Engine Control System - 6.0l - Alternative Fuel (Introductions) Chevrolet Chevy Express G3500

Compressed Natural Gas (CNG) Temperature vs Percent Full

Compressed Natural Gas (CNG) Temperature vs Percent Full

Fuel Tank Pressure (FTP) Sensor Output Voltage vs Pressure

Fuel Tank Pressure (FTP) Sensor Output Voltage vs Pressure

Fuel Rail Pressure (FRP) Sensor Output Voltage vs Pressure

Fuel Rail Pressure (FRP) Sensor Output Voltage vs Pressure

Fuel Tank Temperature (FTT) Sensor Output Voltage vs Temperature Resistance

Fuel Tank Temperature (FTT) Sensor Output Voltage vs Temperature Resistance

Fuel Temperature Sensor (FTS) Output Voltage vs Temperature Resistance

Fuel Temperature Sensor (FTS) Output Voltage vs Temperature Resistance

Fuel Rail Temperature (FRT) Sensor Output Voltage vs Temperature Resistance

Fuel Rail Temperature (FRT) Sensor Output Voltage vs Temperature Resistance

Fastener Tightening Specifications

Fastener Tightening Specifications

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 2

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Scheme 7

Engine Controls Components

Engine Controls Components

Scheme 8

Scheme 9

Powertrain Control Module (PCM) Connector End Views (w/o JL4)

Powertrain Control Module (PCM) Terminal Identification - C1 Connector Part Information 80-Way F Micro-Pack 100W Series Sealed Assembly 12191489 Does not include the following: TPA (BU) 12176408 Terminal - 12084912 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 8 GY 2701 5-Volt Reference 9-10 - - Not Used 11 L-BU 1876 Knock Sensor 2 Signal 12 YE 573 CKP Sensor 1 Signal 13 YE/BK 5694 Fuel Rail Pressure PWM Signal 14-16 - - Not Used 17 D-BU 1225 Transmission Fluid Pressure Switch Signal B 18 OR 1226 Transmission Fluid Pressure Switch Signal C 19 PK 439 Ignition 1 Voltage 20 RD/WH 440 Battery Positive Voltage 21 PU 574 Low Reference 22 - - Not Used 23 TN 2759 Low Reference 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 PU 5607 Fuel Gauge Select Signal 31 - - Not Used 32 TN/WH 771 Transmission Range Switch Signal A 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 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 - - Not Used 42 D-BU 5617 Low Pressure Lock-Off (LPL) Control 43 OR/BK 877 Fuel Injector 7 Control 44 L-BU/BK 844 Fuel Injector 4 Control 45 GY 5634 5-Volt Reference 46 GY 2709 5-Volt Reference 47 - - Not Used 48 GY 597 5-Volt Reference 49-50 - - Not Used 51 D-BU 496 Knock Sensor 1 Signal 52 - - Not Used 53 TN 2762 Low Reference 54 OR/BK 469 Low Reference 55 - - Not Used 56 PK/BK 5605 Fuel Injection Control Module Status 57 RD/WH 440 Battery Positive Voltage 58 D-GN 1049 Class 2 Serial Data 59 YE 710 Class 2 Serial Data 60 TN 2752 Low Reference 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 Off/Run/Crank Voltage 76 TN/WH 845 Fuel Injector 5 Control 77 D-BU/WH 878 Fuel Injector 8 Control 78-79 - - Not Used 80 TN 2761 Low Reference

Powertrain Control Module (PCM) Terminal Identification - C2 Connector Part Information 80-Way F Micro-Pack 100W Series Sealed Assembly 12191488 Does not include the following: TPA (GN) - 15358857 Terminal - 12084912 Pin Wire Color Circuit No. Function 1 BK/WH 1551 Ground 2 BN 418 TCC PWM Solenoid Valve Control 3 L-GN 5606 Fuel Gauge Select Signal 4 - - Not Used 5 OR 2531 Alternative Fuel Operation (AFO) Enable 6 OR/BK 1228 PC Solenoid Valve High Control (Sol. A) 7 - - Not Used 8 L-BU/WH 1229 PC Solenoid Valve Low Control (Sol. A) 9 D-GN/WH 465 Fuel Pump Relay Control - Primary 10-12 - - Not Used 13 L-BU/BK 396 Cruise Control Engaged Signal 14 D-GN/WH 5633 Alternative Fuel Tank Pressure Sensor Signal 15 OR 225 Generator Turn On Signal 16 - - Not Used 17 D-GN/WH 2523 A/C Request Signal 18-19 - - Not Used 20 PU 401 Signal Low - Front 21 YE 400 Signal High - Front 22 OR/BK 1230 AT ISS High Signal 23 D-BU/WH 1231 AT ISS Low Signal 24 D-BU 411 Throttle Position Signal 25 TN 472 IAT Sensor Signal 26 PU 2121 IC 1 Control 27 OR 2127 IC 7 Control 28 L- BU/WH 2126 IC 6 Control 29 D-GN/WH 2124 IC 4 Control 30 D-BU/WH 5695 Fuel Rail Temperature Sensor PWM Signal 31 YE 492 MAF Sensor Signal 32 L-GN 432 MAP Sensor Signal 33 L-BU 5618 High Pressure Lock-Off (HPL) Control 34 D-GN/WHT 428 EVAP Canister Purge Solenoid Control 35-36 - - Not Used 37 D-GN 83 Cruise Control Inhibit Signal 38 - - Not Used 39 OR 631 12-Volt Reference 40 BK/WH 1551 Ground 41-42 - - Not Used 43 D-GN/WH 459 A/C Compressor Clutch Relay Control 44 - - Not Used 45 WH 1310 EVAP Canister Vent Solenoid Control 46 BN/WH 419 MIL Control 47 YE/BK 1223 2-3 Shift Solenoid or Shift Solenoid B Valve Control 48 L-GN 1222 1-2 Shift Solenoid or Shift Solenoid A Valve Control 49 YE/BK 1827 Vehicle Speed Signal 50 D-GN/WH 817 Vehicle Speed Signal 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 - Primary 55 D-GN 603 A/C Low Pressure Switch Signal 56 - - Not Used 57 TN 470 Low Reference 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 OR/WH 2122 IC 2 Control 68 D-GN 2125 IC 5 Control 69 L-BU 2123 IC 3 Control 70-71 - - Not Used 72 L-BLU 5038 HO2S Heater Low Control - Bank 1 Sensor 1 73 D-BU 5632 Alternative Fuel Tank Temperature Signal 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 77 L-GN/BK 444 IAC Coil B Low Control 78 L-BLU/BK 1748 IAC Coil A Low Control 79 L-BU/WH 1747 IAC Coil A High Control 80 - - Not Used

Fuel Injection Control Module Connector End Views

Clear 36-Way Connector End Connector (White) Part Information Connector - 12110487 Seal - 12110489 Strain Relief - 12110490 Terminal - 12084912 TPA (CL) - 12110488 Pin Wire Color Circuit No. Function 1 D-BU 5622 Fuel Rail Pressure (FRP) Sensor Signal 2 GY 474 5-Volt Reference 3 D-BU/WH 878 Fuel Injector 8 Signal 4 OR/BK 877 Fuel Injector 7 Signal 5 YE/BK 846 Fuel Injector 6 Signal 6 TN/WH 845 Fuel Injector 5 Signal 7 L-BU/BK 844 Fuel Injector 4 Signal 8 PK/BK 1746 Fuel Injector 3 Signal 9 L-GN/BK 1745 Fuel Injector 2 Signal 10 TN 1744 Fuel Injector 1 Signal 11 BK/WH 1551 Ground 12 OR 5623 AF Fuel Injector 1 Control 13 PU 5625 AF Fuel Injector 3 Control 14 L-GN 5627 AF Fuel Injector 5 Control 15 D-BU 5629 AF Fuel Injector 7 Control 16 YE/BK 5694 Fuel Rail Pressure (FRP) Sensor PWM Output 17 PK/BK 5605 Fuel Injector Control Module (FICM) Status 18 PK 1020 Ignition Positive Voltage 19 YE 5629 Fuel Rail Temperature (FRT) Sensor Signal 20 TN 476 Ground 21 D-BU/WH 878 Gasoline Fuel Injector 8 Control 22 OR/BK 877 Gasoline Fuel Injector 7 Control 23 YE/BK 846 Gasoline Fuel Injector 6 Control 24 TN/WH 845 Gasoline Fuel Injector 5 Control 25 L-BU/BK 844 Gasoline Fuel Injector 4 Control 26 PK/BK 1746 Gasoline Fuel Injector 3 Control 27 L-GN/BK 1745 Gasoline Fuel Injector 2 Control 28 TN 1744 Gasoline Fuel Injector 1 Control 29 BK/WH 1551 Ground 30 YE 5624 AF Fuel Injector 2 Control 31 BN 5626 AF Fuel Injector 4 Control 32 L-BU 5628 AF Fuel Injector 6 Control 33 D-GN 5630 AF Fuel Injector 8 Control 34 D-BU/WH 5695 Fuel Rail Temperature (FRT) Sensor PWM Output 35 OR 2531 Alternative Fuel (AF) Enable 36 - - Not Used

Engine Controls Connector End Views

C001 Connector End Views Connector Part Information 12160542 20-Way M Micro Pack 100W Series (GY) Connector Part Information 12186609 20-Way F Micro Pack 100W Series (GY) Pin Wire Color Circuit No. Function Pin Wire Color Circuit No. Function A - - Not Used A - - Not Used B OR 5619 LPL Ignition Voltage B OR 5619 LPL Ignition Voltage C TN 1744 Fuel Injector 1 Signal C TN 1744 Fuel Injector 1 Signal D L-GN/BK 1745 Fuel Injector 2 Signal D L-GN/BK 1745 Fuel Injector 2 Signal E PK/BK 1746 Fuel Injector 3 Signal E PK/BK 1746 Fuel Injector 3 Signal F L-BU/BK 844 Fuel Injector 4 Signal F L-BU/BK 844 Fuel Injector 4 Signal G TN/WH 845 Fuel Injector 5 Signal G TN/WH 845 Fuel Injector 5 Signal H YE/BK 846 Fuel Injector 6 Signal H YE/BK 846 Fuel Injector 6 Signal J OR/BK 877 Fuel Injector 7 Signal J OR/BK 877 Fuel Injector 7 Signal K D-BU/WH 878 Fuel Injector 8 Signal K D-BU/WH 878 Fuel Injector 8 Signal L BK/WH 1551 Ground L BK/WH 1551 Ground M D-BU/WH 5695 FRT PWM Output M D-BU/WH 5695 FRT PWM Output N PK/BK 5605 FICM Diagnostic N PK/BK 5605 FICM Diagnostic P PK 1020 FICM Ignition 0 Voltage P PK 1020 FICM Ignition 0 Voltage R YE 5269 FRT Signal R YE 5269 FRT Signal S TN 476 Low Reference S TN 476 Low Reference T OR 5623 CNG Fuel Injector 1 Control T OR 5623 CNG Fuel Injector 1 Control U PU 5625 CNG Fuel Injector 3 Control U PU 5625 CNG Fuel Injector 3 Control V YE 5624 CNG Fuel Injector 2 Control V YE 5624 CNG Fuel Injector 2 Control W BN 5626 CNG Fuel Injector 4 Control W BN 5626 CNG Fuel Injector 4 Control

Scheme 10

C002 Connector End Views Connector Part Information 12160542 20-Way M Micro Pack 100W Series (GY) Connector Part Information 12186609 20-Way F Micro Pack 100W Series (GY) Pin Wire Color Circuit No. Function Pin Wire Color Circuit No. Function A PK 639 Igntion Voltage A PK 639 Ignition Voltage B D-BU 5617 LPL Relay Control B D-BU 5617 LPL Relay Control C TN 5625 Gasoline Fuel Injector 1 Control C TN 5625 Gasoline Fuel Injector 1 Control D L-GN/BK 1745 Gasoline Fuel Injector 2 Control D L-GN/BK 1745 Gasoline Fuel Injector 2 Control E PK/BK 1746 Gasoline Fuel Injector 3 Control E PK/BK 1746 Gasoline Fuel Injector 3 Control F L-BU/BK 844 Gasoline Fuel Injector 4 Control F L-BU/BK 844 Gasoline Fuel Injector 4 Control G TN/WH 845 Gasoline Fuel Injector 5 Control G TN/WH 845 Gasoline Fuel Injector 5 Control H YE/BK 846 Gasoline Fuel Injector 6 Control H YE/BK 846 Gasoline Fuel Injector 6 Control J OR/BK 877 Gasoline Fuel Injector 7 Control J OR/BK 877 Gasoline Fuel Injector 7 Control K D-BU/WH 878 Gasoline Fuel Injector 8 Control K D-BU/WH 878 Gasoline Fuel Injector 8 Control L YE/BK 5694 FRP PWM Output L YE/BK 5694 FRP PWM Output M GY 474 5-Volt Reference M GY 474 5-Volt Reference N BK/WH 1551 Ground N BK/WH 1551 Ground P - - Not Used P - - Not Used R D-BU 5622 FRP Signal R D-BU 5622 FRP Signal S OR 2531 AFO Enable S OR 2531 AFO Enable T L-GN 5627 CNG Fuel Injector 5 Control T L-GN 5627 CNG Fuel Injector 5 Control U D-BU 5629 CNG Fuel Injector 7 Control U D-BU 5629 CNG Fuel Injector 7 Control V L-BU 5628 CNG Fuel Injector 6 Control V L-BU 5628 CNG Fuel Injector 6 Control W D-GN 5630 CNG Fuel Injector 8 Control W D-GN 5630 CNG Fuel Injector 8 Control

C003 Connector End Views Connector Part Information 15326806 2-Way M Sealed 150 Series (BK) Connector Part Information 15326801 2-Way F Sealed 150 Series (BK) Pin Wire Color Circuit No. Function Pin Wire Color Circuit No. Function A L-GN 5606 FIL Control A L-GN 5606 FIL Control B PU 5607 Fuel Gauge Select Switch Signal B PU 5607 Fuel Gauge Select Switch Signal

Scheme 11

C004 Connector End Views Connector Part Information 15326840 8-Way M GT 150 Sealed 4.0 (BK) Connector Part Information 15326835 8-Way F GT 150 Sealed 4.0 (BK) Pin Wire Color Circuit No. Function Pin Wire Color Circuit No. Function A OR/BK 5620 HPL Ignition Voltage - Rear Tanks A OR/BK 5620 HPL Ignition Voltage - Rear Tanks B OR 5621 HPL Ignition Voltage - Mid-frame Tank (KL8) B OR 5621 HPL Ignition Voltage - Mid-frame Tank (KL8) C D-BU 5632 FTT Sensor Signal C D-BU 5632 FTT Sensor Signal D BK/WH 1551 Ground D TN 5631 Low Reference E D-GN/WH 5633 FTP Sensor Signal E D-GN/WH 5633 FTP Sensor Signal F GY 5634 5-Volt Reference F GY 5634 5-Volt Reference G BK 1250 HPL Solenoid Ground G BK 1250 HPL Solenoid Ground H - - Not Used H - - Not Used

C005 Connector End Views Connector Part Information 15326854 12-Way M GT 150 Sealed 4.0 (BK) Connector Part Information 15326849 12-Way F GT 150 Sealed 4.0 (BK) Pin Wire Color Circuit No. Function Pin Wire Color Circuit No. Function A TN 1744 Gasoline Fuel Injector 1 Control A TN 1744 Gasoline Fuel Injector 1 Control B PK/BK 1746 Gasoline Fuel Injector 3 Control B PK/BK 1746 Gasoline Fuel Injector 3 Control C TN/WH 845 Gasoline Fuel Injector 5 Control C TN/WH 845 Gasoline Fuel Injector 5 Control D OR/BK 877 Gasoline Fuel Injector 7 Control D OR/BK 877 Gasoline Fuel Injector 7 Control E PK 139 Ignition Voltage E PK 139 Ignition Voltage F PK 139 Ignition Voltage F PK 139 Ignition Voltage G PK 139 Ignition Voltage G PK 139 Ignition Voltage H PK 139 Ignition Voltage H PK 139 Ignition Voltage J OR 5623 CNG Fuel Injector 1 Control J OR 5623 CNG Fuel Injector 1 Control K PU 5625 CNG Fuel Injector 3 Control K PU 5625 CNG Fuel Injector 3 Control L L-GN 5627 CNG Fuel Injector 5 Control L L-GN 5627 CNG Fuel Injector 5 Control M D-BU 5629 CNG Fuel Injector 7 Control M D-BU 5629 CNG Fuel Injector 7 Control

Scheme 12

C006 Terminal Identification Connector Part Information 15326854 12-Way M GT 150 Sealed 4.0 (BK) Connector Part Information 15326849 12-Way F GT 150 Sealed 4.0 (BK) Pin Wire Color Circuit No. Function Pin Wire Color Circuit No. Function A L-GN/BK 1745 Gasoline Fuel Injector 2 Control A L-GN/BK 1745 Gasoline Fuel Injector 2 Control B L-BU/BK 844 Gasoline Fuel Injector 4 Control B L-BU/BK 844 Gasoline Fuel Injector 4 Control C YE/BK 846 Gasoline Fuel Injector 6 Control C YE/BK 846 Gasoline Fuel Injector 6 Control D D-BU/WH 878 Gasoline Fuel Injector 8 Control D D-BU/WH 878 Gasoline Fuel Injector 8 Control E PK 239 Ignition Voltage E PK 239 Ignition Voltage F PK 239 Ignition Voltage F PK 239 Ignition Voltage G PK 239 Ignition Voltage G PK 239 Ignition Voltage H PK 239 Ignition Voltage H PK 239 Ignition Voltage J YE 5624 CNG Fuel Injector 2 Control J YE 5624 CNG Fuel Injector 2 Control K BR 5626 CNG Fuel Injector 4 Control K BR 5626 CNG Fuel Injector 4 Control L L-BU 5628 CNG Fuel Injector 6 Control L L-BU 5628 CNG Fuel Injector 6 Control M D-GN 5630 CNG Fuel Injector 8 Control M D-GN 5630 CNG Fuel Injector 8 Control

Fuel Rail Pressure Sensor Terminal Identification Connector Part Information 12065287 3-Way F Metri-Pack Sealed 150 Series (BK) Pin Wire Color Circuit No. Function A TN 476 Low Reference B GY 474 5-Volt Reference C D-BU 5622 Sensor Signal

AF Fuel Injector #1 Terminal Identification Connector Part Information 12129140 2-Way F Metri Pack 280.1 Pull to Seat (BK) Pin Wire Color Circuit No. Function A PN 139 Injector Power B OR 5623 Injector Control

AF Fuel Injector #2 Terminal Identification Connector Part Information 12129140 2-Way F Metri Pack 280.1 Pull to Seat (BK) Pin Wire Color Circuit No. Function A PN 239 Injector Power B YE 5624 Injector Control

AF Fuel Injector #3 Terminal Identification Connector Part Information 12129140 2-Way F Metri Pack 280.1 Pull to Seat (BK) Pin Wire Color Circuit No. Function A PN 139 Injector Power B PU 5625 Injector Control

AF Fuel Injector #4 Terminal Identification Connector Part Information 12129140 2-Way F Metri Pack 280.1 Pull to Seat (BK) Pin Wire Color Circuit No. Function A PN 239 Injector Power B BN 5626 Injector Control

AF Fuel Injector #5 Terminal Identification Connector Part Information 12129140 2-Way F Metri Pack 280.1 Pull to Seat (BK) Pin Wire Color Circuit No. Function A PN 139 Injector Power B L-GN 5627 Injector Control

AF Fuel Injector #6 Terminal Identification Connector Part Information 12129140 2-Way F Metri Pack 280.1 Pull to Seat (BK) Pin Wire Color Circuit No. Function A PN 239 Injector Power B L-BU 5628 Injector Control

AF Fuel Injector #7 Terminal Identification Connector Part Information 12129140 2-Way F Metri Pack 280.1 Pull to Seat (BK) Pin Wire Color Circuit No. Function A PN 139 Injector Power B D-BU 5629 Injector Control

AF Fuel Injector #8 Terminal Identification Connector Part Information 12129140 2-Way F Metri Pack 280.1 Pull to Seat (BK) Pin Wire Color Circuit No. Function A PN 239 Injector Power B D-GN 5630 Injector Control

Low Pressure Lock-Off Relay Terminal Identification Connector Part Information 12129716 4-Way F Sealed Flexlock 280 Series (M-GY) Pin Wire Color Circuit No. Function 30 PK 639 Ignition Voltage 85 PK 639 Ignition Voltage 86 D-BU 5617 Relay Control 87 OR 5619 LPL Power

Low Pressure Lock-Off Solenoid Terminal Identification Connector Part Information 12052641 2-Way F Metri-Pack Sealed 150 Series (BK) Pin Wire Color Circuit No. Function A BK 1250 Ground B OR 5619 Solenoid Voltage

High Pressure Lock-Off Solenoid Terminal Identification Connector Part Information 12052641 2-Way F Metri-Pack Sealed 150 Series (BK) Pin Wire Color Circuit No. Function A OR/BK 5620 Solenoid Voltage B BK 12500 Ground

Fuel Tank Temperature Sensor Terminal Identification Connector Part Information 12052644 2-Way F Metri-Pack Sealed 150 Series (L-GY) Pin Wire Color Circuit No. Function A TN 5631 Low Reference B D-BU 5632 Sensor Signal

AF Fuel Tank Pressure Sensor Terminal Identification Connector Part Information 12065287 3-Way F Metri-Pack Sealed 150 Series (BK) Pin Wire Color Circuit No. Function A TN 5631 Low Reference B GY 5634 5-Volt Reference C D-GN/WH 5633 Sensor Signal

Fuel Gauge Select Switch Terminal Identification Connector Part Information 15332145 8-Way F GT 150 Series (BK) Pin Wire Color Circuit No. Function A PU 5607 Fuel Gauge Select Switch Signal B - - Not used C L-GN 5606 Fuel Indicator Lamp Control D-H - - Not Used

Removal Procedure

1. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
2. Remove the fender brace mounting bolts (3).
3. Remove the fender brace.
4. Remove the FICM hold-down screws (7) from the mounting bracket.
5. Remove the connector position assurance lock and disconnect the electrical connector (2) from the FICM.
6. Remove the FICM. If the FICM mounting bracket does not have to be removed proceed to Step 3 of the Installation Procedure.
7. Remove the FICM mounting bracket bolts (1).
8. Remove the FICM mounting bracket nut (4) from the horn mounting stud.
9. Remove the FICM mounting bracket from the vehicle.

Installation Procedure

1. Install the FICM mounting bracket onto the horn mounting stud. Tighten: Tighten the nut to 9 N.m (7 lb ft).
2. Install the FICM mounting bracket bolts (1). Tighten: Tighten the bolts to 12 N.m (9 lb ft).
3. Loosely install all of the FICM hold-down screws (7). Tighten: Tighten the screws to 12 N.m (9 lb ft).
4. Connect the electrical connector (2) to the FICM and install the connector position assurance lock.
5. Install the fender brace and bolts (3). Tighten: Tighten the bolts to 12 N.m (9 lb ft).
6. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.

Fuel Pressure Relief Procedure

Tools Required

J 42435 CNG Tank Venting Kit. See Special Tools and Equipment .

1. With a scan tool communicate with the PCM. If communication cannot be established and the «Diagnostic System Check - Alternative Fuels (Engine Controls)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-diagnostic-information-procedures) has already been performed proceed to Step 9.
2. Store the DTC Information with a scan tool.
3. Clear the DTC Information with a scan tool.
4. Turn OFF the ignition.
5. Start and idle the engine.
6. Ensure that the engine is operating on CNG by observing the following: The fuel indicator lamp (FIL) is OFF (KL6) The AFO Enable scan tool display indicates the engine is operating on alternative fuel.
7. With a scan tool, select the high pressure lock-off (HPL) solenoid special function.
8. While the engine is operating on CNG command the HPL solenoid OFF and observe the fuel tank pressure sensor data parameter. The fuel tank pressure should slowly decrease. If the fuel pressure fails to decrease proceed to Step 9. When the engine stalls or a switch-over to gasoline is observed, perform the following: Turn OFF the ignition. Remove the Alt. Fuels 20-amp fuse in order to disable the CNG fuel system. A small amount of CNG will remain in the fuel lines and components. Slowly open the fittings in order to release any remaining pressure when disconnecting a fuel line. Fuel Pressure Relief for the CNG system is now complete. Proceed to Step 16.
9. Close the manual lock-down screw located on the end of each high pressure lock-off (HPL) solenoid. The manual shut-off fitting is closed by rotating the allen screw clockwise until fully seated.
10. Turn OFF the ignition.
11. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
12. Slowly loosen the fuel line fitting (4) at the tee (1) several turns.
13. Fuel Pressure Relief for the CNG system is complete when the fuel line can be pulled away from the O-ring face seal and fuel does not vent.
14. Replace the O-ring face seals at all fittings that were disconnected or loosened.
15. After all necessary repairs are complete perform the following: Tighten any loosened fittings to the correct torque. Refer to «Fastener Tightening Specifications»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fastener-tightening-specifications) . IMPORTANT: Leave the manual lock-down screws closed on any vehicle that will require CNG fuel tank venting. Open the manual lock-down screws located on the HPL manual shut-off fittings by rotating the allen screw counter-clockwise until fully seated on any vehicle that does not require venting of the CNG fuel tanks.
16. If the service necessary for the vehicle requires the CNG fuel tanks to be relieved of all internal pressure, refer to «Fuel Tank Venting Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-tank-venting-procedure) .

Fuel Tank Inspection

1. Inspect the CNG fuel tank and brackets every three years or 60 000 km (36,000 mi), whichever comes first. Record the inspection information in the CNG Fuel Tank Inspection Record. The CNG Fuel Tank Inspection Record is located in the owner's manual supplement.
2. Do not remove the tank from the vehicle for general inspections.
3. However, if the tank has been exposed to corrosive chemicals such as acid or alkali, remove the tank in order to perform a complete inspection.
4. If the tank is replaced, perform the following steps: Obtain a new CNG Fuel Only label. Obtain a new Bi-fuel Information label. Record the new tank service expiration date, the date of the manufacture plus 15 years, on both labels.

Tank Label Inspection Procedure

Verify that the CNG fuel tank label is in place.

Contact the GM Technical Assistance Center (TAC) if any of the following conditions exist

1. The label is not readable.
2. The label is peeling.
3. The label is missing.

Verify that the tank expiration date matches on the tank and the underhood label. If needed, replace the underhood label so the expiration date matches the tank label.

Tank Inspection Procedure

A multi-coat paint system with a zinc-rich primer protects the metal tank. Inspect and recoat chips in the paint as follows

Level 1 Chips

1. Level 1 chips are chips or abrasions in the coating that do not penetrate the top coat.
2. Level 1 chips do not expose the gray zinc-rich primer.
3. Level 1 chips do not require resurfacing.

Level 2 Chips

1. Level 2 chips are chips or abrasions that penetrate the top coat.
2. Recoat Level 2 chips or abrasions in order to prevent corrosion
3. The following two repair methods are recommended depending on whether the zinc-rich primer is still intact: Method 1: Recoat the chip using any commercial room temperature cure two-component epoxy resin, Loctite® Part No. 14600 or equivalent, if the chip has not penetrated the zinc-rich primer. Method 2: The following procedure is recommended if the chip has penetrated the zinc-rich primer and exposed the bare metal: Sand the damaged area in order to remove any rust and to rough-up the surrounding coating. Clean the damaged area with a commercial prepaint cleaning solvent-Dupont® Prep Sol or equivalent. Apply a zinc-rich cold galvanizing primer-LPS® Part No. 00516 or equivalent. Coat the area after the primer has cured using a room temperature cure two-component epoxy resin-Loctite® Part No. 14600 or equivalent.

Dents

Dents

Gouges

Gouges

Mounting Bracket Inspection Procedure

1. Verify that the rubber isolator is properly seated on the tank brackets and straps.
2. Inspect the rubber isolator for cracks, deterioration or other damage.
3. Replace the rubber isolator if necessary.
4. Inspect the tank brackets, straps, mounting frame and mounting hardware for cracks, corrosion, deformation or other damage.
5. Replace if necessary.

Removing From Service

1. The CNG fuel tank has a fifteen year service life from the date of manufacture.
2. The CNG tank manufacture date appears on a label on the tank.
3. The tank expiration date is on the CNG Fuel Only label and the Bi-fuel Information label.
4. Any tank in service for fifteen years or more must be removed from service using the following procedure: Remove the tank. Refer to «Fuel Tank Replacement - Front (KL8)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) or «Fuel Tank Replacement - Rear (Passenger/Cargo)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) or «Fuel Tank Replacement - Rear (Cutaway)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) . Vent the tank. Refer to «Fuel Tank Venting Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-tank-venting-procedure) . Disconnect the vent hose. Allow the tank to stand for 24 hours with either the tank valve energized or the manual valve opening tool installed. Place the tank outside in a well ventilated area. Drill a 0.64 cm (1/4 in) hole after the last digit of the tank identification number stamped into the valve end of the tank. Dispose of the tank in a safe and approved manner.

1. Remove the weight distributing hitch if equipped. Refer to Weight Distribution Hitch Replacement in Frame and Underbody in the G/H Van Service Manual.
2. Remove the tank shield bolts while an assistant holds the shield in place.
3. Lower the shield from the vehicle.

1. Position the shield around the tank frame.
2. While an assistant holds the shield in place, loosely install the shield retaining bolts. Tighten: Tighten the bolts to 24 N.m (18 lb ft).
3. Install the weight distributing hitch if equipped. Refer to Weight Distribution Hitch Replacement in Frame and Underbody in the G/H Van Service Manual.

Fuel Tank Venting Procedure

Tools Required

J 42435 CNG Tank Vent Kit. See Special Tools and Equipment .

1. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
3. Remove the fuel tank cover. Refer to «Fuel Tank Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
4. In order to vent the rear tanks on cargo/passenger vans the tanks must be removed from the vehicle. Refer to «Fuel Tank Replacement - Rear (Passenger/Cargo)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) or «Fuel Tank Replacement - Rear (Cutaway)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) if applicable.
5. Disconnect the fuel outlet line (4) from the tank.
6. Install a cap (3) supplied from the J 42435 on to the fuel line fitting of the fuel outlet port (4). See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) . Tighten: Tighten the cap to 37 N.m (27 lb ft).
7. Leave the fuel tank pressure (FTP) sensor installed if equipped.
8. Disconnect the fuel inlet line from the tank.
9. Connect the female end of the vent hose to the fuel line fitting.
10. Connect the male end of the vent hose (1) to a vent stack. Refer to the J 42435 container for instructions on how to properly construct a vent stack. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
11. Connect the ground strap to one of the fittings and to the vent stack earth ground (2).
12. Ensure that the manual lock-down screw of the manual shut-off fitting is open by rotating the allen screw counterclockwise until fully seated.
13. If the tank begins venting when the manual lock-down screw is opened do not proceed to the next step until the tank stops venting.
14. Remove the manual shut-off fitting from the HPL.
15. Obtain the manual vent tool supplied from the J 42435 . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
16. Rotate the screw on the manual vent tool counter-clockwise in order to fully retract the plunger.
17. Install the manual vent tool into the HPL port with the plunger fully retracted. Tighten: Tighten the manual vent tool to 12 N.m (108 lb in).
18. Slowly turn the manual vent tool screw clockwise until the plunger is fully extended.
19. Open the J 42435 in-line valve. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) . The tank should always contain some pressure and begin to vent.
20. Allow the CNG fuel tank to vent until the pressure gauge reads 0 kPa (0 psi). When the tank stops venting inspect the vent line or the HPL for a frozen fitting. The fitting will eventually thaw and fuel may continue to vent.
21. When the tank is completely vented remove the vent line from the fuel fitting.
22. Remove the fuel fitting from the fuel outlet port (4).
23. Remove the manual vent tool.
24. If the tank is to be re-used replace the high pressure lock-off. Refer to «High Pressure Lock-Off (HPL) Solenoid Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

Fuel Tank Cleaning

Tools Required

J 44244 CNG Tank Support Harness. See Special Tools and Equipment .

1. Perform the «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Perform the «Fuel Tank Venting Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-tank-venting-procedure) .
3. Perform the high pressure lock-off (HPL) removal procedure leaving the HPL installed into the tank finger-tight. Refer to «High Pressure Lock-Off (HPL) Solenoid Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
4. Place the J 44244 (1) on the shop floor. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
5. Lower the CNG fuel tank (2) on top of the J 44244 (1). See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
6. Place the J 44244 support flap so that the HPL (3) protrudes through the flap. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
7. Place the J 44244 (1) straps around the CNG fuel tank placing the end strap over the HPL (3) and around the neck of the CNG fuel tank. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
8. Securely fasten the J 44244 straps (2) around the CNG fuel tank (1). See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) . Longer CNG fuel tanks will require the use of all the J 44244 straps. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
9. Connect the J 44244 to a suitable lifting device. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
10. Slowly raise the CNG fuel tank (1) until the HPL (2) is several inches above the ground ensuring that the HPL does not contact the floor during the lifting process.
11. Place a container (3) underneath the HPL (2) in order to collect any drained fluids.
12. Remove the HPL (2), allowing any fluids to drain completely from the CNG fuel tank.
13. Dispose of any collected fluids in a safe and approved manner.
14. Flush the inside of the CNG fuel tank using clean water.
15. Dry the inside of the CNG fuel tank using compressed air.
16. Install the HPL (2) finger-tight.
17. Slowly lower the CNG fuel tank (1) back to the ground ensuring the HPL does not contact the ground.
18. Remove the J 44244 (1) from the CNG fuel tank (2). See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
19. Complete the installation of the HPL into the tank and the tank into the vehicle by completing the installation steps as indicated in the «High Pressure Lock-Off (HPL) Solenoid Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

Tools Required

1. J 45878 Combustible Gas Detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
2. J 45397-2 CNG Tank Lifting Tool. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
3. J 45529 CNG Tank Lifting Bar. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
3. Raise and properly support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the G/H Van Service Manual.
4. Remove the fuel tank cover. Refer to «Fuel Tank Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
5. Disconnect the fuel outlet line (2) from the high pressure lock-off (HPL) solenoid.
6. Disconnect the electrical connector (3) at the high pressure lock-off solenoid.
7. Attach the J 45397-2 to a transmission jack. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
8. Support the tank assembly with the J 45397-2 and transmission jack. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
9. Remove the tank assembly retaining bolts (5,7).
10. Rotate the tank straps (4,6) away from the tank.
11. Lower the tank (1) from the vehicle with the transmission jack.
12. Lift the tank from the J 45397-2 using the J 45529 and a suitable overhead lifting device. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
13. Vent the CNG fuel from the CNG fuel tank if necessary. Refer to «Fuel Tank Venting Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-tank-venting-procedure) .

1. Position the tank assembly beneath the vehicle.
2. Raise the tank assembly onto the tank frame mounts.
3. Rotate the tank straps (4,6) against the tank.
4. Install the mounting bolts (5,7). Tighten: Tighten the mounting bolts to 39 N.m (29 lb ft).
5. Connect the fuel outlet line (2) to the high pressure lock-off using a new O-ring. Lubricate the O-ring with petroleum jelly or equivalent. Tighten: Tighten the fitting to 37 N.m (27 lb ft).
6. Connect the electrical connector (3) at the high pressure lock-off solenoid.
7. Connect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
8. Prime the CNG fuel system by cycling the ignition ON and OFF several times.
9. Start the engine and use the J 45878 in order to inspect for CNG fuel system leaks at each serviced fitting. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
10. Install the fuel tank cover. Refer to «Fuel Tank Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

1. J 45878 Combustible Gas Detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
2. J 45397 CNG Dual Tank Lifting Kit. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
3. J 45529 CNG Tank Lifting Bar. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
3. Raise and properly support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the G/H Van Service Manual.
4. Remove the fuel tank cover. Refer to «Fuel Tank Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
5. Disconnect the fuel outlet line (4) from the high pressure lock-off (HPL) solenoid.
6. Disconnect the electrical connectors (1,2,4) at the high pressure lock-off solenoids.
7. Attach the J 45397 (2) to a transmission jack (3). See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
8. Support the tank assembly (1) with the J 45397 and transmission jack. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
9. Remove the exhaust tailpipe from the hanger.
10. Remove all of the tank assembly retaining nuts (2).
11. Lower the tank assembly from the vehicle with the transmission jack.

Disassembly Procedure

1. Fasten the tank assembly to the J 45397 (3) with a suitable strap (2,5). See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) . Ensure the strap captures both tanks and the J 45397 . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) . The strap should not interfere with removal of the tank assembly from the transmission jack.
2. Remove the tank to tank fuel line.
3. Remove the tank strap mounting bolts (1) while holding the appropriate nut with a wrench (2).
4. Attach an overhead lifting device (1) to the tank assembly frame.
5. Remove the mounting hardware (4) that attaches the J 45397 (3) to the transmission jack. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
6. Raise the tank and J 45397 assembly (3) from the transmission jack and place the assembly on the floor. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
7. Remove the strap (2,5).
8. Remove the tank strap (4) clevis pin clips (5) and pins (3).
9. Remove the tank straps (4).
10. Slide the tank away from the mounting frame.
11. Attach the J 45529 (1) straps (2) around the tank. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
12. Lift the tank from the J 45397 (3) using the. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) . J 45529 (1) and a suitable overhead lifting device. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
13. Vent the CNG fuel from the CNG fuel tank if necessary. Refer to «Fuel Tank Venting Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-tank-venting-procedure) .

Assembly Procedure

1. Lower the tank onto the J 45397 (3) with the J 45529 (1) and a suitable overhead lifting device. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
2. Rotate the tank in order to align the fuel line fittings.
3. Slide the tank against the mounting frame.
4. Attach the tank straps (4) to the mounting frame with the clevis pins (3) and clips (5).
5. Fasten the tank assembly to the J 45397 (3) with a suitable strap (2,5). See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) . Ensure the strap captures both tanks and the J 45397 . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) . The strap should not interfere with installation of the tank assembly to the transmission jack.
6. Attach an overhead lifting device (1) to the tank assembly frame.
7. Raise the tank and J 45397 assembly (3) from the floor and place the assembly on the transmission jack (4). See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
8. Attach the J 45397 (3) to the transmission jack (4). See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
9. Install the tank strap mounting bolts (1) while holding the appropriate nut with a wrench (2). Tighten: Tighten the bolts to 39 N.m (29 lb ft).
10. Install the tank to tank fuel line (2,3) with new O-rings. Lubricate the O-rings with petroleum jelly prior to installation. Tighten: Tighten the fuel line fittings to 37 N.m (27 lb ft).

1. Position the tank assembly beneath the vehicle.
2. Raise the tank assembly onto the tank frame studs.
3. Install the mounting nuts. Tighten: Tighten the mounting nuts to 85 N.m (63 lb ft).
4. Connect the fuel outlet line (4) to the high pressure lock-off using a new O-ring. Lubricate the O-ring with petroleum jelly or equivalent. Tighten: Tighten the fitting to 37 N.m (27 lb ft).
5. Connect the electrical connectors (1,2,4) at the high pressure lock-off solenoids.
6. Connect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
7. Prime the CNG fuel system by cycling the ignition ON and OFF several times.
8. Start the engine and use the J 45878 in order to inspect for CNG fuel system leaks at each serviced fitting. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
9. Install the fuel tank cover. Refer to «Fuel Tank Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

1. J 45878 Combustible Gas Detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
2. J 45397 CNG Dual Tank Lifting Kit. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
3. J 45529 CNG Tank Lifting Bar. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
3. Raise and properly support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the G/H Van Service Manual.
4. Remove the fuel tank cover. Refer to «Fuel Tank Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
5. Disconnect the electrical connectors (1-4) at the high pressure lock-off solenoids.
6. Disconnect the fuel outlet line (2) from the high pressure lock-off (HPL) solenoid.
7. Attach the J 45397 (2) to a transmission jack (3). See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
8. Support the tank assembly (1) with the J 45397 and transmission jack. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
9. Remove the tank assembly retaining nuts (1) and bolts (2).
10. Lower the tank assembly from the vehicle with the transmission jack.

1. Fasten the tank assembly to the J 45397 (3) with a suitable strap (2,5). See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) . Ensure the strap captures both tanks and the J 45397 . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) . The strap should not interfere with removal of the tank assembly from the transmission jack.
2. Remove the tank strap mounting bolts (1) while holding the appropriate nut with a wrench (2).
3. Attach an overhead lifting device (1) to the tank assembly frame.
4. Remove the mounting hardware (4) that attaches the J 45397 to the transmission jack. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
5. Raise the tank and J 45397 assembly from the transmission jack and place the assembly on the floor. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
6. Remove the strap (2,5).
7. Remove the tank to tank fuel line (3,4).
8. Remove the tank strap (5) clevis pin clips (6) and pins (4).
9. Remove the tank straps (5).
10. Slide the tank away from the mounting frame.
11. Attach the J 45529 (1) straps (2) around the tank. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
12. Lift the tank from the J 45397 (3) using the. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) . J 45529 and a suitable overhead lifting device. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
13. Vent the CNG fuel from the CNG fuel tank if necessary. Refer to «Fuel Tank Venting Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-tank-venting-procedure) .

1. Lower the tank onto the J 45397 (3) with the J 45529 (1) and a suitable overhead lifting device. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
2. Rotate the tank in order to align the fuel line fittings.
3. Slide the tank against the mounting frame.
4. Attach the tank straps (5) to the mounting frame with the clevis pins (4) and clips (6).
5. Fasten the tank assembly to the J 45397 (3) with a suitable strap (2,5). See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) . Ensure the strap captures both tanks and the J 45397 . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) . The strap should not interfere with installation of the tank assembly to the transmission jack.
6. Attach an overhead lifting device (1) to the tank assembly frame.
7. Raise the tank and J 45397 assembly from the floor and place the assembly on the transmission jack. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
8. Attach the J 45397 (3) to the transmission jack (4). See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
9. Install the tank strap mounting bolts (1) while holding the appropriate nut with a wrench (2). Tighten: Tighten the bolts to 39N.m (29 lb ft).
10. Install the tank to tank fuel line (3,4) with new O-rings. Lubricate the O-rings with petroleum jelly prior to installation. Tighten: Tighten the fuel line fittings to 37N.m (27 lb ft).

1. Position the tank assembly beneath the vehicle.
2. Raise the tank assembly onto the tank frame studs.
3. Install the mounting nuts (1) and bolts (2). Tighten: Tighten the mounting nuts to 81 N.m (60 lb ft).
4. Connect the fuel outlet line (4) to the high pressure lock-off (2) using new O-rings. Lubricate the O-rings with petroleum jelly or equivalent. Tighten: Tighten the fitting to 37 N.m (27 lb ft).
5. Connect the electrical connectors (1-4) at the high pressure lock-off solenoids as necessary.
6. Connect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G Van Service Manual.
7. Prime the CNG fuel system by cycling the ignition ON and OFF several times.
8. Start the engine and use the J 45878 in order to inspect for CNG fuel system leaks at each serviced fitting. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
9. Install the fuel tank cover. Refer to «Fuel Tank Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

1. Remove the screws (3) that retain the fuel filler door to the body.
2. Remove the fuel filler door from the body.

1. Position the fuel filler door to the body.
2. Install the fuel filler door retaining screws (3) to the body. Tighten: Tighten the screws to 5 N.m (44 lb in).

1. Remove the screws (3) and spacers (2) that retain the fuel filler door to the body.
2. Remove the fuel filler door from the body.

1. Position the fuel filler door to the body.
2. Install the fuel filler door retaining screws (3) and spacers (2) to the body. Tighten: Tighten the screws to 5 N.m (44 lb in).

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to the «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
3. Remove the fill line fitting (3) from the fill valve.
4. Remove the fill valve jam nut (1).
5. Remove the fill valve (7) from the mounting plate.

1. Install the fill valve (7) into the mounting plate.
2. Install the fill valve jam nut (1). Tighten: Tighten the nut to 28 N.m (21 lb ft).
3. Install the fill line fitting (3) to the fill valve using a new O-ring. Lubricate the O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the fill line fitting to 37 N.m (27 lb ft).
4. Connect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
5. Prime the CNG fuel system by cycling the ignition ON and OFF several times.
6. Start the engine and use the J 45878 in order to inspect for CNG fuel system leaks at each serviced fitting. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to the «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
3. Remove the fill line fitting (3) from the fill valve.
4. Remove the fill valve jam nut (5).
5. Remove the fill valve (7) from the mounting plate (6).

1. Install the fill valve (7) into the mounting plate (6).
2. Install the fill valve jam nut (5). Tighten: Tighten the nut to 28 N.m (21 lb ft).
3. Install the fill line fitting (3) to the fill valve using a new O-ring. Lubricate the O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the fill line fitting to 37 N.m (27 lb ft).
4. Connect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
5. Prime the CNG fuel system by cycling the ignition ON and OFF several times.
6. Start the engine and use the J 45878 in order to inspect for CNG fuel system leaks at each serviced fitting. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

1. Remove the O-ring (1).
2. Remove the circlip (2).
3. Remove the fill valve filter (3).
4. Clean the filter in solvent.
5. Blow dry the filter using compressed air.
6. Be sure that the filter passages are clear. Replace the filter if needed.

1. Install the fill valve filter (3).
2. Install the circlip (2).
3. Install the O-ring (1).

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to the «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
3. Remove the outlet line (2) from the filter.
4. Discard the copper sealing washer.
5. Remove the inlet line from the filter.
6. Discard the copper sealing washer.
7. Remove the filter hold down clamp bolt.
8. Remove the filter.

1. Install the filter into the hold down clamp. Tighten: Tighten the clamp bolt to 13 N.m (115 lb in).
2. Install the fuel outlet line fitting (2) to the filter with a NEW copper sealing washer. Tighten: Tighten the line fitting to 37 N.m (27 lb ft).
3. Install the fuel inlet line fitting to the filter with a NEW copper sealing washer. Tighten: Tighten the line fitting to 37 N.m (27 lb ft).
4. Connect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
5. Prime the CNG fuel system by cycling the ignition ON and OFF several times.
6. Start the engine and use the J 45878 in order to inspect for CNG fuel system leaks at each serviced fitting. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to the «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
3. Remove the outlet line (3) from the filter.
4. Discard the copper sealing washer.
5. Remove the inlet line from the filter.
6. Discard the copper sealing washer.
7. Remove the filter hold down clamp bolt.
8. Remove the filter.

1. Install the filter into the hold down clamp. Tighten: Tighten the clamp bolt to 13 N.m (115 lb in).
2. Install the fuel outlet line fitting (3) to the filter with a NEW copper sealing washer. Tighten: Tighten the line fitting to 37 N.m (27 lb ft).
3. Install the fuel inlet line fitting to the filter with a NEW copper sealing washer. Tighten: Tighten the line fitting to 37 N.m (27 lb ft).
4. Connect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
5. Prime the CNG fuel system by cycling the ignition ON and OFF several times.
6. Start the engine and use the J 45878 in order to inspect for CNG fuel system leaks at each serviced fitting. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to the «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
3. Remove the CNG fuel tank cover. Refer to «Fuel Tank Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
4. Disconnect the fuel tank pressure (FTP) sensor (2) electrical connector.
5. Remove the FTP sensor (2) from the tank valve. Discard the O-ring.

1. Install the FTP sensor (2) in the tank valve using a new O-ring. Tighten: Tighten the FTP sensor to 15 N.m (133 lb in).
2. Connect the FTP sensor electrical connector.
3. Connect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
4. Start the vehicle and use the J 45878 in order to inspect for CNG fuel leaks at each serviced fitting. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
5. Install the CNG fuel tank cover. Refer to «Fuel Tank Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to the «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
3. Clamp off the coolant hoses using coolant hose pinch pliers.
4. Mark the hoses prior to removal.
5. Remove the hose clamps and hoses from the high pressure regulator coolant fittings (1, 2).
6. Remove the fuel inlet lines (1,4) from the high pressure regulator (3) and discard the O-rings.
7. Remove the fuel outlet line (2) from the filter and discard the copper sealing washer.
8. Remove the mounting bracket bolts (1).
9. Remove the high pressure regulator assembly.

1. Install the high pressure regulator and mounting bracket (2) to the vehicle frame using the mounting bolts (1). Tighten: Tighten the bolts to 38 N.m (28 lb ft).
2. Install the fuel inlet fitting (3) using a new O-ring. Lubricate the O-ring with petroleum jelly or equivalent. Tighten: Tighten the fuel inlet fitting to 45 N.m (33 lb ft).
3. Connect the fuel inlet line (1,4) to the fuel inlet fitting using new O-rings. Lubricate the O-ring with petroleum jelly or equivalent. Tighten: Tighten the fuel inlet line fittings to 45 N.m (33 lb ft).
4. Connect the fuel outlet line (2) to the filter using a new copper sealing washer. Tighten: Tighten the fuel outlet line fitting to 37 N.m (27 lb ft).
5. Install the coolant hoses and clamps to the high pressure regulator coolant fittings (1, 2) as marked during removal.
6. Remove the coolant hose pinch pliers.
7. Connect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
8. Prime the CNG fuel system by cycling the ignition ON and OFF several times.
9. Start the engine and use the J 45878 in order to inspect for CNG fuel system leaks at each serviced fitting. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
10. Inspect for proper coolant level and fill as necessary.

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to the «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
3. Clamp off the coolant hoses using coolant hose pinch pliers.
4. Mark the hoses prior to removal.
5. Remove the hose clamps and hoses from the high pressure regulator coolant fittings (1, 2).
6. Remove the fuel inlet lines (1,4) from the high pressure regulator (2) and discard the O-rings.
7. Remove the fuel outlet line (3) from the filter and discard the copper sealing washer.
8. Remove the mounting bracket bolts (1).
9. Remove the mounting bracket nut (3).
10. Remove the high pressure regulator assembly (2).

1. Install the high pressure regulator and mounting bracket (2) to the vehicle frame using the mounting bolts (1). Tighten: Tighten the bolts to 38 N.m (28 lb ft).
2. Install the high pressure regulator mounting support bracket nut (3). Tighten: Tighten the nut to 38 N.m (28 lb ft).
3. Install the fuel inlet fitting (3) using a new O-ring. Lubricate the O-ring with petroleum jelly or equivalent. Tighten: Tighten the fuel inlet fitting to 45 N.m (33 lb ft).
4. Connect the fuel inlet line (1,4) to the fuel inlet fitting using new O-rings. Lubricate the O-ring with petroleum jelly or equivalent. Tighten: Tighten the fuel inlet line fittings to 45 N.m (33 lb ft).
5. Connect the fuel outlet line (3) to the filter using a new copper sealing washer. Tighten: Tighten the fuel outlet line fitting to 37 N.m (27 lb ft).
6. Install the coolant hoses and clamps to the high pressure regulator coolant fittings (1, 2) as marked during removal.
7. Remove the coolant hose pinch pliers.
8. Connect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
9. Prime the CNG fuel system by cycling the ignition ON and OFF several times.
10. Start the engine and use the J 45878 in order to inspect for CNG fuel system leaks at each serviced fitting. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
11. Inspect for proper coolant level and fill as necessary.

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to the «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
3. Remove the fuel line (4) from the fuel inlet fitting (3).
4. Remove the fuel inlet fitting (3) from the high pressure regulator (2).
5. Remove the fuel filter spring, seal and filter (1).

1. Install the filter spring, filter and seal in order (1).
2. Install the fuel inlet fitting (3) using a new O-ring. Lubricate the O-ring with petroleum jelly or equivalent. Tighten: Tighten the fuel inlet fitting to 45 N.m (33 lb ft).
3. Install the fuel inlet line (4) to the fuel inlet fitting (3) using a new O-ring. Lubricate the O-ring with petroleum jelly or equivalent. Tighten: Tighten the fuel inlet line fitting to 37 N.m (27 lb ft).
4. Connect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
5. Prime the CNG fuel system by cycling the ignition ON and OFF several times.
6. Start the engine and use the J 45878 in order to inspect for CNG fuel system leaks at each serviced fitting. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

1. J 45878 Combustible Gas Detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
2. J 43602 HPL Crowfoot. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

1. Remove the fuel tank cover. Refer to «Fuel Tank Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
2. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
3. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Platform Service Manual.
4. Remove the CNG fuel tank from the vehicle. Refer to «Fuel Tank Replacement - Rear (Passenger/Cargo)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) or «Fuel Tank Replacement - Rear (Cutaway)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
5. Vent the CNG fuel pressure from the tank. Refer to «Fuel Tank Venting Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-tank-venting-procedure) .
6. Disconnect the vent hose (1) from the HPL.
7. Remove the manual vent tool and all fittings.
8. Remove the fuel inlet fitting from the HPL and discard the O-rings.
9. Remove the fuel outlet fitting from the HPL and discard the O-rings.
10. Using the J 43602 HPL crowfoot removal tool, loosen the HPL. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
11. Unthread the HPL from the CNG fuel tank and discard the O-ring.
12. Inspect the inside of the CNG fuel tank for water, rust, or other contaminants.
13. If necessary, clean the CNG fuel tank. Refer to «Fuel Tank Cleaning»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-tank-cleaning) .

1. Install a NEW O-ring on the HPL.
2. Lubricate the O-ring with petroleum jelly.
3. Install the HPL in the tank and tighten hand-tight.
4. Tighten the HPL as specified below. Tighten: Tighten the HPL to a nominal torque of 305 N.m (225 lb ft) at 0 degrees. You must compensate for the torque wrench and the HPL crowfoot. Refer to the formula below for compensation of the torque wrench. To obtain your dial reading perform the following procedure: Multiply your torque wrench length in inches by 305 (225). 18 inch torque wrench example: 18 X 305 = 5,490. Add 3 to the length of your torque wrench. 18 inch torque wrench example: 18 + 3 = 21. Divide the first value obtained by the second value obtained. The result indicates the amount of torque your wrench should tighten the HPL to. 18 inch torque wrench example: 5,490 divided by 21 = 261.4. For an 18 inch long torque wrench tighten the HPL to 261.4 N.m.
5. Complete the fuel tank installation by connecting the fuel lines, electrical connectors and fuel tank pressure sensor. Refer to «Fuel Tank Replacement - Front (KL8)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) or «Fuel Tank Replacement - Rear (Passenger/Cargo)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) or «Fuel Tank Replacement - Rear (Cutaway)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
6. Fuel the vehicle and check for CNG fuel leaks in 3 stages at the following pressures: 500 psi 1,500 psi 3,000 psi
7. With the J 45878 , inspect for fuel leaks at the HPL at EACH pressure. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
8. Connect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van Service Manual.
9. Start and operate the engine on CNG.
10. Inspect for fuel leaks at each serviced fitting with the J 45878 . See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
11. Attach the information label supplied with the replacement HPL in a visible location on the head of the tank.
12. Install the fuel tank cover. Refer to «Fuel Tank Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Before removal, clean the fuel rail assemblies with a spray type engine cleaner, GM X-30A or equivalent, if necessary. Follow the package instructions. Do not soak fuel rails in liquid cleaning solvent.
4. Remove the engine cover. Refer to Engine Cover Replacement in Interior Trim in the G/H Van service manual.
5. Disconnect the low pressure lock-off (LPL) solenoid electrical connector.
6. Remove the LPL solenoid coil retaining nut (2).
7. Remove the LPL solenoid coil (3).
8. Remove the LPL solenoid core tube (4).
9. Disconnect the fuel inlet line (8) and discard the copper sealing washer.
10. Disconnect the fuel crossover line (7) and discard the copper sealing washer.
11. Remove the LPL solenoid housing mounting screws (1).
12. Remove the LPL solenoid housing from the fuel rail (5) and discard the O-ring (12).

1. Install the low pressure lock-off (LPL) solenoid housing to the fuel rail (5) using a new O-ring (12). Lubricate the O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the mounting screws to 4 N.m (35 lb in).
2. Connect the CNG fuel inlet line (8) using a NEW copper sealing washer. Tighten: Tighten the fuel line fitting to 37 N.m (27 lb ft).
3. Connect the CNG fuel crossover line (7) using a NEW copper sealing washer. Tighten: Tighten the fuel line fitting to 27 N.m (20 lb ft).
4. Ensure the LPL piston assembly (5) spring is installed inside the core tube (4). Lubricate the piston O-ring with petroleum jelly or equivalent before installation.
5. Install the core tube (4) and piston assembly (5) into the LPL solenoid housing (1). Lubricate the core tube O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the core tube to 41 N.m (30 lb ft).
6. Install the LPL solenoid coil (3) onto the core tube (4).
7. Install the LPL solenoid coil retaining nut (2). Tighten: Tighten the nut to 14 N.m (10 lb ft).
8. Connect the LPL solenoid electrical connector.
9. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
10. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or equivalent combustible gas detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
11. Install the engine cover. Refer to Engine Cover Replacement in Interior Trim in the G/H Van service manual.

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Relieve the gasoline fuel system pressure. Refer to Fuel Pressure Relief Procedure in Engine Controls in the G/H Van service manual.
3. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
4. Remove the engine cover. Refer to Engine Cover Replacement in Interior Trim in the G/H Van service manual.
5. Before removal, clean the fuel rail assemblies with a spray type engine cleaner, GM X-30A or equivalent, if necessary. Follow the package instructions. Do not soak fuel rails in liquid cleaning solvent.
6. Disconnect the CNG fuel lines (7, 8, 10) from the fuel rails.
7. Disconnect the fuel rail temperature and pressure sensor electrical connectors (3, 4).
8. Disconnect the low pressure lock-off solenoid connector.
9. Disconnect the 8 CNG fuel injector electrical connectors (2, 12).
10. Disconnect the accelerator control cable and the cruise control cable from the cable bracket.
11. Disconnect the cruise control cable engine-end fitting from the stud on the throttle lever, if equipped.
12. Disconnect the accelerator control cable and the cruise control cable from the throttle body.
13. Remove the upper engine wire harness retainer nut.
14. Disconnect the evaporative emission (EVAP) purge valve harness connector.
15. Reposition the upper engine wire harness aside.
16. Mark the electrical connectors to their corresponding gasoline injectors to ensure correct sequential injector firing order after reassembly. Pull the connector position assurance (CPA) (2) of the injector connector up.
17. Pull the tab (1) on the injector connector in.
18. While pushing the tab (1) on the injector connector in, release the CPA (2).
19. Disconnect the fuel injector electrical connector.
20. Repeat steps for each injector connector.
21. Disconnect the fuel feed and return pipes (1, 2) from the fuel rail.
22. Disconnect the fuel pressure regulator vacuum line.
23. Loosen the crossover tube to right fuel rail retainer screw.
24. Remove the right fuel rail attaching nuts (1).
25. Remove the left fuel rail attaching nuts (1).
26. Remove the gasoline and CNG fuel rails as an assembly.

1. Remove the crossover tube rail retainer screws.
2. Remove the crossover tube.
3. Remove the injector (7) retainer bolt and clip (10).
4. Remove the injector from the fuel rail with a pulling a twisting motion.
5. Remove the fuel injector adaptor (9) from the fuel injector.
6. Repeat steps for the remaining fuel injectors.
7. Remove the fuel rail pressure (FRP) sensor (13) and discard the O-ring.
8. Remove the fuel rail temperature (FRT) sensor (11) and discard the O-ring.
9. Remove the low pressure lock-off (LPL) solenoid (2) mounting screws (1) and discard the O-ring (12).

1. Install the fuel injector (7) into the fuel rail (5) using a new O-ring (6). Lubricate the new O-ring with petroleum jelly.
2. Install the fuel injector retainer bolt and clip (10). Tighten: Tighten the retainer bolt to 7 N.m (61 lb in).
3. Lubricate the new injector tip O-ring (8) with clean engine oil.
4. Repeat steps 1, 2 and 3 for the remaining fuel injectors.
5. Install the fuel rail pressure (FRP) sensor (13) using a new O-ring. Lubricate the O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the FRP sensor to 8 N.m (71 lb in).
6. Install the fuel rail temperature (FRT) sensor (11) using a new O-ring. Lubricate the O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the FRP sensor to 13 N.m (10 lb ft).
7. Install the low pressure lock-off (LPL) solenoid (2) to the fuel rail (5) using a new O-ring (12). Lubricate the O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the mounting screws to 4 N.m (35 lb in).
8. Lubricate the new gasoline lower injector O-ring seals (4) with clean engine oil.
9. Install the new O-ring seals (4) on the spray tip end of each fuel injector (3).
10. Install the gasoline fuel injector into the fuel rail.
11. Install the fuel injector retainer clip.
12. Install the end of each fuel injector into the injector adapter.
13. Repeat steps for the remaining injectors.
14. Assemble the CNG fuel injectors into the fuel injector adapters (3).
15. Install new O-rings on the crossover tube (25).
16. Lubricate the new O-rings with clean engine oil.
17. Install the crossover tube (25) into the fuel rails (14, 15).
18. Loosely install the crossover tube fuel rail retainers (5, 21).

1. Install the fuel rail assemblies onto the intake manifold.
2. Apply a 5 mm (0.020 in) band of GM P/N 1234382 threadlock, or equivalent, to the threads of all of the fuel rail attaching studs.
3. Install the right fuel rail attaching nuts (1). Tighten: Tighten the bolts to 4 N.m (35 lb in).
4. Install the left fuel rail attaching nuts (1). Tighten: Tighten the nuts to 4 N.m (35 lb in).
5. Tighten the gasoline crossover pipe retainer screws to 3.8 N.m (34 lb in).
6. Connect the fuel injector electrical connectors to the corresponding engine cylinder injector for both gasoline and CNG (1, 2, 11, 12).
7. Connect the CNG fuel rail pressure sensor (4) and temperature sensor (3) electrical connectors.
8. Connect the low pressure lock-off solenoid electrical connector.
9. Connect the CNG fuel inlet line (8) using a NEW copper sealing washer. Tighten: Tighten the fuel line fitting to 37 N.m (27 lb ft).
10. Connect the CNG fuel crossover line (7, 10) using NEW copper sealing washers. Tighten: Tighten the fuel line fittings to 27 N.m (20 lb ft).
11. Connect the fuel pressure regulator vacuum line.
12. Connect the gasoline fuel feed and return pipes (1, 2) to the fuel rail.
13. Position the upper engine wire harness in place.
14. Connect the EVAP purge solenoid connector.
15. Install the retainer nut to the upper engine wire harness. Tighten: Tighten the nut to 5.5 N.m (49 lb in).
16. Connect the accelerator control cable and the cruise control cable to the cable bracket.
17. Connect the accelerator control cable and the cruise control cable to the throttle body.
18. Connect the cruise control cable engine-end fitting to the stud on the throttle lever, if equipped.
19. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
20. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
21. With a scan tool command a switch-over to gasoline and inspect for gasoline fuel leaks.
22. Install the engine cover. Refer to Engine Cover Replacement in Interior Trim in the G/H Van service manual.

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Remove the engine cover. Refer to Engine Cover Replacement in Interior Trim in the G/H Van service manual.
4. Before removal, clean the fuel rail assemblies with a spray type engine cleaner, GM X-30A or equivalent, if necessary. Follow the package instructions. Do not soak fuel rails in liquid cleaning solvent.
5. Disconnect the CNG fuel lines (7, 8, 10) from the fuel rails.
6. Disconnect the fuel rail temperature and pressure sensor electrical connectors (3, 4).
7. Disconnect the low pressure lock-off solenoid connector.
8. Disconnect the 8 CNG fuel injector electrical connectors (2, 12).
9. Disconnect the accelerator control cable and the cruise control cable from the cable bracket.
10. Disconnect the cruise control cable engine-end fitting from the stud on the throttle lever, if equipped.
11. Disconnect the accelerator control cable and the cruise control cable from the throttle body.
12. Remove the upper engine wire harness retainer nut.
13. Reposition the upper engine wire harness aside.
14. Remove the right fuel rail attaching bolts (1).
15. Remove the CNG fuel rail.
16. Remove the left fuel rail attaching bolts (1).
17. Remove the CNG fuel rail.

1. Remove the injector (7) retainer bolt and clip (10).
2. Remove the injector from the fuel rail with a pulling a twisting motion.
3. Repeat steps for the remaining fuel injectors.
4. Remove the fuel rail pressure (FRP) sensor (13) and discard the O-ring.
5. Remove the fuel rail temperature (FRT) sensor (11) and discard the O-ring.
6. Remove the low pressure lock-off (LPL) solenoid (2) mounting screws (1) and discard the O-ring (12).

1. Install the fuel injector (7) into the fuel rail (5) using a new O-ring (6). Lubricate the new O-ring with petroleum jelly.
2. Install the fuel injector retainer bolt and clip (10). Tighten: Tighten the retainer bolt to 7 N.m (61 lb in).
3. Lubricate the new injector tip O-ring (8) with clean engine oil.
4. Repeat steps 1, 2 and 3 for the remaining fuel injectors.
5. Install the fuel rail pressure (FRP) sensor (13) using a new O-ring. Lubricate the O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the FRP sensor to 8 N.m (71 lb in).
6. Install the fuel rail temperature (FRT) sensor (11) using a new O-ring. Lubricate the O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the FRP sensor to 13 N.m (10 lb ft).
7. Install the low pressure lock-off (LPL) solenoid (2) to the fuel rail (5) using a new O-ring (12). Lubricate the O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the mounting screws to 4 N.m (35 lb in).

1. Install the fuel rail assemblies onto the intake manifold.
2. Apply a 5 mm (0.020 in) band of GM P/N 1234382 threadlock, or equivalent, to the threads of all of the fuel rail attaching bolts.
3. Install the right fuel rail attaching bolts (1). Tighten: Tighten the bolts to 4 N.m (35 lb in).
4. Install the left fuel rail attaching bolts (1). Tighten: Tighten the bolts to 4 N.m (35 lb in).
5. Connect the fuel injector electrical connectors to the corresponding engine cylinder injector (2, 12).
6. Connect the CNG fuel rail pressure sensor (4) and temperature sensor (3) electrical connectors.
7. Connect the low pressure lock-off solenoid electrical connector.
8. Connect the CNG fuel inlet line (8) using a NEW copper sealing washer. Tighten: Tighten the fuel line fitting to 37 N.m (27 lb ft).
9. Connect the CNG fuel crossover line (7, 10) using NEW copper sealing washers. Tighten: Tighten the fuel line fittings to 27 N.m (20 lb ft).
10. Position the upper engine wire harness in place.
11. Install the retainer nut to the upper engine wire harness. Tighten: Tighten the nut to 5.5 N.m (49 lb in).
12. Connect the accelerator control cable and the cruise control cable to the cable bracket.
13. Connect the accelerator control cable and the cruise control cable to the throttle body.
14. Connect the cruise control cable engine-end fitting to the stud on the throttle lever, if equipped.
15. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
16. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
17. Install the engine cover. Refer to Engine Cover Replacement in Interior Trim in the G/H Van service manual.

1. Remove the fuel rail assembly. Refer to «Fuel Rail Assembly Replacement (KL6)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) or «Fuel Rail Assembly Replacement (KL8)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
2. Remove the injector (7) retainer bolt and clip (10).
3. Remove the injector from the fuel rail with a pulling a twisting motion.
4. Repeat steps 2 and 3 for the remaining fuel injectors.

1. Install the fuel injector (7) into the fuel rail (5) using a new O-ring (6). Lubricate the new O-ring with petroleum jelly.
2. Install the fuel injector retainer bolt and clip (10). Tighten: Tighten the retainer bolt to 7 N.m (61 lb in).
3. Lubricate the new injector tip O-ring (8) with clean engine oil.
4. Repeat steps 1, 2 and 3 for the remaining fuel injectors.
5. Install the fuel rail assembly. Refer to «Fuel Rail Assembly Replacement (KL6)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) or «Fuel Rail Assembly Replacement (KL8)»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Before removal, clean the fuel rail with a spray type engine cleaner, GM X-30A or equivalent, if necessary. Follow the package instructions. Do not soak fuel rails in liquid cleaning solvent.
4. Remove the engine cover. Refer to Engine Cover Replacement in Interior Trim in the G/H Van service manual.
5. Disconnect the fuel rail pressure (FRP) sensor electrical connectors (4).
6. Remove the FRP sensor (13) and discard the O-ring.

1. Install the fuel rail pressure (FRP) sensor (13) using a new O-ring. Lubricate the O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the FRP sensor to 8 N.m (71 lb in).
2. Connect the FRP electrical connector (4).
3. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
4. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
5. Install the engine cover. Refer to Engine Cover Replacement in Interior Trim in the G/H Van service manual.

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Before removal, clean the fuel rail with a spray type engine cleaner, GM X-30A or equivalent, if necessary. Follow the package instructions. Do not soak fuel rails in liquid cleaning solvent.
4. Remove the engine cover. Refer to Engine Cover Replacement in Interior Trim in the G/H Van service manual.
5. Disconnect the fuel rail temperature (FRT) sensor electrical connector (3).
6. Remove the FRT sensor (11) and discard the O-ring.

1. Install the fuel rail temperature (FRT) sensor (11) using a new O-ring. Lubricate the O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the FRT sensor to 13 N.m (10 lb ft).
2. Connect the FRT electrical connector (3).
3. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
4. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
5. Install the engine cover. Refer to Engine Cover Replacement in Interior Trim in the G/H Van service manual.

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the G/H Van service manual.
4. Disconnect the fill line fitting (7) at the fill valve and discard the O-ring.
5. Disconnect the fuel line fitting (10) at the check valve (11) and discard the O-ring.
6. Remove the P-clamp screw (8).
7. Remove the fuel line from the vehicle.

1. Connect the fill line fitting (7) to the fill valve using a NEW O-ring. Lubricate the new O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the fill line fitting to 45 N.m (33 lb ft).
2. Connect the fill line fitting (10) to the check valve (11) using a NEW O-ring. Lubricate the new O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the fuel line fitting to 45 N.m (33 lb ft).
3. Install the P-clamp mounting screw (8). Tighten: Tighten the mounting screw to 7 N.m (62 lb in).
4. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
5. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the G/H Van service manual.
4. Disconnect the fill line fitting (1) at the fill valve and discard the O-ring.
5. Disconnect the fuel line fitting (4) at the check valve (5) and discard the O-ring.
6. Remove the P-clamp bolt (2).
7. Remove the fuel line from the vehicle.

1. Connect the fill line fitting (1) to the fill valve using a NEW O-ring. Lubricate the new O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the fill line fitting to 45 N.m (33 lb ft).
2. Connect the fill line fitting (4) to the check valve (5) using a NEW O-ring. Lubricate the new O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the fuel line fitting to 45 N.m (33 lb ft).
3. Install the P-clamp mounting bolt (8), washer and nut. Tighten: Tighten the mounting bolt to 25 N.m (18 lb in).
4. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
5. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Remove the engine cover. Refer to Engine Cover Replacement in Interior Trim in the G/H Van service manual.
4. Disconnect the CNG crossover fuel line (7, 10) from the fuel rails.

1. Connect the CNG fuel crossover line (7, 10) using NEW copper sealing washers. Tighten: Tighten the fuel line fittings to 27 N.m (20 lb ft).
2. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
4. Install the engine cover. Refer to Engine Cover Replacement in Interior Trim in the G/H Van service manual.

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Remove the engine cover. Refer to Engine Cover Replacement in Interior Trim in the G/H Van service manual.
4. Disconnect the CNG fuel line (8) from the fuel rail.
5. Remove the fuel line P-clamp mounting bolts (9).
6. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the G/H Van service manual.
7. Remove the fuel line P-clamp mounting bolt (7).
8. Disconnect the fuel line fitting (2) at the filter.
9. Remove the fuel line from the vehicle.

1. Connect the CNG fuel line fitting (2) to the filter using a NEW copper sealing washer. Tighten: Tighten the fuel line fitting to 37 N.m (27 lb ft).
2. Install the fuel line P-clamp and mounting bolt (7). Tighten: Tighten the bolt to 10 N.m (89 lb in).
3. Install the LEFT fuel line P-clamp and mounting bolt (9). Tighten: Tighten the left P-clamp bolt to 34 N.m (25 lb ft)
4. Install the RIGHT fuel line P-clamp and mounting bolt (9). Tighten: Tighten the right P-clamp bolt to 7 N.m (62 lb in)
5. Connect the fuel line fitting (8) to the fuel rail. Tighten: Tighten the fuel line fitting to 37 N.m (27 lb ft)
6. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
7. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
8. Install the engine cover. Refer to Engine Cover Replacement in Interior Trim in the G/H Van service manual.

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Remove the engine cover. Refer to Engine Cover Replacement in Interior Trim in the G/H Van service manual.
4. Disconnect the CNG fuel line (8) from the fuel rail.
5. Remove the fuel line P-clamp mounting bolts (9).
6. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the G/H Van service manual.
7. Remove the fuel line P-clamp mounting bolt (7).
8. Disconnect the fuel line fitting (3) at the filter.
9. Remove the fuel line from the vehicle.

1. Connect the CNG fuel line fitting (3) to the filter using a NEW copper sealing washer. Tighten: Tighten the fuel line fitting to 37 N.m (27 lb ft).
2. Install the fuel line P-clamp and mounting bolt (7). Tighten: Tighten the bolt to 10 N.m (89 lb in).
3. Install the LEFT fuel line P-clamp and mounting bolt (9). Tighten: Tighten the left P-clamp bolt to 34 N.m (25 lb ft)
4. Install the RIGHT fuel line P-clamp and mounting bolt (9). Tighten: Tighten the right P-clamp bolt to 7 N.m (62 lb in)
5. Connect the fuel line fitting (8) to the fuel rail. Tighten: Tighten the fuel line fitting to 37 N.m (27 lb ft)
6. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
7. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
8. Install the engine cover. Refer to Engine Cover Replacement in Interior Trim in the G/H Van service manual.

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the G/H Van service manual.
4. Disconnect the fuel line fitting (3) at the filter (1) and discard the copper sealing washer.
5. Disconnect the fuel line fitting (2) at the high pressure regulator (HPR) and discard the copper sealing washer.
6. Remove the fuel line from the vehicle.

1. Connect the CNG fuel line fitting (3) to the filter (1) using a NEW copper sealing washer. Tighten: Tighten the fuel line fitting to 37 N.m (27 lb ft).
2. Connect the CNG fuel line fitting (2) to the HPR using a NEW copper sealing washer. Tighten: Tighten the fuel line fitting to 37 N.m (27 lb ft).
3. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
4. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the G/H Van service manual.
4. Disconnect the fuel line fitting (6) at the filter and discard the copper sealing washer.
5. Disconnect the fuel line fitting (3) at the high pressure regulator (HPR) and discard the copper sealing washer.
6. Remove the fuel line from the vehicle.

1. Connect the CNG fuel line fitting (6) to the filter using a NEW copper sealing washer. Tighten: Tighten the fuel line fitting to 37 N.m (27 lb ft).
2. Connect the CNG fuel line fitting (3) to the HPR using a NEW copper sealing washer. Tighten: Tighten the fuel line fitting to 37 N.m (27 lb ft).
3. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
4. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the G/H Van service manual.
4. Remove the CNG fuel tank cover. Refer to «Fuel Tank Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
5. Disconnect the fuel line fitting (2, 3) at each high pressure lock-off (HPL) fitting.
6. Remove the fuel line from the vehicle.

1. Connect the CNG fuel line between the high pressure lock-off solenoid fittings (2, 3) using NEW O-rings. Lubricate the new O-rings with petroleum jelly or equivalent before installation. Tighten: Tighten the fuel line fittings to 45 N.m (33 lb ft).
2. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
4. Install the CNG fuel tank cover. Refer to «Fuel Tank Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the G/H Van service manual.
4. Remove the CNG fuel tank cover. Refer to «Fuel Tank Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
5. Disconnect the fuel line fitting (3, 4) at each high pressure lock-off (HPL) fitting.
6. Remove the fuel line from the vehicle.

1. Connect the CNG fuel line between the high pressure lock-off solenoid fittings (3, 4) using NEW O-rings. Lubricate the new O-rings with petroleum jelly or equivalent before installation. Tighten: Tighten the fuel line fittings to 45 N.m (33 lb ft).
2. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .
4. Install the CNG fuel tank cover. Refer to «Fuel Tank Cover Replacement»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the G/H Van service manual.
4. Disconnect the fill line fitting (10) at the check valve (11) and discard the O-ring.
5. Remove the check valve (11) from the tee fitting (1) and discard the O-ring.

1. Install the check valve (11) to the tee fitting (1) using a NEW O-ring. Lubricate the new O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the check valve to 45 N.m (33 lb ft).
2. Connect the fill line fitting (10) to the check valve (11) using a NEW O-ring. Lubricate the new O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the fuel line fitting to 45 N.m (33 lb ft).
3. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
4. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the G/H Van service manual.
4. Disconnect the fuel line fitting (4) at the check valve (5) and discard the O-ring.
5. Remove the check valve (5) from the tee fitting (7) and discard the O-ring.

1. Install the check valve (5) to the tee fitting (7) using a NEW O-ring. Lubricate the new O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the fill line fitting to 45 N.m (33 lb ft).
2. Connect the fill line fitting (4) to the check valve (5) using a NEW O-ring. Lubricate the new O-ring with petroleum jelly or equivalent before installation. Tighten: Tighten the fuel line fitting to 45 N.m (33 lb ft).
3. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
4. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the G/H Van service manual.
4. Disconnect the fuel line fitting (2) at the check valve tee (1).
5. Mark the location and remove the fuel line P-clamp mounting bolts (2, 3, 4) and clamps.
6. Disconnect the fuel line fitting (4) at the high pressure lock-off (HPL) solenoid.
7. Remove the fuel line from the vehicle.

1. Install the fuel line and P-clamps (2, 3, 4) into the vehicle. Tighten: Tighten the mounting bolts to 10 N.m (89 lb in).
2. Connect the CNG fuel line fitting (2) to the check valve tee (1). Tighten: Tighten the fuel line fitting to 45 N.m (33 lb ft).
3. Connect the CNG fuel line fitting (4) to the HPL. Tighten: Tighten the fuel line fitting to 45 N.m (33 lb ft).
4. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
5. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the G/H Van service manual.
4. Disconnect the fuel line fitting (2) at the check valve tee (1).
5. Disconnect the fuel line fitting (4) at the high pressure lock-off (HPL) solenoid.
6. Remove the fuel line from the vehicle.

1. Connect the CNG fuel line fitting (2) to the check valve tee (1). Tighten: Tighten the fuel line fitting to 45 N.m (33 lb ft).
2. Connect the CNG fuel line fitting (4) to the HPL. Tighten: Tighten the fuel line fitting to 45 N.m (33 lb ft).
3. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
4. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the G/H Van service manual.
4. Disconnect the CNG fuel line (4) from the high pressure regulator (HPR).
5. Mark the location and remove the fuel line P-clamp mounting bolts (1, 2, 5, 6) and clamps.
6. Disconnect the fuel line fitting (4) at the check valve tee (1).
7. Remove the fuel line from the vehicle.

1. Install the fuel line and P-clamps (1, 2, 5, 6) into the vehicle. Tighten: Tighten the U-nut mounting bolts to 10 N.m (89 lb in). Tighten the self-tapping mounting bolts to 7 N.m (62 lb in).
2. Connect the CNG fuel line fitting (4) to the check valve tee. Tighten: Tighten the fuel line fitting to 45 N.m (33 lb ft).
3. Connect the CNG fuel line fitting (4) to the HPR (3). Tighten: Tighten the fuel line fitting to 45 N.m (33 lb ft).
4. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
5. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

J 45878 Combustible Gas Detector. See Special Tools and Equipment .

1. Relieve the CNG fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions__fuel-pressure-relief-procedure) .
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the G/H Van service manual.
4. Disconnect the CNG fuel line (4) from the high pressure regulator (HPR).
5. Mark the location and remove the fuel line P-clamp mounting bolts (1, 2, 3, 4) and clamps.
6. Disconnect the fuel line fitting (4) at the check valve tee (1).
7. Remove the fuel line from the vehicle.

1. Install the fuel line and P-clamps (1, 2, 3, 4) into the vehicle. Tighten: Tighten the mounting bolts to 10 N.m (89 lb in).
2. Connect the CNG fuel line fitting (4) to the check valve tee. Tighten: Tighten the fuel line fitting to 45 N.m (33 lb ft).
3. Connect the CNG fuel line fitting (4) to the HPR (2). Tighten: Tighten the fuel line fitting to 45 N.m (33 lb ft).
4. Install the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical in the G/H Van service manual.
5. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings with the J 45878 or an equivalent leak detector. See «Special Tools and Equipment»(/chevrolet/chevy-express-g3500/1996-2012/remont/testing-diagnostics/#engine-control-system-60l-alternative-fuel-introductions) .

Powertrain Control Module (PCM)

The PCM controls fuel delivery and for KL6 vehicles, determines which fuel system the engine is operating on. The PCM monitors various engine and vehicle functions to provide the correct amount of CNG or gasoline fuel under all operating conditions. This provides excellent driveability and fuel economy while maintaining reduced emission levels. When operating on CNG, the PCM grounds the AFO enable circuit. When the AFO enable circuit is grounded, the fuel injector control module (FICM) will sequentially operate the CNG fuel injectors. The PCM is not capable of operating the high current CNG fuel injectors. The PCM injector pulse width signals are received by the FICM and duplicate pulse width signals are generated by the FICM in order to operate the CNG injectors.

The PCM monitors 3 PWM signals from the FICM in order to determine CNG fuel rail pressure, CNG fuel rail temperature, and the diagnostic status of the FICM. The FICM monitors the CNG fuel rail pressure sensor, and the CNG fuel rail temperature sensor. This information is communicated to the PCM by dedicated PWM circuits. The FICM also performs internal diagnostics, and communicates this information by a dedicated PWM circuit. For further detail refer to Fuel Injector Control Module Description .

The PCM controls the Low Pressure Lock-Off (LPL) solenoids, and the High Pressure Lock-Off (HPL) solenoids. The PCM commands the HPL solenoids open for 1 second at every ignition ON, in order to prime the CNG fuel system. The PCM commands the HPLs, and the LPL open, when the engine is cranking or running on CNG.

When operating on gasoline, the PCM will turn the fuel indicator lamp ON. The fuel indicator lamp (FIL) is located within the headlamp switch assembly near the fuel gauge select switch. The FIL is also turned ON for a two-second bulb check whenever the ignition is turned ON. The fuel gauge select switch allows the vehicle operator the ability to request fuel gauge display of either fuel tank.

The PCM also determines the CNG fuel level. The PCM monitors the FTP and FTT sensors that are located on one of the CNG tank high pressure lock-off solenoids. The PCM performs a calculation of the CNG pressure and CNG temperature in order to determine an accurate CNG fuel level. On Bi-fuel (KL6) models the gasoline fuel level is determined by the PCM in a conventional manner using an in-tank variable resistor sensor.

For further PCM description refer to Powertrain Control Module (PCM) Description in Engine Controls in the G/H Van Service Manual.

Fuel Injector Control Module Description

The fuel injector control module (FICM) is a non-flashable control module that is not capable of serial data communication.

The FICM performs the following tasks

1. internally routes the powertrain control module (PCM) injector control circuits to the CNG injector drivers or the gasoline injectors (KL6 only)
2. operates the CNG injectors based upon the PCM injector signals
3. supplies the reference, ground and signal circuits to the fuel rail pressure (FRP) and fuel rail temperature (FRT) sensors
4. communicates the FRP sensor values to the PCM using a dedicated PWM circuit
5. communicates the FRT sensor values to the PCM using a dedicated PWM circuit
6. communicates FICM, FRP and FRT diagnostic information to the PCM using a dedicated PWM circuit

The PCM controls fuel delivery and determines fuel system operation on Bi-fuel (KL6) equipped vehicles. The PCM monitors various engine and vehicle functions to provide the correct amount of CNG or gasoline fuel under all operating conditions. The fuel injector control circuits, an AF Enable circuit and 3 PWM communication circuits connect the PCM to the FICM. The PCM is not capable of operating the high current CNG fuel injectors. The PCM injector pulse width signals are received by the FICM and duplicate pulse width signals are generated by the FICM in order to operate the CNG injectors. KL6 equipped vehicles utilize a FICM that contains internal relays. When operating on gasoline the internal relays allow the PCM injector pulse width to go directly to the gasoline injectors.

Fuel Mode Operation (KL6 and KL8)

The PCM grounds the AF Enable circuit when operating on CNG. When the AF Enable circuit is grounded the FICM will operate the CNG injectors based upon the PCM pulse width signals. The FICM will convert the FRP and FRT sensors voltage signals to independent PWM signals that the PCM monitors for fuel trim adjustment. The PCM also monitors the FICM Diagnostic Input circuit for proper FICM operation.

KL6 Operation

When gasoline operation is desired the PCM opens the AF Enable circuit. Switchover from one fuel to the other is always performed in an orderly, sequential manner. Since some injectors are in the middle of injecting the previous fuel, the FICM will wait until that cylinders fuel delivery is complete and will then switch over in sequential firing order.

FRP and FRT Sensor PWM Circuits

The fuel rail pressure and temperature sensor information is required by the PCM for fuel trim adjustment. The PCM does not have the ability to supply and monitor the FRP and FRT sensors. The FICM performs this task by supplying the FRP and FRT sensors a 5 volt reference, low reference and signal circuit. The signal voltage of the FRP and FRT sensors are converted into independent PWM signals. The PWM signals are sent to the PCM through dedicated circuits. The PCM converts the PWM signals into pressure and temperature values. The FICM also performs diagnosis of the FRP and FRT circuits as well as internal FICM diagnostic information. The FICM diagnostic information is converted into a PWM signal. The FICM PWM signal is sent to the PCM through a dedicated circuit.

FICM Diagnostic Circuit

The PCM monitors the FICM diagnostic circuit in order to set FICM related DTCs. The FICM diagnostic circuit is a 5 volt circuit that is pulse width modulated by the FICM in order to communicate diagnostic information to the PCM. The FICM Diagnostic Data table indicates the various PWM signals created.

FICM Diagnostic Data

The PCM controls fuel delivery and for KL6 vehicles, determines which fuel system operates the engine. The PCM monitors various engine and vehicle functions to provide the correct amount of CNG or gasoline fuel under all operating conditions. This provides excellent driveability and fuel economy while maintaining reduced emission levels. When operating on gasoline, the PCM will turn the fuel indicator lamp ON. The fuel indicator lamp (FIL) is located within the headlamp switch assembly near the fuel gauge select switch. The FIL is also turned ON for a two-second bulb check whenever the ignition is turned ON. The fuel gauge select switch allows the vehicle operator the ability to request fuel gauge display of either fuel tank.

Fuel Injector Control Module (FICM)

The PCM is connected to the FICM. The PCM is not capable of operating the high current CNG fuel injectors. The PCM injector pulse width signals are received by the FICM and duplicate pulse width signals are generated by the FICM in order to operate the CNG injectors. KL6 equipped vehicles utilize a FICM that contains internal relays. When operating on gasoline the internal relays allow the PCM injector pulse width to go directly to the gasoline injectors. Refer to Fuel Injector Control Module Description for more detailed description information.

Fuel Supply Components

The primary components of the CNG fuel SUPPLY system are as follows

1. Fuel Tanks
2. Fill Valve and Fill Line
3. High Pressure Lock-Off (HPL) solenoids
4. Fuel Tank Pressure (FTP) sensor
5. Fuel Tank Temperature (FTT) sensor
6. Fuel Lines
7. In-line Fuel Filter
8. Low Pressure Lock-Off (LPL) solenoid
9. Fuel Rail

Fuel Tanks

The CNG Fuel Tanks are constructed of high-strength steel covered with a two-stage epoxy coating finish. A high pressure lock-off solenoid is threaded into the end of each fuel tank and is used to prevent fuel flow during non-cranking or running engine conditions. The fuel tanks also have a protective cover. The cover is designed to protect the tank from road debris.

On passenger and cargo vans the fuel tanks are mounted in tandem, transverse behind the rear axle, under the vehicle. On cutaway vans the fuel tanks are mounted in tandem, parallel to the vehicle frame, behind the rear axle. Dedicated equipped vehicles (KL8) also utilize a third, mid-frame mounted tank that is located in place of the gasoline fuel tank.

Federal Government Regulations require that the fuel tank and brackets be inspected every three years or 60 000 km (36,000 miles), which-ever comes first. Fuel tank inspection results should be recorded in the CNG Fuel Tank Inspection Record area of the owners manual supplement (if applicable). The service life of the CNG fuel tank is 15 years from the date of manufacture. All CNG fuel tanks regardless of inspection results must be replaced after 15 years.

Fill Valve and Fill Line

The fill valve receives fuel from the fill nozzle at the CNG dispensing station. The fill valve seals to the dispensing nozzle with an O-ring. Before re-fueling this O-ring must be inspected and replaced if missing or damaged. The fill valve contains an internal filter element designed to trap contaminants. This filter must be periodically inspected and cleaned. The fill valve is mounted behind the fuel filler door. Refer to the owners manual supplement for fuel tank filling procedures.

The fill line is constructed of 3/8 in. flexible, steel-braided hose protected by a plastic cover. The fill line connects the fill valve to a line union check valve and is sealed at all connections with an O-ring.

In the event of fill valve leakage, the line union check valve is designed to minimize the amount of CNG fuel leakage.

High Pressure Lock-Off (HPL) Solenoids

The HPL is a normally closed, solenoid valve. The HPL solenoids, and a low pressure lock-off (LPL) solenoid in the fuel line, prevent fuel flow. The PCM commands ONLY the HPLs open for 1 second at EVERY ignition ON in order to prime the CNG fuel system. The CNG prime pulse is performed in order to allow the fuel tank pressure (FTP) sensor to monitor the amount of fuel pressure in the fuel line. The PCM commands BOTH the HPLs and the LPL open when engine RPM indicates that the engine is cranking or running on CNG.

Fuel Tank Pressure (FTP) Sensor

The FTP sensor is a pressure transducer. The PCM supplies about 5 volts on the FTP reference circuit. The PCM also supplies a signal and ground circuit to the FTP. When the fuel tanks are full (high pressure) a high voltage signal will be monitored by the PCM. The FTP sensor is threaded into one of the rear fuel tank HPL solenoids.

The volume of CNG will vary with temperature and pressure. Accurate CNG fuel level cannot be determined by pressure only. In order to compensate for the different volume factors a fuel tank temperature (FTT) sensor is mounted within the HPL. The PCM monitors the FTT sensor and performs a calculation on the FTP voltage vs. the in-tank temperature. The PCM will then display the temperature corrected fuel level.

The CNG FTP sensor should not be confused with the gasoline fuel tank pressure (FTP) sensor that is utilized for Evaporate (EVAP) emissions monitoring.

Fuel Tank Temperature (FTT) Sensor

The FTT is a thermistor mounted inside the HPL and is not serviceable separately from the HPL.

The FTT thermistor has high resistance when cold and low resistance when hot. The PCM supplies about 5 volts to the FTT signal circuit. When FTT resistance is high (cold sensor) the FTT signal voltage is high. As the FTT warms and resistance drops, less signal voltage is monitored by the PCM.

The volume of CNG will vary with temperature and pressure. Accurate CNG fuel level cannot be determined by pressure only. In order to compensate for the different volume factors a fuel tank temperature (FTT) sensor is mounted within the HPL. The PCM monitors the FTT sensor and performs a calculation on the FTP voltage vs. the in-tank temperature. The PCM will then display the temperature corrected fuel level.

Fuel Lines

The CNG fuel system uses different fuel line types. The type used is dependent upon the pressure the fuel line is required to handle.

High Pressure Line

The high pressure line is stainless steel tubing with matching high pressure O-ring face seal (ORFS) fittings. The individual tubes are pre-formed with fittings installed. All O-ring face seal fittings use nitrile rubber O-rings that are specific for gaseous fuel operation. These O-rings must be replaced with the correct replacement part whenever a line is opened.

Intermediate Pressure Fuel Hose

The intermediate pressure fuel hose assemblies are unique flexible lines for connection at fuel injector pressures. The individual lines connect using flared fittings.

When installing pipe thread fittings DO NOT use Teflon® tape. Tape fragments could lodge in a regulator and allow fuel pressure to exceed specified levels. The use of pipe sealant with Teflon® is required.

All hose, lines and fittings must be replaced ONLY with the correct replacement GMSPO part number.

In-line Fuel Filter

The in-line fuel filter is located under the vehicle between the high pressure regulator and the low pressure lock-off (LPL) solenoid. The filter is serviced at regular intervals.

Low Pressure Lock-Off (LPL)

The HPL is a normally closed, solenoid valve. The solenoid provides a fuel shut-off to the fuel rails. The LPL solenoid is mounted to the right hand fuel rail. The LPL is only commanded ON when engine RPM indicates the engine is cranking or running on CNG.

Fuel Rail

The CNG fuel rails are constructed of aluminum and are mounted on either side of the intake manifold. Fuel enters the right fuel rail from the LPL solenoid that is mounted to the rail. A crossover fuel line connects the two fuel rails. The fuel rails are mounted in the same location as the gasoline fuel rails on KL8 equipped vehicles. The fuel rails are mounted slightly above the gasoline fuel rails on KL6 equipped vehicles. KL6 vehicles also utilize an injector tee in order to allow both fuels to inject into the same cylinder.

Fuel Metering Components

The primary components of the CNG fuel METERING system are as follows

1. High Pressure Regulator (HPR)
2. CNG Fuel Injectors
3. Fuel Rail Pressure Sensor
4. Fuel Rail Temperature Sensor

High Pressure Regulator (HPR)

The HPR is supplied with fuel from the CNG fuel tank at up to 24821 kPa (3600 psi) through high pressure stainless steel lines. The HPR reduces fuel pressure to around 1241 kPa (180 psi). The pressure drop within the regulator causes fuel temperature to drop. The HPR is connected to the vehicle engine cooling system in order to prevent HPR freeze-up. The outlet of the HPR is the injector pressure stage. Fuel flows out of the HPR and through the inline filter and into the low pressure lock-off (LPL) solenoid. The HPR contains an over-pressure relief device (PRD) which will not allow pressure above 1896 kPa (275 psi) on the output stage of the HPR. The HPR has an internal, serviceable 40 micron filter. This filter must be serviced periodically.

Gaseous Fuel Injectors

The gaseous fuel injectors are pulse-width modulated and sequentially fired. The injector voltage is supplied by a fuse. The FICM controls the ground path. KL6 vehicles utilize an injector tee in order to allow both fuels to inject into the same cylinder. KL8 vehicles mount the injectors directly into the intake manifold port.

Fuel Rail Pressure Sensor

The fuel rail pressure (FRP) sensor is a pressure transducer. The FICM supplies about 5 volts on the FRP sensor reference circuit. The FICM also supplies a signal and ground circuit to the FRP sensor. When fuel pressure is high the signal voltage is high. The FRP sensor data is transmitted to the PCM through a PWM signal circuit. The FRP signal is used by the PCM for fuel trim.

Fuel Rail Temperature Sensor

The fuel rail temperature (FRT) sensor is a thermistor. The FRT thermistor has high resistance when cold and low resistance when hot. The FICM supplies about 5 volts to the FRT sensor signal circuit. When the FRT sensor is cold its resistance is high and the signal voltage is high. As the FRT sensor warms and resistance drops, less signal voltage is monitored by the FICM. The FRT sensor data is transmitted to the PCM through a PWM signal circuit. The FRT signal is used by the PCM in order to adjust fuel trim.

Bi-Fuel (KL6) CNG System Operation

The primary fuel source of a Bi-fuel vehicle is compressed natural gas (CNG). The vehicle will only switch-over to gasoline operation if one of the following conditions is present

1. The fuel tank pressure sensor indicates CNG fuel pressure is below 896 kPa (130 psi).
2. Every 100th start the vehicle will start and run briefly on gasoline. After this, a switch-over to CNG will occur during the first decel condition.
3. A system fault is detected by the PCM or FICM.
4. The engine cranks for 5 seconds and fails to start on CNG.

60 Day Cycle

It is recommended that every 60 days the vehicle be cycled between CNG and gasoline. This ensures the gasoline fuel system stays in good working condition and also accommodates for seasonal changes in gasoline formulation. Perform the following steps every 60 days.

1. With the vehicle operating on CNG check and fill the gasoline level.
2. Operate the vehicle until the CNG fuel tank is empty and the vehicle switches over to gasoline operation.
3. Operate the vehicle until the gasoline tank is near empty.
4. Refill both fuel tanks.
5. The vehicle will switch-over to CNG operation.
6. Repeat procedure in 60 days.

Fuel Indicator Lamp (FIL)

The fuel indicator lamp (FIL) is contained within the headlamp switch assembly. The fuel indicator lamp indicates which fuel system the vehicle is operating on. The PCM controls the operation of the fuel indicator lamp. The fuel indicator lamp illuminates only when the engine is operating on gasoline. The fuel indicator lamp will also illuminate for several seconds during start-up as a bulb check.

Fuel Gauge Operation

The CNG fuel level is determined by the PCM. The PCM monitors the FTP and FTT sensors that are located on one of the CNG tank high pressure lock-off solenoids. The PCM performs a calculation of the CNG pressure and CNG temperature in order to determine an accurate CNG fuel level. On Bi-fuel (KL6) models the gasoline fuel level is determined by the PCM in a conventional manner using an in-tank variable resistor sensor.

Bi-Fuel (KL6) Fuel Gauge Operation

Under normal conditions the instrument panel fuel gauge displays the level of fuel that the vehicle is operating on. A fuel gauge selector switch allows the two different fuel system tank levels to be displayed by the one instrument panel fuel gauge. The fuel gauge selector switch is a momentary-closed type switch located within the headlamp switch assembly. The fuel gauge switch allows the vehicle operator to observe the fuel level of the non-operating fuel system. The PCM monitors the status of the switch. When the switch is depressed the PCM changes the fuel level signal to display the non-operating system fuel level. Once requested, the non-operating fuel system level will be displayed for about 10 seconds.

The PCM communicates fuel level to the instrument panel fuel gauge through serial data.

Dedicated CNG (KL8) Fuel System Operation

The dedicated CNG fuel system operation is functionally the same as the bi-fuel CNG fuel system. The vehicle does not contain any gasoline fuel system components. A third CNG fuel tank is placed in the location of the frame mounted gasoline fuel tank. The vehicle does utilize a PCM that operates in conjunction with the FICM. The calibration programmed into the PCM has disabled the gasoline specific DTCs. The PCM still performs diagnostics on the vehicle sensors such as ECT, TP, IAT, etc.

Special Tools

Special Tools Illustration Tool Number/Description 7000081 Tech-2 Diagnostic Scan Tool J 26792 Spark Tester J 34142-B 12V Unpowered Test Light J 34730-2C TBI Harness Test Lamp J 35616-A Connector Test Adapter Kit J 38125-B Terminal Repair Kit J 39021 Fuel Injector Coil and Balance Tester J 39200 High Impedance Digital Multimeter (DMM) J 39970 CNG Electronic Pressure Gauge Kit J 45878 Combustible Gas Detector J 42435-A CNG Tank Venting Kit J 42598 Vehicle Data Recorder J 43602 HPL Crowsfoot - 2.5 in J 44244 CNG Tank Support Harness J 45397 CNG Dual Tank Lifting Kit J 45397-2 CNG Tank Lifting Tool J 45529 Tank Removal Tool

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Scheme 21

Scheme 22

Scheme 23

See also:
• Diagnostic System Check - Alternative Fuels (Engine Controls)
• Fastener Notice
• Engine Controls Component Views
• Engine Controls Connector End Views
• Fuel Injection Control Module Connector End Views
• Fastener Tightening Specifications
• Fuel Tank Venting Procedure
• Fuel Pressure Relief Procedure
• Fuel Tank Cleaning
• Fuel Injector Control Module Description