Engine Control System (Introduction) - 3.5l (lx9) — Chevrolet Malibu VI (2003-2006)

Temperature vs Resistance

°C	°F	OHMS
Temperature vs Resistance Values (Approximate)
150	302	47
140	284	60
130	266	77
120	248	100
110	230	132
100	212	177
90	194	241
80	176	332
70	158	467
60	140	667
50	122	973
45	113	1188
40	104	1459
35	95	1802
30	86	2238
25	77	2796
20	68	3520
15	59	4450
10	50	5670
5	41	7280
0	32	9420
5	23	12300
10	14	16180
15	5	21450
20	4	28680
30	22	52700
40	40	100700

Temperature vs Resistance

Altitude vs Barometric Pressure

Altitude Measured in Meters (m)	Altitude Measured in Feet (ft)	Barometric Pressure Measured in Kilopascals (kPa)
Determine your altitude by contacting a local weather station or by using another reference source.
4 267	14,000	56-64
3 962	13,000	58-66
3 658	12,000	61-69
3 353	11,000	64-72
3 048	10,000	66-74
2 743	9,000	69-77
2 438	8,000	71-79
2 134	7,000	74-82
1 829	6,000	77-85
1 524	5,000	80-88
1 219	4,000	83-91
914	3,000	87-95
610	2,000	90-98
305	1,000	94-102
0	0 Sea Level	96-104
305	1,000	101-105

Altitude vs Barometric Pressure

Ignition System Specifications

Application	Specification
Application	Metric	English
Firing Order	1-2-3-4-5-6
Spark Plug Gap	1.52 mm	0.060 in
Spark Plug Torque	15 N.m	11 lb ft
Spark Plug Type	GM P/N 12568387 AC Delco #41-101
Spark Plug Wire Resistance	4,018 ohms per meter (1,225 ohms per ft)

Ignition System Specifications

Fastener Tightening Specifications

Application	Specification
Application	Metric	English
Accelerator Cable Bracket Retaining Bolts	13 N.m	115 lb in
Accelerator Cable Bracket Retaining Nut	10 N.m	89 lb in
Accelerator Pedal Retaining Bolt	3 N.m	27 lb in
Air Cleaner Duct Clamps	2 N.m	18 lb in
Air Cleaner Housing Nuts	10 N.m	89 lb in
Air Cleaner Retainer Screws	6 N.m	40 lb in
Air Cleaner Upper Cover Bolt	2.3 N.m	20 lb in
Camshaft Position (CMP) Sensor Retaining Bolt	8 N.m	71 lb in
Crankshaft Position 7X (CKP) Sensor Bolts	11 N.m	97 lb in
Crankshaft Position 24X (CKP) Sensor Bolts	10 N.m	89 lb in
Engine Coolant Temperature (ECT) Sensor	20 N.m	15 lb ft
EVAP Canister Purge Valve Retaining Bolt	10 N.m	89 lb in
EVAP Canister Retainer Bolt	10 N.m	89 lb in
Exhaust Gas Recirculation (EGR) Pipe Bolt	25 N.m	18 lb ft
Exhaust Gas Recirculation Pipe Nut	25 N.m	18 lb ft
Exhaust Gas Recirculation Valve Bolts	30 N.m	22 lb ft
Exhaust Shield Bolt	2 N.m	18 lb in
Exhaust Shield Nut	1 N.m	9 lb in
Fuel Feed and Return Pipes to Fuel Rail	17 N.m	13 lb ft
Fuel Filler Hose Clamp	3 N.m	27 lb in
Fuel Filler Pipe Attaching Screw	10 N.m	89 lb in
Fuel Filter Fitting	27 N.m	20 lb ft
Fuel Pipe Mounting Bolts	6 N.m	53 lb in
Fuel Pipe Retainer Bolt	25 N.m	18 lb ft
Fuel Pressure Regulator Attaching Screw	8.5 N.m	75 lb in
Fuel Rail Attaching Bolts	10 N.m	89 lb in
Fuel Tank Retaining Strap Bolts	35 N.m	26 lb ft
Heated Oxygen Sensors (HO2S)	41 N.m	30 lb ft
Idle Air Control (IAC) Valve Attaching Screws	3 N.m	27 lb in
Ignition Coil to Ignition Control Module Screws	4.5 N.m	40 lb in
Knock Sensor (KS)	19 N.m	14 lb in
Manifold Absolute Pressure (MAP) Sensor Retaining Screws	3 N.m	27 lb in
PCM Connector Screws	8 N.m	71 lb in
Spark Plugs	15 N.m	11 lb ft
Throttle Body Retaining Nuts or Bolts	10 N.m	89 lb in
Throttle Position (TP) Sensor Screws	2 N.m	18 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.

Conditions for Clearing the MIL/DTC - Type A or Type B

The control module turns OFF the MIL after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC Last Test Failed 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 current DTC, clears when the diagnostic runs and passes.
Use a scan tool in order to clear the DTC.

Conditions for Clearing the DTC - Type X

This DTC is available in the PCM software, but has been disabled, or turned OFF. In this case, the diagnostic does not run, no DTCs are stored, and the MIL does not illuminate. Type X DTCs are used primarily for export vehicles that do not require MIL illumination or DTC storing.

Diagnostic Trouble Code (DTC) Type(s)

DTC	Type
P0030	B
P0036	B
P0050	B
P0056	B
P0068	A
P0101	B
P0102	B
P0103	B
P0107	B
P0108	B
P0112	B
P0113	B
P0116	B
P0117	B
P0118	B
P0120	A
P0125	B
P0128	B
P0130	B
P0131	B
P0132	B
P0133	B
P0134	B
P0135	B
P0136	B
P0137	B
P0138	B
P0140	B
P0141	B
P0150	B
P0151	B
P0152	B
P0153	B
P0154	B
P0155	B
P0156	B
P0157	B
P0158	B
P0160	B
P0161	B
P0171	B
P0172	B
P0174	B
P0175	B
P0201	B
P0202	B
P0203	B
P0204	B
P0205	B
P0206	B
P0218	C
P0220	A
P0230	C
P0300	B
P0315	A
P0325	B
P0327	B
P0332	B
P0335	A
P0340	B
P0401	A
P0403	B
P0404	B
P0405	B
P0420	A
P0430	A
P0442	A
P0443	B
P0446	B
P0449	B
P0452	B
P0453	B
P0455	B
P0462	C
P0463	C
P0480	B
P0481	B
P0496	B
P0502	B
P0503	B
P0506	B
P0507	A
P0520	C
P0530	C
P0560	C
P0572	C
P0573	C
P0575	C
P0601	A
P0602	A
P0604	A
P0606	A
P0608	C
P0621	C
P0641	B
P0645	C
P0650	B
P0651	B
P0685	C
P0703	C
P0705	C
P0711	C
P0712	C
P0713	C
P0716	B
P0717	B
P0730	C
P0741	B
P0742	B
P0748	C
P0751	B
P0752	B
P0753	A
P0756	A
P0757	A
P0758	A
P0815	C
P0816	C
P0826	C
P1106	C
P1107	C
P1111	C
P1112	C
P1114	C
P1115	C
P1125	A
P1133	B
P1134	B
P1153	B
P1154	B
P1258	A
P1351	B
P1352	B
P1353	B
P1361	B
P1362	B
P1363	B
P1404	B
P1516	A
P1518	A
P1574	C
P1626	C
P1630	C
P1631	C
P1640	C
P1650	C
P1660	C
P1750	C
P1810	B
P1811	C
P1816	B
P1818	B
P1860	B
P1876	C
P1877	B
P1887	B
P2101	A
P2107	C
P2108	A
P2119	C
P2120	A
P2125	A
P2135	A
P2138	A
P2535	C
P2610	B
U0001	C
U1300	C
U1301	C
U2107	C
U2108	C

Diagnostic Trouble Code (DTC) Type(s)

Scheme 2

Scheme 2: Emission Hose Routing Diagram

Callout	Component Name
1	To Brake Booster
2	EVAP Service Port
3	EVAP Purge Line
4	EVAP Canister Purge Solenoid Valve
5	Throttle Actuator Control
6	PCV Valve
7	Camshaft Position (CMP) Sensor
8	Intake Manifold

Scheme 3

Scheme 3: Evaporative Emissions (EVAP) Hose Routing Diagram

Callout	Component Name
1	EVAP Canister Purge Solenoid Valve
2	EVAP Canister
3	Fuel Fill Neck/Fill Cap
4	Rollover Valve/Fuel Tank Pressure (FTP) Sensor
5	Fuel Tank
6	EVAP Canister Vent Solenoid Valve
7	Vent Hose/Pipe
8	EVAP Vapor Pipe
9	EVAP Purge Pipe
10	EVAP Service Port

Scheme 4

Scheme 4: Fuel Hose/Pipes Routing Diagram

Callout	Component Name
1	Fuel Feed Pipe
2	Fuel Tank
3	Fuel Filler Tube
4	Modular Returnless Assembly
5	Multec 2 Injector
6	Fuel Service Port

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 5

Scheme 5: Engine Controls Schematic Icons

Scheme 6

Scheme 7

Scheme 7: Engine Controls Schematics

Scheme 8

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Scheme 17

Scheme 17: Engine Controls Component Views

Callout	Component Name
1	Coolant Level Switch
2	Battery
3	Electronic Brake Control Module (EBCM)
4	C101
5	G103
6	Fuse Block - Underhood
7	Powertrain Control Module (PCM)
8	Powertrain Control Module (PCM), C3
9	Powertrain Control Module (PCM), C2
10	Powertrain Control Module (PCM), C1

Scheme 18

Callout	Component Name
1	Engine Oil Pressure (EOP) Switch
2	Starter
3	Starter Solenoid
4	Knock Sensor (KS) 2

Scheme 19

Callout	Component Name
1	Spark Plug Wires
2	C100
3	Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1

Scheme 20

Callout	Component Name
1	Fuel Injector 1
2	Fuel Injector 3
3	Fuel Injector 5
4	Fuel Rail
5	Fuel Injector 6
6	Fuel Injector 4
7	Fuel Injector 2

Scheme 21

Callout	Component Name
1	Generator
2	Fuel Injector 1
3	Camshaft Position (CMP) Sensor
4	Mass Air Flow (MAF)/Intake Air Temperature (IAT) Sensor
5	C130

Scheme 22

Callout	Component Name
1	Crankshaft Position (CKP) Sensor
2	Knock Sensor (KS) 2

Scheme 23

Callout	Component Name
1	G105
2	G106 (LX9)
3	Engine Coolant Temperature (ECT) Sensor (LX9)
4	Park Neutral Position (PNP) Switch

Scheme 24

Callout	Component Name
1	Manifold Absolute Pressure (MAP) Sensor
2	Generator
3	Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1
4	Ignition Control Module (ICM)
5	Exhaust Gas Recirculation (EGR) Valve
6	Evaporative Emission (EVAP) Canister Purge Solenoid
7	Throttle Actuator Control (TAC) Module

Scheme 25

Callout	Component Name
1	Generator
2	Engine Coolant Heater
3	Knock Sensor (KS) 1
4	Ignition Control Module (ICM)
5	Exhaust Gas Recirculation (EGR) Valve
6	Ignition Coils

Scheme 26

Callout	Component Name
1	Brake Pedal Position Sensor
2	Accelerator Pedal Position (APP) Sensor
3	Accelerator Pedal
4	Brake Pedal

Scheme 27

Callout	Component Name
1	Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2
2	Heated Oxygen Sensor (HO2S) Bank 2 Sensor 2

Scheme 28

Callout	Component Name
1	Evaporative Emission (EVAP) Canister
2	Evaporative Emission (EVAP) Canister Vent Solenoid Valve
3	Fuel Tank Filler Neck

Scheme 29

Callout	Component Name
1	Fuel Tank Pressure (FTP) Sensor, Connector
2	Fuel Pump and Sender Assembly
3	Fuel Pump and Sender Assembly Connector
4	Fuel Tank

Powertrain Control Module (PCM) Connector End Views

Powertrain Control Module (PCM) Connector End Views - Powertrain Control Module (PCM) C1 Connector Part Information 15430208 56-Way F Micro-Pack 64 Series Sealed (BU) Pin Wire Color Circuit No. Function 1 TN/BK 2500 High Speed GMLAN Serial Data Bus+ 2 TN 2501 High Speed GMLAN Serial Data Bus- 3 - - Not Used 4 GY 2700 5-Volt Reference B 5 - - Not Used 6 BN/WH 419 MIL Control 7 TN 5514 Low Reference 8 OG/BK 1057 Low Reference 9 - - Not Used 10 WH 1310 EVAP Canister Vent Solenoid Control 11 - - Not Used 12 OG/BK 1057 Low Reference 13-14 - - Not Used 15 PU 1807 Class 2 Serial Data (Primary) 16-17 - - Not Used 18 BN 4 Accessory Voltage 19 PK 639 Ignition 1 Voltage 20 RD/WH 540 Battery Positive Voltage 21 - - Not Used 22 BN 818 Vehicle Speed Signal 23 YE 447 Starter Relay Coil Control 24 BN 5069 Main Relay Control 25 - - Not Used 26 D-GN 890 Fuel Tank Pressure Sensor Signal 27-30 - - Not Used 31 OG/BK 380 A/C Refrigerant Pressure Sensor Signal 32 WH 17 Stop Lamp Switch Signal 33 D-GN/WH 459 A/C Compressor Clutch Relay Control 34-36 - - Not Used 37 D-GN/WH 465 Fuel Pump Relay Control High 38-42 - - Not Used 43 PU 1589 Fuel Level Sensor Signal 44 - - Not Used 45 PU 5526 Tap Up/Tap Down Switch Signal 46-47 - - Not Used 48 D-GN 335 Low Speed Cooling Fan Relay Control 49 - - Not Used 50 D-BU 473 High Speed Cooling Fan Relay Control 51-52 - - Not Used 53 GY 705 5-Volt Reference A 54-56 - - Not Used

Powertrain Control Module (PCM) Connector End Views - Powertrain Control Module (PCM) C2 Connector Part Information 15430226 73-Way F Micro-Pack 64 Series Sealed (BK) Pin Wire Color Circuit No. Function 1 BN 1456 EGR Valve Position Signal 2 OG/BK 1061 UART Serial Data (Secondary) 3 TN 800 UART Serial Data (Primary) 4 PK/BK 1746 Fuel Injector 3 Control 5 TN 1744 Fuel Injector 1 Control 6 L-GN/BK 1745 Fuel Injector 2 Control 7 TN/WH 845 Fuel Injector 5 Control 8 TN 2753 Low Reference 9 YE/BK 846 Fuel Injector 6 Control 10 L-BU/BK 844 Fuel Injector 4 Control 11 OG/WH 2122 IC 2 Control 12 GY/WH 3113 HO2S Heater Low Control (Bank 1 Sensor 1) 13 OG 1676 EGR Solenoid High Control 14 - - Not Used 15 PU 574 Low Reference 16 GY 435 EGR Solenoid Low Control 17 - - Not Used 18 L-GN 432 MAP Sensor Signal 19-20 - - Not Used 21 OG 631 12-Volt Reference 22 L-GN 1867 12-Volt Reference 23-24 - - Not Used 25 TN/WH 3211 HO2S Low Reference (Bank 2 Sensor 1) 26 BN/WH 633 CMP Sensor Signal 27 L-BU/BK 647 Medium Resolution Engine Speed Signal 28-29 - - Not Used 30 OG/BK 469 Low Reference 31 - - Not Used 32 PK/BK 632 Low Reference 33 GY 5047 5-Volt Reference 34 GY 2704 5-Volt Reference A 35 - - Not Used 36 GY 2303 Low Reference 37 YE 2174 Low Reference 38 D-BU 496 Knock Sensor 1 Signal 39 GY/BK 1798 Drain Wire 40 GY 1716 Low Reference 41 D-GN/WH 428 EVAP Canister Purge Solenoid Control 42-46 - - Not Used 47 TN/WH 3111 HO2S Low Reference (Bank 1 Sensor 1) 48 PU/WH 3110 HO2S Reference Voltage (Bank 1 Sensor 1) 49-52 - - Not Used 53 OG 225 Generator Turn On Signal 54 L-BU 1876 Knock Sensor 2 Signal 55 YE 410 ECT Sensor Signal 56 OG/BK 645 Drain Wire 57 TN/BK 231 Oil Pressure Switch Signal 58-59 - - Not Used 60 PU/WH 3210 HO2S Reference Voltage (Bank 2 Sensor 1) 61 PU 2121 IC 1 Control 62 L-GN 3212 HO2S Heater Low Control (Bank 2 Sensor 1) 63 L-BU 2123 IC 3 Control 64-72 - - Not Used 73 BK/WH 451 Ground

Powertrain Control Module (PCM) Connector End Views - Powertrain Control Module (PCM) C3 Connector Part Information 15430211 56-Way F Micro 64 Series Sealed (GY) Pin Wire Color Circuit No. Function 1-2 - - Not Used 3 TN 3221 HO2S Low Signal (Bank 2 Sensor 2) 4 TN/WH 3121 HO2S Low Signal (Bank 1 Sensor 2) 5 YE/BK 1227 TFT Sensor Signal 6 YE 492 MAF Sensor Signal 7 - - Not Used 8 GY/WH 3122 HO2S Heater Low Control (Bank 1 Sensor 2) 9 - - Not Used 10 OG/WH 3223 HO2S Heater Low Control (Bank 2 Sensor 2) 11 OG/BK 1230 A/T ISS High Signal 12 YE 400 VSS High Signal 13-14 - - Not Used 15 GY 773 Transmission Range Switch Signal C 16-17 - - Not Used 18 PU 3220 HO2S High Signal (Bank 2 Sensor 2) 19 PU 3120 HO2S High Signal (Bank 1 Sensor 2) 20-21 - - Not Used 22 YE 772 Transmission Range Switch Signal B 23 WH 776 Transmission Range Switch Signal P 24 YE 657 TCC Release Switch Signal 25 - - Not Used 26 TN 472 IAT Sensor Signal 27-28 - - Not Used 29 D-BU 1225 Transmission Fluid Pressure Switch Signal B 30 OG 1226 Transmission Fluid Pressure Switch Signal C 31-32 - - Not Used 33 L-GN 1222 1-2 Shift Solenoid Valve Control 34 TN/WH 771 Transmission Range Switch Signal A 35-38 - - Not Used 39 BN 418 TCC PWM Solenoid Valve Control 40-43 - - Not Used 44 PU 401 VSS Low Signal 45 - - Not Used 46 YE/BK 1223 2-3 Shift Solenoid Valve Control 47 OG/BK 1228 PC Solenoid Valve High Control (Sol. A) 48 TN 2762 Low Reference 49 D-BU/WH 1231 A/T ISS Low Signal 50 TN/BK 2760 Low Reference 51 L-BU/WH 1229 PC Solenoid Valve Low Control (Sol. A) 52-56 - - Not Used

Engine Controls Connector End Views

Engine Controls Connector End Views - Accelerator Pedal Position (APP) Sensor Connector Part Information 15326830 6-Way F GT 150 Series (BK) Pin Wire Color Circuit No. Function A PU 1272 Low Reference B L-BU 1162 APP Sensor 2 Signal C TN 1274 5-Volt Reference D BN 1271 Low Reference E D-BU 1161 APP Sensor 1 Signal F WH/BK 1164 5-Volt Reference

Engine Controls Connector End Views - Camshaft Position (CMP) Sensor Connector Part Information 15336065 3-Way F GT 150 Series, Sealed (BK) Pin Wire Color Circuit No. Function A BN/WH 633 CMP Sensor Signal B BK 407 Low Reference C RD/WH 812 12-Volt Reference

Engine Controls Connector End Views - Crankshaft Position (CKP) Sensor Connector Part Information 15326808 3-Way F GT 150 Series, SLD 4.5 (BK) Pin Wire Color Circuit No. Function A L-GN 1867 12-Volt Reference B PU 574 Low Reference C L-BU/BK 647 Medium Resolution Engine Speed Signal

Engine Controls Connector End Views - Engine Coolant Temperature (ECT) Sensor Connector Part Information 12162194 2-Way F Metri-Pack 150.2 Series, Sealed P2S (BK) Pin Wire Color Circuit No. Function A OG/BK 469 Low Reference B YE 410 ECT Sensor Signal

Engine Controls Connector End Views - Evaporative Emission (EVAP) Canister Purge Solenoid Connector Part Information 12052643 2-Way F Metri-Pack 150 Series Sealed (RD) Pin Wire Color Circuit No. Function A PK/BK 5291 Ignition 1 Voltage B D-GN/WH 428 EVAP Canister Purge Solenoid Control

Engine Controls Connector End Views - Evaporative Emission (EVAP) Canister Vent Solenoid Connector Part Information 12052643 2-Way F Metri-Pack 150 Series Sealed (RD) Pin Wire Color Circuit No. Function A RD/WH 1540 Battery Positive Voltage B WH 1310 EVAP Canister Vent Solenoid Control

Engine Controls Connector End Views - Exhaust Gas Recirculation (EGR) Valve Connector Part Information 15326389 5-Way F Metri-Pack 150 (BK) Pin Wire Color Circuit No. Function A GY 435 EGR Solenoid Low Control B TN 2753 Low Reference C BN 1456 EGR Valve Position Signal D GY 5047 5-Volt Reference E OG 1676 EGR Solenoid High Control

Engine Controls Connector End Views - Fuel Injector 1 Connector Part Information 15326180 2-Way F Micro-Pack 64 Series Sealed (BK) Pin Wire Color Circuit No. Function A PK 639 Ignition 1 Voltage B BK 1744 Fuel Injector 1 Control

Engine Controls Connector End Views - Fuel Injector 2 Connector Part Information 15326180 2-Way F Micro-Pack 64 Series Sealed (BK) Pin Wire Color Circuit No. Function A PK 639 Ignition 1 Voltage B L-GN/BK 1745 Fuel Injector 2 Control

Engine Controls Connector End Views - Fuel Injector 3 Connector Part Information 15326180 2-Way F Micro-Pack 64 Series Sealed (BK) Pin Wire Color Circuit No. Function A PK 639 Ignition 1 Voltage B PK/BK 1746 Fuel Injector 3 Control

Engine Controls Connector End Views - Fuel Injector 4 Connector Part Information 15326180 2-Way F Micro-Pack 64 Series Sealed (BK) Pin Wire Color Circuit No. Function A PK 639 Ignition 1 Voltage B L-BU/BK 844 Fuel Injector 4 Control

Engine Controls Connector End Views - Fuel Injector 5 Connector Part Information 15326180 2-Way F Micro-Pack 64 Series Sealed (BK) Pin Wire Color Circuit No. Function A PK 639 Ignition 1 Voltage B BK/WH 845 Fuel Injector 5 Control

Engine Controls Connector End Views - Fuel Injector 6 Connector Part Information 15326180 2-Way F Micro-Pack 64 Series Sealed (BK) Pin Wire Color Circuit No. Function A PK 639 Ignition 1 Voltage B YE/BK 846 Fuel Injector 6 Control

Engine Controls Connector End Views - Fuel Pump and Sender Assembly Connector Part Information 22666266 4-Way F (GY) Pin Wire Color Circuit No. Function 1 GY 120 Fuel Pump Supply Voltage 2 PU 1589 Fuel Level Sensor Signal 3 BK/WH 651 Ground 4 BK 1250 Ground

Engine Controls Connector End Views - Fuel Tank Pressure (FTP) Sensor Connector Part Information 12059595 3-Way F Metri-Pack 150 Series, Sealed (BK) Pin Wire Color Circuit No. Function A BK/WH 469 Low Reference B PU 890 Fuel Tank Pressure Sensor Signal C GY 705 5-Volt Reference

Engine Controls Connector End Views - Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1 Connector Part Information 12176897 4-Way F Metri-Pack 150 Sealed (GY) Pin Wire Color Circuit No. Function A TN/WH 3111 HO2S Low Reference (Bank 1 Sensor 1) B PU/WH 3110 HO2S Reference Voltage (Bank 1 Sensor 1) C GY/WH 3113 HO2S Heater Low Control (Bank 1 Sensor 1) D PK/BK 5291 Ignition 1 Voltage

Engine Controls Connector End Views - Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 Connector Part Information 12176897 4-Way F Metri-Pack 150 Sealed (GY) Pin Wire Color Circuit No. Function A TN/WH 3211 HO2S Low Reference (Bank 2 Sensor 1) B PU/WH 3210 HO2S Reference Voltage (Bank 2 Sensor 1) C L-GN 3212 HO2S Heater Low Control (Bank 2 Sensor 1) D PK/BK 5291 Ignition 1 Voltage

Engine Controls Connector End Views - Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2 Connector Part Information 15326423 4-Way M Metri-Pack 150 Sealed (GY) Pin Wire Color Circuit No. Function A TN/WH 3121 HO2S Low Signal (Bank 1 Sensor 2) B PU 3120 HO2S High Signal (Bank 1 Sensor 2) C GY/WH 3122 HO2S Heater Low Control (Bank 1 Sensor 2) D PK/BK 5291 Ignition 1 Voltage

Engine Controls Connector End Views - Heated Oxygen Sensor (HO2S) Bank 2 Sensor 2 Connector Part Information 15326423 4-Way M Metri-Pack 150 Sealed (GY) Pin Wire Color Circuit No. Function A TN 3221 HO2S Low Signal (Bank 2 Sensor 2) B PU 3220 HO2S High Signal (Bank 2 Sensor 2) C OG/WH 3223 HO2S Heater Low Control (Bank 2 Sensor 2) D PK/BK 5291 Ignition 1 Voltage

Engine Controls Connector End Views - Ignition Control Module (ICM) Connector Part Information 15326829 6-Way F 150 Sealed (BK) Pin Wire Color Circuit No. Function A OG/WH 2122 IC 2 Control B PU 2121 IC 1 Control C L-BU 2123 IC 3 Control D YE 2174 Low Reference E BK 450 Ground F PK 239 Ignition 1 Voltage

Engine Controls Connector End Views - Knock Sensor (KS) 1 Connector Part Information 15374222 2-Way F GT 150 Series (WH) Sealed Pin Wire Color Circuit No. Function A D-BU 496 Knock Sensor 1 Signal B GY 1716 Low Reference

Engine Controls Connector End Views - Knock Sensor (KS) 2 Connector Part Information 15374222 2-Way F GT 150 Series (WH) Sealed Pin Wire Color Circuit No. Function A L-BU 1876 Knock Sensor 2 Signal B GY 2303 Low Reference

Engine Controls Connector End Views - Manifold Absolute Pressure (MAP) Sensor Connector Part Information 12129946 3-Way F Metri-Pack 150 Sealed (GY) Pin Wire Color Circuit No. Function A OG 469 Low Reference B L-GN 432 MAP Sensor Signal C GY 2704 5-Volt Reference

Engine Controls Connector End Views - Mass Air Flow (MAF)/Intake Air Temperature (IAT) Sensor Connector Part Information 15326822 5-Way F GT 150 SLD 4.0 (BK) Pin Wire Color Circuit No. Function A YE 492 MAF Sensor Signal B PK/BK 5291 Ignition 1 Voltage C BK/WH 451 Ground D TN 472 IAT Sensor Signal E TN/BK 2760 Low Reference

Engine Controls Connector End Views - Throttle Actuator Control (TAC) Module Connector Part Information 15355368 20-Way M Metri-Pack 150 Series (GY) Pin Wire Color Circuit No. Function 1 TN 1274 5-Volt Reference 2 PU 1272 Low Reference 3 L-BU 1162 APP Sensor 2 Signal 4 BN 818 Vehicle Speed Signal 5 - - Not Used 6 WH 17 Stop Lamp Switch Signal 7 TN 800 UART Serial Data (Primary) 8 BK/WH 451 Ground 9-10 - - Not Used 11 D-BU 1161 APP Sensor 1 Signal 12 BN 1271 Low Reference 13 WH/BK 1164 5-Volt Reference 14-15 - - Not Used 16 OG/BK 1061 UART Serial Data (Secondary) 17 BK/WH 451 Ground 18 PK/BK 5290 Ignition 1 Voltage 19-20 - - Not Used

Removal Procedure

Using a scan tool, retrieve the percentage of remaining engine oil. Record the remaining engine oil life.
Record the preset radio stations.
Turn the ignition OFF.
Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/malibu/vi-2003-2006/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Disconnect the PCM harness connectors.
Release the retaining tab located in the battery box lower half using a small screwdriver or other suitable tool.
Remove the PCM by lifting upward after releasing the tab.

Installation Procedure

Slide the PCM into the PCM bracket on the front of the battery box.
Push down on the PCM until the retaining tab snaps into place.
Connect the PCM harness connectors.
Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/malibu/vi-2003-2006/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical. Tighten: Tighten the battery terminal bolts to 17 N.m (13 lb ft).
Perform the crankshaft relearn procedure. Refer to «DTC P0315»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-controls-diagnosis-dtc-p0140-to-dtc-p0496-22l-l61) .
Verify no DTCs exist.
Reset the clock and preset radio stations.

CKP System Variation Learn Procedure

Install a scan tool.
Monitor the powertrain control module (PCM) for DTCs with a scan tool. If other DTCs are set, except DTC P0315, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/oem-general-information/#vehicle-dtc-information__diagnostic-trouble-code-dtc-list) in Vehicle DTC Information for the applicable DTC.
Select the crankshaft position variation learn procedure with a scan tool.
The scan tool instructs you to perform the following: Accelerate to wide open throttle (WOT). Observe fuel cut-off for applicable engine. Release throttle when fuel cut-off occurs. Engine should not accelerate beyond calibrated RPM value. Release throttle immediately if value is exceeded. Block drive wheels. Set parking brake. DO NOT apply brake pedal. Cycle ignition from OFF to ON. Apply and hold brake pedal. Start and idle engine. Turn the A/C OFF. Vehicle must remain in Park or Neutral. The scan tool monitors certain component signals to determine if all the conditions are met to continue with the procedure. The scan tool only displays the condition that inhibits the procedure. The scan tool monitors the following components: Crankshaft position (CKP) sensors activity-If there is a CKP sensor condition, refer to the applicable DTC. Camshaft position (CMP) signal activity-If there is a CMP signal condition, refer to the applicable DTC. Engine coolant temperature (ECT)-If the engine coolant temperature is not warm enough, idle the engine until the engine coolant temperature reaches the correct temperature.
Enable the CKP system variation learn procedure with the scan tool and perform the following: IMPORTANT: While the learn procedure is in progress, release the throttle immediately when the engine starts to decelerate. The engine control is returned to the operator and the engine responds to throttle position after the learn procedure is complete. Accelerate to WOT. Release throttle when fuel cut-off occurs.
The scan tool displays Learn Status: Learned this ignition. If the scan tool indicates that DTC P0315 ran and passed, the CKP variation learn procedure is complete. If the scan tool indicates DTC P0315 failed or did not run, refer to «DTC P0315»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-controls-diagnosis-dtc-p0161-to-dtc-p453-35l-lx9) . If any other DTCs set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/oem-general-information/#vehicle-dtc-information__diagnostic-trouble-code-dtc-list) in Vehicle DTC Information for the applicable DTC.
Turn OFF the ignition for 30 seconds after the learn procedure is completed successfully.

The CKP system variation learn procedure is also required when the following service procedures have been performed, regardless of whether or not DTC P0315 is set

An engine replacement
A PCM replacement
A harmonic balancer replacement
A crankshaft replacement
A CKP sensor replacement
Any engine repairs which disturb the crankshaft to CKP sensor relationship.

Note. Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.

Partially drain the cooling system. Refer to «Draining and Filling Cooling System (L61)»(/chevrolet/malibu/vi-2003-2006/remont/cooling-fan/#engine-cooling-system) or «Draining and Filling Cooling System (LX9)»(/chevrolet/malibu/vi-2003-2006/remont/cooling-fan/#engine-cooling-system) in Engine Cooling.
Disconnect the engine coolant temperature (ECT) sensor electrical connector.
Remove the ECT sensor.

Note. Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage.

Coat the threads with sealer GM P/N 13246004 (Canadian P/N 10953480) or equivalent.
Install the ECT sensor. Tighten: Tighten the ECT sensor to 20 N.m (15 lb ft).
Connect the ECT electrical connector.
Fill the cooling system. Refer to «Draining and Filling Cooling System (L61)»(/chevrolet/malibu/vi-2003-2006/remont/cooling-fan/#engine-cooling-system) or «Draining and Filling Cooling System (LX9)»(/chevrolet/malibu/vi-2003-2006/remont/cooling-fan/#engine-cooling-system) in Engine Cooling.

Remove the positive crankcase ventilation fresh air tube from the air cleaner intake duct.
Disconnect the mass air flow (MAF) sensor electrical connector.
Loosen the clamps and remove the air cleaner intake duct with the MAF sensor from the throttle body and the air cleaner housing cover.
Loosen the clamp and remove the MAF sensor from the air cleaner intake duct.

Install the MAF sensor to the air cleaner intake duct. Tighten: Tighten the clamp to 2 N.m (18 lb in).
Install the air cleaner intake duct with the MAF sensor to the throttle body and the air cleaner housing cover. Tighten: Tighten the clamps to 2 N.m (18 lb in).
Connect the MAF sensor electrical connector.
Install the positive crankcase ventilation fresh air tube to the air cleaner intake duct.
Start and idle the engine.
Inspect the air intake duct for leaks.

Disconnect the MAP sensor electrical connector.
Remove the MAP sensor attaching screw.
Remove the MAP sensor and MAP sensor seal from the upper intake manifold.

Install the MAP sensor and MAP sensor seal into the upper intake manifold.
Install the MAP sensor attaching screw. Tighten: Tighten the attaching screw to 6.5 N.m (5.7 lb in).
Connect the MAP sensor electrical connector.

Tools Required

J 39194-B Heated Oxygen Sensor Wrench. See Special Tools and Equipment .

Disconnect the heated oxygen sensor (HO2S) 1 electrical connector.
Use the J 39194-B to remove the HO2S 1. See «Special Tools and Equipment»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .

Coat the threads of the HO2S 1 with anti-seize compound GM P/N 12377953 or an equivalent, if necessary.
Install the HO2S 1. Tighten: Use the J 39194-B to tighten the sensor to 41 N.m (30 lb ft). See «Special Tools and Equipment»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .
Connect the H02S 1 electrical connector.

J 39194-B Heated Oxygen Sensor Wrench. See Special Tools and Equipment .

Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Disconnect the heated oxygen sensor (HO2S) 2 electrical connector.
Use the J 39194-B to remove the HO2S 2. See «Special Tools and Equipment»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .

Coat the threads of the HO2S 2 with anti-seize compound GM P/N 12377953 or an equivalent, if necessary.
Install the HO2S 2. Tighten: Use the J 39194-B to tighten the sensor to 41 N.m (30 lb ft). See «Special Tools and Equipment»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .
Connect the H02S 2 electrical connector.
Lower the vehicle.

J 39194-B Heated Oxygen Sensor Wrench. See Special Tools and Equipment .

Disconnect the heated oxygen sensor (HO2S) 1 electrical connector.
Use the J 39194-B to remove the HO2S 1. See «Special Tools and Equipment»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .

Coat the threads of the HO2S 1 with anti-seize compound GM P/N 12377953 or an equivalent, if necessary.
Install the HO2S 1. Tighten: Use the J 39194-B to tighten the sensor to 41 N.m (30 lb ft). See «Special Tools and Equipment»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .
Connect the H02S 1 electrical connector.

J 39194-B Heated Oxygen Sensor Wrench. See Special Tools and Equipment .

Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Disconnect the heated oxygen sensor (HO2S) 2 electrical connector.
Use the J 39194-B to remove the HO2S 2. See «Special Tools and Equipment»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .

Coat the threads of the HO2S 2 with anti-seize compound GM P/N 12377953 or an equivalent, if necessary.
Install the HO2S 2. Tighten: Use the J 39194-B to tighten the sensor to 41 N.m (30 lb ft). See «Special Tools and Equipment»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .
Connect the H02S 2 electrical connector.
Lower the vehicle.

Disconnect the accelerator pedal position sensor electrical connector.
Remove the accelerator mounting bolts (1) from the accelerator bracket.
Remove the accelerator assembly (2) from the vehicle.

Install the accelerator assembly (2) to the vehicle.
Install the accelerator mounting bolts (1) to the accelerator bracket. Tighten: Tighten the accelerator pedal nuts to 10 N.m (89 lb in).
Connect the accelerator pedal position sensor electrical connector.
Confirm that the accelerator sensor connector locking clip is fully secured.
Verify the operation of the accelerator pedal.

Remove the air cleaner intake duct. Refer to «Air Cleaner Intake Duct Replacement»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .
Disconnect the electronic throttle control (ETC) electrical connector.
Remove the heater pipe nut at the throttle body.
Remove the nuts and the bolts from the throttle body.
Remove the throttle body assembly.
Remove the throttle body gasket.
Clean and inspect the throttle body gasket mating surfaces.

Install a new gasket, if necessary.
Install the throttle body assembly.
Install the throttle body nuts and the bolts. Tighten: Tighten the nuts and the bolts to 10 N.m (89 lb in).
Install the heater pipe nut to the throttle body. Tighten: Tighten the nut to 25 N.m (18 lb ft).
Connect the ETC electrical connector.
Install the air cleaner intake duct. Refer to «Air Cleaner Intake Duct Replacement»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .

Fuel Pressure Relief Procedure

CAUTION

Refer to Battery Disconnect Caution in Cautions and Notices.

Loosen the fuel filler cap in order to relieve the tank pressure. Do not tighten at this time.
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Disconnect the fuel pump electrical connector.
Lower the vehicle.
Start and run the engine until the fuel supply remaining in the fuel pipes is consumed. Engage the starter for 3.0 seconds in order to assure relief of any remaining pressure.
Raise the vehicle.
Connect the fuel pump electrical connector.
Lower the vehicle.
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»(/chevrolet/malibu/vi-2003-2006/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.

J 34730-1A Fuel Pressure Gage

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.

Install the J 34730-1A to the fuel pressure service connection, located on the fuel rail.
Turn ON the ignition.
Place the bleed hose of the fuel pressure gage into an approved gasoline container.
Open the bleed valve on the fuel pressure gage in order to bleed the air from the fuel pressure gage.
Command the fuel pump ON with a scan tool.
Close the bleed valve on the fuel pressure gage.
Inspect for fuel leaks.

Place the fuel pressure gage bleed hose into an approved container and open the bleed valve in order to bleed OFF fuel system pressure.
Place a shop towel under the fuel pressure gage in order to catch any remaining fuel spillage.
Remove the fuel pressure gage from the fuel pressure connection.
Drain any fuel remaining in the fuel pressure gage into an approved container.
Inspect for leaks using the following procedure: Turn ON the ignition, with the engine OFF for 2 seconds. Turn OFF the ignition, for 10 seconds. Turn ON the ignition, with the engine OFF. Inspect for fuel leaks.
Install the cap on the fuel pressure connection.

Tool Required

J 37088-A Fuel Line Disconnect Tool Set. See Special Tools and Equipment .

Relieve the fuel system pressure before servicing any fuel system connection. Refer to the «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .
Remove the retainer from the quick-connect fitting.
Blow dirt out of the fitting using compressed air.
Choose the correct tool from the J 37088-A for the size of the fitting. See «Special Tools and Equipment»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) . Insert the tool into the female connector, then push inward in order to release the locking tabs.
Pull the connection apart.
Use a clean shop towel in order to 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 fitting together in order to snap the retaining tabs into place.
Once installed, pull on both sides of the fitting in order to make sure the connection is secure.
Install the retainer to the quick-connect fitting.

Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__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.
Wipe off the male pipe end using a clean shop towel.
Inspect both ends of the fitting for dirt and burrs.
Clean or replace the components as required.

CAUTION

In order to reduce the risk of fire and personal injury, before connecting fuel pipe fittings, always apply a few drops of clean engine oil to the male pipe ends. This will ensure proper reconnection and prevent a possible fuel leak. During normal operation, the O-rings located in the female connector will swell and may prevent proper reconnection if not lubricated.

Apply a few drops of clean engine oil to the male pipe end.
Push both sides of the quick-connect fitting together in order to cause the retaining tabs to snap into place.
Pull on both sides of the quick connect fitting in order to make sure the connection is secure.

Fuel Tank Draining Procedure

Tools Required

J 36850 Transjel Lubricant. See «Special Tools and Equipment»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .
J 42960-2 Fuel Flapper Door Holder
J 45004 Fuel Tank Drain Hose

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.
Insert the J 45004 into the fuel tank until the hose reaches the bottom of the fuel tank.
Use an hand or air operated pump device in order to drain as much fuel through the fuel fill pipe as possible.

Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-pressure-relief-procedure) .
Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-tank-draining-procedure) .
Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Disconnect the fuel pump module harness electrical connector from the vehicle underbody wiring harness.
Disconnect the evaporative emissions (EVAP) vent valve solenoid harness electrical connector from the vehicle underbody wiring harness.
If applicable, disengage the antilock brake system (ABS) wiring harness from the retainer on the side of the EVAP canister.
Disconnect the fuel feed and purge lines at the fuel and brake line bundle on the right side of the vehicle.
Cap or plug the fuel tank feed and vapor return pipes to prevent fuel loss and/or contamination.
Loosen the fuel filler pipe jumper hose clamp at the fuel tank (1).
Disconnect the fuel filler pipe jumper hose from the fuel tank.
Disconnect the vapor recirculation line that runs parallel to the fuel filler pipe jumper hose.
Release the exhaust pipe insulators from the underbody hangers.
Release the muffler insulator from the underbody hanger and slowly lower the exhaust to rest on a tall jackstand. If this is not possible, remove the rear half of the exhaust system at the take down flange.
Have an assistant support the fuel tank during fuel tank strap removal, and during tank removal. Or use an appropriate jack to support the fuel tank during removal
Remove front LH fuel tank strap bolts.
Remove the RH tank strap bolts.
In order to clear the exhaust pipe, slowly lower the RH side of the fuel tank.
Once the tank is clear of the RH frame rail, remove the fuel tank down and forward toward the RH side of the vehicle.
If only the fuel tank is to be replaced, remove the fuel pump module assembly from the fuel tank. Refer to «Fuel Sender Assembly Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Sender Assembly Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .

If fuel tank replacement was necessary, install the fuel pump module assembly to the fuel tank. Refer to «Fuel Sender Assembly Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Sender Assembly Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Have an assistant support the fuel tank during fuel tank and fuel tank strap installation.
Begin to install the LH side of the fuel tank over the exhaust pipe.
Raise the RH side of the fuel tank into position inboard of the RH frame rail. Use care in feeding the fuel feed, the EVAP vapor pipe, and the fuel pump module electrical harness over the exhaust system.
Install the RH fuel tank strap and strap bolts.
Install the LH fuel tank strap and strap bolts.
Tighten the fuel tank strap bolts. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
Raise the exhaust into position and install the muffler insulator to the underbody hanger.
Install the exhaust extension pipe insulators to the underbody hangers.
Connect the fuel pump module harness electrical connector to the vehicle underbody connector.
Connect the fuel filler pipe jumper hose to the fuel tank.
Tighten the fuel filler pipe jumper hose clamp (1) at the fuel tank. Tighten: Tighten the clamp to 4 N.m (35 lb in).
Connect vapor recirculation line that runs parallel to the fuel filler pipe jumper hose.
Remove the caps or plugs from the fuel tank feed and vapor return pipes.
Connect the fuel feed and vapor purge lines to the fuel and brake line bundle on the right side of the vehicle.
Connect the fuel sender electrical connector to the underbody harness and connect the EVAP purge valve electrical connector to the underbody harness.
Attach the ABS harness (if applicable) to the retainer on the side of the EVAP canister.
Lower the vehicle.
Refill the fuel tank.
Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/malibu/vi-2003-2006/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Inspect for fuel leaks using the following procedure: Turn ON the ignition, with the engine OFF for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition, with the engine OFF. Inspect for fuel leaks.

Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-pressure-relief-procedure) .
Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-tank-draining-procedure) .
Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Disconnect the fuel pump module harness electrical connector from the vehicle underbody wiring harness.
Disconnect the evaporative emissions (EVAP) vent valve solenoid harness electrical connector from the vehicle underbody wiring harness.
If applicable, disengage the antilock brake system (ABS) wiring harness from the retainer on the side of the EVAP canister.
Disconnect the fuel feed and purge lines at the fuel and brake line bundle on the right side of the vehicle.
Cap or plug the fuel tank feed and vapor return pipes to prevent fuel loss and/or contamination.
Loosen the fuel filler pipe jumper hose clamp at the fuel tank (1).
Disconnect the fuel filler pipe jumper hose from the fuel tank.
Disconnect the vapor recirculation line that runs parallel to the fuel filler pipe jumper hose.
Release the exhaust pipe insulators from the underbody hangers.
Release the muffler insulator from the underbody hanger and slowly lower the exhaust to rest on a tall jackstand. If this is not possible, remove the rear half of the exhaust system at the take down flange.
Have an assistant support the fuel tank during fuel tank strap removal, and during tank removal. Or use an appropriate jack to support the fuel tank during removal
Remove front LH fuel tank strap bolts.
Remove the RH tank strap bolts.
In order to clear the exhaust pipe, slowly lower the RH side of the fuel tank.
Once the tank is clear of the RH frame rail, remove the fuel tank down and forward toward the RH side of the vehicle.
If only the fuel tank is to be replaced, remove the fuel pump module assembly from the fuel tank. Refer to «Fuel Sender Assembly Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Sender Assembly Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .

If fuel tank replacement was necessary, install the fuel pump module assembly to the fuel tank. Refer to «Fuel Sender Assembly Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Sender Assembly Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Have an assistant support the fuel tank during fuel tank and fuel tank strap installation.
Begin to install the LH side of the fuel tank over the exhaust pipe.
Raise the RH side of the fuel tank into position inboard of the RH frame rail. Use care in feeding the fuel feed, the EVAP vapor pipe, and the fuel pump module electrical harness over the exhaust system.
Install the RH fuel tank strap and strap bolts.
Install the LH fuel tank strap and strap bolts.
Tighten the fuel tank strap bolts. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
Raise the exhaust into position and install the muffler insulator to the underbody hanger.
Install the exhaust extension pipe insulators to the underbody hangers.
Connect the fuel pump module harness electrical connector to the vehicle underbody connector.
Connect the fuel filler pipe jumper hose to the fuel tank.
Tighten the fuel filler pipe jumper hose clamp (1) at the fuel tank. Tighten: Tighten the clamp to 4 N.m (35 lb in).
Connect vapor recirculation line that runs parallel to the fuel filler pipe jumper hose.
Remove the caps or plugs from the fuel tank feed and vapor return pipes.
Connect the fuel feed and vapor purge lines to the fuel and brake line bundle on the right side of the vehicle.
Connect the fuel sender electrical connector to the underbody harness and connect the EVAP purge valve electrical connector to the underbody harness.
Attach the ABS harness (if applicable) to the retainer on the side of the EVAP canister.
Lower the vehicle.
Refill the fuel tank.
Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/malibu/vi-2003-2006/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Inspect for fuel leaks using the following procedure: Turn ON the ignition, with the engine OFF for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition, with the engine OFF. Inspect for fuel leaks.

Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/malibu/vi-2003-2006/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Relieve the system fuel pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-pressure-relief-procedure) .
Drain fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-tank-draining-procedure) .
Remove the fuel tank. Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Remove the electrical connector from the fuel tank pressure (FTP) sensor.
Remove the FTP sensor from modular fuel sender.

Install the new FTP sensor to modular fuel sender.
Install the electrical connector to FTP sensor.
Install the fuel tank. Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Refill the tank.
Install the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/malibu/vi-2003-2006/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.

Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/malibu/vi-2003-2006/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Relieve the system fuel pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-pressure-relief-procedure) .
Drain fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-tank-draining-procedure) .
Remove the fuel tank. Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Remove the electrical connector from the fuel tank pressure sensor.
Remove the fuel tank pressure sensor from modular fuel sender.

Install the new fuel tank pressure sensor to modular fuel sender.
Install the electrical connector to fuel tank pressure sensor.
Install the fuel tank. Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Refill tank.
Install the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/malibu/vi-2003-2006/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.

Remove the fuel pump module assembly. Refer to «Fuel Sender Assembly Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Sender Assembly Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Release the fuel level sensor wiring harness from the molded-in tab on the pump module bowl.
Disconnect the fuel level sensor electrical connector from the pump module cover.
Depress the retaining tab on the sensor and begin to slide the level sensor away from the pump module.
Carefully slide the level sensor the rest of the way off of the pump module.

Carefully slide the fuel level sensor into the slots on the fuel pump module bowl.
Secure the retaining tab on the sensor into the slot on the pump module bowl.
Connect the fuel level sensor electrical connector to the pump module cover.
Install the fuel level sensor wiring harness to the molded-in tab on the pump module bowl.
Install the fuel pump module assembly. Refer to «Fuel Sender Assembly Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Sender Assembly Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .

Remove the fuel pump module assembly. Refer to «Fuel Sender Assembly Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Sender Assembly Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Release the fuel level sensor wiring harness from the molded-in tab on the pump module bowl.
Disconnect the fuel level sensor electrical connector from the pump module cover.
Depress the retaining tab on the sensor and begin to slide the level sensor away from the pump module.
Carefully slide the level sensor the rest of the way off of the pump module.

Carefully slide the fuel level sensor into the slots on the fuel pump module bowl.
Secure the retaining tab on the sensor into the slot on the pump module bowl.
Connect the fuel level sensor electrical connector to the pump module cover.
Install the fuel level sensor wiring harness to the molded-in tab on the pump module bowl.
Install the fuel pump module assembly. Refer to «Fuel Sender Assembly Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Sender Assembly Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .

Remove the fuel fill cap.
Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-tank-draining-procedure) .
Remove the fuel filler pipe bolt from the fuel fill pocket.
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Remove the fuel filler pipe attaching screw from the underbody.
Loosen the fuel filler hose clamp at the fuel tank.
Remove the fuel filler hose from the fuel tank.
Remove the fuel filler pipe assembly.

Install the fuel filler pipe upper end to the fuel filler pocket and position fuel filler pipe.
Install the fuel filler pipe attaching screw to the underbody. Tighten: Tighten the fuel filler pipe attaching screw to 10 N.m (89 lb in).
Install the fuel filler jumper hose to the fuel tank.
Position the fuel filler hose clamp at the fuel tank and fuel fill tube. Tighten: Tighten the fuel tank filler hose clamps to 4 N.m (35 lb in).
Lower the vehicle.
Install the bolt in the fuel filler pocket. Tighten: Tighten the fuel tank filler pocket bolt to 1.5 N.m (13 lb in).
Install the fuel filler cap.

Note. Cap the fittings and plug the holes when servicing the fuel system in order to prevent dirt and other contaminants from entering the open pipes and passages.

Remove the fuel fill cap.
Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-tank-draining-procedure) .
Remove the fuel filler pipe bolt from the fuel fill pocket.
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Remove the fuel filler pipe attaching screw from the underbody.
Loosen the fuel filler hose clamp at the fuel tank.
Remove the fuel filler hose from the fuel tank.
Remove the fuel filler pipe assembly.

Install the fuel filler pipe upper end to the fuel filler pocket and position fuel filler pipe.
Install the fuel filler pipe attaching screw to the underbody. Tighten: Tighten the fuel filler pipe attaching screw to 10 N.m (89 lb in).
Install the fuel filler jumper hose to the fuel tank.
Position the fuel filler hose clamp at the fuel tank and fuel fill tube. Tighten: Tighten the fuel tank filler hose clamps to 4 N.m (35 lb in).
Lower the vehicle.
Install the bolt in the fuel filler pocket. Tighten: Tighten the fuel tank filler pocket bolt to 1.5 N.m (13 lb in).
Install the fuel filler cap.

J 45722 Fuel Sender Lock Ring Wrench

CAUTION

In order to reduce the risk of fire and personal injury that may result from a fuel leak, always replace the fuel sender gasket when reinstalling the fuel sender assembly.

Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/malibu/vi-2003-2006/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Relieve the system fuel pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-pressure-relief-procedure) .
Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-tank-draining-procedure) .
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Remove the fuel tank. Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Disconnect the electrical and ventilation connections on the modular fuel sender assembly cover.
While having an assistant hold the fuel tank, use J 45722 to turn the modular fuel sender assembly lock ring counter-clockwise until the ring is released from the fuel tank.
Raise the fuel sender assembly out of the tank far enough to access the ventilation harness connection on the underside of the module cover.
Disconnect the ventilation harness quick connect before attempting to fully remove the modular fuel sender assembly.

Install a new O-ring on the modular fuel sender to tank.
Connect the ventilation harness inside the fuel tank to the bottom of the modular fuel sender cover.
Slowly apply pressure to the top of the spring loaded sender cover until the sender aligns flush with the surface of the tank.
Align the locking ring with the matching features on the fuel tank and install the J 45722 .
Turn the lock ring until the ring seats on the second detent.
Connect the electrical and ventilation connections to the modular fuel sender assembly cover.
Install the fuel tank. Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Lower the vehicle.
Refill the tank.
Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/malibu/vi-2003-2006/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Inspect for fuel leaks through the following steps: Turn the ignition to the ON position for two seconds Turn the ignition to the OFF position for ten seconds. Turn the ignition to the ON position Check for fuel leaks.

J 45722 Fuel Sender Lock Ring Wrench

CAUTION

In order to reduce the risk of fire and personal injury that may result from a fuel leak, always replace the fuel sender gasket when reinstalling the fuel sender assembly.

Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/malibu/vi-2003-2006/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Relieve the system fuel pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-pressure-relief-procedure) .
Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-tank-draining-procedure) .
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Remove the fuel tank. Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Disconnect the electrical and ventilation connections on the modular fuel sender assembly cover.
While having an assistant hold the fuel tank, use J 45722 to turn the modular fuel sender assembly lock ring counter-clockwise until the ring is released from the fuel tank.
Raise the fuel sender assembly out of the tank far enough to access the ventilation harness connection on the underside of the module cover.
Disconnect the ventilation harness quick connect before attempting to fully remove the modular fuel sender assembly.

Install a new O-ring on the modular fuel sender to tank.
Connect the ventilation harness inside the fuel tank to the bottom of the modular fuel sender cover.
Align the cover "paddle" or anti-rotation feature with the corresponding feature in the top of the fuel tank.
Slowly apply pressure to the top of the spring loaded sender cover until the sender aligns flush with the surface of the tank.
Align the locking ring with the matching features on the fuel tank and install the J 45722 .
Turn the lock ring until the ring seats on the second detent.
Connect the electrical and ventilation connections to the modular fuel sender assembly cover.
Install the fuel tank. Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Lower the vehicle.
Refill the tank.
Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/malibu/vi-2003-2006/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Inspect for fuel leaks through the following steps: Turn the ignition to the ON position for two seconds Turn the ignition to the OFF position for ten seconds. Turn the ignition to the ON position Check for fuel leaks.

Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-pressure-relief-procedure) .
Disconnect the engine fuel feed pipe from the chassis fuel flex hose. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Disconnect the engine fuel feed pipe from the Fuel Rail. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Remove the two fuel feed pipe fasteners.
Remove the engine fuel feed pipe.

Install the fuel feed pipe to the fuel rail Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Install the engine fuel feed pipe fasteners located on the engine. Tighten: Tighten the fuel feed pipe fasteners to 10 N.m (89 lb in).
Connect the engine fuel feed pipe to the chassis fuel flex hose. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/malibu/vi-2003-2006/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Inspect for leaks using the following procedure: Turn ON the ignition, with the engine OFF for 2 seconds. Inspect for fuel leaks. Turn OFF the ignition for 10 seconds. Turn ON the ignition.

Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-pressure-relief-procedure) .
Remove the pipe retaining clip from the fuel feed pipe (1).
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Disconnect the fuel feed pipe from the engine fuel rail. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Cap or plug the fuel pipe and the engine fuel rail to prevent contamination.
Remove the rear brake pipe bracket retaining nuts and release the brackets from the body studs.
Release the pipe retainers (1) from the vehicle underbody.
Remove the fuel feed pipe from the pipe retainers.
Lower the rear of the pipe while moving the pipe rearward slightly, then lower the front of the pipe.
Remove the fuel feed pipe from the vehicle.

Position the fuel feed pipe to the vehicle.
With the rear of the pipe positioned slightly rearward and down, raise the front of the pipe into position.
Install the remainder of the pipe into position.
Install the fuel feed pipe to the pipe retainers.
Secure the pipe retainers (1) to the vehicle underbody.
Connect the fuel feed pipe and vapor return pipe to the lines at the fuel tank.
Lower the vehicle.
Remove the caps or plugs from the fuel pipe and the engine fuel rail.
Connect the fuel feed pipe to the engine fuel rail. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Install the pipe retaining clip (1) to the fuel feed pipe.
Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/malibu/vi-2003-2006/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Inspect for fuel leaks using the following procedure: Turn ON the ignition, with the engine OFF for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition, with the engine OFF. Inspect for fuel leaks.

Fuel System Cleaning

IMPORTANT

If the fuel filter is plugged, the fuel tank should be inspected internally and cleaned if necessary.

Remove the fuel tank. Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Remove the fuel pump module assembly. Refer to «Fuel Sender Assembly Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Sender Assembly Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Inspect the fuel pump module strainer. Replace the pump module assembly if the fuel strainer is contaminated.
Flush the fuel tank with hot water.
Pour the water out of the fuel sender assembly opening in the fuel tank. Rock the fuel tank in order to be sure that the removal of the water from the fuel tank is complete.
Allow the tank to dry completely before reassembly.
Disconnect the fuel feed pipe at the engine fuel rail. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Clean the fuel pipes by applying air pressure in the opposite direction of the fuel flow.
Connect the fuel feed pipe to the engine fuel rail. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Install the fuel pump module assembly. Refer to «Fuel Sender Assembly Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Sender Assembly Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Install the fuel tank. Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .

An 8-digit identification number is stamped on the fuel rail. Refer to this number if servicing or part replacement is required.

Remove the engine fuel feed pipe from the fuel rail.
Relieve fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-pressure-relief-procedure) .
Remove the upper intake manifold. Refer to «Intake Manifold Replacement - Upper»(/chevrolet/malibu/vi-2003-2006/remont/mechanical/#engine-mechanical-35l-lx9) in Engine Mechanical - 3.5L.
Disconnect the main injector harness electrical connector.
Disconnect the main fuel injector electrical harness connector.
Pull up the lock release (2) of the fuel injector electrical connectors.
Depress the lock tabs (1) and disconnect the fuel injector electrical connectors.
Remove the fuel injector electrical wiring harness from the fuel rail.
Remove the fuel rail bolts.
Remove the fuel rail assembly.
Remove the fuel injector O-ring seal from the spray tip end of each injector.
Remove and discard O-rings if damaged.

Replace any damaged O-ring seals that were removed.
Lubricate the O-ring seals with clean engine oil.
Install the fuel rail assembly into the intake manifold. Tilt the fuel rail assembly slightly to install the injectors.
Install the fuel rail bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in).
Install the fuel injector electrical wiring harness to the fuel rail.
Connect the fuel injector electrical connectors.
Push the slide locks (2) into position.
Connect the main fuel injector electrical harness connector.
Install the fuel feed pipe to the fuel rail.
Install the upper intake manifold. Refer to «Intake Manifold Replacement - Upper»(/chevrolet/malibu/vi-2003-2006/remont/mechanical/#engine-mechanical-35l-lx9) in Engine Mechanical - 3.5L.
Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/malibu/vi-2003-2006/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Inspect for fuel leaks with the following procedure: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.

Fuel Injector Cleaning Procedure

Tools Required

J 37287 Fuel Line Shut-Off Adapters
J 35800-A Fuel Injector Cleaner
J 42873-1 3/8 Fuel Line Shut-Off Valve
J 42873-2 5/16 Return Pipe Shut-Off Valve
J 42964-1 3/8 Fuel Pipe Shut-Off Valve
J 42964-2 5/16 Fuel Pipe Shut-Off Valve

Note. GM Top-Engine Cleaner is the only injector cleaning agent recommended. Do not use other cleaning agents, as they may contain methanol which can damage fuel system components. Under NO circumstances should the top engine cleaner be added to the vehicles fuel tank, as it may damage the fuel pump and other system components. Do not exceed a 10 percent cleaning solution concentration. Higher concentrations may damage fuel system components. Testing has demonstrated that exceeding the 10 percent cleaning solution concentration does not improve the effectiveness of this procedure.

IMPORTANT

Vehicles with less than 160 km (100 mi) on the odometer should not have the injectors cleaned. These vehicles should have the injectors replaced.

IMPORTANT

During this procedure you will need a total of 960 ml (32.4 oz) of cleaning solution. That is 2 tanks of solution for the J 35800-A . Other brands of tools may have a different capacity and would therefore require more or less tanks to complete the procedure. You must use all 960 ml (32.4 oz) of solution to ensure complete injector cleaning.

Obtain J 35800-A (2).
For US dealers, empty 2 pre-measured GM Top-Engine Cleaner containers, 24 ml (0.812 oz) each, GM P/N 12346535, into the J 35800-A .
For Canadian dealers, measure and dispense 48 ml (1.62 oz) of Top-Engine Cleaner, Canadian P/N 992872, into the J 35800-A .
If you are using any other brand of tank you will need a total of 96 ml (3.24 oz) of Top-Engine Cleaner mixed with 864 ml (29.16 oz) of regular unleaded gasoline.
Fill the injector cleaning tank with regular unleaded gasoline. Be sure to follow all additional instructions provided with the tool.
Electrically disable the vehicle fuel pump by removing the fuel pump relay and disconnecting the oil pressure switch connector, if equipped.
Disconnect the fuel feed and return line, if equipped, at the fuel rail. Plug the fuel feed and return line, if equipped, coming off the fuel rail with J 37287 , or J 42964-1 , and J 42964-2 or J 42873-1 , and J 42873-2 as appropriate for the fuel system.
Connect the J 35800-A to the vehicle fuel rail.
Pressurize the J 35800-A to 510 kPa (75 psi).
Start and idle the engine until it stalls due to lack of fuel. This should take approximately 15-20 minutes.
Disconnect J 35800-A from the fuel rail.
Reconnect the vehicle fuel pump relay and oil pressure switch connector, if equipped.
Remove J 37287 or J 42964-1 , and J 42964-2 or J 42873-1 , and J 42873-2 and reconnect the vehicle fuel feed and return lines.
Start and idle the vehicle for an additional 2 minutes to ensure residual injector cleaner is flushed from the fuel rail and fuel lines.
Repeat steps 1-5 of the Injector Balance Test, and record the fuel pressure drop from each injector.
Subtract the lowest fuel pressure drop from the highest fuel pressure drop. If the value is 15 kPa (2 psi) or less, no additional action is required. If the value is greater than 15 kPa (2 psi), replace the injector with the lowest fuel pressure drop.
Add one ounce of Port Fuel Injector Cleaner, GM P/N 12345104 (Canadian P/N 10953467), to the vehicle fuel tank for each gallon of gasoline estimated to be in the fuel tank. Instruct the customer to add the reminder of the bottle of Port Fuel Injector Cleaner to the vehicle fuel tank at the next fill-up.
Advise the customer to change brands of fuel and to add GM Port Fuel Injector Cleaner every 5 000 km (3,000 mi). GM Port Fuel Injector Cleaner contains the same additives that the fuel companies are removing from the fuel to reduce costs. Regular use of GM Port Fuel Injector Cleaner should keep the customer from having to repeat the injector cleaning procedure.
Road test the vehicle to verify that the customer concern has been corrected.

Note. Use care in removing the fuel injectors in order to prevent damage to the fuel injector electrical connector pins or the fuel injector nozzles. Do not immerse the fuel injector in any type of cleaner. The fuel injector is an electrical component and may be damaged by this cleaning method.

IMPORTANT

If the fuel injectors are found to be leaking, the engine oil may be contaminated with fuel.

Remove the fuel rail. Refer to «Fuel Rail Assembly Replacement»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .
Remove the fuel injector retaining clip (1).
Remove the fuel injector (3) from the fuel rail.
Remove the fuel injector upper O-ring (2).
Remove the fuel injector lower O-ring (4).

The fuel injector assembly (1) is stamped with a part number identification (2).
Lubricate the new injector O-rings (2, 4) with clean engine oil.
Install the fuel injector upper O-ring (2).
Install the fuel injector lower O-ring (4).
Install the fuel injector (3) to the fuel rail.
Install the fuel injector retaining clip (1).
Install the fuel rail. Refer to «Fuel Rail Assembly Replacement»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .

Disconnect the evaporative emission (EVAP) canister purge valve electrical connector.
Disconnect the EVAP canister purge pipe from the EVAP canister purge valve. Refer to «Quick Connect Fitting(s) Service (Plastic Collar)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Remove the EVAP canister purge valve bolt.
Remove the EVAP canister purge valve from the intake manifold.

Position the EVAP canister purge valve to the intake manifold.
Installing EVAP Canister Purge Valve Bolt. Tighten: Tighten the bolt to 10 N.m (89 lb in).
Connect the EVAP canister purge pipe to the EVAP canister purge valve. Refer to «Quick Connect Fitting(s) Service (Plastic Collar)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Connect the EVAP canister purge valve electrical connector.

Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Lower the fuel tank enough on the RH side to access the purge valve. Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) . It is not necessary to fully remove the fuel tank from the vehicle
Disconnect the evaporative emission (EVAP) vent valve electrical connector.
Remove the vent hose.
Depress the locking tab on the EVAP vent valve mount and slide the valve rearward off of the fuel tank.

Install the EVAP canister vent valve on the mount on the fuel tank, push the valve forward until the locking tab engages. Tighten: Tighten the bolt to 10 N.m (89 lb in).
Connect the vent hose.
Connect the electrical connector.
Install the fuel tank Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Lower the vehicle.

Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Lower the fuel tank enough on the RH side to access the purge valve. Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) . It is not necessary to fully remove the fuel tank from the vehicle
Disconnect the evaporative emission (EVAP) vent valve electrical connector.
Remove the vent hose.
Depress the locking tab on the EVAP vent valve mount and slide the valve rearward off of the fuel tank.

Install the EVAP canister vent valve on the mount on the fuel tank, push the valve forward until the locking tab engages. Tighten: Tighten the bolt to 10 N.m (89 lb in).
Connect the vent hose.
Connect the electrical connector.
Install the fuel tank Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Lower the vehicle.

Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__fuel-pressure-relief-procedure) .
Remove the pipe retaining clip from the fuel feed pipe (1).
Disconnect the fuel feed pipe from the engine fuel rail. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Cap or plug the fuel pipe and the engine fuel rail to prevent contamination.
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Remove the rear brake pipe bracket retaining nuts and release the brackets from the body studs.
Release the pipe retainers (1) from the vehicle underbody.
Remove the fuel feed pipe from the pipe retainers.
Lower the rear of the pipe while moving the pipe rearward slightly, then lower the front of the pipe.
Remove the fuel feed pipe from the vehicle.

Position the fuel feed pipe to the vehicle.
With the rear of the pipe positioned slightly rearward and down, raise the front of the pipe into position.
Install the remainder of the pipe into position.
Install the fuel feed pipe to the pipe retainers.
Secure the pipe retainers (1) to the vehicle underbody.
Connect the fuel feed pipe and vapor return pipe to the lines at the fuel tank.
Lower the vehicle.
Remove the caps or plugs from the fuel pipe and the engine fuel rail.
Connect the fuel feed pipe to the engine fuel rail. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Install the pipe retaining clip (1) to the fuel feed pipe.
Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/malibu/vi-2003-2006/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Inspect for fuel leaks using the following procedure: Turn ON the ignition, with the engine OFF for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition, with the engine OFF. Inspect for fuel leaks.

Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Remove the fuel tank from the vehicle. Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Disconnect the EVAP canister vent valve hose.
Disconnect the vapor line from the fuel tank to the EVAP canister.
Disconnect the purge line from the EVAP canister.
Remove the screw in the EVAP canister mounting pad on the fuel tank and slide the EVAP canister upward off of the mount.

Slide the new EVAP canister onto the mount on the fuel tank.
Install the screw into the EVAP canister mount to secure the canister to the fuel tank.
Connect purge line to the EVAP canister.
Connect the vapor line from the fuel tank to the EVAP canister.
Connect the EVAP canister vent valve hose to the vent valve.
Install the fuel tank back in the vehicle. Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .

Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Remove the fuel tank from the vehicle. Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .
Disconnect the EVAP canister vent valve hose.
Disconnect the vapor line from the fuel tank to the EVAP canister.
Disconnect the purge line from the EVAP canister.
Remove the screw in the EVAP canister mounting pad on the fuel tank and slide the EVAP canister upward off of the mount.

Slide the new EVAP canister onto the mount on the fuel tank.
Install the screw into the EVAP canister mount to secure the canister to the fuel tank.
Connect purge line to the EVAP canister.
Connect the vapor line from the fuel tank to the EVAP canister.
Connect the EVAP canister vent valve hose to the vent valve.
Install the fuel tank back in the vehicle. Refer to «Fuel Tank Replacement (Malibu Sedan)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) or «Fuel Tank Replacement (Malibu MAXX)»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61) .

Note the position of the spark plug wires for the installation and disconnect the spark plug wires from the ignition coil and module assembly.
Remove the 4 screws securing the ignition coil and module assembly to the bracket.
Remove the ignition coil and module assembly.

Install the ignition coil and module assembly to the bracket.
Install the ignition coil and module assembly screws. Tighten: Tighten the screws to 4.5 N.m (40 lb in).
Connect the spark plug wires as noted during the removal.

Note the position of the spark plug wires for the installation and disconnect the spark plug wires from the ignition coil and module assembly.
Remove the 4 screws securing the ignition coil and module assembly to the bracket.
Remove the ignition coil and module assembly.

Install the ignition coil and module assembly to the bracket.
Install the ignition coil and module assembly screws. Tighten: Tighten the screws to 4.5 N.m (40 lb in).
Connect the spark plug wires as noted during the removal.

Spark Plug Wire Inspection

Spark plug wire integrity is vital for proper engine operation. A thorough inspection will be necessary to accurately identify conditions that may affect engine operation. Refer to the list below for items to be inspected.

Inspect for correct routing of the spark plug wires. Improper routing may cause cross-firing. Refer to «Spark Plug Wire Replacement»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .
Inspect each wire for any signs of cracks or splits in the wire.
Inspect each boot for the following conditions: Tearing Piercing Arcing Carbon Tracking Corroded terminal

If corrosion, carbon tracking or arcing are indicated on a spark plug wire boot or terminal both the wire and the component connected to the wire should be replaced.

Remove the spark plug wires (2,4, and 6) from the engine left side spark plugs.
Remove the spark plug wires from the retaining clips.
Remove the spark plug wires (1,3, and 5) from the engine right side spark plugs.
Remove the spark plug wires from the retaining clip.
Remove the spark plug wires from the ignition coils.
Remove the spark plug wires from the engine.
If you are replacing the spark plug wires, transfer any of the following components: Spark plug wire conduit Spark plug wire retaining clips

Install the spark plug wires to the engine.
Install the spark plug wires to the ignition coils.
Install the spark plug wires (1,3, and 5) to the engine right side spark plugs.
Install the spark plug wires to the retaining clip.
Install the spark plug wires (2,4, and 6) to the engine left side spark plugs.
Install the spark plug wires to the retaining clips.

Spark Plug Usage

Ensure that the correct spark plug is installed. An incorrect spark plug causes driveability conditions. Refer to «Ignition System Specifications»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__ignition-system-specifications) for the correct spark plug.
Ensure that the spark plug has the correct heat range. An incorrect heat range causes the following conditions: Spark plug fouling - colder plug Pre-ignition causing spark plug and/or engine damage - hotter plug

Spark Plug Inspection

Inspect the terminal post (1) for damage. Inspect for a bent or broken terminal post (1). Test for a loose terminal post (1) by twisting and pulling the post. The terminal post (1) should NOT move.
Inspect the insulator (2) for flashover or carbon tracking, soot. This is caused by the electrical charge traveling across the insulator (2) between the terminal post (1) and ground. Inspect for the following conditions: Inspect the spark plug boot for damage. Inspect the spark plug recess area of the cylinder head for moisture, such as oil, coolant, or water. A spark plug boot that is saturated causes arcing to ground.
Inspect the insulator (2) for cracks. All or part of the electrical charge may arc through the crack instead of the electrodes (3, 4).
Inspect for evidence of improper arcing. Measure the gap between the center electrode (4) and the side electrode (3) terminals. Refer to «Ignition System Specifications»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__ignition-system-specifications) . An excessively wide electrode gap can prevent correct spark plug operation. Inspect for the correct spark plug torque. Refer to «Ignition System Specifications»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-22l-l61__ignition-system-specifications) . Insufficient torque can prevent correct spark plug operation. An over torqued spark plug, causes the insulator (2) to crack. Inspect for signs of tracking that occurred near the insulator tip instead of the center electrode (4). Inspect for a broken or worn side electrode (3). Inspect for a broken, worn, or loose center electrode (4) by shaking the spark plug. A rattling sound indicates internal damage. A loose center electrode (4) reduces the spark intensity. Inspect for bridged electrodes (3, 4). Deposits on the electrodes (3, 4) reduce or eliminates the gap. Inspect for worn or missing platinum pads on the electrodes (3, 4) If equipped. Inspect for excessive fouling.
Inspect the spark plug recess area of the cylinder head for debris. Dirty or damaged threads can cause the spark plug not to seat correctly during installation.

Spark Plug Visual Inspection

Normal operation-Brown to grayish-tan with small amounts of white powdery deposits are normal combustion by-products from fuels with additives.
Carbon Fouled-Dry, fluffy black carbon, or soot caused by the following conditions: Rich fuel mixtures Leaking fuel injectors Excessive fuel pressure Restricted air filter element Incorrect combustion Reduced ignition system voltage output Weak coils Worn ignition wires Incorrect spark plug gap Excessive idling or slow speeds under light loads can keep spark plug temperatures so low that normal combustion deposits may not burn off.
Deposit Fouling-Oil, coolant, or additives that include substances such as silicone, very white coating, reduces the spark intensity. Most powdery deposits will not effect spark intensity unless they form into a glazing over the electrode.

Note. Observe the following service precautions: Allow the engine to cool before removing the spark plugs. Attempting to remove spark plugs from a hot engine can cause the spark plugs to seize. This can damage the cylinder head threads. Clean the spark plug recess area before removing the spark plug. Failure to do so can result in engine damage due to dirt or foreign material entering the cylinder head, or in contamination of the cylinder head threads. Contaminated threads may prevent proper seating of the new spark plug. Use only the spark plugs specified for use in the vehicle. Do not install spark plugs that are either hotter or colder than those specified for the vehicle. Installing spark plugs of another type can severely damage the engine.

If you are replacing the engine left bank spark plugs, remove the air cleaner intake duct. Refer to «Air Cleaner Intake Duct Replacement»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .
Remove the spark plug wires from the spark plugs. Refer to «Spark Plug Wire Replacement»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .
Remove the spark plugs from the engine.

Gap the spark plugs to the specifications. Refer to «Ignition System Specifications»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9__ignition-system-specifications) .
Install the spark plugs to the engine. Tighten: If installing the spark plugs to a new cylinder head tighten the plugs to 20 N.m (15 lb ft). If installing the spark plugs to an existing cylinder head tighten the plugs to 15 N.m (11 lb ft).
Install the spark plug wires to the spark plugs. Refer to «Spark Plug Wire Replacement»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .

Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Disconnect the crankshaft position (CKP) sensor electrical connector.
Remove the CKP sensor bolt.
Remove the CKP sensor.
Inspect for wear, cracks, or leakage if the sensor is not being replaced.

Lubricate the O-ring with clean engine oil before installation and replace the O-ring if necessary.
Install the CKP sensor.
Install the CKP sensor bolt. Tighten: Tighten the bolt to 11 N.m (97 lb in).
Connect the CKP sensor electrical connector.
Lower the vehicle.
Perform the CKP system variation learn procedure. Refer to «CKP System Variation Learn Procedure»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9__ckp-system-variation-learn-procedure) .

Disconnect the camshaft position (CMP) sensor electrical connector.
Remove the CMP sensor bolt.
Remove the CMP sensor.
Inspect the sensor O-ring for wear, cracks, or leakage if the sensor is not being replaced.

Lubricate the O-ring with clean engine oil and replace the O-ring if damaged.
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.

Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Disconnect the knock sensor wiring harness electrical connector.
Remove the knock sensor.

IMPORTANT

DO NOT apply thread sealant to the sensor threads. The sensor threads are coated at the factory. Applying additional sealant affects the sensors ability to detect detonation.

Install the knock sensor. Tighten: Tighten the knock sensors to 25 N.m (18 lb ft).
Connect the knock sensor wiring harness electrical connector.
Lower the vehicle.

Disconnect the exhaust gas recirculation (EGR) valve electrical connector.
Remove the EGR pipe bolt and carefully pull the pipe assembly back.
Remove the EGR valve bolts.
Remove EGR valve.
Remove the EGR valve gasket.
Clean and inspect the EGR valve gasket mating surfaces.

Install a new EGR valve gasket.
Install the EGR valve.
Install the EGR valve bolts. Tighten: Tighten the bolt to 30 N.m (22 lb ft).
Install the EGR pipe to the EGR valve.
Install the EGR pipe. Tighten: Tighten the bolt to 25 N.m (18 lb ft).
Connect the EGR valve electrical connector.

Remove the exhaust gas recirculation (EGR) pipe bolt and carefully pull the pipe assembly back.
Remove the EGR pipe assembly bolts from the exhaust manifold.
Remove the EGR pipe.

Install the EGR pipe to the exhaust manifold. Tighten: Tighten the EGR pipe bolts to 25 N.m (18 lb ft).
Install the EGR pipe to the EGR valve.
Install the EGR pipe bolt. Tighten: Tighten the bolt to 30 N.m (22 lb ft).

Exhaust Gas Recirculation (EGR) System Cleaning

CAUTION

Avoid breathing fumes and swallowing EGR exhaust deposits when removing components for cleaning as bodily injury may result.

IMPORTANT

Whenever the EGR valve is removed the EGR system should be inspected and cleaned if needed. This will ensure that the EGR system will function properly under all operating conditions.

Proper EGR system service consists of the following steps

Clean and inspect the EGR pipe from the exhaust manifold to the EGR valve. Refer to «Exhaust Gas Recirculation (EGR) Pipe Replacement»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .
Clean the EGR valve. The EGR valve can be removed, inspected for deposits, cleaned, and reinstalled. Use the following procedure for this operation: Remove the EGR valve from the engine. Refer to «Exhaust Gas Recirculation (EGR) Valve Replacement»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) . While holding the EGR valve base in your hand, try to rotate the connector housing. Replace the valve that exhibits looseness. Inspect the EGR valve pintle and seat for deposits. Use a cloth or other suitable soft device to remove deposits. Remove all loose particles. If deposits are such that pintle/base interface cannot be cleaned adequately to allow the pintle to seal against the seat, replace the valve. Damage to the EGR valve base will occur if cleaned with solvents, sharp tools, wire brush, wheel or sand blasting. Cleaning by these methods is not recommended. Install the EGR valve on engine, using a new gasket. Refer to «Exhaust Gas Recirculation (EGR) Valve Replacement»(/chevrolet/malibu/vi-2003-2006/remont/testing-diagnostics/#engine-control-system-introduction-35l-lx9) .

Loosen the 2 intake air duct clamps from the mass airflow (MAF) sensor and the throttle body.
Disconnect the positive crankcase ventilation clean air tube from the intake duct.
Disconnect the MAF sensor electrical connector.
Remove the fastener that attaches the air intake duct to the upper tie-bar.
Remove the air cleaner cover fasteners and remove the air intake duct and air cleaner cover.
Separate the air intake duct from the MAF sensor.

Install the air intake duct to the MAF sensor.
Install the air intake duct to the throttle body and the air cleaner cover to the air cleaner assembly.
Install the air cleaner cover fasteners.
Install the fastener that attaches the air intake duct to the upper tie-bar.
Tighten the air intake duct clamps fastener at the upper tie bar. Tighten: Tighten the intake air duct clamps to 10 N.m (89 lb in).
Reconnect the MAF sensor electrical connector.
Reconnect the positive crankcase ventilation clean air tube to the air intake duct.
Tighten the air intake duct clamps. Tighten: Tighten the intake air duct clamps to 2 N.m (18 lb in).

Disconnect the manifold absolute pressure (MAP) sensor harness connector.
Remove the upper air cleaner cover screws.
Remove the upper air cleaner cover.
Remove the air cleaner filter from the lower air cleaner housing.
Inspect the air cleaner filter for dust, dirt and water contamination.
Replace as necessary. Refer to «Scheduled Maintenance»(/chevrolet/malibu/vi-2003-2006/remont/lubrication-system/#maintenance-and-lubrication__scheduled-maintenance) in Maintenance and Lubrication.

Install the air cleaner filter into the lower air cleaner housing.
Install the upper air cleaner cover to the lower air cleaner housing.
Secure the air cleaner housing cover. Tighten: Tighten the air cleaner cover screws to 5 N.m (44 lb in).
Connect the mass air flow (MAF) sensor harness connector.

Loosen the outlet duct clamp at the air cleaner assembly.
Remove the air cleaner assembly attachment nut.
Remove the air cleaner.

Position the air cleaner assembly.
Install the air cleaner assembly attachment nut. Tighten: Tighten the nut to 10 N.m (89 lb in).
Connect the air cleaner resonator to the air cleaner assembly. Tighten: Tighten the air cleaner intake duct clamp to 5 N.m (44 lb in).

Powertrain

The powertrain has electronic controls to reduce exhaust emissions while maintaining excellent driveability and fuel economy. The powertrain control module (PCM) is the control center of this system. The PCM monitors numerous engine and vehicle functions. The PCM constantly looks at the information from various sensors and other inputs, and controls the systems that affect vehicle performance and emissions. The PCM also performs the diagnostic tests on various parts of the system. The PCM can recognize operational problems and alert the driver via the malfunction indicator lamp (MIL). When the PCM detects a malfunction, the PCM stores a diagnostic trouble code (DTC). The problem area is identified by the particular DTC that is set. The control module supplies a buffered voltage to various sensors and switches. Review the components and wiring diagrams in order to determine which systems are controlled by the PCM.

The following are some of the functions that the PCM controls

The engine fueling
The ignition control (IC)
The knock sensor (KS) system
The evaporative emissions (EVAP) system
The secondary air injection (AIR) system (if equipped)
The exhaust gas recirculation (EGR) system
The automatic transmission functions
The generator
The A/C clutch control
The cooling fan control

Powertrain Control Module Function

The powertrain control module (PCM) constantly looks at the information from various sensors and other inputs and controls systems that affect vehicle performance and emissions. The PCM also performs diagnostic tests on various parts of the system. The PCM can recognize operational problems and alert the driver via the malfunction indicator lamp (MIL). When the PCM detects a malfunction, the PCM stores a diagnostic trouble code (DTC). The problem area is identified by the particular DTC that is set. The control module supplies a buffered voltage to various sensors and switches. The input and output devices in the PCM include analog-to-digital converters, signal buffers, counters, and output drivers. The output drivers are electronic switches that complete a ground or voltage circuit when turned on. Most PCM controlled components are operated via output drivers. The PCM monitors these driver circuits for proper operation and, in most cases, can set a DTC corresponding to the controlled device if a problem is detected.

Scheme 30

Scheme 30: Malfunction Indicator Lamp (MIL) Operation

The malfunction indicator lamp (MIL) is located in the instrument panel cluster. The MIL will display as either SERVICE ENGINE SOON or one of the following symbols when commanded ON

Scheme 31

The MIL indicates that an emissions related fault has occurred and vehicle service is required.

The following is a list of the modes of operation for the MIL

The MIL illuminates when the ignition is turned ON, with the engine OFF. This is a bulb test to ensure the MIL is able to illuminate.
The MIL turns OFF after the engine is started if a diagnostic fault is not present.
The MIL remains illuminated after the engine is started if the control module detects a fault. A diagnostic trouble code (DTC) is stored any time the control module illuminates the MIL due to an emissions related fault. The MIL turns OFF after three consecutive ignition cycles in which a Test Passed has been reported for the diagnostic test that originally caused the MIL to illuminate.
The MIL flashes if the control module detects a misfire condition which could damage the catalytic converter.
When the MIL is illuminated and the engine stalls, the MIL will remain illuminated as long as the ignition is ON.
When the MIL is not illuminated and the engine stalls, the MIL will not illuminate until the ignition is cycled OFF and then ON.

Trip

A trip is an interval of time during which the diagnostic test runs. A trip may consist of only a key cycle to power up the powertrain control module (PCM), allow the diagnostic to run, then cycle the key off to power down the PCM. A trip may also involve a PCM power up, meeting specific conditions to run the diagnostic test, then powering down the PCM. The definition of a trip depends upon the diagnostic. Some diagnostic tests run only once per trip (i.e., catalyst monitor) while other tests run continuously during each trip (i.e., misfire).

Warm-Up Cycle

The powertrain control module (PCM) uses warm-up cycles to run some diagnostics and to clear any diagnostic trouble codes (DTCs). A warm-up cycle occurs when the engine coolant temperature increases 22°C (40°F) from the start-up temperature. The engine coolant must also achieve a minimum temperature of 71°C (160°F). The PCM counts the number of warm-up cycles in order to clear the malfunction indicator lamp (MIL). The PCM will clear the DTCs when 40 consecutive warm-up cycles occur without a malfunction.

Diagnostic Trouble Codes (DTCs)

The powertrain control module (PCM) is programmed with test routines that test the operation of the various systems the PCM controls. Some tests monitor internal PCM functions. Many tests are run continuously. Other tests run only under specific conditions, referred to as Conditions for Running the DTC. When the vehicle is operating within the conditions for running a particular test, the PCM monitors certain parameters and determines if the values are within an expected range. The parameters and values considered outside the range of normal operation are listed as Conditions for Setting the DTC. When the Conditions for Setting the DTC occur, the PCM executes the Action Taken When the DTC Sets. Some DTCs alert the driver via the malfunction indicator lamp (MIL) or a message. Other DTCs do not trigger a driver warning, but are stored in memory. The PCM also saves data and input parameters when most DTCs are set. This data is stored in the Freeze Frame and/or Failure Records.

The DTCs are categorized by type. The DTC type is determined by the MIL operation and the manner in which the fault data is stored when a particular DTC fails. In some cases there may be exceptions to this structure. Therefore, when diagnosing the system it is important to read the Action Taken When the DTC Sets and the Conditions for Clearing the DTC in the supporting text.

There are different types of DTCs and different actions taken when the DTCs set. Refer to Diagnostic Trouble Code (DTC) Type Definitions for a description of the general characteristics of each DTC type.

DTC Status

When the scan tool displays a DTC, the status of the DTC is also displayed. The following DTC statuses are indicated only when they apply to the DTC that is set.

Purpose

The throttle actuator control (TAC) system delivers improved throttle response and greater reliability and eliminates the need for mechanical cable. The TAC system performs the following functions

Accelerator pedal position sensing
Throttle positioning to meet driver and engine demands
Throttle position sensing
Internal diagnostics
Cruise control functions
Manage TAC electrical power consumption

The TAC system includes the following components

The accelerator pedal position (APP) sensors
The throttle body assembly
The powertrain control module (PCM)

Accelerator Pedal Position (APP) Sensor

The accelerator pedal contains two individual APP sensors within the assembly. The APP sensors 1 and 2 are potentiometer type sensors each with 3 circuits

A 5-volt reference circuit
A low reference circuit
A signal circuit

The APP sensors are used to determine the pedal angle. The PCM provides each APP sensor a 5-volt reference circuit and a low reference circuit. The APP sensors provide the PCM with signal voltage proportional to the pedal movement. Both APP sensor signal voltages are low at rest position and increase as the pedal is applied.

Throttle Body Assembly

The throttle assembly contains the following components

The throttle blade
The throttle actuator motor
The throttle position (TP) sensor 1 and 2
The TAC module

The throttle body functions similar to a conventional throttle body with the following exceptions

An electric motor opens and closes the throttle valve.
The TAC module is located within the throttle body assembly.
The throttle blade is spring loaded in both directions and the default position is slightly open.
There are 2 individual TP sensors within the throttle body assembly.

The TP sensors are used to determine the throttle plate angle. The TP sensors provide the PCM with a signal voltage proportional to throttle plate movement. Both TP sensor signal voltages are low at closed throttle and increase as the throttle opens.

Throttle Actuator Control Module

The TAC module is the control center for the TAC system. The TAC system uses Electronically Erasable Programmable Read Only Memory and is self-diagnosing. The TAC module provides diagnostic information to the PCM through a dedicated serial data line. The TAC achieves throttle positioning by providing a pulse width modulated voltage to the TAC motor as directed by the PCM. The TAC module is not serviced and just be replaced with the throttle body assembly.

Powertrain Control Module

The PCM determines the drivers intent and then calculates the appropriate throttle response. This information is sent to the TAC module through a dedicated serial data line.

Normal Mode

During the operation of the TAC system, several modes or functions are considered normal. The following modes may be entered during normal operation

Minimum pedal value-At key-up the PCM updates the learned minimum pedal value.
Minimum TP values-At key-up the PCM updates the learned minimum TP value. In order to learn the minimum TP value, the throttle blade is moved to the closed position.
Ice break mode-If the throttle is not able to reach a predetermined minimum throttle position, the ice break mode is entered. During the ice break mode, the PCM commands the maximum pulse width several times to the throttle actuator motor in the closing direction.
Battery saver mode-After a predetermined time without engine RPM, the PCM commands the battery saver mode. During the battery saver mode, the TAC module removes the voltage from the motor control circuits, which removes the current draw used to maintain the idle position and allows the throttle to return to the spring loaded default position.

Reduced Engine Power Mode

When the PCM detects a condition with the TAC system, the PCM may enter a reduced engine power mode. Reduced engine power may cause one or more of the following conditions

Acceleration limiting-The PCM will continue to use the accelerator pedal for throttle control; however, the vehicle acceleration is limited.
Limited throttle mode-The PCM will continue to use the accelerator pedal for throttle control; however, the maximum throttle opening is limited.
Throttle default mode-The PCM will turn off the throttle actuator motor and the throttle will return to the spring loaded default position.
Forced idle mode-The PCM will perform the following actions: Limit engine speed to idle by positioning the throttle position, or by controlling the fuel and spark if the throttle is turned off. Ignore the accelerator pedal input.
Engine shutdown mode-The PCM will disable fuel and de-energize the throttle actuator.

Fuel System Overview

The fuel tank stores the fuel supply. An electric fuel pump, located in the fuel tank with the fuel sender assembly, pumps fuel through an in-tank fuel filter to the fuel rail assembly. The pump provides fuel at a pressure that is more than is needed by the injectors. The fuel pressure regulator, part of the fuel rail assembly, keeps fuel available to the injectors at a regulated pressure.

Scheme 32

Scheme 32: Fuel Tank

The fuel tank stores the fuel supply. The fuel tank is located in the rear of the vehicle. The fuel tank is held in place by 2 metal straps that attach to the frame. The fuel tank is molded from high density polyethylene.

Scheme 33

Scheme 33: Fuel Fill Pipe

The fuel fill pipe (2) has a built-in restrictor and deflector in order to prevent refueling with leaded fuel.

Scheme 34

Scheme 34: Fuel Filler Cap

Note. If a fuel tank filler cap requires replacement, use only a fuel tank filler cap with the same features. Failure to use the correct fuel tank filler cap can result in a serious malfunction of the fuel and EVAP system.

The fuel fill pipe has a tethered fuel filler cap. A torque-limiting device prevents the cap from being over tightened. To install the cap, turn the cap clockwise until you hear audible clicks. This indicates that the cap is correctly torqued and fully seated. A built-in device indicates that the fuel filler cap is fully seated. A fuel filler cap that is not fully seated may cause a malfunction in the emission system.

Scheme 35

Scheme 35: Fuel Sender Assembly

The fuel sender assembly consists of the following major components

The fill limit vent valve (1)
The fuel tank pressure sensor (2)
The fuel feed pipe (3)
The fuel pump (4)
The fuel level sensor (5)
The fuel pressure regulator (6)
The fuel sender assembly (7)

Scheme 36

Scheme 36: Fuel Level Sensor

The fuel level sensor consists of a float, a wire float arm, and a ceramic resistor card. The position of the float arm indicates the fuel level. The fuel level sensor contains a variable resistor which changes resistance in correspondence with the amount of fuel in the fuel tank. The powertrain control module (PCM) sends the fuel level information via the class 2 circuit to the instrument panel cluster (IPC). This information is used for the instrument panel (I/P) fuel gage and the low fuel warning indicator, if applicable. The PCM also monitors the fuel level input for various diagnostics.

Fuel Pump

The fuel pump is mounted in the fuel sender assembly reservoir. The fuel pump is an electric high pressure pump. Fuel is pumped to the fuel rail at a specified flow and pressure. Excess fuel from the fuel rail assembly returns to the fuel tank through the fuel return pipe. The fuel pump delivers a constant flow of fuel to the engine even during low fuel conditions and aggressive vehicle maneuvers. The powertrain control module (PCM) controls the electric fuel pump operation through a fuel pump relay. The fuel pump flex pipe acts to dampen the fuel pulses and noise generated by the fuel pump.

Fuel Strainer

The fuel strainer attaches to the lower end of the fuel sender. The fuel strainer is made of woven plastic. The functions of the fuel strainer are to filter contaminants and to wick fuel. The fuel strainer is self-cleaning and normally requires no maintenance. Fuel stoppage at this point indicates that the fuel tank contains an abnormal amount of sediment or water.

Fuel Feed Pipe

The fuel feed pipe carries fuel from the fuel tank to the fuel rail assembly. The fuel pipes consist of 2 sections

The rear fuel pipe assembly is located from the top of the fuel tank to the chassis fuel pipe. The rear fuel pipe is constructed of nylon.
The chassis fuel pipe is located under the vehicle and connect the rear fuel pipe to the fuel rail pipe. This pipe is constructed of steel.

Nylon Fuel Pipe

CAUTION

Refer to Fuel and EVAP Pipe Caution in Cautions and Notices.

Nylon pipes are constructed to withstand maximum fuel system pressure, exposure to fuel additives, and changes in temperature. There are 2 sizes of nylon pipes used: 3/8 in ID for the fuel feed, and 1/2 in ID for the vent. Heat resistant rubber hose or corrugated plastic conduit protect the sections of the pipes that are exposed to chafing, high temperature, or vibration.

Nylon fuel pipes are somewhat flexible and can be formed around gradual turns under the vehicle. However, if nylon fuel pipes are forced into sharp bends, the pipes kink and restrict the fuel flow. Also, once exposed to fuel, nylon pipes may become stiffer and are more likely to kink if bent too far. Take special care when working on a vehicle with nylon fuel pipes.

Quick-Connect Fittings

Quick-connect fittings provide a simplified means of installing and connecting fuel system components. The fittings consist of a unique female connector and a compatible male pipe end. O-rings, located inside the female connector, provide the fuel seal. Integral locking tabs inside the female connector hold the fittings together.

Fuel Pipe O-Rings

O-rings seal the threaded connections in the fuel system. Fuel system O-ring seals are made of special material. Service the O-ring seals with the correct service part.

Scheme 37

Scheme 37: Fuel Rail Assembly

The fuel rail assembly attaches to the engine intake manifold. The fuel rail assembly performs the following functions

Positions the injectors (2) in the intake manifold
Distributes fuel evenly to the injectors
Integrates the fuel pressure regulator with the fuel metering system

Scheme 38

Scheme 38: Fuel Injectors

The Multec 2 fuel injector assembly is a solenoid operated device, controlled by the powertrain control module (PCM), that meters pressurized fuel to a single engine cylinder. The PCM energizes the high-impedance (12.0 ohms) injector solenoid (2) to open a normally closed ball valve (3). This allows fuel to flow into the top of the injector, past the ball valve, and through a director plate at the injector outlet. The director plate has four machined holes that control the fuel flow, generating a spray of finely atomized fuel at the injector tip. Fuel from the injector tip is directed at the intake valve, causing it to become further atomized and vaporized before entering the combustion chamber. An injector stuck partly open can cause a loss of pressure after engine shutdown. Consequently, long cranking times would be noticed on some engines.

Fuel Pressure Regulator

The fuel pressure regulator is a diaphragm operated relief valve. The fuel pump pressure is on one side of the regulator and the regulator spring pressure is on the other side. The function of the fuel pressure regulator is to maintain a constant fuel pressure under all of the operating conditions. The pressure regulator DOES NOT compensate for the engine load by increasing the fuel pressure as the engine intake manifold vacuum drops. The vent on the fuel pressure regulator is an atmospheric vent only. The fuel pressure regulator is mounted on the fuel tank module.

Fuel Metering Modes of Operation

The powertrain control module (PCM) monitors voltages from several sensors in order to determine how much fuel to give the engine. The fuel is delivered under one of several conditions called modes. The PCM controls all modes.

Starting Mode

With the ignition switch in the ON position, before engaging the starter, the powertrain control module (PCM) energizes the fuel pump relay for 2 seconds allowing the fuel pump to build up pressure. The PCM first tests speed density, then switches to the mass air flow (MAF) sensor. The PCM also uses the engine coolant temperature (ECT), the throttle position (TP), and the manifold absolute pressure (MAP) sensors to determine the proper air/fuel ratio for starting. The PCM controls the amount of fuel delivered in the starting mode by changing the pulse width of the injectors. This is done by pulsing the injectors for very short times.

Clear Flood Mode

If the engine floods, clear the engine by pressing the accelerator pedal down to the floor and then crank the engine. When the throttle position (TP) sensor is at wide open throttle, the powertrain control module (PCM) reduces the injector pulse width in order to increase the air to fuel ratio. The PCM holds this injector rate as long as the throttle stays wide open and the engine speed is below a predetermined RPM. If the throttle is not held wide open, the PCM returns to the starting mode.

Run Mode

The run mode has 2 conditions called Open Loop and Closed Loop. When the engine is first started and the engine speed is above a predetermined RPM, the system begins Open Loop operation. The powertrain control module (PCM) ignores the signal from the heated oxygen sensor (HO2S) and calculates the air/fuel ratio based on inputs from the engine coolant temperature (ECT), mass air flow (MAF), manifold absolute pressure (MAP), and throttle position (TP) sensors. The system stays in Open Loop until meeting the following conditions

Both HO2S have varying voltage output, showing that they are hot enough to operate properly. This depends upon the engine temperature.
The ECT sensor is above a specified temperature.
A specific amount of time has elapsed after starting the engine.

Specific values for the above conditions exist for each different engine, and are stored in the electrically erasable programmable read-only memory (EEPROM). The system begins Closed Loop operation after reaching these values. In Closed Loop, the PCM calculates the air/fuel ratio (injector on-time) based upon the signal from various sensors, but mainly from the HO2S. This allows the air/fuel ratio to stay very close to 14.7:1.

Acceleration Mode

When the driver pushes on the accelerator pedal, air flow into the cylinders increases rapidly, while fuel flow tends to lag behind. To prevent possible hesitation, the powertrain control module (PCM) increases the pulse width to the injectors to provide extra fuel during acceleration. The PCM determines the amount of fuel required based upon the throttle position, the coolant temperature, the manifold air pressure, the mass air flow, and the engine speed.

Deceleration Mode

When the driver releases the accelerator pedal, air flow into the engine is reduced. The powertrain control module (PCM) reads the corresponding changes in throttle position, manifold air pressure, and mass air flow. The PCM shuts OFF fuel completely if the deceleration is very rapid, or for long periods, such as long, closed-throttle coast-down. The fuel shuts OFF in order to protect the catalytic converters.

Battery Voltage Correction Mode

When the battery voltage is low, the powertrain control module (PCM) compensates for the weak spark delivered by the ignition system in the following ways

Increasing the amount of fuel delivered
Increasing the idle RPM
Increasing the ignition dwell time

Fuel Cutoff Mode

The powertrain control module (PCM) cuts off fuel from the fuel injectors when the following conditions are met in order to protect the powertrain from damage and improve driveability

The ignition is OFF. This prevents engine run-on.
The ignition is ON but there is no ignition reference signal. This prevents flooding or backfiring.
The engine speed is too high, above red line.
The vehicle speed is too high, above rated tire speed.
During an extended, high speed, closed throttle coast down. This reduces emissions and increases engine braking.
During extended deceleration, in order to protect the catalytic converters.

Short Term Fuel Trim

The short term fuel trim values change rapidly in response to the heated oxygen sensor (HO2S) signal voltages. These changes "fine tune" the engine fueling. The ideal fuel trim values are around 0 percent. A positive fuel trim value indicates that the powertrain control module (PCM) is adding fuel in order to compensate for a lean condition. A negative fuel trim value indicates that the PCM is reducing the amount of fuel in order to compensate for a rich condition.

When the PCM determines that the short term fuel trim is out of the operating range, the following DTCs will set

DTC P0171 Bank 1 Too Lean
DTC P0172 Bank 1 Too Rich

Long Term Fuel Trim

The long term fuel trim is a matrix of cells arranged by RPM and manifold absolute pressure (MAP). Each cell of the long term fuel trim is a register like the short term fuel trim. As the engine operating conditions change, the powertrain control module (PCM) will switch from cell to cell to determine what long term fuel trim factor to use in the base pulse width equation.

While in any given cell, the PCM also monitors the short term fuel trim. If the short term fuel trim is far enough from 0 percent, the PCM will change the long term fuel trim value. Once the long term fuel trim value is changed, it should force the short term fuel trim back toward 0 percent. If the mixture is still not correct, the short term fuel trim will continue to have a large deviation from the ideal 0 percent. In this case, the long term fuel trim value will continue to change until the short term fuel trim becomes balanced. Both the short term fuel trim and long term fuel trim have limits which vary by calibration. If the mixture is off enough so that long term fuel trim reaches the limit of its control and still cannot correct the condition, the short term fuel trim would also go to its limit of control in the same direction. If the mixture is still not corrected by both short term fuel trim and long term fuel trim at their extreme values, a fuel trim diagnostic trouble code (DTC) will likely result. When the PCM determines that the long term fuel trim is out of the operating range, the following DTCs will set

DTC P0171 Bank 1 Too Lean
DTC P0172 Bank 1 Too Rich

Under the conditions of power enrichment, the PCM sets the short term fuel trim to 0 percent until power enrichment is no longer in effect. This is done so the Closed Loop factor and the long term fuel trim will not try to correct for the power enrichment condition.

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 solenoid valve to the 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 solenoid valve ON, allowing engine vacuum to be applied to the EVAP canister. With the EVAP vent solenoid valve OFF, fresh air is drawn through the vent solenoid valve and the 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 solenoid 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 evaporative emission (EVAP) system. The control module commands the EVAP vent solenoid valve ON and commands the EVAP purge solenoid valve ON, 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 solenoid valve OFF, 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 will set.

Small Leak Test

The engine off natural vacuum (EONV) diagnostic is the small-leak detection diagnostic for the evaporative emission (EVAP) system. While previous leak detection methods were performed with the engine running, the EONV diagnostic monitors the EVAP system pressure or vacuum with the ignition OFF. Because of this, it may be normal for the control module to remain active for up to 40 minutes after the ignition is turned OFF. This is important to remember when performing a parasitic draw test on vehicles equipped with EONV.

The EONV utilizes the temperature changes in the fuel tank immediately following a drive cycle to use the naturally occurring vacuum or pressure in the fuel tank. When the vehicle is driven, the temperature rises in the tank. After the vehicle is parked, the temperature in the tank continues to rise for a period of time, then starts to drop. The EONV diagnostic relies on this temperature change and the corresponding pressure change in a sealed system, 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 system is sealed, a finite amount of pressure or vacuum will be observed. When a 0.51 mm (0.020 in) leak is present, often 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 evaporative emission (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 solenoid valve ON, commanding the EVAP vent solenoid valve OFF, and monitoring the fuel tank pressure (FTP) sensor for an increase in vacuum. If the vacuum increases more than a calibrated value, DTC P0446 will set.

Purge Solenoid Valve Leak Test

If the evaporative emission (EVAP) purge solenoid 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 solenoid valve OFF and the vent solenoid valve ON, sealing the system, and monitors the fuel tank pressure (FTP) for an increase in vacuum. If the control module detects that the EVAP system vacuum increases above a calibrated value, DTC P0496 will set.

Check Gas Cap Message

The powertrain control module (PCM) sends a class 2 message to the driver information center (DIC) illuminating the Check Gas Cap message when any of the following occur

A malfunction in the evaporative emission (EVAP) system and a large leak test fails
A malfunction in the EVAP system and a small leak test fails

EVAP System Components

The evaporative emission (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 Solenoid Valve

The EVAP purge solenoid valve controls the flow of vapors from the EVAP system to the intake manifold. The purge solenoid valve opens when commanded ON by the control module. 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 Solenoid Valve

The EVAP vent solenoid valve controls fresh airflow into the EVAP canister. The valve is normally open. The control module commands the valve ON, closing the valve during some EVAP tests, allowing the system to be tested for leaks.

Fuel Tank Pressure Sensor

The fuel tank pressure (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. A high FTP sensor voltage indicates a low fuel tank pressure or vacuum. A low FTP sensor voltage indicates a high fuel tank pressure.

EVAP Service Port

The EVAP service port is located in the EVAP purge pipe between the EVAP purge solenoid valve and the EVAP canister. The service port is identified by a green colored cap.

Electronic Ignition (EI) System Operation

The electronic ignition (EI) system produces and controls the high energy secondary spark. This spark ignites the compressed air/fuel mixture at precisely the correct time, providing optimal performance, fuel economy, and control of exhaust emissions. The powertrain control module (PCM) primarily collects information from the crankshaft position (CKP) and camshaft position (CMP) sensors to control the sequence, dwell, and timing of the spark.

Crankshaft Reluctor Wheel

The crankshaft reluctor wheel is mounted in the middle of the crankshaft. The wheel is comprised of three 120 degree segments. Each segment represents a pair of cylinders at top dead center (TDC), and is further divided into six 20-degree segments. Within each 20-degree segment is a notch of two different sizes. Each 120 degree segment has a unique pattern of notches. This is known as pulse width encoding. This pulse width encoding pattern allows the PCM to quickly recognize which pair of cylinders are at TDC. The reluctor wheel is also a dual track, or mirror image, design. This means there is an additional wheel pressed against the first wheel with a gap of equal size to each notch of the mating wheel. When one sensing element of the CKP sensor is reading a notch, the other is reading a set of teeth. The resulting signals are then converted into a digital square wave output by the circuitry within the CKP sensor.

Crankshaft Position (CKP) Sensor

The CKP sensor is a three wire sensor based on the magneto resistive principle. A magneto resistive sensor uses two magnetic pickups between a permanent magnet. As an element such as a reluctor wheel passes the magnets, the resulting change in the magnetic field is used by the sensor electronics to produce a digital output pulse. The CKP sensor returns a digital ON/OFF pulse 24 times per crankshaft revolution. The pulse width encoding pattern is used to synchronize the coil firing sequence with the crankshaft position. The CKP sensor is used for ignition timing, fuel injector timing, misfire diagnostics, and tachometer display. The PCM supplies a 12-volt reference, a low reference, and a medium resolution engine speed signal circuit to the CKP sensor.

Camshaft Position (CMP) Sensor

The CMP sensor signal is a digital ON/OFF pulse output once 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 PCM to determine the position of the valve train relative to the crankshaft position. By monitoring the CMP and CKP signals, the PCM can accurately time the operation of the fuel injectors. The PCM supplies the sensor with a 12-volt reference circuit, a low reference circuit, and a signal circuit.

Ignition Control Module (ICM)/Coils

There are 3 dual-tower ignition coils that are part of the ignition control module (ICM). The ICM contains coil driver circuits that command the coils to operate. The ICM has the following circuits

An ignition voltage circuit
A ground circuit
An IC 1 control circuit for the 1-4 ignition coil
An IC 2 control circuit for the 2-5 ignition coil
An IC 3 control circuit for the 3-6 ignition coil
A low reference circuit

The PCM controls each dual-tower ignition coil by transmitting timing pulses on the IC control circuit to the ICM for the proper coil to enable a spark event.

The spark plugs are connected to each coil tower by spark plug wires. The spark plug wires conduct the spark energy from the coil to the spark plug. The spark plug electrode is tipped with platinum for long wear and higher efficiency.

Powertrain Control Module (PCM)

The PCM controls all ignition system functions, and constantly corrects the basic spark timing. The PCM monitors information from various sensor inputs that include the following

The throttle position (TP) sensor
The engine coolant temperature (ECT) sensor
The mass airflow (MAF) sensor
The intake air temperature (IAT) sensor
The vehicle speed sensor (VSS)
The transmission gear position or range information sensors
The engine knock sensor (KS)

Modes of Operation

There is one normal mode of operation with the spark under PCM control. If the CKP pulses are lost, the engine will not run. The loss of a CMP signal may result in a longer crank time since the PCM cannot determine which stroke the pistons are on. Diagnostic trouble codes are available to accurately diagnose the ignition system with a scan tool.

The knock sensor (KS) system enables the control module to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The control module uses the KS system to test for abnormal engine noise that may indicate detonation, also known as spark knock.

Sensor Description

This KS system uses one or two flat response two-wire sensors. The sensor uses piezo-electric crystal technology that produces an AC voltage signal of varying amplitude and frequency based on the engine vibration or noise level. The amplitude and frequency are dependant upon the level of knock that the KS detects. The control module receives the KS signal through a signal circuit. The KS ground is supplied by the control module through a low reference circuit.

The control module learns a minimum noise level, or background noise, at idle from the KS and uses calibrated values for the rest of the RPM range. The control module uses the minimum noise level to calculate a noise channel. A normal KS signal will ride within the noise channel. As engine speed and load change, the noise channel upper and lower parameters will change to accommodate the normal KS signal, keeping the signal within the channel. In order to determine which cylinders are knocking, the control module only uses KS signal information when each cylinder is near top dead center (TDC) of the firing stroke. If knock is present, the signal will range outside of the noise channel.

If the control module has determined that knock is present, it will retard the ignition timing to attempt to eliminate the knock. The control module will always try to work back to a zero compensation level, or no spark retard. An abnormal KS signal will stay outside of the noise channel or will not be present. KS diagnostics are calibrated to detect faults with the KS circuitry inside the control module, the KS wiring, or the KS voltage output. Some diagnostics are also calibrated to detect constant noise from an outside influence such as a loose/damaged component or excessive engine mechanical noise.

Exhaust Gas Recirculation (EGR) System

The exhaust gas recirculation (EGR) system is used to reduce the amount of nitrogen oxide (NOx) emission levels caused by combustion temperatures exceeding 816°C (1,500°F). It does this by introducing small amounts of exhaust gas back into the combustion chamber. The exhaust gas absorbs a portion of the thermal energy produced by the combustion process and thus decreases combustion temperature. The EGR system will only operate under specific temperature, barometric pressure and engine load conditions in order to prevent drivability concerns and to increase engine performance.

Scheme 39

Scheme 39: Linear EGR Valve

The linear EGR valve consists of the following

The EGR valve position sensor
The EGR valve position sensor cap
The bobbin and coil assembly
The valve pintle
The primary pole piece
The armature sleeve
The armature and base assembly
The exhaust gas inlet port
The exhaust gas outlet port

Linear EGR Control

The linear EGR valve is controlled by a high side driver within the PCM. The high side driver provides 12 volts that is pulse width modulated (PWM) by a duty cycle via the high control circuit of the EGR valve. The ground path is provided by the low control circuit of the EGR valve. The PCM calculates the amount of EGR needed based on the following inputs

The engine coolant temperature (ECT) sensor
The intake air temperature (IAT) sensor
The barometric pressure (BARO)
The manifold absolute pressure (MAP) sensor
The throttle position (TP) sensor
The mass air flow (MAF) sensor

EGR Diagnostics

The PCM tests the EGR flow during deceleration by momentarily commanding the EGR valve to open while monitoring the signal of the manifold absolute pressure (MAP) sensor. When the EGR valve is opened, the PCM will expect to see a predetermined increase in MAP. If the expected increase in MAP is not detected, the PCM records the amount of MAP difference that was detected and adjusts a calibrated fail counter towards a calibrated fail threshold level. When the fail counter exceeds the fail threshold level, the PCM will set a diagnostic trouble code (DTC).

Normally, the PCM will only allow one EGR Flow Test Count during an ignition cycle. To aid in verifying a repair, the PCM allows eighteen EGR Flow Test Counts during the first ignition cycle following a code clear or a battery disconnect. Between nine and eighteen EGR Flow Test Counts should be sufficient for the PCM to determine adequate EGR flow and pass the EGR flow test. If the PCM detects an EGR flow error, a DTC will set.

The PCM monitors the position of the EGR valve pintle via the EGR position sensor. If the PCM detects a calibrated variance between the Desired EGR Position parameter and the EGR Position Sensor parameter, actual position, for a calibrated amount of time a DTC will set.

The PCM also monitors the EGR solenoid high control circuit and the EGR solenoid low control circuit for electrical faults. If an EGR control circuit fault is detected for a calibrated amount of time a DTC will set.

Air Intake System Description

The primary function of the Air Intake System is to provide filtered air to the engine. The system uses a cleaner element mounted in a housing. The cleaner housing is remotely mounted and uses intake ducts to route the incoming air into the throttle body. The secondary function of the Air Intake System is to muffle air induction noise. This is achieved through the use of resonators attached to the air intake ducts. The resonators are tuned to the specific powertrain. The mass air flow (MAF)/intake air temperature (IAT) sensor is used to measure the temperature and the volume of the air entering the engine.

Special Tools

Special Tools Illustration Tool Number/Description TECH 2 GE 41415-50 Interrupted Thread Fuel Tank Cap Adaptor J 23738-A Mityvac J 26792 Spark Tester J 34730-1A Fuel Pressure Gage J 35616-B GM-Approved Terminal Test Kit J 36850 Transjel Lubricant J 37088-A Fuel Line Disconnect Tool Set J 38522 Variable Signal Generator J 39021 Fuel Injector Coil/Balance Tester J 39021-210 Injector Selector Switch Box J 39021-410 Fuel Injector Harness Adapter J 39194-B Heated Oxygen Sensor Wrench J 39765 Fuel Sender Lock Nut Wrench J 41413-200 Evaporative Emissions System Tester (EEST) J 41413-SPT High Intensity White Light J 41413-VLV EVAP Service Port Vent Fitting J 41415-40 Fuel Tank Cap Adaptor J 42598 Vehicle Data Recorder J 42960-2 Fuel Flapper Door Holder J 43244 Relay Puller Pliers J 43937 Fuel Pressure Adapter Line J 44175 Fuel Composition Tester J 44603 Injector Test Lamp J 45004 Fuel Tank Drain Hose SA 9127E Gage Bar Set SA 9127E-7 Fuel Pressure Gage Adapter