) in Power Steering System.
- Remove the camshaft position (CMP) actuator valve electrical connector.
- Remove the CMP actuator valve bolt.
- Remove the CMP actuator valve.
- Install the CMP actuator valve.
- Install the CMP actuator valve bolt. Tighten: Tighten the CMP actuator valve bolt to 10 N.m (89 lb in).
- Install the CMP actuator valve electrical connector.
- Install the power steering fluid reservoir. Refer to «Remote Power Steering Fluid Reservoir Replacement (LH2)»(/cadillac/sts/i-2004-2007/remont/manual-power-steering/#power-steering-system) or «Remote Power Steering Fluid Reservoir Replacement (LY7)»(/cadillac/sts/i-2004-2007/remont/manual-power-steering/#power-steering-system) in Power Steering System.
- Turn the ignition OFF.
- Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) in General Information.
- Reposition the wiring harness heat shield to obtain access.
- Remove the knock sensor (KS) electrical connector.
- Remove the KS bolt.
- Remove the KS.
- Install the KS.
- Install the KS bolt. Tighten: Tighten the KS bolt to 23 N.m (17 lb ft).
- Install the KS electrical connector.
- Install the wiring harness heat shield to the original position.
- Lower the vehicle.
- Turn the ignition OFF.
- Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) in General Information.
- Remove the wiring harness heat shield from the oil level indicator tube to gain access.
- Remove the knock sensor (KS) electrical connector.
- Remove the KS bolt.
- Remove the KS.
- Install the KS.
- Install the KS bolt. Tighten: Tighten the KS bolt to 23 N.m (17 lb ft).
- Install the KS electrical connector.
- Install the wiring harness heat shield to the oil level indicator tube.
- Lower the vehicle.
- Remove the upper intake manifold with the lower intake manifold. Refer to «Intake Manifold Replacement - Lower»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
- Remove the intake manifold runner control solenoid bolts.
- Remove the intake manifold runner control solenoid.
- Install the intake manifold runner control solenoid.
- Install the intake manifold runner control solenoid bolts. Tighten: Tighten the intake manifold runner control solenoid bolts to 10 N.m (89 lb in).
- Install the upper intake manifold. Refer to «Intake Manifold Replacement - Lower»(/cadillac/sts/i-2004-2007/remont/mechanical/#engine-mechanical-36l-ly7-2-of-6) in Engine Mechanical - 3.6L (LY7).
- Remove the air cleaner intake duct. Refer to «Air Cleaner Intake Duct Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Loosen the air cleaner cover screws.
- Open the air cleaner cover and remove the air cleaner element.
- Install the air cleaner element and close the air cleaner cover.
- Install the air cleaner cover screws. Tighten: Tighten the air cleaner cover screws to 8 N.m (71 lb in).
- Install the air cleaner intake duct. Refer to «Air Cleaner Intake Duct Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Turn the ignition OFF.
- Remove the air cleaner intake duct. Refer to «Air Cleaner Intake Duct Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Disconnect the mass air flow (MAF) electrical connector.
- Remove the air cleaner bolts.
- Remove the air cleaner.
- Install the air cleaner.
- Install the air cleaner bolts. Tighten: Tighten the air cleaner bolts to 9 N.m (78 lb in).
- Connect the MAF electrical connector.
- Install the air cleaner intake duct. Refer to «Air Cleaner Intake Duct Replacement»(/cadillac/sts/i-2004-2007/remont/testing-diagnostics/#engine-control-system-36l-ly7-introduction) .
- Turn the ignition OFF.
- Remove the front compartment sight shields as necessary. Refer to «Sight Shields, Hood Adjuster, Hood Bumper, Hood Latch Replacement»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
- Remove the positive crankcase ventilation (PCV) hose from the air cleaner duct resonator.
- Loosen the air cleaner duct clamps.
- Remove the air cleaner duct.
- Install the air cleaner intake duct.
- Install the PCV hose to the intake duct resonator.
- Tighten the air cleaner duct clamps. Tighten: Tighten the clamps to 4 N.m (35 lb in).
- Install the front compartment sight shields as necessary. Refer to «Sight Shields, Hood Adjuster, Hood Bumper, Hood Latch Replacement»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
Scheme 29
| Callout | Component Name |
|---|---|
| 1 | Engine Control Module (ECM) |
| 2 | Fuel Injector Multi-Way Harness Connector |
| 3 | Ignition Coil Ground |
| 4 | ECM Ground |
| 5 | Throttle Body Assembly |
| 6 | ECM Connector C1 |
| 7 | ECM Connector C2 |
The engine control module (ECM) (1) interacts with many more emission related components and systems, and monitors emission related components and systems for deterioration. OBD II diagnostics monitor the system performance and a diagnostic trouble code (DTC) sets if the system performance degrades.
The malfunction indicator lamp (MIL) operation and the DTC storage are dictated by the DTC type. A DTC is ranked as a Type A or Type B if the DTC is emissions related. Type C is a non-emissions related DTC.
The ECM is in the engine compartment. The ECM is the control center of the engine controls system. The ECM controls the following components
- The fuel injection system
- The ignition system
- The emission control systems
- The on-board diagnostics
- The A/C and fan systems
- The throttle actuation control (TAC) system
The ECM constantly monitors the information from various sensors and other inputs, and controls the systems that affect the vehicle performance and the emissions. The ECM also performs diagnostic tests on various parts of the system. The ECM can recognize operational problems and alert the driver via the MIL. When the ECM detects a malfunction, the ECM stores a DTC. The condition area is identified by the particular DTC that is set. This aids the technician in making repairs.
ECM Function
The ECM can supply 5 volts or 12 volts to the various sensors or switches. This is done through pull-up resistors to the regulated power supplies within the ECM. In some cases, even an ordinary shop voltmeter will not give an accurate reading because the resistance is too low. Therefore, a DMM with at least 10 megaohms input impedance is required in order to ensure accurate voltage readings.
The ECM controls the output circuits by controlling the ground or the power feed circuit through the transistors or a device called an output driver module.
EEPROM
The electronically erasable programmable read only memory (EEPROM) is a permanent memory that is physically part of the ECM. The EEPROM contains program and calibration information that the ECM needs in order to control the powertrain operation.
Special equipment, as well as the correct program and calibration for the vehicle, are required in order to reprogram the ECM.
Theft Deterrent System Frequency Code Programming
This vehicle is equipped with a theft deterrent system which interfaces with the ECM. If the ECM is replaced, program the new ECM with the frequency code of the theft deterrent module that is currently on the vehicle. The vehicle will not start until this procedure is completed.
KS Module
The ECM employs an internal integrated circuit to continuously monitor the knock control evaluation circuit. The knock sensor (KS) module contains the circuitry that allows the ECM to utilize the knock sensor (KS) signals and diagnose the KS sensors and circuitry. If the ECM detects a fault in the ability of the KS module to sample these signals, a DTC sets.
Data Link Connector (DLC)
The data link connector (DLC) is a 16-pin connector that provides the technician a means of accessing serial data for aid in the diagnosis. This connector allows the technician to use a scan tool in order to monitor the various serial data parameters, and display the DTC information. The DLC is located inside of the drivers compartment, underneath the dash.
Malfunction Indicator Lamp (MIL)
The malfunction indicator lamp (MIL) is inside of the instrument panel cluster (IPC). The MIL is controlled by the ECM and illuminates when the ECM detects a condition that affects the vehicle emissions.
ECM Service Precautions
The ECM, by design, can withstand the normal current draws that are associated with the vehicle operations. However, care must be used in order to avoid overloading any of these circuits. When testing for opens or shorts, do not ground or apply voltage to any of the ECM circuits unless the diagnostic procedure instructs you to do so. These circuits should only be tested with a DMM.
Emissions Diagnosis For State I/M Programs
This OBD II equipped vehicle is designed to diagnose any conditions that could lead to excessive levels of the following emissions
- Hydrocarbons (HC)
- Carbon monoxide (CO)
- Oxides of nitrogen (NOx)
- Evaporative emission (EVAP) system losses
Should this vehicles on-board diagnostic system (ECM) detect a condition that could result in excessive emissions, the ECM turns ON the MIL and stores a DTC that is associated with the condition.
Aftermarket (Add-On) Electrical And Vacuum Equipment
Note. Do not attach add-on vacuum operated equipment to this vehicle. The use of add-on vacuum equipment may result in damage to vehicle components or systems.
Note. Connect any add-on electrically operated equipment to the vehicle's electrical system at the battery (power and ground) in order to prevent damage to the vehicle.
Aftermarket, add-on, electrical and vacuum equipment is defined as any equipment installed on a vehicle after leaving the factory that connects to the vehicles electrical or vacuum systems. No allowances have been made in the vehicle design for this type of equipment.
Add-on electrical equipment, even when installed to these strict guidelines, may still cause the powertrain system to malfunction. This may also include equipment not connected to the vehicle electrical system, such as portable telephones and radios. Therefore, the first step in diagnosing any powertrain condition is to eliminate all of the aftermarket electrical equipment from the vehicle. After this is done, if the problem still exists, the problem may be diagnosed in the normal manner.
Electrostatic Discharge (ESD) Damage
| IMPORTANT | In order to prevent possible electrostatic discharge damage to the ECM, DO NOT touch the connector pins on the ECM. |
The electronic components that are used in the control systems are often designed to carry very low voltage. The electronic components are susceptible to damage caused by electrostatic discharge. Less than 100 volts of static electricity can cause damage to some electronic components. By comparison, it takes as much as 4,000 volts for a person to even feel the zap of a static discharge.
There are several ways for a person to become statically charged. The most common methods of charging are by friction and by induction. An example of charging by friction is a person sliding across a car seat.
Charging by induction occurs when a person with well insulated shoes stands near a highly charged object and momentarily touches ground. Charges of the same polarity are drained off leaving the person highly charged with the opposite polarity. Static charges can cause damage, therefore, it is important to use care when handling and testing electronic components.
Emissions Control Information Label
The underhood Vehicle Emissions Control Information Label contains important emission specifications and setting procedures. In the upper left corner is the exhaust emission information. This identifies the year, the manufacturing division of the engine, the displacement of the engine in liters, the class of the vehicle, and type of fuel metering system. There is also an illustrated emission components and vacuum hose schematic.
This label is located in the engine compartment of every General Motors vehicle. If the label has been removed, it can be ordered from GM service parts operations (GMSPO).
Underhood Inspection
| IMPORTANT | This inspection is very important and must be done carefully and thoroughly. |
Perform a careful underhood inspection when performing any diagnostic procedure or diagnosing the cause of an emission test failure. This can often lead to repairing a condition without further steps. Use the following guidelines when performing an inspection
- Inspect all of the vacuum hoses for correct routing, pinches, cuts, or disconnects.
- Inspect any hoses that are difficult to see.
- Inspect all of the wires in the engine compartment for the following conditions: Burned or chafed spots Pinched wires Contact with sharp edges Contact with hot exhaust manifolds
Basic Knowledge Required
Note. Lack of basic knowledge of this powertrain when performing diagnostic procedures could result in incorrect diagnostic performance or damage to powertrain components. Do not attempt to diagnose a powertrain problem without this basic knowledge.
A basic understanding of hand tools is necessary in order to effectively use this section of the Service Manual.
You must be familiar with some of the basics of engine operation and electrical diagnosis in order to use this section of the service manual.
- Basic electrical circuits-You should have an understanding of basic electricity and know the meaning of voltage (volts), current (amps), and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire, and you should be able to identify a shorted or open circuit by using a DMM. You should be able to read and understand a wiring diagram.
- Use of digital multimeter-You should be familiar with the DMM, particularly the essential tool. You should be able to use the meter in order to measure the voltage (volts), the resistance (ohms), the current (amps), intermittents (min/max), and frequency (Hertz).
- Use of circuit testing tools-You should not use a test lamp to diagnose the engine controls system unless you are specifically instructed to do so. You should know how to the use jumper wires in order to test the components and allow the DMM readings without damaging the terminals. You should know how to use the J 35616 connector test adapter kit and use the kit whenever the diagnostic procedures call for front probing any connector.
Throttle Actuator Control (TAC) System Description
The throttle actuator control (TAC) system is used to improve emissions, fuel economy, and driveability. The TAC system eliminates the mechanical link between the accelerator pedal and the throttle plate. The TAC system eliminates the need for a cruise control module and idle air control motor. The following is a list of TAC system components
- The accelerator pedal assembly includes the following components: The accelerator pedal The accelerator pedal position (APP) sensor 1 The APP sensor 2
- The throttle body assembly includes the following components: The throttle position (TP) sensor 1 The TP sensor 2 The throttle actuator motor The throttle plate
- The engine control module (ECM)
The ECM monitors the driver demand for acceleration with 2 APP sensors. The APP sensor 1 signal voltage range is from about 0.98-4.16 volts as the accelerator pedal is moved from the rest pedal position to the full pedal travel position. The APP sensor 2 range is from about 0.49-2.08 volts as the accelerator pedal is moved from the rest pedal position to the full pedal travel position. The ECM processes this information along with other sensor inputs to command the throttle plate to a certain position.
The throttle plate is controlled with a direct current motor called a throttle actuator control motor. The ECM can move this motor in the forward or reverse direction by controlling battery voltage and/or ground to 2 internal drivers. The throttle plate is held at a 7 percent rest position using a constant force return spring. This spring holds the throttle plate to the rest position when there is no current flowing to the actuator motor.
The ECM monitors the throttle plate angle with 2 TP sensors. The TP sensor 1 signal voltage range is from about 0.5-4.25 volts as the throttle plate is moved from 0 percent to wide open throttle (WOT). The TP sensor 2 voltage range is from about 4.45-0.7 volts as the throttle plate is moved from 0 percent to WOT.
The ECM performs diagnostics that monitor the voltage levels of both APP sensors, both TP sensors, and the throttle actuator control motor circuit. It also monitors the spring return rate of both return springs that are housed internal to the throttle body assembly. These diagnostics are performed at different times based on whether the engine is running, not running, or whether the ECM is currently in a throttle body relearn procedure.
Every ignition cycle, the ECM performs a quick throttle return spring test to make sure the throttle plate can return to the 7 percent rest position from the 0 percent position. This is to ensure that the throttle plate can be brought to the rest position in case of an actuator motor circuit failure. Observe, under cold conditions, the ECM commands the throttle plate to 7 percent with the ignition ON and the engine OFF to release any ice that may have formed on the throttle plate.
Throttle Body Relearn Procedure
The engine control module (ECM) stores values that include the lowest possible throttle position (TP) sensor positions-0 percent, the rest positions-7 percent, and the return rate of both springs. These values will only be erased or overwritten if the ECM is reprogrammed or if a throttle body relearn procedure is performed. Observe, if the battery is disconnected, the ECM will immediately perform a throttle body relearn procedure when the ignition is turned ON.
A throttle body relearn procedure is performed anytime the ignition is turned ON, with the engine OFF for longer than 29 seconds when the following conditions have been met
- The engine speed is less than 40 RPM.
- The vehicle speed is 0 km/h (0 mph).
- The engine coolant temperature (ECT) is between 5-85°C (41-185°F).
- The intake air temperature (IAT) is more than 5-60°C (41-140°F).
- The accelerator pedal position (APP) sensor angle is less than 14.9 percent.
- The ignition 1 voltage is more than 10 volts.
After 29 seconds, the ECM commands the throttle plate from the rest position to full closed, then to around 10 percent open. This procedure takes about 6-8 seconds. If any faults occur in the throttle actuator control (TAC) system, a DTC sets. At the start of this procedure, the scan tool TAC Learn Counter parameter should display 0, then count up to 11 after the procedure is completed. If the counter did not start at 0, or if the counter did not end at 11, a fault has occurred and a DTC should set.
TAC System Default Actions/Reduce Power Modes
There are 2 reduce power modes that the engine control module (ECM) can default to if an error is detected in the throttle actuator control (TAC) system. If an accelerator pedal position (APP) sensor 1 or APP sensor 2 circuit fault, throttle position (TP) sensor 2 circuit fault, or if a TP sensor 1 circuit fault is detected with some APP angle, the ECM goes into one of the 2 reduce power modes. In this mode, the engine torque is limited so that the vehicle cannot reach speeds of more than 100 km/h (60 mph). The ECM remains in this reduce power mode during the entire ignition cycle even if the fault is corrected.
If there is a condition with the throttle actuator control circuits, throttle actuator command vs actual position fault, return spring check fault, or a TP sensor 1 circuit fault, the ECM goes into the other reduce engine power mode. In this mode, the engine speed is limited to 2,500 RPM and the 3-6 fuel injectors are randomly turned OFF. At this time the Reduced Power indicator is commanded ON. The ECM remains in the reduce power mode during the entire ignition cycle even if the fault is corrected. Observe, if a TP sensor 1 or throttle actuator control circuit fault is present at the time the vehicle is at idle, with no accelerator pedal angle, the engine may stall.
Scheme 30
| Callout | Component Name |
|---|---|
| 1 | Camshaft Actuator Vane |
| 2 | Timing Chain Sprocket |
| 3 | Engine Oil Pressure-For retarding the camshaft |
| 4 | Camshaft |
| 5 | Input Signals from Engine Sensors |
| 6 | Engine Control Module (ECM) |
| 7 | Camshaft Actuator Solenoid |
| 8 | Engine Oil Pump |
| 9 | Engine Oil Pressure Supply |
| 10 | Engine Oil Drain |
| 11 | Engine Oil Pressure-For advancing the camshaft |
| 12 | Camshaft Actuator Rotor |
| 13 | Camshaft Position Sensor Reluctor |
| 14 | Camshaft Actuator Lock Pin |
| 15 | Camshaft Actuator Housing |
The camshaft actuator system enables the engine control module (ECM) to change camshaft timing of all 4 camshafts while the engine is operating. The CMP actuator assembly (15) varies the camshaft position in response to directional changes in oil pressure. The CMP actuator solenoid valve controls the oil pressure that is applied to advance or retard a camshaft. Modifying camshaft timing under changing engine demand provides better balance between the following performance concerns
- Engine power output
- Fuel economy
- Lower tailpipe emissions
The CMP actuator solenoid valve (7) is controlled by the ECM. The crankshaft position (CKP) sensor and the CMP sensors are used to monitor changes in camshaft positions. The ECM uses the following information in order to calculate the desired camshaft positions
- The engine coolant temperature (ECT) sensor
- The calculated engine oil temperature (EOT)
- The mass air flow (MAF) sensor
- The throttle position (TP) sensor
- The vehicle speed sensor (VSS)
- The volumetric efficiency
Operation
The CMP actuator assembly has an outer housing that is driven by an engine timing chain. Inside the assembly is a rotor with fixed vanes that is attached to the camshaft. Oil pressure that is applied to the fixed vanes will rotate a specific camshaft in relationship to the crankshaft. The movement of the intake camshafts will advance the intake valve timing up to a maximum of 50 crankshaft degrees. The movement of the exhaust camshafts will retard the exhaust valve timing up to a maximum of 50 crankshaft degrees. When oil pressure is applied to the return side of the vanes, the camshafts will return to 0 crankshaft degrees, or top dead center (TDC). The CMP actuator solenoid valve directs the oil flow that controls the camshaft movement. The ECM commands the CMP solenoid to move the solenoid plunger and spool valve until oil flows from the advance passage (11). Oil flowing thru the CMP actuator assembly from the CMP solenoid advance passage applies pressure to the advance side of the vanes in the CMP actuator assembly. When the camshaft position is retarded, the CMP actuator solenoid valve directs oil to flow into the CMP actuator assembly from the retard passage (3). The ECM can also command the CMP actuator solenoid valve to stop oil flow from both passages in order to hold the current camshaft position.
The ECM operates the CMP actuator solenoid valve by pulse width modulation (PWM) of the solenoid coil. The higher the PWM duty cycle, the larger the change in camshaft timing. The CMP actuator assembly also contains a lock pin (14) that prevents movement between the outer housing and the rotor vane assembly. The lock pin is released by oil pressure before any movement in the CMP actuator assembly takes place. The ECM is continuously comparing CMP sensor inputs with CKP sensor input in order to monitor camshaft position and detect any system malfunctions. If a condition exists in either the intake or exhaust camshaft actuator system, the opposite bank, intake or exhaust, camshaft actuator will default to 0 crankshaft degrees.
| Driving Condition | Change in Camshaft Position | Objective | Result |
|---|---|---|---|
| Idle | No Change | Minimize Valve Overlap | Stabilize Idle Speed |
| Light Engine Load | Retard Valve Timing | Decrease Valve Overlap | Stable Engine Output |
| Medium Engine Load | Advance Valve Timing | Increase Valve Overlap | Better Fuel Economy with Lower Emissions |
| Low to Medium RPM with Heavy Load | Advance Valve Timing | Advance Intake Valve Closing | Improve Low to Mid-range Torque |
| High RPM with Heavy Load | Retard Valve Timing | Retard Intake Valve Closing | Improve Engine Output |
CMP Actuator System Operation
Fuel Tank
The fuel storage tank is made of high density polyethylene. The fuel storage tank is held in place by 2 metal straps that are attached to the under body of the vehicle. The tank shape includes a sump in order to maintain a constant supply of fuel around the fuel pump strainer during low fuel conditions or during aggressive maneuvers.
The fuel tank also contains a fuel vapor vent valve with a roll-over protection. The vent valve also features a 2-phase vent calibration which increases the fuel vapor flow to the canister when the operating temperatures increase the tank pressure beyond an established threshold.
On-Board Refueling Vapor Recovery (ORVR) System
The on-board refueling vapor recovery (ORVR) system is an on-board vehicle system to recover fuel vapors during the vehicle refueling operation. The flow of liquid fuel down to the fuel tank filler neck provides a liquid seal. The purpose of ORVR is to prevent refueling vapor from exiting the fuel tank filler neck. The ORVR components are listed below, with a brief description of their operation
- The fuel tank-The fuel tank contains the modular fuel sender, the fuel limiter vent valve (FLVV), and 1 rollover valve.
- The fuel filler pipe-The fuel filler pipe carries fuel from the fuel nozzle to the fuel tank.
- The evaporative emission (EVAP) canister-The EVAP canister receives refueling vapor from the fuel system, stores the vapor, and releases the vapor to the engine upon demand.
- The vapor lines-The vapor lines transport fuel vapor from the tank assembly to the EVAP canister and engine.
- The check valve-The check valve limits fuel spit-back from the fuel tank during the refueling operation by allowing fuel flow only into the fuel tank. The check valve is located at the bottom of the fuel filler pipe.
- The modular fuel sender assembly-The modular fuel sender assembly pumps fuel to the engine from the fuel tank.
- The fuel tank pressure (FTP) sensor is located on top of the fuel tank vapor dome.
- The FLVV-The FLVV acts as a shut-off valve. The FLVV is located in the fuel tank. This valve has the following functions: Controlling the fuel tank fill level by closing the primary vent from the fuel tank Preventing fuel from exiting the fuel tank via the vapor line to the canister Providing fuel spillage protection in the event of a vehicle rollover by closing the vapor path from the tank to the engine
- The pressure vacuum relief valve-The pressure vacuum relief valve provides venting of excessive fuel tank pressure and vacuum. The valve is located in the fuel fill cap.
- The vapor recirculation line-The vapor recirculation line is used to transport vapor from the fuel tank to the top of the fill pipe during refueling to reduce vapor loading to the enhanced EVAP canister.
Fuel Tank Filler Pipe
In order to prevent refueling with leaded fuel, the fuel filler pipe has a built-in restrictor and a deflector. The opening in the restrictor will accept only the smaller unleaded gasoline fuel nozzle which must be fully inserted in order to bypass the deflector. The tank is vented during filling by an internal vent tube inside of the filler pipe.
Scheme 31
| Callout | Component Name |
|---|---|
| 1 | Fuel Tank Filler Cap |
| 2 | Fuel Tank Filler Pipe |
| 3 | Fuel Filler Door |
Note. Use a fuel tank filler pipe cap with the same features as the original when a replacement is necessary. Failure to use the correct fuel tank filler pipe cap can result in a serious malfunction of the fuel system.
The fuel tank filler pipe is equipped with a turn to vent screw on the type cap which incorporates a ratchet action in order to prevent over-tightening.
The turn to vent feature allows the fuel tank pressure relief prior to removal. Instructions for proper use are imprinted on the cap cover. A vacuum safety relief valve is incorporated into this cap.
Scheme 32
| Callout | Component Name |
|---|---|
| 1 | Secondary Fuel Level Sensor - Left |
| 2 | Fuel Return Pipe from Engine |
| 3 | Fuel Feed Pipe to Engine |
| 4 | 2-Way Check Valve - Fuel Supply |
| 5 | Siphon Jet Pump |
| 6 | Primary Fuel Level Sensor - Right |
| 7 | Fuel Reservoir/Bucket |
| 8 | Fuel Pump |
| 9 | Fuel Strainer/Pick up |
| 10 | Return Fuel Check Valve for Reservoir |
| 11 | Return Fuel Jet Pump |
| 12 | Fuel Pressure Regulator |
| 13 | Fuel Transfer Line |
| 14 | Fuel Strainer/Pickup |
The modular fuel sender assembly mounts to the threaded opening of the plastic fuel tank with a seal and a retainer ring. The reservoir, containing the exterior inlet strainer, the electric fuel pump and the pump strainer, maintains contact with the tank bottom. This design provides
- Optimum fuel level in the integral fuel reservoir during all fuel tank levels and during driving conditions
- An improved tank fuel level measuring accuracy
- An improved coarse straining and added pump inlet filtering
- More extensive internal fuel pump isolation for noiseless operation
The modular fuel sender assembly maintains an optimum fuel level in the reservoir (bucket). The fuel entering the reservoir is drawn in by the following components
- The first stage of the fuel pump through the external strainer and/or
- The secondary umbrella valve or
- The return fuel line, whenever the level of fuel is below the top of the reservoir
Fuel Pump
The electric fuel pump is a turbine pump which is located inside of the modular fuel sender. The electric fuel pump operation is controlled by the engine control module (ECM) through the fuel pump relay.
Fuel Sender Strainers
The strainers act as a coarse filter to perform the following functions
- Filter contaminants
- Separate water from fuel
- Provide a wicking action that helps draw fuel into the fuel pump
Fuel stoppage at the strainer indicates that the fuel tank contains an abnormal amount of sediment or water. Therefore, the fuel tank will need to be removed and cleaned, and the filter strainer should be replaced.
Scheme 33
The fuel filter is located on the fuel feed pipe, between the fuel pump and the fuel rail. The electric fuel pump supplies fuel through the in-line fuel filter to the fuel injection system. The fuel pressure regulator keeps the fuel available to the fuel injectors at a regulated pressure. Unused fuel is returned from the fuel filter to the fuel tank by a separate fuel return pipe. The paper filter element (2) traps particles in the fuel that may damage the fuel injection system. The filter housing (1) is made to withstand maximum fuel system pressure, exposure to fuel additives, and changes in temperature. There is no service interval for fuel filter replacement. Replace a restricted fuel filter.
EVAP Lines and Hoses
The EVAP line extends from the fuel tank vent valve to the EVAP canister and into the engine compartment. The EVAP line is made of nylon and connects to the EVAP canister with a quick connect fitting.
Scheme 34
The fuel pressure regulator attaches to the fuel return pipe on the fuel sender assembly. The fuel pressure regulator is a diaphragm-operated relief valve. A software bias compensates the injector on-time because the fuel pressure regulator is not referenced to manifold vacuum. The injector pulse width varies with the signal from the mass air flow (MAF)/intake air temperature (IAT) sensor.
With the engine running at idle, the system fuel pressure at the pressure test connection should be between 380-410 kPa (55-60 psi). With the system pressurized and the pump OFF the pressure should stabilize and hold. If the pressure regulator supplies a fuel pressure which is too low or too high, a driveability condition will result.
Fuel Rail
The fuel rail consists of 3 parts
- The pipe that carries fuel to each injector
- The fuel pressure test port
- Six individual fuel injectors
The fuel rail is mounted on the intake manifold and distributes the fuel to each cylinder through the individual injectors.
Fuel Injectors
The fuel injector is a solenoid device that is controlled by the ECM. When the ECM energizes the injector coil, a normally closed ball valve opens, allowing the fuel to flow past a director plate to the injector outlet. The director plate has holes that control the fuel flow, generating a dual conical spray pattern of finely atomized fuel at the injector outlet. The fuel from the outlet is directed at both of the intake valves, causing the fuel to become further vaporized before entering the combustion chamber.
The fuel injectors will cause various driveability conditions if the following conditions occur
- If the injectors will not open
- If the injectors are stuck open
- If the injectors are leaking
- If the injectors have a low coil resistance
Fuel Pump Relay
The fuel pump relay allows the ECM to energize the fuel pump. The ECM enables the fuel pump whenever the crankshaft position (CKP) sensor pulses are detected.
Engine Fueling
The engine is fueled by six individual injectors, one for each cylinder, that are controlled by the ECM. The ECM controls each injector by energizing the injector coil for a brief period once every other engine revolution. The length of this brief period, or pulse, is carefully calculated by the ECM to deliver the correct amount of fuel for proper driveability and emissions control. The period of time when the injector is energized is called the pulse width and is measured in milliseconds, thousandths of a second.
While the engine is running, the ECM is constantly monitoring the inputs and recalculating the appropriate pulse width for each injector. The pulse width calculation is based on the injector flow rate, mass of fuel the energized injector will pass per unit of time, the desired air/fuel ratio, and actual air mass in each cylinder and is adjusted for battery voltage, short term, and long term fuel trim. The calculated pulse is timed to occur as each cylinders intake valves are closing to attain largest duration and most vaporization.
Fueling during a crank is slightly different than fueling during an engine run. As the engine begins to turn, a prime pulse may be injected to speed starting. As soon as the ECM can determine where in the firing order the engine is, the ECM begins pulsing the injectors. The pulse width during the crank is based on the coolant temperature and the engine load.
The fueling system has several automatic adjustments in order to compensate for the differences in the fuel system hardware, the driving conditions, the fuel used, and the vehicle aging. The basis for the fuel control is the pulse width calculation that is described above. Included in this calculation are an adjustment for the battery voltage, the short term fuel trim, and the long term fuel trim. The battery voltage adjustment is necessary since the changes in the voltage across the injector affect the injector flow rate. The short term and the long term fuel trims are fine and gross adjustments to the pulse width that are designed in order to maximize the driveability and emissions control. These fuel trims are based on the feedback from the oxygen sensors in the exhaust stream and are only used when the fuel control system is in a Closed Loop operation.
Under certain conditions, the fueling system will turn OFF the injectors for a period of time. This is referred to as fuel shut-off. Fuel shut-off is used in order to improve traction, save fuel, improve emissions, and protect the vehicle under certain extreme or abusive conditions.
In case of a major internal problem, the ECM may be able to use a back-up fuel strategy for limp in mode that will run the engine until service can be performed.
Sequential Fuel Injection (SFI)
The ECM controls the fuel injectors based on information that the ECM receives from several information sensors. Each injector is fired individually in the engine firing order, which is called sequential fuel injection. This allows precise fuel metering to each cylinder and improves the driveability under all of the driving conditions.
The ECM has several operating modes for fuel control, depending on the information that has been received from the sensors.
Starting Mode
When the ECM detects reference pulses from the CKP sensor, the ECM will enable the fuel pump. The fuel pump runs and builds up pressure in the fuel system. The ECM then monitors the MAF, IAT, engine coolant temperature (ECT), and the throttle position (TP) sensor signal in order to determine the required injector pulse width for starting.
Clear Flood Mode
If the engine is flooded with fuel during starting and will not start, the Clear Flood Mode can be manually selected. To select Clear Flood Mode, push the accelerator to wide open throttle (WOT). With this signal, the ECM will completely turn OFF the injectors and will maintain this stage as long as the ECM indicates a WOT condition with engine speed below 1,000 RPM.
Run Mode
The Run Mode has 2 conditions: Open Loop operation and Closed Loop operation. When the engine is first started and the engine speed is above 480 RPM, the system goes into Open Loop operation. In Open Loop operation, the ECM ignores the signals from the oxygen sensors and calculates the required injector pulse width based primarily on inputs from the MAF, IAT and ECT sensors.
In Closed Loop, the ECM adjusts the calculated injector pulse width for each bank of injectors based on the signals from each oxygen sensor.
Acceleration Mode
The ECM monitors the changes in the TP and the MAF sensor signals in order to determine when the vehicle is being accelerated. The ECM will then increase the injector pulse width in order to provide more fuel for improved performance.
Deceleration Mode
The ECM monitors changes in TP and MAF sensor signals to determine when the vehicle is being decelerated. The ECM will then decrease injector pulse width or even shut OFF injectors for short periods to reduce exhaust emissions, and for better (engine braking) deceleration.
Battery Voltage Correction Mode
The ECM can compensate in order to maintain acceptable vehicle driveability when the ECM sees a low battery voltage condition. The ECM compensates by performing the following functions
- Increasing the injector pulse width in order to maintain the proper amount of fuel being delivered
- Increasing the idle speed to increase the generator output
Fuel Shut-Off Mode
The ECM has the ability to completely turn OFF all of the injectors or selectively turn OFF some of the injectors when certain conditions are met. These fuel shut-off modes allow the ECM to protect the engine from damage and also to improve the vehicles driveability.
The ECM will disable all of the six injectors under the following conditions
- Ignition OFF-Prevents engine run-on
- Ignition ON but no CKP signal-Prevents flooding or backfiring
- A high engine speed-Above the red line
- A high vehicle speed-Above the rated tire speed
- Closed throttle cast down-Reduces the emissions and increases engine braking.
The ECM will selectively disable the injectors under the following conditions
- The torque management enabled-Transmission shifts or abusive maneuvers.
- The traction control enabled-In conjunction with the front brakes applying
EVAP System Operation
The evaporative emission (EVAP) control system limits fuel vapors from escaping into the atmosphere. Fuel tank vapors are allowed to move from the fuel tank, due to pressure in the tank, through the vapor pipe, into the EVAP canister. Carbon in the canister absorbs and stores the fuel vapors. Excess pressure is vented through the vent line and EVAP vent valve to atmosphere. The EVAP canister stores the fuel vapors until the engine is able to use them. At an appropriate time, the control module will command the EVAP purge valve ON, open, allowing engine vacuum to be applied to the EVAP canister. With the EVAP vent valve OFF, open, fresh air will be drawn through the valve and vent line to the EVAP canister. Fresh air is drawn through the canister, pulling fuel vapors from the carbon. The air/fuel vapor mixture continues through the EVAP purge pipe and EVAP purge valve into the intake manifold to be consumed during normal combustion. The control module uses several tests to determine if the EVAP system is leaking.
Large Leak Test
This tests for large leaks and blockages in the EVAP system. The control module will command the EVAP vent valve ON, closed, and command the EVAP purge valve ON, open, with the engine running, allowing engine vacuum into the EVAP system. The control module monitors the fuel tank pressure (FTP) sensor voltage to verify that the system is able to reach a predetermined level of vacuum within a set amount of time. The control module then commands the EVAP purge valve OFF, closed, sealing the system and monitors the vacuum level for decay. If the control module does not detect that the predetermined vacuum level was achieved, or the vacuum decay rate is more than a calibrated level on 2 consecutive tests, DTC P0455 sets.
Small Leak Test
The engine off natural vacuum, (EONV), diagnostic is the small leak detection diagnostic for the EVAP system. The EONV diagnostic monitors the EVAP system pressure or vacuum with the key OFF. The EONV utilizes the temperature changes and the resulting naturally occurring vacuum or pressure in the fuel tank immediately following a drive cycle. When the vehicle is driven, the temperature in the fuel tank rises. When the vehicle is parked with the engine OFF and key OFF, the temperature in the fuel tank will continue to rise for a period of time, and then begin to decrease. The EONV diagnostic relies on this temperature change, and the corresponding pressure change to determine if an EVAP system leak is present. The EONV diagnostic is designed to detect leaks as small as 0.51 mm (0.020 in). The diagnostic can determine if a small leak is present based on vacuum or pressure readings in the EVAP system. When the EVAP system is sealed a finite amount of pressure or vacuum will be observed. When a 0.51 mm (0.020 in) leak is present, little or no pressure or vacuum is observed. If the test reports a failing value, DTC P0442 will set.
Canister Vent Restriction Test
If the EVAP vent system is restricted, fuel vapors will not be properly purged from the EVAP canister. The control module tests this by commanding the EVAP purge valve ON, open; and commanding the EVAP vent valve OFF, open; and monitoring the FTP sensor for an increase in vacuum. If vacuum increases more than a calibrated value, DTC P0446 sets.
Purge Valve Leak Test
If the EVAP purge valve does not seal properly, fuel vapors could enter the engine at an undesired time, causing driveability concerns. The control module tests for this by commanding the EVAP purge valve OFF, closed; and vent valve ON, closed; sealing the system, and monitoring the FTP for an increase in vacuum. If the control module detects that EVAP system vacuum increases above a calibrated value, DTC P0496 sets.
EVAP System Components
The EVAP system consists of the following components
EVAP Canister
The canister is filled with carbon pellets used to absorb and store fuel vapors. Fuel vapor is stored in the canister until the control module determines that the vapor can be consumed in the normal combustion process.
EVAP Purge Valve
The EVAP purge valve controls the flow of vapors from the EVAP system to the intake manifold. This normally closed valve is pulse width modulated (PWM) by the control module to precisely control the flow of fuel vapor to the engine. The valve will also be opened during some portions of the EVAP testing, allowing engine vacuum to enter the EVAP system.
EVAP Vent Valve
The EVAP vent valve controls fresh airflow into the EVAP canister. The valve is normally open. The control module will command the valve closed during some EVAP tests, allowing the system to be tested for leaks.
Fuel Tank Pressure Sensor
The FTP sensor measures the difference between the pressure or vacuum in the fuel tank and outside air pressure. The control module provides a 5-volt reference and a ground to the FTP sensor. The FTP sensor provides a signal voltage back to the control module that can vary between 0.1-4.9 volts. As FTP increases, FTP sensor voltage decreases, high pressure = low voltage. As FTP decreases, FTP voltage increases, low pressure or vacuum = high voltage.
EVAP Service Port
The EVAP service port is located in the EVAP purge pipe between the EVAP purge valve and the EVAP canister. The service port is identified by a green colored cap.
Electronic Ignition (EI) System Description
The electronic ignition (EI) system produces and controls a high-energy secondary spark. This spark is used to ignite the compressed air/fuel mixture at precisely the correct time. This provides optimal performance, fuel economy, and control of exhaust emissions. This ignition system uses an individual coil for each cylinder. The ignition coils are mounted in the center of each camshaft cover with short integrated boots connecting the coils to the spark plugs. The driver modules within each ignition coil are commanded ON/OFF by the engine control module (ECM). The ECM primarily uses engine speed, the MAF sensor signal, and position information from the crankshaft position (CKP) and the camshaft position (CMP) sensors. This controls the sequence, dwell, and timing of the spark. The EI system consists of the following components
Crankshaft Position (CKP) Sensor
The crankshaft position (CKP) sensor works in conjunction with a 58 tooth reluctor wheel on the crankshaft. The engine control module (ECM) monitors the voltage between the CKP sensor signal circuits. As each reluctor wheel tooth rotates past the sensor, the sensor creates an analog signal. This analog signal is processed by the ECM. The reluctor wheel teeth are 6 degrees apart. Having only 58 teeth leaves a 12 degree span that is uncut. This creates a signature pattern that enables the ECM to determine the CKP. The ECM can determine which pair of cylinders is approaching top dead center based on the CKP signal alone. The camshaft position (CMP) sensor signals are used in order to determine which of these 2 cylinders is on a firing stroke, and which is on the exhaust stroke. The ECM uses this to properly synchronize the ignition system, the fuel injectors, and the knock control. This sensor is also used in order to detect misfire.
Camshaft Position (CMP) Sensor
This engine uses 4 camshaft position (CMP) sensors, one for each camshaft. The CMP sensor signals are a digital ON/OFF pulse, output 4 times per revolution of the camshaft. The CMP sensor does not directly affect the operation of the ignition system. The CMP sensor information is used by the engine control module (ECM) to determine the position of the 4 camshafts relative to the crankshaft position. By monitoring the CMP and crankshaft position (CKP) signals the ECM can accurately time the operation of the fuel injectors. The ECM supplies the CMP sensor with a 5-volt reference circuit and a low reference circuit. The CMP sensor signals are an input to the ECM. These signals are also used to detect camshaft alignment with the crankshaft.
Ignition Coils
Each ignition coil contains a solid state driver module as its primary element. The engine control module (ECM) signals the coil driver to initiate a firing event by applying ignition control (IC) circuit current for the appropriate time, or dwell. When the current is removed the coil fires the spark plug. The ignition coils use the following circuits
- An ignition 1 voltage supply circuit
- An IC circuit
- Two ground circuits
Engine Control Module (ECM)
The engine control module (ECM) controls all ignition system functions, and constantly corrects the spark timing. The ECM monitors information from various sensor inputs that include the following components
- The throttle position (TP) sensor
- The engine coolant temperature (ECT) sensor
- The mass air flow (MAF) sensor
- The intake air temperature (IAT) sensor
- The vehicle speed sensor (VSS)
- The transmission gear position or range information sensors
- The engine knock sensors (KS)
- Ambient pressure sensor (BARO)
Knock Sensor (KS) System Description
You can diagnose all of the sensors and most of the input circuits with a scan tool. Within this section is a short description of how to use a scan tool wherever possible to diagnose these circuits. You can also use the scan tool to compare the values for an engine that is running normally with the engine you are diagnosing.
The knock sensor (KS) system detects engine knocking or pinging. The ECM will retard the spark timing based on the signals from the KS system. The KS produce an AC voltage that is sent to the engine control module (ECM). The amount of the AC voltage produced is proportional to the amount of knock.
The ECM monitors the voltage of the sensors after each cylinder has fired.
If knock occurs in any of the cylinders, the ignition will be retarded for that particular cylinder. If the knocking then stops, the ignition will be restored to what it was before in steps.
Should knocking continue in the same cylinder in spite of the ignition being retarded, the ECM will retard the ignition an additional steps, and so on, up to a maximum of 12 degrees of retard. The ignition will also be retarded at high ambient temperatures in order to counteract knocking tendencies provoked by high intake air temperatures.
Should either bank 1 or bank 2 sensor fail to work, or should an internal circuit problem occur, the ignition timing will then use a default strategy. The default strategy will retard the ignition the maximum allowed amount to protect the engine from possible damage.
Scheme 35
| Callout | Component Name |
|---|---|
| 1 | Electrical Connector |
| 2 | MAF Sensor |
| 3 | Circuit Board Cover |
| 4 | Circuit Board |
| 5 | IAT Sensor |
| 6 | Circuitry Housing |
The MAF sensor measures the amount of air coming into the engine. This direct airflow measurement is more accurate than the calculated airflow information obtained from the other sensor inputs. The MAF sensor also houses an integrated intake air temperature (IAT) sensor. The MAF sensor uses the following circuits
- An ignition 1 voltage circuit
- A 5-volt reference circuit
- A low reference circuit
- A signal circuit
- IAT signal circuit
The MAF sensor that is used on this vehicle is a hot film type and is used in order to measure the air flow rate. The MAF output voltage is a function of the power required to keep the air flow sensing elements at a fixed temperature above the ambient temperature. The air flowing through the sensor cools the sensing elements. The amount of cooling is proportional to the amount of air flow. As the air flow increases, more current is needed in order to maintain the hot film at a constant temperature. The MAF sensor converts the changes in the current draw to a voltage signal that the ECM monitors. The ECM calculates the air flow based on this signal.
The ECM monitors the MAF sensor signal voltage and can determine if the sensor signal voltage is too low or too high. The ECM can also detect airflow that is inappropriate for a given operating condition based on the signal voltage.
The scan tool displays the MAF value and displays the value in grams per second (g/s). Values should change rather quickly on acceleration, but should remain fairly stable at any given engine speed. If the ECM detects a condition with the MAF sensor circuits, the following DTCs set
- P0101 Mass Air Flow (MAF) Sensor Performance
- P0102 Mass Air Flow (MAF) Sensor Circuit Low Voltage
- P0103 Mass Air Flow (MAF) Sensor Circuit High Voltage
Scheme 36
The characteristic torque curve of a normally aspirated engine depends mainly on how the engines average pressure changes over the engine speed band. The average pressure is proportional to the volume of the air mass present in the cylinder when the inlet valve is closed. The design of the inlet system determines how large an air mass can be drawn into a cylinder at a given engine speed.
An intake manifold runner control (IMRC) valve (2) is used to change the intake manifold runner configuration. When the IMRC valve is open, the intake manifold is configured to one large plenum (4). When the IMRC valve is closed, the intake manifold is configured to two smaller plenums (3). The two intake manifold runner sizes result in different torque curves which improves performance at low and high engine speeds. The IMRC valve is located in the intake manifold (1). The IMRC valve solenoid is supplied with ignition 1 voltage and is controlled by the engine control module (ECM).
Special Tools
Special Tools Illustration Tool Number/Description EL 39021-460 Injector Harness Adapter GE 44602 Injector Test Adapter J 23738-A Vacuum Pump J 26792 Spark Tester J 34730-1A Fuel Pressure Gage J 34730-405 Injector Test Lamp J 35616 Connector Test Adapter Kit J 35616-200 Un-powered Test Light Kit J 36850 Transjel Lubricant J 37088-A Fuel Line Disconnect Tool Set J 37287 Inlet and Return Fuel Line Shut-Off Adapters J 37287-100 Fuel Line Shut-Off Quick Connect Adapters J 39021 Fuel Injector Coil/Balance Test J 39021-210 Injector Switch Box J 39200 Digital Multimeter (DMM) J 41413-200 Evaporative Emission System Tester (EEST) J 41413-300 EVAP Cap and Plug Kit J 41413-SPT High Intensity White Light J 41413-VLV Evaporative Emission Service Port Fitting J 41415-50 Fuel Tank Cap Adapter J 42598-B CAN+ Vehicle Data Recorder J 42960-02 Fuel Flap Door Holder J 44175 Fuel Composition Tester J 45004 Fuel Tank Drain Hose J 45289 Controller Area Network Diagnostic Interface (CANdi) Module J 45747 Fuel Sender Lock Ring Wrench 70000081 Tech II Scan Tool
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See also:
• Sight Shields, Hood Adjuster, Hood Bumper, Hood Latch Replacement
• Electrical Center Identification Views
• Battery Negative Cable Disconnect/Connect Procedure
• Fastener Notice
• Control Module References
• Draining and Filling Cooling System
• Fuel Injector Sight Shield Replacement
• Lifting and Jacking the Vehicle
• Oxygen Sensor Notice
• Component Fastener Tightening Notice
• Closeout/Insulator Panel Replacement - Left
• Disengaging Connectors Notice
• Gasoline/Gasoline Vapors Caution
• Exhaust System Replacement
• Propeller Shaft Replacement - Rear (AWD)
• Propeller Shaft Replacement - Rear (RWD)
• Fuel Tank Leak Test
• Tire and Wheel Removal and Installation
• Wheelhouse Liner Panel Replacement - Rear
• Relieving Fuel Pressure Caution
• Transmission Support Replacement
• Safety Glasses and Compressed Air Caution
• Remote Power Steering Fluid Reservoir Replacement (LH2)
• Air Cleaner Intake Duct Replacement
• Idle Learn Procedure
• Special Tools
• Fuel Pressure Relief Procedure
• Quick Connect Fitting(s) Service (Metal Collar)
• Fuel Tank Draining Procedure
• Quick Connect Fitting(s) Service (Plastic Collar)
• Ignition System Specifications