Engine Control System - 4.8l, 5.3l & 6.0l (Introduction) — Chevrolet Chevy Express G3500 (1996-2012)

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	1-8-7-2-6-5-4-3
Spark Plug Wire Resistance	1000 ohms per ft
Spark Plug Torque	15 N.m	11 lb ft
Spark Plug Gap	1.52 mm	0.060 in
Spark Plug Type	25171803 [AC plug type] 12567759 [NGK plug type]

Ignition System Specifications

Fastener Tightening Specifications

Application	Specifications
Application	Metric	English
Accelerator Control Cable Bracket Bolts	10 N.m	89 lb in
Accelerator Pedal Mounting Bolts	20 N.m	15 lb ft
Camshaft Position (CMP) Sensor Bolt	29 N.m	21 lb ft
Crankshaft Position (CKP) Sensor Bolt	25 N.m	18 lb ft
Engine Coolant Temperature (ECT) Sensor	20 N.m	15 lb ft
EGR (Exhaust Gas Recirculation) Valve Bolts (First Pass)	10 N.m	89 lb in
EGR Valve Bolts (Final Pass)	25 N.m	18 lb ft
EGR Valve Pipe-to-Cylinder Head Bolts	50 N.m	37 lb ft
EGR Valve Pipe-to-Exhaust Manifold Bolts	25 N.m	18 lb ft
EGR Valve Pipe-to-Intake Manifold	12 N.m	106 lb in
Engine Wiring Harness Retaining Nut	5.5 N.m	49 lb in
EVAP Canister Bracket Bolt	25 N.m	18 lb ft
EVAP Canister Mounting Bolt	25 N.m	18 lb ft
EVAP Canister Mounting Nuts	10 N.m	89 lb in
EVAP Canister Purge Valve Shoulder Bolt	10.5 N.m	93 lb in
EVAP Canister Vent Valve Bracket Mount Bolt	12 N.m	106 lb in
Fuel Fill Hose Clamp	2.75 N.m	24 lb in
Fuel Fill Pipe Bracket Bolt	6 N.m	53 lb in
Fuel Fill Pipe Ground Strap Bolt	9 N.m	80 lb in
Fuel Fill Pipe Housing to Fill Pipe Bolts	2.3 N.m	20 lb in
Fuel Fill Vent Hose Clamps	2.75 N.m	24 lb in
Fuel Filler Bracket Bolt	12 N.m	106 lb in
Fuel Filter Fitting	27 N.m	20 lb ft
Fuel Rail Attaching Bolts	10 N.m	89 lb in
Fuel Rail Crossover Pipe Retainer Clip Attaching Screw	3.8 N.m	34 lb in
Fuel Return Pipe Attaching Screw	5 N.m	44 lb in
Fuel Tank Strap Bolts	20.5 N.m	15 lb ft
Heated Oxygen Sensor (HO2S)	42 N.m	31 lb ft
Idle Air Control (IAC) Valve Attaching Screws	3 N.m	27 lb in
Ignition Coil Mounting Bolts	8 N.m	71 lb in
Intake Manifold Sight Shield Fasteners	10 N.m	89 lb in
Knock Sensor (KS)	20 N.m	15 lb ft
MAF/IAT Attaching Bolts	11 N.m	97 lb in
Powertrain Control Module (PCM) Connector End Bolts	8 N.m	71 lb in
Throttle Body Attaching Bolts and Nuts	10 N.m	89 lb in
Throttle Position (TP) Sensor Attaching Screws	2 N.m	18 lb in
Upper Engine Wiring Harness Nut	5.5 N.m	49 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	United States Canada RPO NC1, NF2, and NB6	Unleaded Export RPO NN8	Unleaded Heavy Duty (greater than 8600 GVW) RPO NF2
P0068	A	A	A
P0101	B	B	B
P0102	B	B	B
P0103	B	B	B
P0106	B	B	B
P0107	B	B	B
P0108	B	B	B
P0112	B	B	B
P0113	B	B	B
P0116	B	B	B
P0117	B	B	B
P0118	B	B	B
P0120	A	A	A
P0121	B	B	B
P0122	B	B	B
P0123	B	B	B
P0125	B	B	B
P0128	B	B	B
P0131	B	B	B
P0132	B	B	B
P0133	B	B	B
P0134	B	B	B
P0135	B	B	B
P0136	B	B	B
P0137	B	B	B
P0138	B	B	B
P0140	B	B	B
P0141	B	B	B
P0151	B	B	B
P0152	B	B	B
P0153	B	B	B
P0154	B	B	B
P0155	B	B	B
P0156	B	B	B
P0157	B	B	B
P0158	B	B	B
P0160	B	B	B
P0161	B	B	B
P0171	B	B	B
P0172	B	B	B
P0174	B	B	B
P0175	B	B	B
P0200	B	B	B
P0218	C	C	C
P0220	A	A	A
P0230	B	B	B
P0300	B	B (No MIL)	B (No MIL)
P0315	A	A	A
P0325	B	B	B
P0327	B	B	B
P0332	B	B	B
P0335	B	B	B
P0336	B	B	B
P0341	B	B	B
P0342	B	B	B
P0343	B	B	B
P0351	B	B	B
P0352	B	B	B
P0353	B	B	B
P0354	B	B	B
P0355	B	B	B
P0356	B	B	B
P0357	B	B	B
P0358	B	B	B
P0420	A	A	A
P0430	A	A	A
P0442	A	A	A
P0443	B	B	B
P0446	A	A	A
P0449	B	B	B
P0452	B	B	B
P0453	B	B	B
P0455	A	A	A
P0461	C	C	C
P0462	C	C	C
P0463	C	C	C
P0496	B	B	B
P0502	B	C	C
P0503	B	C	C
P0506	B	B	B
P0507	B	B	B
P0522	C	C	C
P0523	C	C	C
P0562	C	C	C
P0563	C	C	C
P0567	C	C	C
P0568	C	C	C
P0601	A	A	A
P0602	A	A	A
P0604	A	A	A
P0606	A	A	A
P0608	C	C	C
P0609	C	C	C
P0622	C	C	C
P0641	B	B	B
P0650	B (No MIL)	B (No MIL)	B (No MIL)
P0651	B	B	B
P0706	C	C	C
P0711	C	C	C
P0712	C	C	C
P0713	C	C	C
P0716	B	C	C
P0717	B	C	C
P0719	C	C	C
P0724	C	C	C
P0730	C	C	C
P0740	B	B	X
P0741	B	B	C
P0742	B	B	C
P0748	C	C	C
P0751	B	B	C
P0752	B	B	C
P0753	B	B	C
P0756	A	A	C
P0757	A	A	C
P0758	A	A	C
P0785	B	B	B
P0894	C	C	C
P1106	C	C	C
P1107	C	C	C
P1111	C	C	C
P1112	C	C	C
P1114	C	C	C
P1115	C	C	C
P1121	C	C	C
P1122	C	C	C
P1125	A	A	A
P1133	B	B	B
P1134	B	B	B
P1153	B	B	B
P1154	B	B	B
P1258	A	A	A
P1380	C	C	C
P1381	C	C	C
P1516	A	A	A
P1574	C	C	C
P1626	C	C	C
P1631	C	C	C
P1637	C	C	C
P1810	B	B	C
P2101	A	A	A
P2108	A	A	A
P2120	C	C	C
P2121	C	C	C
P2125	C	C	C
P2135	A	A	A
P2610	B	B	B
P2761	C	B	B
U0107	A	A	A
U1026	C	C	C
U1041	C	C	C
U1056	C	C	C
U1064	C	C	C
U1300	C	C	C
U1301	C	C	C

Diagnostic Trouble Code (DTC) Type(s)

Scheme 24

Scheme 24: Emission Hose Routing Diagram

Callout	Component Name
1	Manifold Absolute Pressure (MAP) Sensor
2	EVAP Canister Purge Hose
3	EVAP Service Port
4	Positive Crankcase Ventilation (PCV) Valve
5	Throttle Body
6	EVAP Canister Purge Valve
7	AIR Module, if equipped

Scheme 25

Scheme 25: 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 26

Scheme 26: Fuel Hose/Pipes Routing Diagram (Single Fuel Tank)

Callout	Component Name
1	Fuel Pressure Service Connection
2	Fuel Injector Rail
3	Fuel Rail Feed Pipe
4	Fuel Feed Hose
5	Fuel Injector

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

Scheme 27

Scheme 27: Engine Controls Schematic Icons

Scheme 28

Scheme 28: Engine Controls Schematics

Scheme 29

Scheme 30

Scheme 31

Scheme 32

Scheme 33

Scheme 34

Scheme 35

Scheme 36

Scheme 37

Scheme 38

Scheme 39

Scheme 40

Scheme 41

Scheme 41: Engine Controls Component Views

Callout	Component Name
1	Evaporative Emissions (EVAP) Canister Purge Solenoid
2	Idle Air Control (IAC) Valve (w/o JL4)
3	Throttle Position (TP) Sensor (w/o JL4)
4	Generator
5	Throttle Body

Scheme 42

Callout	Component Name
1	Crankshaft Position (CKP) Sensor Connector
2	A/C High Pressure Switch Connector (C60)
3	A/C Compressor Clutch Connector (C60)
4	Engine Oil Level Switch Connector
5	Starter Motor

Scheme 43

Callout	Component Name
1	Fuel Injector 1 Connector
2	Fuel Injector 3 Connector
3	Fuel Injector 5 Connector
4	S101
5	C103
6	S102
7	Fuel Injector 7 Connector
8	Ignition Coil/Module 7 Connector
9	Ignition Coil/Module 5 Connector
10	C126
11	Ignition Coil/Module 3 Connector
12	Engine Coolant Temperature (ECT) Sensor Connector
13	Ignition Coil/Module 1 Connector

Scheme 44

Callout	Component Name
1	Fuel Injector 8 Connector
2	Fuel Injector 6 Connector
3	Fuel Injector 4 Connector
4	Fuel Injector 2 Connector
5	Ignition Coil/Module 2 Connector
6	Ignition Coil/Module 4 Connector
7	Ignition Coil/Module 6 Connector
8	C127
9	Ignition Coil/Module 8 Connector

Scheme 45

Callout	Component Name
1	Manifold Absolute Pressure (MAP) Sensor Connector
2	S102
3	S101
4	C103

Scheme 46

Callout	Component Name
1	Knock Sensor (KS) 1
2	Knock Sensor (KS) 2

Scheme 47

Callout	Component Name
1	G102
2	Engine Oil Pressure (EOP) Sensor Connector
3	G103
4	Camshaft Position (CMP) Sensor Connector

Scheme 48

Callout	Component Name
1	C109
2	Powertrain Control Module (PCM) C1, C2
3	Fuse Block Underhood - C6
4	Horn Assembly Connector
5	Fuse Block Underhood - C1
6	C100
7	C101
8	Brake Fluid Level Switch Connector (Heavy Duty)

Scheme 49

Callout	Component Name
1	Throttle Actuator Control (TAC) Module

Scheme 50

Callout	Component Name
1	Blower Motor Resistor Assembly
2	Blower Motor
3	Intake Air Temperature (IAT) / Mass Air Flow (MAF) Sensor
4	A/C Low Pressure Switch (C60)

Scheme 51

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

Scheme 52

Callout	Component Name
1	Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1
2	Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1
3	Heated Oxygen Sensor (HO2S) Bank 2 Sensor 2
4	Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2
5	Park/Neutral Position (PNP) Switch

Scheme 53

Callout	Component Name
1	C128
2	Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 Connector
3	Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2 Connector
4	Heated Oxygen Sensor (HO2S) Bank 2 Sensor 2 Connector
5	Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1 Connector

Scheme 54

Callout	Component Name
1	Evaporative Emission (EVAP) Canister Vent Solenoid
2	Electronic Brake Control Module (EBCM)

Scheme 55

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

Scheme 56

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

Powertrain Control Module (PCM) Connector End Views

Powertrain Control Module (PCM) - C1 Connector End Connector Part Information 12191489 80-Way F Micro-Pack 100W Sealed (BU) Pin Wire Color Circuit No. Function 1 BK/WH 1551 Ground 2 L-GN 1867 12-Volt Reference 3 PK/BK 1746 Fuel Injector 3 Control 4 L-GN/BK 1745 Fuel Injector 2 Control 5-6 - - Not Used 7 GY 2705 5-Volt Reference A 8 GY 2701 5-Volt Reference A (w/o JL4) 9-10 - - Not Used 11 L-BU 1876 Knock Sensor 2 Signal 12 YE 573 CKP Sensor Signal 13 OG/BK 463 Requested Torque Signal (JL4) 14 OG/BK 1061 UART Serial Data (JL4) 15 D-BU/WH 774 UART Serial Data (JL4) 16 - - Not Used 17 D-BU 1225 Transmission Fluid Pressure Switch Signal B 18 OG 1226 Transmission Fluid Pressure Switch Signal C (Late Production) RD 1226 Transmission Fluid Pressure Switch Signal C (Early Production) 19 PK 439 Ignition 1 Voltage 20 RD/WH 440 Battery Positive Voltage (Late Production) OG 440 Battery Positive Voltage (Early Production) 21 PU 574 Low Reference 22 - - Not Used 23 TN 2759 Low Reference (Late Production) BK 2759 Low Reference (Early Production) 24 BK/WH 1551 Ground 25 TN 1671 HO2S Low Signal - Bank 2 Sensor 2 26 TN 1667 HO2S Low Signal - Bank 2 Sensor 1 27 BK/WH 1551 Ground 28 TN/WH 1669 HO2S Low Signal - Bank 1 Sensor 2 29 TN 1664 HO2S Low Signal - Bank 1 Sensor 1 30-31 - - Not Used 32 TN/WH 771 Transmission Range Switch Signal A (Late Production) BK/WH 771 Transmission Range Switch Signal A (Early Production) 33 PU 420 TCC Brake Switch/Cruise Control Release Signal 34 WH 776 Transmission Range Switch Signal P 35 - - Not Used 36 TN 1744 Fuel Injector 1 Control (Late Production) BK 1744 Fuel Injector 1 Control (Early Production) 37 YE/BK 846 Fuel Injector 6 Control 38 - - Not Used 39 YE/BK 625 Starter Enable Relay Control 40 BK/WH 1551 Ground 41-42 - - Not Used 43 OG/BK 877 Fuel Injector 7 Control (Late Production) RD/BK 877 Fuel Injector 7 Control (Early Production) 44 L-BU/BK 844 Fuel Injector 4 Control 45 - - Not Used 46 GY 2709 5-Volt Reference B 47 - - Not Used 48 GY 597 5-Volt Reference A 49-50 - - Not Used 51 D-BU 496 Knock Sensor 1 Signal 52 - - Not Used 53 TN 2762 Low Reference (Late Production) BK 2762 Low Reference (Early Production) 54 OG/BK 469 Low Reference 55-56 - - Not Used 57 RD/WH 440 Battery Positive Voltage (Late Production) OG 440 Battery Positive Voltage (Early Production) 58 D-GN 1049 Class 2 Serial Data 59 YE 710 Class 2 Serial Data (Early Production) 60 TN 2752 Low Reference (Late Production w/o JL4) BK 2752 Low Reference (Early Production w/o JL4) 61 PK/BK 632 Low Reference 62 - - Not Used 63 BK 2755 Low Reference 64 BK/WH 1551 Ground 65 PU 1670 HO2S High Signal - Bank 2 Sensor 2 66 PU 1666 HO2S High Signal - Bank 2 Sensor 1 67 BK/WH 1551 Ground 68 PU/WH 1668 HO2S High Signal - Bank 1 Sensor 2 69 PU/WH 1665 HO2S High Signal - Bank 1 Sensor 1 70 BN 1174 Oil Level Switch Signal 71 - - Not Used 72 YE 772 Transmission Range Switch Signal B 73 BN/WH 633 CMP Sensor Signal 74 YE 410 ECT Sensor Signal 75 PK 1020 Ignition 0 Voltage 76 TN/WH 845 Fuel Injector 5 Control (Late Production) BK/WH 845 Fuel Injector 5 Control (Early Production) 77 D-BU/WH 878 Fuel Injector 8 Control 78 - - Not Used 79 WH 687 3-2 Shift Solenoid Valve Control (5.3L) 80 TN 2761 Low Reference (Late Production) BK 2761 Low Reference (Early Production)

Powertrain Control Module (PCM) - C2 Connector End Connector Part Information 12191488 80-Way F Micro-Pack 100W Sealed (GN) Pin Wire Color Circuit No. Function 1 BK/WH 1551 Ground 2 BN 418 TCC PWM Solenoid Valve Control 3-4 - - Not Used 5 TN/BK 464 Delivered Torque Signal (JL4) 6 OG/BK 1228 PC Solenoid Valve High Control (Late Production) RD/BK 1228 PC Solenoid Valve High Control (Early Production) 7 - - Not Used 8 L-BU/WH 1229 PC Solenoid Valve Low Control 9 D-GN/WH 465 Fuel Pump Relay Control - Primary 10-12 - - Not Used 13 L-BU/BK 396 Cruise Control Engaged Signal (w/o JL4) 14 - - Not Used 15 OG 225 Generator Turn On Signal (Late Production) RD 225 Generator Turn On Signal (Early Production) 16 - - Not Used 17 D-GN/WH 2523 A/C Request Signal (C60) 18-19 - - Not Used 20 PU 401 Signal Low - Front 21 YE 400 Signal High - Front 22 OG/BK 1230 AT ISS High Signal (Late Production 4L80-E) RD/BK 1230 AT ISS High Signal (Early Production 4L80-E) 23 D-BU/WH 1231 AT ISS Low Signal (4L80-E) 24 D-BU 411 TP Sensor Signal (w/o JL4) 25 TN 472 IAT Sensor Signal 26 PU 2121 IC 1 Control 27 OG 2127 IC 7 Control (Late Production) RD 2127 IC 7 Control (Early Production) 28 L-BU/WH 2126 IC 6 Control 29 D-GN/WH 2124 IC 4 Control 30 - - Not Used 31 YE 492 MAF Sensor Signal 32 L-GN 432 MAP Sensor Signal 33 - - Not Used 34 D-GN/WH 428 EVAP Canister Purge Solenoid Valve Control 35-36 - - Not Used 37 D-GN 83 Cruise Control Inhibit Signal 38 - - Not Used 39 OG 631 12-Volt Reference (Late Production) RD 631 12-Volt Reference (Early Production) 40 BK/WH 1551 Ground 41 - - Not Used 42 TN/BK 422 TCC Solenoid Valve Control (5.3L) 43 D-GN/WH 459 A/C Compressor Clutch Relay Control (C60) 44 - - Not Used 45 WH 1310 EVAP Canister Vent Solenoid Valve Control 46 BN/WH 419 MIL Control 47 YE/BK 1223 2-3 Shift Solenoid Valve Control 48 L-GN 1222 1-2 Shift Solenoid Valve Control 49 YE/BK 1827 Vehicle Speed Signal 50 D-GN/WH 817 Vehicle Speed Signal (w/o JL4) 51 YE/BK 1227 TFT Sensor Signal 52 PU 5035 HO2S Heater Low Control - Bank 1 Sensor 2 53 YE 5036 HO2S Heater Low Control - Bank 2 Sensor 2 54 PU 1589 Fuel Level Sensor Signal 55 D-GN 603 A/C Low Pressure Switch Signal (C60) 56 - - Not Used 57 TN 470 Low Reference (Late Production) BK 470 Low Reference (Early Production) 58 TN/WH 331 Oil Pressure Sensor Signal 59 PU 806 Crank Voltage 60 BN 2129 Low Reference 61 BN/WH 2130 Low Reference 62 GY 773 Transmission Range Switch Signal C 63 PK 1224 Transmission Fluid Pressure Switch Signal A 64 D-GN 890 Fuel Tank Pressure Sensor Signal 65 - - Not Used 66 PU/WH 2128 IC 8 Control 67 OG/WH 2122 IC 2 Control (Late Production) RD/WH 2122 IC 2 Control (Early Production) 68 D-GN 2125 IC 5 Control 69 L-BU 2123 IC 3 Control 70-71 - - Not Used 72 L-BU 5038 HO2S Heater Low Control - Bank 1 Sensor 1 73 - - Not Used 74 PU/WH 5037 HO2S Heater Low Control - Bank 2 Sensor 1 75 GY 23 Generator Field Duty Cycle Signal 76 L-GN/WH 1749 IAC Coil B High Control (w/o JL4) 77 L-GN/BK 444 IAC Coil B Low Control (w/o JL4) 78 L-BU/BK 1748 IAC Coil A Low Control (w/o JL4) 79 L-BU/WH 1747 IAC Coil A High Control (w/o JL4) 80 - - Not Used

Engine Controls Connector End Views

Accelerator Pedal Position (APP) Sensor Connector End (JL4) Connector Part Information 12177081 10-Way F 150 Series Sealed (BK) Pin Wire Color Circuit No. Function A BN 1271 Low Reference B PU 1272 Low Reference C L-BU 1162 APP Sensor 2 Signal D TN 1274 5-Volt Reference E - - Not Used F D-BU 1161 APP Sensor 1 Signal G WH/BK 1164 5-Volt Reference H-K - - Not Used

Camshaft Position (CMP) Sensor Connector End Connector Part Information 12059595 3-Way F Metri-Pack 150 Series Sealed (BK) Pin Wire Color Circuit No. Function A BN/WH 633 CMP Sensor Signal B PK/BK 632 Low Reference C OG 631 12-Volt Reference (Late Production) RD 631 12-Volt Reference (Early Production)

Crankshaft Position (CKP) Sensor Connector End Connector Part Information 15324165 3-Way F Metri-Pack 150 Series (NA) Pin Wire Color Circuit No. Function A YE 573 CKP Sensor Signal B PU 574 Low Reference C L-GN 1867 12-Volt Reference

Engine Coolant Temperature (ECT) Sensor Connector End Connector Part Information 15359366 2-Way F GT 150 Sealed (BK) Pin Wire Color Circuit No. Function A YE 410 ECT Sensor Signal B TN 2761 Low Reference (Late Production) BK 2761 Low Reference (Early Production)

Evaporative Emission (EVAP) Canister Purge Solenoid Valve Connector End Connector Part Information 12124037 2-Way F Metri-Pack 150 Series Sealed (BK) Pin Wire Color Circuit No. Function A PK 139 Ignition 1 Voltage B D-GN/WH 428 EVAP Canister Purge Solenoid Valve Control

Evaporative Emission (EVAP) Canister Vent Solenoid Valve Connector End Connector Part Information 12052643 2-Way F Metri-Pack 150 Series Sealed (RD) Pin Wire Color Circuit No. Function A RD/WH 140 Battery Positive Voltage (Late Production) OG 140 Battery Positive Voltage (Early Production) B WH 1310 EVAP Canister Vent Solenoid Valve Control

Fuel Injector 1 Connector End Connector Part Information 15411634 2-Way F Micro-Pack 064 Series Sealed (GY) Pin Wire Color Circuit No. Function A PK 139 Ignition 1 Voltage B TN 1744 Fuel Injector 1 Control (Late Production) BK 1744 Fuel Injector 1 Control (Early Production)

Fuel Injector 2 Connector End Connector Part Information 15411634 2-Way F Micro-Pack 064 Series Sealed (GY) Pin Wire Color Circuit No. Function A PK 239 Ignition 1 Voltage B L-GN/BK 1745 Fuel Injector 2 Control

Fuel Injector 3 Connector End Connector Part Information 15411634 2-Way F Micro-Pack 064 Series Sealed (GY) Pin Wire Color Circuit No. Function A PK 139 Ignition 1 Voltage B PK/BK 1746 Fuel Injector 3 Control

Fuel Injector 4 Connector End Connector Part Information 15411634 2-Way F Micro-Pack 064 Series Sealed (GY) Pin Wire Color Circuit No. Function A PK 239 Ignition 1 Voltage B L-BU/BK 844 Fuel Injector 4 Control

Fuel Injector 5 Connector End Connector Part Information 15411634 2-Way F Micro-Pack 064 Series Sealed (GY) Pin Wire Color Circuit No. Function A PK 139 Ignition 1 Voltage B TN/WH 845 Fuel Injector 5 Control (Late Production) BK/WH 845 Fuel Injector 5 Control (Early Production)

Fuel Injector 6 Connector End Connector Part Information 15411634 2-Way F Micro-Pack 064 Series Sealed (GY) Pin Wire Color Circuit No. Function A PK 239 Ignition 1 Voltage B YE/BK 846 Fuel Injector 6 Control

Fuel Injector 7 Connector End Connector Part Information 15411634 2-Way F Micro-Pack 064 Series Sealed (GY) Pin Wire Color Circuit No. Function A PK 139 Ignition 1 Voltage B OG/BK 877 Fuel Injector 7 Control (Late Production) RD/BK 877 Fuel Injector 7 Control (Early Production)

Fuel Injector 8 Connector End Connector Part Information 15411634 2-Way F Micro-Pack 064 Series Sealed (GY) Pin Wire Color Circuit No. Function A PK 239 Ignition 1 Voltage B D-BU/WH 878 Fuel Injector 8 Control

Fuel Pump & Sender Assembly Connector End Connector Part Information 15326631 4-Way F GT 280 Sealed 5.8 (BK) Pin Wire Color Circuit No. Function A BK 150 Ground B PU 1589 Fuel Level Sensor Signal C TN 2759 Low Reference (Late Production) BK 2759 Low Reference (Early Production) D GY 120 Fuel Pump Supply Voltage

Fuel Tank Pressure (FTP) Sensor Connector End Connector Part Information 12059595 3-Way F Metri-Pack 150 Series Sealed (BK) Pin Wire Color Circuit No. Function A TN 2759 Low Reference (Late Production) BK 2759 Low Reference (Early Production) B D-GN 890 Fuel Tank Pressure Sensor Signal C GY 2709 5-Volt Reference B

Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1 Connector End Connector Part Information 15326423 4-Way M Metri-Pack 150 Sealed (GY) Pin Wire Color Circuit No. Function A TN 1664 HO2S Low Signal - Bank 1 Sensor 1 B PU/WH 1665 HO2S High Signal - Bank 1 Sensor 1 C L-BU 5038 HO2S Heater Low Control - Bank 1 Sensor 1 D PK 539 Ignition 1 Voltage

Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2 Connector End Connector Part Information 15326423 (5.3L) 12160825 (4.8L/6.0L) 4-Way M Metri-Pack 150 Sealed (GY) 5.3L or (BK) 4.8L/6.0L Pin Wire Color Circuit No. Function A TN/WH 1669 HO2S Low Signal - Bank 1 Sensor 2 B PU/WH 1668 HO2S High Signal - Bank 1 Sensor 2 C PU 5035 HO2S Heater Low Control - Bank 1 Sensor 2 D PK 1539 Ignition 1 Voltage

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 Connector End Connector Part Information 12160825 4-Way M Metri-Pack 150 Sealed (BK) Pin Wire Color Circuit No. Function A TN 1667 HO2S Low Signal - Bank 2 Sensor 1 B PU 1666 HO2S High Signal - Bank 2 Sensor 1 C PU/WH 5037 HO2S Heater Low Control - Bank 2 Sensor 1 D PK 539 Ignition 1 Voltage

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 2 Connector End Connector Part Information 12160825 (5.3L) 15326423 (4.8L/6.0L) 4-Way M Metri-Pack 150 Sealed (BK) 5.3L or (GY) 4.8L/6.0L Pin Wire Color Circuit No. Function A TN 1671 HO2S Low Signal - Bank 2 Sensor 2 B PU 1670 HO2S High Signal - Bank 2 Sensor 2 C YE 5036 HO2S Heater Low Control - Bank 2 Sensor 2 D PK 1539 Ignition 1 Voltage

Idle Air Control (IAC) Valve Connector End (w/o JL4) Connector Part Information 15354716 4-Way F GT 150 Sealed 3.2 X 4.0 (BK) Pin Wire Color Circuit No. Function A L-GN/BK 444 IAC Coil B Low Control B L-GN/WH 1749 IAC Coil B High Control C L-BU/BK 1748 IAC Coil A Low Control D L-BU/WH 1747 IAC Coil A High Control

Ignition Coil/Module 1 Connector End Connector Part Information 12162724 4-Way F Metri-pack 150 Series (BK) Pin Wire Color Circuit No. Function A BK 151 Ground B BN 2129 Low Reference C PU 2121 IC 1 Control D PK 39 Ignition 1 Voltage

Ignition Coil/Module 2 Connector End Connector Part Information 12162724 4-Way F Metri-pack 150 Series (BK) Pin Wire Color Circuit No. Function A BK 151 Ground B BN 2129 Low Reference C RD 2122 IC 2 Control D PK 39 Ignition 1 Voltage

Ignition Coil/Module 3 Connector End Connector Part Information 12162724 4-Way F Metri-pack 150 Series (BK) Pin Wire Color Circuit No. Function A BK 151 Ground B BN 2129 Low Reference C L-BU 2123 IC 3 Control D PK 39 Ignition 1 Voltage

Ignition Coil/Module 4 Connector End Connector Part Information 12162724 4-Way F Metri-pack 150 Series (BK) Pin Wire Color Circuit No. Function A BK 151 Ground B BN 2129 Low Reference C D-GN 2124 IC 4 Control D PK 39 Ignition 1 Voltage

Ignition Coil/Module 5 Connector End Connector Part Information 12162724 4-Way F Metri-pack 150 Series (BK) Pin Wire Color Circuit No. Function A BK 151 Ground B BN 2129 Low Reference C D-GN 2125 IC 5 Control D PK 39 Ignition 1 Voltage

Ignition Coil/Module 6 Connector End Connector Part Information 12162724 4-Way F Metri-pack 150 Series (BK) Pin Wire Color Circuit No. Function A BK 151 Ground B BN 2129 Low Reference C L-BU 2126 IC 6 Control D PK 39 Ignition 1 Voltage

Ignition Coil/Module 7 Connector End Connector Part Information 12162724 4-Way F Metri-pack 150 Series (BK) Pin Wire Color Circuit No. Function A BK 151 Ground B BN 2129 Low Reference C RD 2127 IC 7 Control D PK 39 Ignition 1 Voltage

Ignition Coil/Module 8 Connector End Connector Part Information 12162724 4-Way F Metri-pack 150 Series (BK) Pin Wire Color Circuit No. Function A BK 151 Ground B BN 2129 Low Reference C PU 2128 IC 8 Control D PK 39 Ignition 1 Voltage

Intake Air Temperature (IAT)/Mass Air Flow (MAF) Sensor Connector End Connector Part Information 15326822 5-Way F GT 150 Sealed 4.0 (BK) Pin Wire Color Circuit No. Function A YE 492 MAF Sensor Signal B PK 139 Ignition 1 Voltage C BK/WH 1551 Ground D TN 472 IAT Sensor Signal E TN 470 Low Reference (Late Production) BK 470 Low Reference (Early Production)

Manifold Absolute Pressure (MAP) Sensor Connector End Connector Part Information 12129946 3-Way F Metri-Pack 150 Series Sealed (GY) Pin Wire Color Circuit No. Function A OG/BK 469 Low Reference B L-GN 432 MAP Sensor Signal C GY 597 5-Volt Reference A

Throttle Actuator Control (TAC) Module - C1 Connector End (JL4) Connector Part Information 12191065 16-Way F Micro-Pack 100 Series (GY) Pin Wire Color Circuit No. Function 1 D-GN 485 TP Sensor 1 Signal 2 GY 416 5-Volt Reference 3 BK 452 Low Reference 4 D-BU 84 Cruise Control Set/Coast Switch Signal 5 GY/BK 87 Cruise Control Resume/Accel Switch Signal 6 L-BU 1320 CHMSL Supply Voltage/Stop Lamp Supply Voltage 7 PK 1339 Ignition 1 Voltage 8 BN 582 TAC Motor Control - 2 9 L-BU/BK 1688 5-Volt Reference 10 BK/WH 1704 Low Reference 11 PU 486 TP Sensor 2 Signal 12 OG/BK 1061 UART Serial Data 13 D-BU/WH 774 UART Serial Data 14 GY 397 Cruise Control On Switch Signal 15 BK 1250 Ground 16 YE 581 TAC Motor Control - 1

Throttle Actuator (TAC) Module - C2 Connector End (JL4) Connector Part Information 12177081 10-Way F 150 Series Sealed (BK) Pin Wire Color Circuit No. Function A - - Not Used B PU 1272 Low Reference C L-BU 1162 APP Sensor 2 Signal D TN 1274 5-Volt Reference E - - Not Used F D-BU 1161 APP Sensor 1 Signal G WH/BK 1164 5-Volt Reference H - - Not Used J BN 1271 Low Reference K - - Not Used

Throttle Body Connector End (JL4) Connector Part Information 15326836 8-Way F GT 150 Sealed (BK) Pin Wire Color Circuit No. Function A YE 581 TAC Motor Control - 1 B BK/WH 1704 Low Reference C BN 582 TAC Motor Control - 2 D BK 452 Low Reference E L-BU/BK 1688 5-Volt Reference F PU 486 TP Sensor 2 Signal G D-GN 485 TP Sensor 1 Signal H GY 416 5-Volt Reference

Throttle Position (TP) Sensor Connector End (w/o JL4) Connector Part Information 15344137 3-Way F GT 150 Sealed 5.2 (BK) Pin Wire Color Circuit No. Function 1 GY 2701 5-Volt Reference A 2 TN 2752 Low Reference (Late Production) BK 2752 Low Reference (Early Production) 3 D-BU 411 TP Sensor Signal

Powertrain Control Module (PCM) Replacement

Note. Turn the ignition OFF when installing or removing the PCM connectors and disconnecting or reconnecting the power to the PCM (battery cable, PCM pigtail, PCM fuse, jumper cables, etc.) in order to prevent internal PCM damage.

Service of the powertrain control module (PCM) should normally consist of either replacement of the PCM or electrically erasable programmable read only memory (EEPROM) programming. If the diagnostic procedures call for the PCM to be replaced, the PCM should be inspected first to see if the correct part is being used. If the correct part is being used, remove the faulty PCM and install the new service PCM.

IMPORTANT

Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM module connector gaskets when diagnosing or replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the PCM.

IMPORTANT

The replacement PCM must be programmed.

Removal Procedure

Using a scan tool, retrieve the percentage of remaining engine oil. Record the remaining engine oil life.
Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Disconnect the PCM harness connectors.
Release the spring latch from the PCM.
Lift the PCM from the PCM mounting tray.
Remove the PCM from the engine compartment.

Installation Procedure

Install the PCM to the PCM mounting tray.
Secure the spring latch to the PCM.
Connect the PCM connectors to the PCM. Tighten: Tighten the PCM connector end fasteners to 8 N.m (71 lb in).
Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
If a new PCM is being installed, program the PCM. Refer to «Service Programming System (SPS)»(/chevrolet/chevy-express-g3500/1996-2012/remont/communication-devices/#service-programming-system) in Programming.

Disconnect the instrument panel (I/P) harness electrical connector (2).
Release the red connector position assurance (CPA) retainer.
Disconnect the engine wiring harness electrical connector (1).
Remove the throttle actuator control (TAC) module nuts.
Remove the TAC module.

Install the TAC module.
Install the TAC module nuts. Tighten: Tighten the nuts to 9 N.m (80 lb in).
Connect the engine wiring harness electrical connector (1).
Install the red CPA retainer.
Connect the I/P harness electrical connector (2).

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»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-diagnostic-information-procedures__diagnostic-trouble-code-dtc-list) for the applicable DTC that set.
Select the crankshaft position (CKP) variation learn procedure with a scan tool.
The scan tool instructs you to perform the following: Accelerate to wide open throttle (WOT). Release throttle when fuel cut-off occurs. Observe fuel cut-off for applicable engine. 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 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: CKP sensors activity-If there is a CKP sensor condition, refer to the applicable DTC that set. Camshaft position (CMP) sensor activity-If there is a CMP sensor condition, refer to the applicable DTC that set. Engine coolant temperature (ECT)-If the ECT is not warm enough, idle the engine until the engine coolant temperature reaches the correct temperature.
Enable the CKP system variation learn procedure with a scan tool.
Accelerate to WOT.
Release when the fuel cut-off occurs.
The scan tool displays Test In Progress.
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/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-diagnosis-48l-53l-60l-dtc-p0136-to-dtc-p0452) . If any other DTCs set, refer to «Diagnostic Trouble Code (DTC) List»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-diagnostic-information-procedures__diagnostic-trouble-code-dtc-list) for the applicable DTC that set.
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 DTC P0315 is set: A CKP sensor replacement An engine replacement A PCM replacement A harmonic balancer replacement A crankshaft replacement Any engine repairs which disturb the CKP sensor relationship

Turn OFF the ignition.
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-g3500/1996-2012/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Drain the cooling system below the level of the ECT sensor. Refer to «Draining and Filling Cooling System»(/chevrolet/chevy-express-g3500/1996-2012/remont/cooling-system-mechanical/#engine-cooling-system) in Engine Cooling.
Lower the vehicle.
Disconnect the electrical connector from the engine coolant temperature (ECT) sensor.
Remove the ECT sensor.

Coat the ECT sensor threads with sealer GM P/N 12346004 (Canadian P/N 10953480) or the equivalent.
Install the ECT sensor. Tighten: Tighten the ECT sensor to 20 N.m (15 lb ft).
Connect the ECT sensor electrical connector.
Refill the engine coolant. Refer to «Draining and Filling Cooling System»(/chevrolet/chevy-express-g3500/1996-2012/remont/cooling-system-mechanical/#engine-cooling-system) in Engine Cooling.

IMPORTANT

Take care when handling the mass air flow/ intake air temperature (MAF/IAT) sensor. Do not dent, puncture, or otherwise damage the honeycell located at the air inlet end of the MAF/IAT. Do not touch the sensing elements or allow anything including cleaning solvents and lubricants to come in contact with them. Use a small amount of a non-silicone based lubricant, on the air duct only, to aid in installation. Do not drop or roughly handle the MAF/IAT sensor.

Disconnect the MAF/IAT sensor electrical connector.
Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Loosen the clamp securing the MAF/IAT sensor to the air cleaner duct.
Remove the MAF/IAT sensor bolts from the air cleaner assembly.
Remove the MAF/IAT from the air cleaner.

IMPORTANT

The embossed arrow on the MAF/IAT sensor indicates the proper air flow direction. The arrow must point toward the engine.

Locate the air flow direction arrow (2) on the MAF/IAT sensor.
Install the MAF/IAT sensor onto the air cleaner housing.
Install the MAF/IAT sensor retaining bolts. Tighten: Tighten the bolts to 11 N.m (97 lb in).
Tighten the clamp securing the MAF/IAT sensor to the air cleaner duct.
Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Connect the MAF/IAT electrical connector.

Remove the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.
Disconnect the manifold absolute pressure (MAP) sensor electrical connector.
Remove the MAP sensor (1) from the intake manifold.

IMPORTANT

Lightly coat the MAP sensor seal with clean engine oil before installing the sensor.

Install the MAP sensor to the upper intake manifold.
Connect the MAP sensor electrical connector.
Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.

Tools Required

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

Raise the vehicle.
Disconnect the connector (1) for the HO2S.
Remove the HO2S (2) using a J 39194-B . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .

Coat the threads of the oxygen sensor with anti-seize compound GM P/N 5613695, if necessary.
Install the HO2S (2) using a J 39194-B . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) . Tighten: Tighten the sensor to 42 N.m (31 lb ft).
Connect the HO2S harness connector (1).
Lower the vehicle.

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

Raise the vehicle.
Disconnect the connector (1) for the HO2S.
Remove the HO2S (2) using a J 39194-B . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .

Coat the threads of the oxygen sensor with anti-seize compound GM P/N 5613695, if necessary.
Install the HO2S (2) using a J 39194-B . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) . Tighten: Tighten the sensor to 42 N.m (31 lb ft).
Connect the HO2S harness connector (1).
Lower the vehicle.

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

Raise the vehicle.
Disconnect the connector (1) for the HO2S.
Remove the HO2S (2) using a J 39194-B . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .

Coat the threads of the oxygen sensor with anti-seize compound GM P/N 5613695, if necessary.
Install the HO2S (2) using a J 39194-B . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) . Tighten: Tighten the sensor to 42 N.m (31 lb ft).
Connect the HO2S harness connector (1).
Lower the vehicle.

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

Raise the vehicle.
Disconnect the connector (1) for the HO2S.
Remove the HO2S (2) using a J 39194-B . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .

Coat the threads of the oxygen sensor with anti-seize compound GM P/N 5613695, if necessary.
Install the HO2S (2) using a J 39194-B . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) . Tighten: Tighten the sensor to 42 N.m (31 lb ft).
Connect the HO2S harness connector (1).
Lower the vehicle.

CAUTION

Refer to the Battery Disconnect Caution in Cautions and Notices.

Note. The TP sensor is an electrical component. Do not soak the TP sensor in any liquid cleaner or solvent as damage may result.

Disconnect the negative battery cable.
Remove the generator. Refer to «Generator Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (4.3L)»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Disconnect the throttle position (TP) sensor electrical connector.
Remove the TP sensor attaching screws (5).
Remove the TP sensor (6).
Remove the TP sensor O-ring seal (7).

Install the TP sensor O-ring seal (7) on the TP sensor (6).
Install the TP sensor on the throttle body with the throttle valve in the closed position. Make sure the TP sensor lever lines up with the TP sensor drive lever on the throttle shaft. NOTE: Refer to «Fastener Notice»(/chevrolet/chevy-express-g3500/1996-2012/remont/oem-general-information/#cautions-and-notices__fastener-notice) in Cautions and Notices.
Install the TP sensor attaching screws (5). Tighten: Tighten the screws to 2 N.m (18 lb in).
Connect the TP sensor electrical connector.
Install the generator. Refer to «Generator Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (4.3L)»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Connect the negative battery cable.

Note. Handle the electronic throttle control components carefully. Use cleanliness in order to prevent damage. Do not drop the electronic throttle control components. Do not roughly handle the electronic throttle control components. Do not immerse the electronic throttle control components in cleaning solvents of any type.

Remove the connector position assurance (CPA) retainer.
Disconnect the accelerator pedal position (APP) sensor electrical connector.
Reposition the carpet to access the lower nut.
Remove the accelerator pedal nuts.
Remove the accelerator pedal assembly.

Install the accelerator pedal assembly.
Install the accelerator pedal nuts. Tighten: Tighten the nuts to 20 N.m (15 lb ft).
Connect the APP sensor electrical connector.
Reposition the carpet.
Connect a scan tool in order to test for proper throttle-opening and throttle-closing range.
Operate the accelerator pedal and monitor the throttle angles. The accelerator pedal should operate freely, without binding, between a closed throttle, and a wide open throttle (WOT).
Verify that the vehicle meets the following conditions: The vehicle is not in a reduced engine power mode. The ignition is ON. The engine is OFF.
Inspect the carpet fit under the accelerator pedal.

Remove the generator. Refer to «Generator Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (4.3L)»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Disconnect the idle air control (IAC) valve electrical connector.
Remove the IAC valve attaching screws (4).
Remove the IAC valve (3).
Remove the IAC valve O-ring seal (2).
Clean the IAC valve O-ring sealing surface, the pintle valve seat, and the air passage. Clean the IAC valve using GM cleaner P/N 1052626 or GM X-66A. Use a shop towel or parts brush to remove heavy deposits. If the air passage has heavy deposits, remove the throttle body for complete cleaning. Shiny spots on the pintle or seat are normal and do not indicate misalignment or a bent pintle shaft.
Inspect the IAC valve O-ring for cuts, cracks, or distortion. Replace the O-ring if the O-ring is damaged.

Measure the distance between the tip of the IAC valve pintle and the mounting surface (1). If the distance is more than 28 mm (1.1 in) use finger pressure to slowly retract the pintle. The force required to retract the pintle of a new valve does not cause damage to the valve.
Lubricate the IAC valve O-ring (2) with clean engine oil.
Install the IAC valve O-ring (2) on the IAC valve (3).
Install the IAC valve (3).
Apply LOCTITE 262 to the IAC valve attaching screw threads if necessary. NOTE: Refer to «Fastener Notice»(/chevrolet/chevy-express-g3500/1996-2012/remont/oem-general-information/#cautions-and-notices__fastener-notice) in Cautions and Notices.
Install the IAC valve attaching screws (4). Tighten: Tighten the screws to 3 N.m (27 lb in).
Connect the IAC valve electrical connector.
Install the generator. Refer to «Generator Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (4.3L)»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.

Remove the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.
Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Disconnect the accelerator cable from the throttle body lever.
Remove the accelerator cable from the cable bracket.
Unclip the accelerator cable from the engine sight shield mounting bracket and the generator bracket.
Remove the left instrument panel (IP) insulator.
Disconnect the accelerator cable retainer (3) from the accelerator pedal lever (2).
Squeeze the accelerator cable cover tangs (1) and push the cable through the dash panel.
Remove the accelerator cable.

Install the accelerator cable through the dash panel. Snap the accelerator cable cover tangs (1) through the dash panel.
Install the accelerator cable through the slot in the accelerator pedal lever (2).
Seat the retainer (3) in the accelerator pedal lever (2).
Connect the accelerator cable to the throttle body lever.
Slide the accelerator cable into the slot on the accelerator cable bracket. Snap the locking tab into position on the engine sight shield mounting bracket. Clip the accelerator cable onto the generator bracket.
Clip the accelerator cable into the engine sight shield mounting bracket.
Test for complete throttle opening and closing range by operating the accelerator pedal. Also inspect the carpet fit under the accelerator pedal. The throttle should operate freely without binding between full closed throttle and wide open throttle (WOT).
Install the left instrument panel insulator.
Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.

Remove the left instrument panel (IP) insulator.
Disconnect the accelerator cable retainer (3) from the accelerator pedal lever (2).
Remove the accelerator pedal retaining bolt.
Remove the accelerator pedal from the vehicle.

Install the accelerator pedal.
Install the accelerator pedal retaining bolt. Tighten: Tighten the bolt to 20 N.m (15 lb ft).
Install the accelerator cable through the slot in the accelerator pedal lever (2).
Seat the retainer (3) in the accelerator pedal lever (2).
Test for complete throttle opening and closing range by operating the accelerator pedal. Also inspect the carpet fit under the accelerator pedal. The throttle should operate freely and without binding between full closed throttle and wide open throttle (WOT).
Install the left instrument panel insulator.

IMPORTANT

Do not for any reason, insert a screwdriver or other small hand tools into the throttle body to hold open the throttle plate, as the wedge inside the throttle body could be damaged.

Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Disconnect the accelerator control cable and the cruise control cable from the throttle body.
Disconnect the vacuum hose from the throttle body.
Disconnect the throttle position (TP) sensor and idle air control (IAC) valve harness connectors.
Disconnect the coolant hose from the throttle body.
Disconnect the coolant hose from the vapor vent pipe.
Remove the throttle body attaching nuts.
Remove the throttle body and the gasket. Discard the gasket.
Clean the gasket sealing surfaces.

Install the throttle body with a new gasket.
Install the throttle body attaching nuts. Tighten: Tighten the nuts to 10 N.m (89 lb in).
Connect the coolant hose to the throttle body.
Connect the coolant hose to the vapor vent pipe.
Connect the accelerator control cable and the cruise control cable to the throttle body.
Connect the TP sensor and the IAC valve electrical connectors.
Connect the vacuum hose to the throttle body.
Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
With the engine OFF, verify that the accelerator pedal moves freely. Depress the accelerator pedal to the floor and release the pedal.
In order to reset the IAC valve, perform the following procedure: Turn ON the ignition for 10 seconds. Turn OFF the ignition for 5 seconds. Start the engine and check for the proper idle speed.

Fuel Pressure Relief Procedure

Tools Required

J 34730-1A Fuel Pressure Gage

CAUTION

Relieve the fuel system pressure before servicing fuel system components in order to reduce the risk of fire and personal injury. After relieving the system pressure, a small amount of fuel may be released when servicing the fuel lines or connections. In order to reduce the chance of personal injury, cover the regulator and the fuel line fittings with a shop towel before disconnecting. This will catch any fuel that may leak out. Place the towel in an approved container when the disconnection is complete.

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/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Loosen the fuel filler cap in order to relieve the fuel tank vapor pressure.
Remove the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.
Connect the J 34730-1A to the fuel pressure valve. Wrap a shop towel around the fitting while connecting the gage in order to avoid spillage.
Install the bleed hose of the gauge into an approved container.
Open the valve on the gage to bleed the system pressure. The fuel connections are now safe for servicing.
Drain any fuel remaining in the gauge into an approved container.

Tool Required

J 34730-1A Fuel Pressure Gage

CAUTION

Refer to Gasoline/Gasoline Vapors Caution in Cautions and Notices.

Remove the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.
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 to bleed OFF fuel system pressure.
Place a shop towel under the J 34730-1A to catch any remaining fuel spillage.
Remove the J 34730-1A 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.
Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.

J 37088-A Fuel Line Quick-Connect Separator, Tool Set

Relieve the fuel system pressure before servicing any fuel system connection. Refer to the «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction__fuel-pressure-relief-procedure) .
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 tool set for the size of the fitting. 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 before servicing any fuel system connection. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction__fuel-pressure-relief-procedure) .
Using compressed air, blow any dirt out of the quick-connect fitting.
Squeeze the plastic retainer release tabs.
Pull the connection apart.

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

Fuel Tank Draining Procedure

Remove the fuel filler cap.
Use a hand or air operated pump device in order to drain as much fuel through the fuel filler pipe as possible.

Disconnect the negative battery cable.
Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-pressure-relief-procedure) .
Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-tank-draining-procedure) .
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-g3500/1996-2012/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Clean all fuel pipe and hose connections and surrounding areas before disconnecting the fuel pipes in order to avoid contamination of the fuel system.
Loosen the fuel fill hose clamp.
Disconnect the fuel fill hose from the fuel fill pipe.
Disconnect the rear evaporative emission (EVAP) pipe at the EVAP canister.
With the aid of an assistant, support the fuel tank.
Remove the attaching bolts (1) from the fuel tank strap.
Remove the fuel tank straps (2).
Carefully lower the fuel tank.
Disconnect the fuel feed pipe and the fuel return pipe at the fuel sender. Refer to «Quick Connect Fitting(s) Service (Plastic Collar)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Disconnect the electrical connectors from the fuel sender and the fuel pressure sensor.
Remove the fuel tank.
Place the fuel tank in a suitable work area.
Cap the open fuel and EVAP pipes on the vehicle in order to prevent possible fuel system contamination.
Remove the EVAP pipe from the roll over valves and the retainer clips.
Remove the fuel sender assembly from the fuel tank. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Remove the fuel fill hose from the fuel tank.

Install the fuel tank insulators (6).
Remove the caps from the fuel and EVAP pipes.
Install the fuel fill hose to the fuel tank. Tighten: Tighten the fuel fill hose clamp to 2.75 N.m (24 lb in).
Install the fuel sender assembly to the fuel tank. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Connect the EVAP pipe to the roll-over valves and the retainer clips.
With the aid of an assistant, position and support the fuel tank.
Raise the fuel tank slightly.
Connect the electrical connectors to the fuel sender and the fuel pressure sensor.
Connect the fuel feed pipe and the fuel return pipe to the fuel sender. Refer to «Quick Connect Fitting(s) Service (Plastic Collar)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Raise the tank fully.
Install the fuel tank straps (2).
Install the new attaching bolts (1) to the fuel tank strap. Tighten: Tighten the fuel tank strap attaching bolts to 20.5 N.m (15 lb ft).
Connect the rear EVAP pipe (1) to the EVAP canister.
Connect the fuel fill hose to the fuel fill pipe. Tighten: Tighten the fuel fill hose clamp to 2.75 N.m (24 lb in).
Lower the vehicle.
Refill the fuel tank.
Tighten the fuel filler cap.
Connect the negative battery cable.
Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.

Disconnect the negative battery cable.
Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-pressure-relief-procedure) .
Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-tank-draining-procedure) .
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-g3500/1996-2012/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Loosen the fuel fill hose clamp.
Disconnect the fuel fill hose from the fuel tank.
Clean all the fuel pipe connections and the surrounding areas before disconnecting the fuel pipes in order to avoid possible contamination of the fuel system.
Disconnect the rear fuel return pipe at the chassis fuel return pipe. Refer to «Quick Connect Fitting(s) Service (Plastic Collar)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Disconnect the chassis fuel feed pipe at the fuel filter. Refer to «Quick Connect Fitting(s) Service (Plastic Collar)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Disconnect the chassis evaporative emission (EVAP) purge pipe at the EVAP canister.
Cap the fuel and EVAP pipes in order to prevent fuel system contamination.
With the aid of an assistant, support the fuel tank.
Remove the attaching bolts (4) from the fuel tank strap.
Remove the fuel tank straps (3).
Carefully lower the fuel tank.
Disconnect the fuel sender and the fuel pressure sensor electrical connectors.
Remove the fuel tank.
Place the fuel tank in a suitable work area.
Disconnect the EVAP pipe at the front roll-over valve (5), the rear roll-over valve (2), the EVAP canister (4), and the retainer clips.
Remove the fuel sender assembly and the fuel pipes (6) from the fuel tank and the fuel filter. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Remove the fuel fill hose from the fuel tank.
Remove the fuel tank from the fuel tank shield.

Install the fuel tank insulators (3).
Install the fuel tank into the fuel tank shield.
Install the fuel fill hose to the fuel tank. Tighten: Tighten the fuel fill hose clamp to 2.75 N.m (24 lb in).
Install the fuel sender assembly and the fuel pipes (6) to the fuel tank and the fuel filter. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Connect the EVAP pipe at the front roll-over valve (5), the rear roll-over valve (2), the EVAP canister (4), and the retainer clips.
With the aid of an assistant, position and support the fuel tank.
Raise the fuel tank slightly.
Connect the electrical connectors to the fuel sender and the fuel pressure sensor.
Raise the tank fully.
Install the fuel tank straps (3).
Install the new attaching bolts (4) to the fuel tank strap. Tighten: Tighten the bolts to 20.5 N.m (15 lb ft).
Remove the caps from the fuel and EVAP pipes.
Connect the chassis EVAP purge pipe to the EVAP canister.
Connect the chassis fuel feed pipe to the fuel filter. Refer to «Quick Connect Fitting(s) Service (Plastic Collar)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Connect the rear fuel return pipe to the chassis fuel return pipe. Refer to «Quick Connect Fitting(s) Service (Plastic Collar)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Connect the fuel fill hose to the fuel fill pipe. Tighten: Tighten the fuel fill hose clamp to 2.75 N.m (24 lb in).
Lower the vehicle.
Refill the fuel tank.
Tighten the fuel filler cap.
Connect the negative battery cable.
Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.

Disconnect the negative battery cable.
Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-pressure-relief-procedure) .
Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-tank-draining-procedure) .
Raise the vehicle. This must be done with a frame hoist in order to allow the rear suspension to hang. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-g3500/1996-2012/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Loosen the fuel fill hose clamp (2).
Disconnect the fuel fill hose from the fuel tank (1).
Clean all the fuel pipe connections and the surrounding areas before disconnecting the fuel pipes in order to avoid contamination of the fuel system.
Disconnect the rear fuel and evaporative emissions (EVAP) pipes (2) at the chassis fuel and EVAP pipes. Refer to «Quick Connect Fitting(s) Service (Plastic Collar)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Cap the fuel and EVAP pipes in order to prevent fuel system contamination.
With the aid of an assistant, support the fuel tank.
Remove the attaching bolts (4) from the fuel tank strap.
Remove the fuel tank straps (3).
Carefully lower the fuel tank.
Disconnect the electrical connectors from the fuel sender and the fuel pressure sensor.
Remove the fuel tank.
Place the fuel tank in a suitable work area.
Remove the fuel sender assembly and the rear fuel and EVAP pipes from the fuel tank. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .

Install the fuel tank insulators.
Install the fuel sender assembly and the rear fuel and EVAP pipes to the fuel tank. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
With the aid of an assistant, position and support the fuel tank.
Raise the fuel tank slightly.
Connect the electrical connectors to the fuel sender and the fuel pressure sensor.
Raise the tank fully.
Install the fuel tank straps (3).
Install the new attaching bolts (4) to the fuel tank strap. Tighten: Tighten the bolts to 20.5 N.m (15 lb ft).
Remove the caps from the fuel and EVAP pipes.
Connect the rear fuel and EVAP pipes (2) to the chassis fuel and EVAP pipes. Refer to «Quick Connect Fitting(s) Service (Plastic Collar)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Connect the fuel fill hose to the fuel tank (1). Tighten: Tighten the fuel fill hose clamp (2) to 2.75 N.m (24 lb in).
Lower the vehicle.
Refill the fuel tank.
Tighten the fuel filler cap.
Connect the negative battery cable.
Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.

Remove the fuel tank. Refer to «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Remove the fuel pressure sensor (1).

Install the fuel pressure sensor (1).
Install the fuel tank. Refer to «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .

Remove the fuel tank. Refer to «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Remove the fuel pressure sensor (1).

Install the fuel pressure sensor (1).
Install the fuel tank. Refer to «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .

Remove the fuel sender assembly. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Remove the two wire fuel level sensor connectors from the fuel sender assembly.
Using one of two pocket screwdrivers, pull the front retaining tab away from the front of the fuel level sensor while with the second pocket screwdriver push the fuel level sensor away and down from the fuel sender assembly.
Remove the fuel level sensor from the fuel sender assembly.

Install the fuel level sensor (1).
Connect the electrical connector to the fuel tank sender.
Install the fuel sender assembly. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .

Clean all the fuel pipe and hose connections and the surrounding areas before disconnecting in order to avoid contamination of the fuel system.
Remove the fuel filler cap.
Drain the fuel below the level of the fuel tank fill hose. Refer to «Fuel Tank Draining Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-tank-draining-procedure) .
Remove the 2 retaining bolts and push-pin that retain the filler neck to the body.
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-g3500/1996-2012/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Remove the fuel filler tube ground strap bolt.
Loosen the fuel fill hose to fuel fill pipe clamp.
Disconnect the fuel fill hose from the fuel fill pipe.
Remove the fuel fill pipe assembly.

Install the fuel fill pipe to the fuel fill hose.
Align the fuel fill pipe to the fuel fill pipe housing. Tighten: Tighten the fuel fill hose clamp to 2.75 N.m (24 lb in).
Install the fuel filler tube ground strap bolt. Tighten: Tighten the fuel filler tube ground strap bolt to 8 N.m (70 lb in).
Lower the vehicle.
Install the fuel fill pipe housing bolts and push-pin. Tighten: Tighten the fuel fill pipe housing bolts to 6 N.m (53 lb in).
Refill the fuel tank.
Install the fuel filler cap.

Clean all the fuel pipe and hose connections and the surrounding areas before disconnecting in order to avoid contamination of the fuel system.
Remove the fuel filler cap.
Drain the fuel below the level of the fuel tank fill hose. Refer to «Fuel Tank Draining Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-tank-draining-procedure) .
Remove the 2 retaining bolts and push-pin that retain the filler neck to the body.
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-g3500/1996-2012/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Remove the fuel filler tube ground strap bolt.
Loosen the fuel fill hose to fuel fill pipe clamp.
Disconnect the fuel fill hose from the fuel fill pipe.
Remove the fuel fill pipe assembly.

Install the fuel fill pipe to the fuel fill hose.
Align the fuel fill pipe to the fuel fill pipe housing. Tighten: Tighten the fuel fill hose clamp to 2.75 N.m (24 lb in).
Install the fuel filler tube ground strap bolt. Tighten: Tighten the fuel filler tube ground strap bolt to 8 N.m (70 lb in).
Lower the vehicle.
Install the fuel fill pipe housing bolts and push-pin. Tighten: Tighten the fuel fill pipe housing bolts to 6 N.m (53 lb in).
Refill the fuel tank.
Install the fuel filler cap.

Clean all the fuel pipe and hose connections and the surrounding areas before disconnecting in order to avoid contamination of the fuel system.
Remove the fuel filler cap.
Drain the fuel below the level of the fuel tank fill hose. Refer to «Fuel Tank Draining Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-tank-draining-procedure) .
Remove the 2 retaining bolts and push-pin that retain the filler neck to the body.
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-g3500/1996-2012/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Remove the fuel filler tube ground strap bolt.
Loosen the fuel fill hose to fuel fill pipe clamp.
Disconnect the fuel fill hose from the fuel fill pipe.
Remove the fuel fill pipe assembly.

Install the fuel fill pipe to the fuel fill hose.
Align the fuel fill pipe to the fuel fill pipe housing. Tighten: Tighten the fuel fill hose clamp to 2.75 N.m (24 lb in).
Install the fuel filler tube ground strap bolt. Tighten: Tighten the fuel filler tube ground strap bolt to 8 N.m (70 lb in).
Lower the vehicle.
Install the fuel fill pipe housing bolts and push-pin. Tighten: Tighten the fuel fill pipe housing bolts to 6 N.m (53 lb in).
Refill the fuel tank.
Install the fuel filler cap.

J 39765 Fuel Sender Lock Nut Wrench

Disconnect the negative battery cable.
Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-pressure-relief-procedure) .
Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-tank-draining-procedure) .
Remove the fuel tank. Refer to «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Remove the retaining ring from the fuel sender assembly using the J 39765
Remove the fuel sender assembly and the seal. Discard the seal.
Clean the fuel sender sealing surfaces.

Install the new seal on the fuel tank.
Install the fuel sender assembly into the fuel tank.
Install the retaining ring to the fuel sender assembly using the J 39765
Install the fuel tank. Refer to «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Refill the fuel tank.
Tighten the fuel filler cap.
Connect the negative battery cable.
Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.

Disconnect the negative battery cable.
Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-pressure-relief-procedure) .
Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-tank-draining-procedure) .
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-g3500/1996-2012/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Disconnect the fuel feed pipe at the fuel filter.
Disconnect the chassis fuel return pipe at the rear fuel return pipe.
Disconnect the chassis fuel feed and return pipes at the rear fuel feed and return pipes.
Remove the fuel pipe retaining clips.
Remove the fuel feed and return pipes.

Install the fuel feed and return pipes and the fuel pipe retaining clips (2) to the frame rail (1). Tighten: Tighten the bolts to 12 N.m (106 lb in).
Connect the chassis fuel feed and return pipes to the rear fuel feed and return pipes (2).
Connect the chassis fuel return pipe to the rear fuel return pipe.
Connect the fuel feed pipe to the fuel filter.
Lower the vehicle.
Refill the fuel tank.
Tighten the fuel filler cap.
Connect the negative battery cable.
Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition switch. Inspect for fuel leaks.
Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.

Disconnect the negative battery cable.
Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-pressure-relief-procedure) .
Disconnect the fuel feed and return pipes (3) from the engine compartment fuel pipes (4).
Remove the fuel pipes from the bellhousing stud retainer clip.
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-g3500/1996-2012/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Disconnect the fuel feed pipe at the fuel filter.
Disconnect the chassis fuel return pipe at the rear fuel return pipe.
Remove the fuel pipe retaining clips. Note the location of the retaining clips for installation.
Remove the fuel feed and return pipes.

Position the fuel feed and return pipes in the vehicle.
Install the fuel pipe retaining clips (1). Tighten: Tighten the clips to 12 N.m (106 lb in).
Connect the chassis fuel return pipe (4) to the rear fuel return pipe.
Connect the fuel feed pipe (5) to the fuel filter.
Lower the vehicle.
Install the fuel feed and return pipes to the engine compartment fuel pipes. Tighten: Tighten the fuel pipe fittings to 27 N.m (20 lb ft).
Install the fuel pipes to the retainer clip. Tighten: Tighten the fuel pipe retainer clip nut to 28 N.m (21 lb ft).
Tighten the fuel filler cap.
Connect the negative battery cable.
Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.
Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.

Disconnect the negative battery cable.
Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-pressure-relief-procedure) .
Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-tank-draining-procedure) .
Remove the fuel tank. Refer to «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Disconnect the fuel feed pipe at the fuel filter.
Disconnect the chassis fuel return pipe at the rear fuel return pipe.
Remove the fuel pipe retaining clips.
Remove the fuel feed and return pipes.

Install the fuel feed and return pipes and the fuel pipe retaining clips (1). Tighten: Tighten the bolts to 12 N.m (106 lb in).
Connect the chassis fuel return pipe to the rear fuel return pipe.
Connect the fuel feed pipe to the fuel filter.
Install the fuel tank. Refer to «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Lower the vehicle.
Refill the fuel tank.
Tighten the fuel filler cap.
Connect the negative battery cable.
Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.
Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.

Disconnect the negative battery cable.
Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-pressure-relief-procedure) .
Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-tank-draining-procedure) .
Remove the fuel tank. Refer to «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Remove the fuel feed and return pipes (6) from the fuel sender (1), the fuel filter, and the retaining clips.

Install the fuel feed and return pipes (6) to the fuel sender (1), the fuel filter, and the retaining clips.
Install the fuel tank. Refer to «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Lower the vehicle.
Refill the fuel tank.
Tighten the fuel filler cap.
Connect the negative battery cable.
Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.

Disconnect the negative battery cable.
Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-pressure-relief-procedure) .
Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-tank-draining-procedure) .
Remove the fuel tank. Refer to «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Remove the fuel feed and return pipes (4) from the fuel sender (2).

Install the fuel feed and return pipes (4) to the fuel sender (2).
Install the fuel tank. Refer to «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Lower the vehicle.
Refill the fuel tank.
Tighten the fuel filler cap.
Connect the negative battery cable.
Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.

Disconnect the negative battery cable.
Clean all the fuel pipe and hose connections and the surrounding areas before disconnecting in order to avoid possible contamination of the fuel system.
Remove the fuel filler cap.
Drain the fuel below the level of the fuel tank fill hose. Refer to «Fuel Tank Draining Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction__fuel-tank-draining-procedure) .
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-g3500/1996-2012/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Loosen the fuel fill hose clamps (2, 3).
Remove the fuel fill hose (6).
Cap the open end of the fuel tank.

Uncap the fuel tank.
Install the fuel fill hose (6). Tighten: Tighten the fuel fill hose clamps (2, 3) to 2.75 N.m (24 lb in).
Lower the vehicle.
Refill the fuel tank.
Install the fuel filler cap.
Connect the negative battery cable.

Fuel Tank Cleaning

IMPORTANT

Only use oil free compressed air to blow out the fuel pipes. Inspect the fuel tank internally and clean the fuel tank if you find a plugged fuel filter.

Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction__fuel-pressure-relief-procedure) .
Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction__fuel-tank-draining-procedure) .
Remove the fuel tank. Refer to «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Remove the fuel sender assembly. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Inspect the fuel pump strainer. Replace a contaminated strainer and inspect the fuel pump.
Inspect the fuel pump inlet for dirt and debris. Replace the fuel pump if you find dirt or debris in the fuel pump inlet.
Flush the fuel tank with hot water.
Pour the water out of the fuel sender assembly opening. Rock the tank to be sure that removal of the water from the tank is complete.
Remove the fuel rail assembly. Refer to «Fuel Rail Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Drain the fuel from the fuel rail. It will be necessary to remove the fuel injectors from the fuel rail to properly clear all debris from the fuel rail and fuel injectors. Use light shop air to remove any debris from the fuel rail and injectors.
Replace the fuel injector O-rings.
Use light shop air in the opposite direction of the fuel flow in order to remove any debris from the fuel lines. Catch any fuel from the fuel lines with an approved gasoline container.
Install the injectors to the fuel rail.
Install the fuel rail assembly onto the engine. Refer to «Fuel Rail Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
If equipped with a serviceable fuel filter, replace the fuel filter.
Install the fuel sender assembly. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Install the fuel tank. Refer to «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Refill the fuel tank.
Install the fuel filler cap.
Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Purge the fuel sender assembly. Disconnect the fuel feed line from the fuel filter. Connect a length of hose to the fuel feed pipe. Insert the other end of the hose into an empty 3.8 liter (1 gallon) approved gasoline container. Add 23 liters (6 gallons) of clean fuel into the fuel tank. Turn on the fuel pump using the scan tool until 2 liters (1/2 gallon) of fuel flows into the fuel container.
Inspect for leaks. Turn the ignition switch ON for 2 seconds. Turn the ignition switch OFF for 10 seconds. Turn the ignition switch ON. Inspect for fuel leaks.

Remove the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.
Remove the air cleaner resonator outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Before removal, if necessary, clean the fuel rail assembly with a spray type engine cleaner, use GM X-30A or equivalent. Follow the package instructions. Do not soak fuel rail assembly in any liquid cleaning solvent.
Disconnect the accelerator control cable and the cruise control cable from the cable bracket, if equipped.
Disconnect the cruise control cable engine-end fitting from the stud on the throttle lever, if equipped.
Disconnect the accelerator control cable and the cruise control cable from the throttle body, if equipped.
Remove the upper engine wire harness retainer nut.
Disconnect the evaporative emission (EVAP) purge valve harness connector.
Reposition the upper engine wire harness aside.
Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction__fuel-pressure-relief-procedure) .
Mark the electrical connectors to their corresponding injectors to ensure correct sequential injector firing order after reassembly.
Pull the connector position assurance (CPA) (2) on the injector connector up.
Push the tab (1) on the injector connector in.
While pushing the tab (1) on the injector connector in, release the CPA (2).
Disconnect the fuel injector connector electrical connector.
Repeat steps for each injector connector.
Disconnect the fuel feed and return pipes (1, 2) from the fuel rail.
Disconnect the fuel pressure regulator vacuum line.
Loosen the crossover tube to right fuel rail retainer screw (22).
Remove the fuel rail bolts.
Remove the fuel rail.
Remove and discard the fuel injector lower O-ring seals (4) from the injectors (3).

Lubricate the NEW fuel injector lower O-ring seals (4) with clean engine oil.
Install the NEW O-ring seals (4) to the end of each injector (3).
Remove the retaining clip attaching screw (22) and crossover pipe retainer (21) to the right hand fuel rail.
Remove the crossover pipe rail (25) from the right fuel rail (15).
Remove the crossover pipe O-ring (20).
Lubricate a NEW O-ring (20) with clean engine oil.
Install a NEW crossover pipe O-ring (20) on the crossover pipe (25).
Install the crossover pipe (25) into the right fuel rail (15). IMPORTANT: When installing the retaining clip attaching screw for the crossover pipe, always start the screw by hand. This will prevent consequent stripping of the threads in the fuel rail.
Loosely install the crossover pipe retainer (21) and retaining clip attaching screw (22) to the right fuel rail.
Install the fuel rail.
Apply a 5 mm (0.020 in) band of GM P/N 12345382 (Canadian P/N 10953489) threadlock, or equivalent, to the threads of the fuel rail bolts. NOTE: Refer to «Fastener Notice»(/chevrolet/chevy-express-g3500/1996-2012/remont/oem-general-information/#cautions-and-notices__fastener-notice) in Cautions and Notices.
Install the fuel rail bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in). Tighten the screw to 3.8 N.m (34 lb in).
Connect the fuel pressure regulator vacuum line.
Connect the fuel feed and return pipes (1, 2) to the fuel rail.
Connect the fuel injector electrical connectors. Install each connector onto the correct injector in order to ensure correct sequential injector firing order. Rotate the injectors as required in order to avoid stretching the wire harness.
Position the upper engine wire harness in place.
Connect the EVAP purge solenoid connector.
Install the retainer nut to the upper engine wire harness. Tighten: Tighten the nut to 5.5 N.m (49 lb in).
Connect the accelerator control cable and the cruise control cable to the cable bracket, if equipped.
Connect the accelerator control cable to the throttle body, if equipped.
Connect the cruise control cable engine-end fitting to the stud on the throttle lever, if equipped.
Install the air cleaner resonator outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.
Use the following procedure in order to inspect for leaks: 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.

IMPORTANT

The fuel rail for the 5.3L regular production option (RPO) L59 (VIN Z) is compatible with fuel that has a composition of up to 85 percent Ethanol (E85). Because of this, the fuel rail will be serviced as an entire assembly, that includes both the left and right rail assemblies and the crossover pipe rail.

Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction__fuel-pressure-relief-procedure) .
Disconnect the fuel feed (1) and the fuel return (2) pipes from the fuel rail.
Remove the fuel return pipe attaching screw (3) and the fuel return pipe retainer (2).
Remove the fuel return pipe (1).
Remove and discard the fuel return pipe O-ring (6).
Remove the fuel pressure connection core assembly (24) from the crossover pipe rail (25).
Remove the retaining clip attaching screw (22) and the crossover fuel pipe retainer clip (21).
Remove the retaining clip attaching screw (4) and the crossover fuel pipe retainer clip (5).
Remove the crossover pipe rail assembly (25) from the left hand rail assembly (14) and the right hand rail assembly (15).
Remove and discard the crossover fuel pipe O-rings (7, 20).

Lubricate the NEW crossover fuel pipe O-rings (7, 20) with clean engine oil.
Install the NEW crossover fuel pipe O-rings (7, 20) onto the crossover pipe rail assembly (25).
Install the crossover pipe rail assembly (25) to the left hand rail assembly (14) and the right hand rail assembly (15). NOTE: Refer to Fastener Notice in Cautions and Notices. IMPORTANT: When installing the retaining clip attaching screws for the crossover pipe, always start them by hand. This will prevent consequent stripping of the threads in the rail.
Install the crossover fuel pipe retainer clip (21). Loosely install the retaining clip attaching screw (22).
Lubricate the NEW fuel return pipe O-ring (6) with clean engine oil.
Install the NEW fuel return pipe O-ring (6) on the fuel return pipe (1).
Install the fuel return pipe (1).
Install the fuel return pipe retainer (2). Loosely install the fuel return pipe attaching screw (3). IMPORTANT: When installing the retaining clip attaching screws for the crossover pipe, always start them by hand. This will prevent consequent stripping of the threads in the rail.
Install the crossover fuel pipe retainer clip (5). Loosely install the retaining clip attaching screw (4). Tighten: Tighten the crossover fuel pipe retainer clip attaching screws to 3.8 N.m (34 lb in). Tighten the fuel return pipe attaching screw to 5 N.m (44 lb in).
Install the fuel pressure connection core assembly (24) to the crossover pipe rail assembly (25).
Connect the fuel return (2) and fuel feed (1) pipes to the fuel rail.
Tighten the fuel fill cap.
Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Use the following procedure in order to inspect for leaks: 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 fuel pressure connection cap.

IMPORTANT

The fuel rail for the 5.3L regular production option (RPO) L59 (VIN Z) is compatible with fuel that has a composition of up to 85 percent Ethanol (E85). Because of this, the fuel rail will be serviced as an entire assembly that includes both left and right rail assemblies and the fuel return pipe.

Relieve the fuel system pressure. Refer to the «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction__fuel-pressure-relief-procedure) .
Disconnect the fuel feed (1) and fuel return (2) pipes from the fuel rail.
Remove the retaining clip attaching screw (4).
Remove the crossover fuel pipe retainer clip (5).
Remove the fuel return pipe attaching screw (3) and the fuel return pipe retainer (2).
Remove the fuel return pipe (1).
Remove and discard the fuel return pipe O-ring (6).

Lubricate a NEW fuel return pipe O-ring (6) with clean engine oil.
Install the fuel return pipe O-ring (6) onto the fuel return pipe (1).
Install the fuel return pipe (1). NOTE: Refer to the Fastener Notice in Cautions and Notices.
Install the fuel return pipe retainer (2) and the fuel return pipe attaching screw (3).
Install the crossover fuel pipe retainer clip (5).
Install the retaining clip attaching screw (4). Tighten: Tighten the crossover fuel pipe retainer clip attaching screw (4) to 3.8 N.m (34 lb in). Tighten the fuel return pipe attaching screw (3) to 5 N.m (44 lb in).
Connect the fuel return (2) and fuel feed (1) pipes to the fuel rail.
Tighten the fuel fill cap.
Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Use the following procedure in order to inspect for leaks: 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 fuel pressure connection cap.

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

The Denso fuel injectors that are installed in the 5.3L (L59) E85 application will not have O-rings and retaining clips serviced separately. Therefore, the fuel injectors will be replaced whenever an O-ring or clips needs to be replaced.

IMPORTANT

The engine oil may be contaminated with fuel if the fuel injectors are leaking.

Remove the fuel rail. Refer to «Fuel Rail Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Remove the fuel injector retainer clip (19).
Remove the fuel injector (17).
Discard the injector retainer clip (1).
Remove and discard the fuel injector O-ring seals (2, 4) from the injector.

IMPORTANT

When ordering new fuel injectors, you must order the correct injector for the application being serviced.

The fuel injector (1) is stamped with a part number identification (2). A four-digit build date code (3), which indicates the month (4), day (5), year (6), and the shift (7) that built the fuel injector.
Lubricate the NEW fuel injector O-ring seals (2, 4) with clean engine oil.
Install the NEW injector O-ring seals onto the fuel injector.
Install a NEW retainer clip (1) onto the fuel injector.
Install the fuel injector (17) into the fuel rail injector socket with the electrical connector facing outward. The retainer clip (19) locks onto a flange on the fuel rail injector socket.
Install the fuel rail. Refer to «Fuel Rail Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .

Fuel Injector Cleaning Procedure

Tools Required

J 37287 Fuel Line Shut-Off Adapters
J 35800-A Fuel Injector Cleaner. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
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. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
J 42964-2 5/16 Fuel Pipe Shut-Off Valve. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .

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. See Special Tools and Equipment .

Obtain J 35800-A (2). See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
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 . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
For Canadian dealers, measure and dispense 48 ml (1.62 oz) of Top-Engine Cleaner, Canadian P/N 992872, into the J 35800-A . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
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 . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) . J 42873-1 , and J 42873-2 as appropriate for the fuel system.
Connect the J 35800-A to the vehicle fuel rail. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Pressurize the J 35800-A to 510 kPa (75 psi). See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
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. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Reconnect the vehicle fuel pump relay and oil pressure switch connector, if equipped.
Remove J 37287 or J 42964-1 and J 42964-2 . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) . 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.

Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Push the evaporative emission (EVAP) pipe quick connect fitting retainer inward.
Disconnect the EVAP pipe (2) from the EVAP purge solenoid (1).
Disconnect the EVAP purge solenoid electrical connector.
Remove the EVAP purge solenoid mount bolt (2).
Remove the EVAP purge solenoid (3) and the insulator (1) from the engine.

Install the insulator (1) on the EVAP canister purge valve (3).
Install the EVAP canister purge valve (3) to the engine. NOTE: Refer to «Fastener Notice»(/chevrolet/chevy-express-g3500/1996-2012/remont/oem-general-information/#cautions-and-notices__fastener-notice) in Cautions and Notices.
Install the EVAP canister purge valve mount bolt (2). Tighten: Tighten the EVAP canister purge valve mount bolt to 10.5 N.m (93 lb in).
Connect the EVAP pipe (2) to the EVAP canister purge valve (1).
Connect the EVAP canister purge valve electrical connector.
Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .

Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-g3500/1996-2012/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Disconnect the electrical connector from the EVAP vent valve.
Disconnect the canister vent hose.
Bend back the tang on the bracket.
Slide the EVAP vent valve off the bracket.

Slide the EVAP vent valve onto the bracket.
Connect the canister vent hose.
Connect the electrical connector to the EVAP vent valve.
Lower the vehicle.

IMPORTANT

When replacing the evaporative emission (EVAP) pipe, always replace the pipe with original equipment or parts that meet the GM specifications for this part. The replacement pipe must have the same type of fittings as the original pipe in order to ensure the integrity of the connection.

Clean the pipe connections and the surrounding areas before disconnecting in order to avoid possible contamination of the EVAP system.
Disconnect the engine compartment EVAP pipe at the EVAP canister purge valve.
Disconnect the engine compartment EVAP pipe (1) at the chassis EVAP pipe (2).
Remove the EVAP pipe from the engine.
Cap the EVAP canister purge valve and the chassis EVAP pipe in order to prevent possible EVAP system contamination.

Remove the caps from the EVAP canister purge valve and the chassis EVAP pipe.
Install the EVAP pipe on the engine.
Connect the engine compartment EVAP pipe (1) to the chassis EVAP pipe (2).
Connect the engine compartment EVAP pipe at the EVAP canister purge valve.

IMPORTANT

Remove the fuel tank. Refer to «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Disconnect the rear EVAP vapor pipe (1) from the fuel sender (2), the fuel tank roll over valve (3), and the fuel tank clips (6).
Remove the EVAP vapor pipe from the fuel tank.
Cap the fuel sender EVAP pipe and the fuel tank roll over valve.

Remove the caps from the fuel sender EVAP pipe and the fuel tank roll over valve.
Position the EVAP vapor pipe on the fuel tank.
Connect the EVAP vapor pipe (1) to the fuel sender (2), the fuel tank roll over valve (3), and the fuel tank clips (6).
Install the fuel tank. Refer to «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .

IMPORTANT

Remove the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.
Clean all the EVAP pipe connections and the surrounding areas before disconnecting the pipes in order to avoid possible contamination of the EVAP system.
Disconnect the engine compartment EVAP pipe (1) from the chassis EVAP pipe (2).
Cap the engine compartment EVAP pipe.
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-g3500/1996-2012/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Remove the EVAP pipe from the bellhousing stud clip.
Remove the EVAP pipe from the transmission bracket clip.
Remove the EVAP pipe from the transfer case bracket clip, AWD drive only.
Disconnect the rear EVAP purge pipe (3) from the chassis EVAP purge pipe (2).
Cap the rear EVAP purge pipe (3).
Note the position of the EVAP pipe for aid in installation.
Remove the EVAP pipe from the retaining clips (1).
Remove the EVAP pipe.

Install the EVAP pipe into the retaining clips (1).
Remove the cap from the rear EVAP pipe.
Connect the rear EVAP purge pipe (3) to the chassis EVAP purge pipe (2).
Install the EVAP pipe into the transfer case bracket clip, AWD drive only.
Install the EVAP pipe into the transmission bracket clip.
Install the EVAP pipe into the bellhousing stud clip (3).
Lower the vehicle.
Remove the cap from the engine compartment EVAP pipe.
Connect the engine compartment EVAP pipe (1) to the chassis EVAP pipe (2).
Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.

Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-g3500/1996-2012/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Disconnect the vent hose from the canister.
Disconnect the chassis EVAP purge pipe from the EVAP canister.
Disconnect the fuel tank EVAP pipe from the canister.
Remove the EVAP canister from the EVAP canister bracket.

Install the EVAP canister to the EVAP canister bracket.
Connect the fuel tank EVAP pipe to the canister.
Connect the chassis EVAP purge pipe to the EVAP canister.
Connect the vent hose to the canister.
Lower the vehicle.

Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-g3500/1996-2012/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Disconnect the vent hose from the canister.
Disconnect the chassis EVAP purge pipe from the EVAP canister.
Disconnect the fuel tank EVAP pipe from the canister.
Remove the EVAP canister from the EVAP Canister bracket.

Connect the fuel tank EVAP pipe to the canister.
Connect the chassis EVAP purge pipe to the EVAP canister.
Connect the vent hose to the canister.
Install the EVAP canister to the EVAP Canister bracket.
Install the EVAP canister bracket bolt. Tighten: Tighten the bolt to 12 N.m (106 lb in).
Lower the vehicle.

J 41413 EVAP Pressure/Purge Diagnostic Station

Inspection Procedure

Note. Use the EVAP Pressure/Purge Diagnostic Station J 41413 in order to provide a clean, dry, low pressure gas source. Do not substitute any other pressurized gas source. Damage may result to the EVAP system.

IMPORTANT

Do not perform this procedure unless instructed by an EVAP diagnostic.

Turn OFF the ignition.
Remove the EVAP canister purge solenoid valve. Refer to «Evaporative Emission (EVAP) Canister Purge Solenoid Valve Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Lightly tap the EVAP canister purge solenoid valve on a clean hard surface.
Inspect for carbon particles exiting either of the vacuum ports. If no carbon particles are found reinstall the EVAP canister purge solenoid valve and continue with the EVAP cleaning procedure. Refer to «Evaporative Emission (EVAP) Canister Purge Solenoid Valve Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) If carbon particles are found during the inspection procedure, replace the EVAP canister purge solenoid valve and continue with the EVAP cleaning procedure. Refer to «Evaporative Emission (EVAP) Canister Purge Solenoid Valve Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) . If you were instructed to replace the EVAP canister purge solenoid valve, and no carbon particles are found, return to the EVAP diagnostic procedure. Do not perform the EVAP cleaning procedure.

EVAP Cleaning Procedure

Remove the EVAP canister. Refer to «Evaporative Emission (EVAP) Canister Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Evaporative Emission (EVAP) Canister Replacement (Cutaway Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Turn OFF the main valve on the J 41413 EVAP pressure/purge diagnostic station.
Disconnect the hose from the diagnostic station pressure regulator.
Using a section of vacuum hose, connect one end to the diagnostic station pressure regulator.
Connect the other end of the vacuum hose to the canister side of the purge pipe.
Turn ON the main nitrogen cylinder valve and continue to discharge nitrogen for 15 seconds.
If the nitrogen does not dislodge the carbon particles, replace the purge pipe. Refer to «Evaporative Emission (EVAP) System Hoses/Pipes Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Return the EVAP pressure/purge diagnostic station to the stations original condition.
Install a new EVAP canister. Refer to «Evaporative Emission (EVAP) Canister Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) or «Evaporative Emission (EVAP) Canister Replacement (Cutaway Van)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-43l-introduction) .
Connect all previously disconnected EVAP pipe connectors.
Lower the vehicle.
Continue with the published service manual diagnostic DTC procedure.

Remove the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.
Disconnect the spark plug wires at the ignition coils.
Disconnect the ignition coil harness connector.
Remove the ignition coil mounting bolts.
Remove the ignition coil.

Install the ignition coil to the bracket.
Install the ignition coil mounting bolts. Tighten: Tighten the ignition coil mounting bolts to 8 N.m (71 lb in).
Connect the ignition coil harness connector.
Connect the spark plug wires at the ignition coils.
Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.

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. Inspect for the following conditions

Correct routing of the spark plug wires-Incorrect routing may cause cross-firing.
Any signs of cracks or splits in the wires
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 on a terminal, replace the wire and the component connected to the wire.

Remove the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.
Disconnect the spark plug wire at each spark plug. Twist each spark plug wire 1/2 turn. Pull only on the boot in order to remove the wire from each spark plug.
Disconnect the spark plug wire from the ignition coil. Twist each spark plug boot 1/2 turn. Pull only on the boot in order to remove the wires from the ignition coil.

Spark Plug Wire Length V8

The Melco® (square design) uses a spark plug wire (1) that is 145 mm (5.70 in) length cable seal to cable seal.
The Delphi® (round design) uses a spark plug wire (2) that is 110 mm (4.30 in) length cable seal to cable seal.
There are 2 different manufacturers for the ignition coils. the Melco® (1) (square design), and the Delphi® (2) (round design). These 2 coils use 2 different spark plug wire, and mounting brackets.
Melco® (square design) coil mounting bracket (1).
Delphi® (round design) coil mounting bracket (2).

Install the spark plug wires at the ignition coil.
Install the spark plug wire to each spark plug.
Inspect the wires for proper installation: Push sideways on each boot in order to inspect the seating. Reinstall any loose boot.
Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.

Spark Plug Usage

Ensure that the correct spark plug is installed. An incorrect spark plug causes driveability conditions. Refer to «Ignition System Specifications»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction__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/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction__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/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction__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.

Remove the spark plug wires. Refer to «Spark Plug Wire Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Loosen each spark plug 1 or 2 turns.
Brush or air blast away any dirt from around the spark plugs.
Remove the spark plugs 1 at a time. Place each plug in a tray marked with the corresponding cylinder numbers.

Properly position each spark plug washer.
Inspect each spark plug gap. Adjust each plug as needed. Specification: Spark plug gap: 1.524 mm (0.060 in)
Hand start the spark plugs in the corresponding cylinders.
Tighten the spark plugs. Tighten: For used heads tighten the spark plugs to 15 N.m (11 lb ft). For new aluminum heads tighten the spark plugs to 20 N.m (15 lb ft). For new iron heads, tighten the spark plugs to 30 N.m (22 lb ft).
Install the spark plug wires. Refer to «Spark Plug Wire Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .

CAUTION

Before servicing any electrical component, the ignition key must be in the OFF or LOCK position and all electrical loads must be OFF, unless instructed otherwise in these procedures. If a tool or equipment could easily come in contact with a live exposed electrical terminal, also disconnect the negative battery cable. Failure to follow these precautions may cause personal injury and/or damage to the vehicle or its components.

IMPORTANT

Perform the CKP System Variation Learn Procedure when the CKP sensor is removed or replaced.

Refer to Battery Disconnect Caution in Cautions and Notices. Disconnect the negative battery cable.
Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-g3500/1996-2012/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
Remove the starter. Refer to «Starter Motor Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Starter Motor Replacement (4.3L)»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Disconnect the crankshaft position (CKP) sensor electrical connector.
Clean the area around the CKP sensor before removal in order to avoid debris from entering the engine.
Remove the CKP sensor retaining fastener.
Remove the CKP sensor.

Install the CKP sensor. NOTE: Refer to Fastener Notice in Cautions and Notices.
Install the CKP sensor retaining fastener. Tighten: Tighten the fastener to 25 N.m (18 lb ft).
Connect the CKP sensor electrical connector.
Install the starter. Refer to «Starter Motor Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Starter Motor Replacement (4.3L)»(/chevrolet/chevy-express-g3500/1996-2012/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
Lower the vehicle.
Connect the negative battery cable.
Perform the CKP system variation learn procedure. Refer to «CKP System Variation Learn Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction__ckp-system-variation-learn-procedure) .

IMPORTANT

Clean the area around the camshaft position (CMP) sensor before removal in order to prevent debris from entering the engine.

Remove the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.
Disconnect the CMP sensor electrical connector.
Remove the CMP sensor bolt.
Remove the CMP sensor.

Install the CMP sensor.
Install the CMP sensor bolt. Tighten: Tighten the bolt to 25 N.m (18 lb ft).
Connect the CMP sensor electrical connector.
Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.

Remove the intake manifold. Refer to «Intake Manifold Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/mechanical/#engine-mechanical-removal-installation-1-of-3-48l-53l-60l) in Engine Mechanical.
Remove the KS wiring harness assembly.
Remove the KS.

Install the KS. Tighten: Torque the sensor to 20 N.m (15 lb ft).
Install the KS wiring harness assembly.
Install the intake manifold. Refer to «Intake Manifold Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/mechanical/#engine-mechanical-removal-installation-1-of-3-48l-53l-60l) in Engine Mechanical.

IMPORTANT

Do not try to disassemble the exhaust gas recirculation (EGR) valve. Service the valve only as a complete assembly.

IMPORTANT

Carefully note the position of the EGR valve before removal. Do not rotate the EGR valve 180 degrees.

Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Disconnect the EGR electrical connector.
Remove the valve to flange attaching fasteners.
Remove the EGR valve.
Remove the flange gasket.
Clean the EGR valve gasket surface.

Install the new flange gasket
Install the EGR valve. NOTE: Refer to Fastener Notice in Cautions and Notices.
Install the valve to flange fasteners. Tighten: Tighten the fasteners the first time to 10 N.m (89 lb in) each. Tighten the fasteners a final time to 25 N.m (18 lb ft) each.
Connect the electrical connector.
Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .

Remove the exhaust gas recirculation (EGR) valve. Refer to «Exhaust Gas Recirculation (EGR) Valve Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Remove the EGR pipe (2) to intake manifold fasteners.
Remove the EGR pipe to exhaust manifold fasteners.
Remove the EGR pipe mounting fasteners from the right cylinder head.
Remove the EGR pipe.

Install the EGR pipe.
Install the EGR pipe mounting fasteners to the right cylinder head. Tighten: Tighten the fasteners to 50 N.m (37 lb ft).
Install the EGR pipe (2) to exhaust manifold fasteners. Tighten: Tighten the fasteners to 25 N.m (18 lb ft).
Install the EGR pipe to intake manifold fasteners. Tighten: Tighten the fasteners to 12 N.m (106 lb in).
Install the EGR valve. Refer to «Exhaust Gas Recirculation (EGR) Valve Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Install air intake duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .

Exhaust Gas Recirculation (EGR) System Cleaning

CAUTION

Refer to Exhaust Gas Recirculation (EGR) Caution in Cautions and Notices.

Remove the exhaust gas recirculation (EGR) valve. Refer to «Exhaust Gas Recirculation (EGR) Valve Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Depress the pintle several times using a pencil eraser or other suitable soft instrument. The pintle should move in and out smoothly. Replace the valve if the valve exhibits tendencies to stick.
Try to rotate the EGR valve electrical connector housing. Repeat for the coil housing. Replace the valve if the valve exhibits any looseness.
Inspect the EGR valve pintle and seat for deposits. Use a cloth or other suitable soft device to remove the deposits. Remove all loose particles. Replace the valve if the deposits are such that the pintle to base interface cannot be cleaned adequately to allow the pintle to seal against the seat. Damage to the powdered metal EGR valve base occurs if cleaned with solvents, sharp tools, wire brush or wheel, or sand blasting. Cleaning by these methods is not recommended.
Remove the EGR pipe (2). Refer to «Exhaust Gas Recirculation (EGR) Valve Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Clean the passages with a wire brush. Remove all loose particles.
Install the EGR pipe. Refer to «Exhaust Gas Recirculation (EGR) Pipe Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Install the EGR valve. Refer to «Exhaust Gas Recirculation (EGR) Valve Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .

Unclip the air filter cover (2).
Lift and rotate the top cover (2) of the air cleaner housing to gain access to the air filter element.
Pull out the air filter element.
Inspect the air filter element for dust, dirt, or water. Clean or replace the air filter element if required.

Install the air filter element into the air cleaner housing (1).
Rotate and install the top cover (2) to the air cleaner housing (1).

Remove the air intake duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-48l-53l-60l-introduction) .
Disconnect the mass air flow/intake air temperature (MAF/IAT) sensor (5) connector.
Loosen the clamp securing the MAF/IAT sensor to the air cleaner assembly.
Remove the MAF/IAT sensor.
Pull up on the air cleaner assembly (1) to release the retainers from the air cleaner adaptor (2).

Position the air cleaner assembly (4) onto the air cleaner adaptor. Ensure the retainers fit properly into the air cleaner adaptor (3).
Secure the air cleaner assembly (4) onto the air cleaner adaptor (3).
Install the MAF/IAT sensor (5) to the air cleaner assembly.
Secure the clamps at the MAF/IAT sensor and the air cleaner assembly.
Connect the MAF/IAT connector (5).
Install the air intake duct.

Loosen the clamp and separate the air cleaner resonator outlet duct (1) from the mass air flow/intake air temperature (MAF/IAT) sensor assembly.
Loosen the clamp and separate the air cleaner resonator outlet duct from the throttle body assembly.
Remove the air cleaner resonator outlet duct.

Install the air cleaner resonator outlet duct to the throttle body assembly and the MAF/IAT sensor assembly.
Tighten the clamps at the throttle body assembly and the MAF/IAT sensor assembly.

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.

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 57

Scheme 57: Malfunction Indicator Lamp (MIL) Operation

Scheme 58

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.

Throttle Actuator Control (TAC) System Description

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 (APP) 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 components include the following

The APP sensors
The throttle body assembly
The TAC module
The powertrain control module (PCM)

Accelerator Pedal Position (APP) Sensor

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

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

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

Throttle Body Assembly

The throttle body assembly consists of the throttle body, the throttle position (TP) sensors, and the throttle actuator motor. The throttle body functions similar to a similar to a conventional throttle body with the following exceptions

An electric motor opens and closes the throttle valve.
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 1 and 2 are potentiometer type sensors, each with the following circuits

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

The TP sensors are used to determine the throttle plate angle. The control module provides each TP sensor a 5-volt reference circuit and a low reference circuit. The TP sensors then provide the control module with 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 throttle actuator control (TAC) module is the control center for the throttle actuator control system. The TAC system is self-diagnosing and provides diagnostic information to the powertrain control module (PCM) through a dedicated serial data line. The TAC achieves throttle positioning by providing a pulse width modulated voltage to the TAC, as directed by the PCM.

Powertrain Control Module

The powertrain control module (PCM) determines the driver's intent, then calculates the appropriate throttle response. This information is sent to the throttle actuator control (TAC) module through a dedicated serial data line.

Normal Mode

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

Fuel System Overview

The Fuel System is a returnless on-demand design. The fuel pressure regulator is a part of the fuel sender assembly, eliminating the need for a return pipe from the engine. A returnless fuel system reduces the internal temperature of the fuel tank by not returning hot fuel from the engine to the fuel tank. Reducing the internal temperature of the fuel tank results in lower evaporative emissions.

An electric turbine style fuel pump attaches to the fuel sender assembly inside the fuel tank. The fuel pump supplies high pressure fuel through the fuel filter and the fuel feed pipe to the fuel injection system. The fuel pump provides fuel at a higher rate of flow than is needed by the fuel injection system. The fuel pump also supplies fuel to a venturi pump located on the bottom of the fuel sender assembly. The function of the venturi pump is to fill the fuel sender assembly reservoir. The fuel pressure regulator, a part of the fuel sender assembly, maintains the correct fuel pressure to the fuel injection system. The fuel pump and sender assembly contains a reverse flow check valve. The check valve and the fuel pressure regulator maintain fuel pressure in the fuel feed pipe and the fuel rail in order to prevent long cranking times.

Fuel Tanks

The fuel tanks store the fuel supply. 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 59

Scheme 59: Fuel Fill Pipe

The fuel fill pipe has a built-in restrictor in order to prevent refueling with leaded fuel. Once the fill vent is obstructed, fuel backs up the fill pipe and trips the dispensing nozzle. The fuel tank vent valves are connected and route to the canister to collect hydrocarbon emissions during operation of the vehicle.

Scheme 60

Scheme 60: Fuel Filler Cap

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 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 61

Scheme 61: Fuel Sender Assembly

The fuel sender assembly on single tank applications consists of the following major components

The fuel level sensor
The fuel tank pressure (FTP) sensor
The fuel tank fuel pump module
The fuel strainer
The fuel filter

Fuel Level Sensor

The fuel level sensor consists of a float, a wire float arm, and a ceramic resistor cord. The position of the float arm indicates the fuel level. The fuel level sensor contains a variable resistor, which changes resistance in correspondence to 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 (I/P) cluster. This information is used for the 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. The fuel pump delivers a constant flow of fuel to the engine 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. Fuel stoppage at this point indicates that the fuel tank contains an abnormal amount of sediment.

Fuel Filter

The fuel filter is contained in the fuel sender assembly inside the fuel tank. the paper filter element of the fuel filter traps particles in the fuel that may damage the fuel injection system. The fuel filter housing is made to withstand maximum fuel system pressure, exposure to fuel additives, and changes in temperature. There is no service interval for fuel filter replacement.

Nylon Fuel Pipes

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 3 sizes of nylon pipes used: 9.5 mm (3/8 in) ID for the fuel supply, 7.6 mm (5/16 in) ID for the fuel return, and 12.7 mm (1/2 in) ID for the vent. Heat resistant rubber hose or corrugated plastic conduit protects the sections of the pipes that are exposed to chafing, to high temperatures, or to 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.

On-Board Refueling Vapor Recovery System (ORVR)

The On-Board Refueling Vapor Recovery System (ORVR) is an on-board vehicle system designed to recover fuel vapors during the vehicle refueling operation. The flow of liquid fuel down the fuel filler pipe provides a liquid seal which prevents vapor from leaving the fuel filler pipe. An EVAP pipe transports the fuel vapor to the EVAP canister for use by the engine.

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 62

Scheme 62: Fuel Rail Assembly

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

Positions the injectors (3) in the intake manifold
Distributes fuel evenly to the injectors
Integrates the fuel dampener (2) into the fuel metering system

Fuel Injectors

The fuel injector assembly is a solenoid device controlled by the PCM that meters pressurized fuel to a single engine cylinder. The PCM energizes the injector solenoid to open a normally closed ball valve. This allows the 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 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 the fuel to become further atomized and vaporized before entering the combustion chamber. This fine atomization improves fuel economy and emissions.

Fuel Pressure Regulator

The fuel pressure regulator is contained in the left fuel sender assembly.

Fuel Metering Modes of Operation

The PCM monitors voltages from several sensors in order to determine how much fuel to give the engine. The PCM controls the amount of fuel delivered to the engine by changing the fuel injector pulse width. The fuel is delivered under one of several modes.

Starting Mode

When the ignition is first turned ON, the PCM energizes the fuel pump relay for 2 seconds. This allows the fuel pump to build pressure in the fuel system. The PCM 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 starting mode until the engine speed reaches a predetermined RPM.

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 TP sensor is at wide open throttle (WOT), the PCM reduces the fuel 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 PCM ignores the signal from the heated oxygen sensors (HO2S). The PCM calculates the air/fuel ratio based on inputs from the ECT, MAF, MAP, and TP sensors. The system stays in Open Loop until meeting the following conditions

Both front HO2S have varying voltage output, showing that both HO2S are hot enough to operate properly.
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. To prevent possible hesitation, the PCM increases the pulse width to the injectors to provide extra fuel during acceleration. This is also known as power enrichment. The PCM determines the amount of fuel required based upon the TP, the ECT, the MAP, the MAF, and the engine speed.

Deceleration Mode

When the driver releases the accelerator pedal, air flow into the engine is reduced. The PCM monitors the corresponding changes in the TP, the MAP, and the MAF. 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 prevent damage to the catalytic converters.

Battery Voltage Correction Mode

When the battery voltage is low, the 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 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 prevent damage to the catalytic converters

Fuel Trim

The powertrain control module (PCM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. The PCM monitors the HO2S signal voltage while in Closed Loop and regulates the fuel delivery by adjusting the pulse width of the fuel injectors based on this signal. The ideal fuel trim values are around 0 percent for both short term and long term fuel trim. A positive fuel trim value indicates the PCM is adding fuel in order to compensate for a lean condition by increasing the pulse width. A negative fuel trim value indicates that the PCM is reducing the amount of fuel in order to compensate for a rich condition by decreasing the pulse width. A change made to the fuel delivery changes the short term and long term fuel trim values. The short term fuel trim values change rapidly in response to the HO2S signal voltage. These changes fine tune the engine fueling. The long term fuel trim makes coarse adjustments to the fueling in order to re-center and restore control to short term fuel trim. A scan tool can be used to monitor the short term and long term fuel trim values. The long term fuel trim diagnostic is based on an average of several of the long term speed load learn cells. The PCM selects the cells based on the engine speed and engine load. If the PCM detects an excessive lean or rich condition, the PCM will set a fuel trim diagnostic trouble code (DTC).

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 Description

The electronic ignition (EI) system is responsible for producing and controlling a high energy secondary spark. This spark is used to ignite the compressed air/fuel mixture at precisely the correct time. This provides optimal performance, fuel economy, and control of exhaust emissions. This ignition system consists of a separate ignition coil connected to each spark plug by a short secondary wire. The driver modules within each coil assembly are commanded ON/OFF by the powertrain control module (PCM). The PCM primarily uses engine speed and position information from the crankshaft and camshaft position (CMP) sensors to control the sequence, dwell, and timing of the spark. The EI system consists of the following components

Crankshaft Position (CKP) Sensor

The crankshaft position (CKP) sensor 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 PCM supplies a 12-volt, low reference, and signal circuit to the CKP sensor. The sensor returns a digital ON/OFF pulse 24 times per crankshaft revolution.

Crankshaft Reluctor Wheel

The crankshaft reluctor wheel is mounted on the rear of the crankshaft. The wheel is comprised of four 90 degree segments. Each segment represents a pair of cylinders at TDC, and is further divided into six 15 degree segments. Within each 15 degree segment is a notch of 1 of 2 different sizes. Each 90 degree segment has a unique pattern of notches. This is known as pulse width encoding. This pulse width encoded pattern allows the PCM to quickly recognize which pair of cylinders are at top dead center (TDC). The reluctor wheel is also a dual track-or mirror image-design. This means there is an additional wheel pressed against the first, 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.

Camshaft Position (CMP) Sensor

The CMP sensor is also a magneto resistive sensor, with the same type of circuits as the CKP sensor. The CMP sensor signal is a digital ON/OFF pulse, output once per revolution of the camshaft. The CMP sensor information is used by the PCM to determine the position of the valve train relative to the CKP.

Camshaft Reluctor Wheel

The camshaft reluctor wheel is either pressed onto the camshaft or part of the timing gear depending on the application. The feature-or target- is read in a radial or axial fashion respectively. The wheel is a smooth track, half of which is of a lower profile than the other half. This feature allows the CMP sensor to supply a signal as soon as the key is turned ON, since the CMP sensor reads the track profile, instead of a notch.

Ignition Coils

Each ignition coil has an ignition 1 feed and a ground. The PCM supplies a low reference and an ignition control (IC) circuit. Each ignition coil contains a solid state driver module. The PCM will command the IC circuit ON, this allows the current to flow through the primary coil windings for the appropriate time or dwell. When the PCM commands the IC circuit OFF, this will interrupt current flow through the primary coil windings. The magnetic field created by the primary coil windings will collapse across the secondary coil windings, which induces a high voltage across the spark plug electrodes. The coils are current limited to prevent overloading if the IC current is held high too long. The spark plugs are connected to their respective coils by a short secondary wire. The spark plugs are tipped with iridium for long life and 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 air flow (MAF) sensor
The intake air temperature (IAT) sensor
The vehicle speed sensor (VSS)
The transmission gear position or range information sensors
The engine knock sensors (KS)

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.

Purpose

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 knock sensor (KS) system uses one or 2 broadband one-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 dependent 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 engine block through the sensor housing.

One way the control module monitors the system is by output of a bias voltage on the KS signal wire. The bias voltage creates a voltage drop that the control module monitors and uses to help diagnose KS faults. The KS noise signal rides along this bias voltage, and due to the constantly fluctuating frequency and amplitude of the signal, will always be outside of the bias voltage parameters.

Another way the control module monitors the system is by learning the average normal noise output from the KS. 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. The control module uses this noise channel, and the KS signal that rides along the noise channel, in much the same way as the bias voltage type does. As engine speed and load change, the noise channel upper and lower parameters will change to accommodate the normal KS signal.

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 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 fall within 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.

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) sensor is attached to the outlet of the air cleaner housing. The air cleaner life indicator is located on an intake duct between the air cleaner housing and the throttle plate.

Special Tools

Special Tools Illustration Tool Number/Description GE 41415-50 Fuel Tank Cap Adapter J 23738-A Vacuum Pump J 26792 Spark Tester J 34142-B Test Lamp J 34730-E Fuel Pressure Gage Kit J 34730-1A Fuel Pressure Gage J 34730-375 Harness Test Lamp J 35616-A Connector Test Adapter Kit J 35800-A Fuel Injector Cleaner J 37027-1A IAC Motor Driver You may also use an IAC Motor Driver from one of the approved manufacturers listed below: OTC Thexton CTI Snap On MAC Tools NAPA/Balkamp J 37088-A Fuel Line Quick Connect Separator J 37287 Inlet and Return Fuel Line Shut-Off Adapters J 39021 Fuel Injector Coil and Balance Tester J 39021-380 Fuel Injector Test Harness J 39194-B Oxygen Sensor Wrench J 39200 Digital Multimeter J 41415-40 Fuel Tank Cap Adapter J 41413-200 Evaporative Emissions System Tester (EEST) J 41413-VLV EVAP Service Port Vent Fitting J 41413-SPT High Intensity White Light J 41416 Ultrasonic Leak Detector J 42598 Vehicle Data Recorder J 42964-1 3/8 Fuel Line Shut-Off Adapter J 42964-2 5/16 Fuel Line Shut-Off Adapter J 43013 Fuel Injector Assembly Removal Tool J 44175 Fuel Composition Tester J 45722 Fuel Sender Lock Ring Wrench Tech 2 Kit 7000081