A: No Start

A: Introduction See: A: No Start - Introduction

A1 CHECK PASSIVE ANTI-THEFT SYSTEM (SECURILOCK)

Note: This vehicle may have an anti-theft system, which may be activated, causing the no start condition. Verify by viewing anti-theft indicator light on instrument panel or a Diagnostic Trouble Code (DTC P1260) may be present.

• Verify anti-theft system.

Is the system activated?
Yes

• REFER to Antitheft and Alarm Systems.

No

• GO to A2

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A2 ATTEMPT TO CRANK ENGINE

Note: Verify inertia fuel shutoff (IFS) switch is set (button pushed in). Refer to Owner Guide for location.
Does engine crank?
Yes

• GO to A3

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No

• REFER to the Starting Systems.

A3 IDENTIFY TYPE OF NO START

Note: The purpose of this Test Step is to identify intermittent No Starts in order to guide the technician to the proper repair procedure.
Does the vehicle start now?
Yes

• Vehicle is an intermittent No Start. GO to Z2 See: Z: Intermittent - Pinpoint Test

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No

• Natural gas vehicles:
• KEY OFF. GO to HA47 See: Pinpoint Tests\HA: Natural Gas Fuel Control - Pinpoint Test

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• All others:
• KEY OFF. GO to A4

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A4 CHECK VREF VOLTAGE TO THROTTLE POSITION (TP) SENSOR

• Disconnect TP sensor.
• Key on, engine off.
• Measure voltage between VREF and SIG RTN circuit at the TP sensor harness connector. GO to Pinpoint Test DH See: Pinpoint Tests\DH: Throttle Position (TP) Sensor - Introduction to refer to the schematic.

Is voltage between 4.0 and 6.0 volts?
Yes

• KEY OFF. RECONNECT TP sensor. GO to A5

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No

• KEY OFF. GO to C1 See: Pinpoint Tests\C: Reference Voltage - Pinpoint Test

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A5 CHECK FLASH EPROM POWER SUPPLY (FEPS) CIRCUIT FOR SHORT TO POWER IN HARNESS

• Key on, engine off.
• Measure voltage between Pin 13 at the data link connector and battery negative post.
• (Refer to the Wiring Diagrams for connector location.)

Is voltage greater than 9.0 volts?
Yes

• REPAIR short to power.

No

• For coil-on-plug vehicles:
• KEY OFF. GO to A17

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• All others:
• KEY OFF. GO to A6

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A6 CHECK RPM IN THE PCM

Note: The scan tool must be connected to a reliable power source that is powered with the key in the START position (such as directly to the vehicle battery). Also verify that the vehicle battery is fully charged.

• Access RPM PID.
• While viewing the RPM PID, crank engine.

Does the RPM PID indicate cranking speed?
Yes

• KEY OFF. GO to JB1 See: JB: Secondary Ignition - Pinpoint Test

0. To check ignition.

• If OK:Natural Gas Vehicles

: GO to A9
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• All others:
• GO to A7

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No

• KEY OFF. GO to JD1 See: JD: Crankshaft Position (CKP) Sensor - Pinpoint Test

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A7 CHECK FUEL PRESSURE

WARNING: BEFORE SERVICING OR REPLACING ANY COMPONENTS IN THE FUEL SYSTEM, REDUCE THE POSSIBILITY OF INJURY OR FIRE BY FOLLOWING DIRECTIONS IN PINPOINT TEST HC WARNING, CAUTION, AND HANDLING.

• Release the fuel pressure.
• Install fuel pressure tester.
• Scan Tool connected.
• Key on, engine off.
• Enter Output Test Mode (refer to Section 2 See: SECTION 2: Diagnostic Methods ) and run the fuel pump to obtain maximum fuel pressure.

Is fuel pressure at the specified pressure (use the fuel pressure chart in Pinpoint Test HC)?
Yes

• GO to A8

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No

• KEY OFF. GO to HC1 See: HC: Fuel Delivery System - Pinpoint Test

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A8 CHECK FUEL PRESSURE LEAKDOWN

• GO to Pinpoint Test HC See: HC: Fuel Delivery System - Introduction and observe WARNING, CAUTION AND HANDLING.
• Fuel pressure tester installed.
• Scan Tool connected.
• Key on, engine off.
• Access Output Test Mode and run fuel pump to obtain maximum fuel pressure.
• Exit Output Test Mode.
• Verify fuel pressure remains within 34 kPa (5 psi) of the maximum pressure for 1 minute after turning pump off.

Does fuel pressure remain within 34 kPa (5 psi)?
Yes

• KEY OFF. GO to A9

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No

• KEY OFF. GO to HC1 See: HC: Fuel Delivery System - Pinpoint Test

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A9 CHECK FUEL INJECTORS FOR VPWR

Note: Check at least two fuel injectors, one on each bank. A no start condition can exist only if greater than 50% of the fuel injectors are without VPWR.

• Disconnect any two fuel injectors.
• Key on.
• Measure VPWR circuit voltage at fuel injector harness connectors.

Is voltage greater than 10.5 volts?
Yes

• KEY OFF.Natural Gas Vehicles:
• GO to A15

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• All Others:
• GO to A10

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No

• REPAIR VPWR circuit.

A10 CHECK FUEL INJECTORS ABILITY TO DELIVER FUEL

• Connect fuel pressure gauge to Schrader valve.
• Cycle key several times.
• Locate and disconnect the inertia fuel shutoff (IFS) switch.
• Monitor pressure gauge while cranking the engine for at least five seconds.

Is there a pressure drop greater than 34 kPa (5 psi) while cranking the engine?
Yes

• The electronic engine control system is not the cause of the

no start. RETURN to Section 3, Symptom Chart for further diagnosis. See: Symptom Related Diagnostic Procedures

No

• REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Programming and Relearning\Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM).

A15 CHECK FUEL PRESSURE ON NATURAL GAS VEHICLES

• Connect scan tool to DLC.
• Access FRP PID (fuel pressure).
• Record fuel pressure.
• Connect fuel pressure gauge to Schrader valve.
• Key on, engine off.
• Record fuel pressure.

Is fuel pressure between 552 and 827 kPa (80 and 120 psi) on the Scan Tool and fuel pressure gauge?
Yes

• KEY OFF. GO to A16

.

No

• KEY OFF. GO to HB1 See: Pinpoint Tests\HB: Natural Gas Fuel Delivery System - Pinpoint Test

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A16 CHECK INJECTOR SIGNAL FROM NGV MODULE

Note: This test requires a standard 12 volt test lamp. A properly operating system will show a dim glow.

• Connect test lamp between the injector signal circuit and VPWR circuit pin at the injector harness.
• Crank engine.

Does test lamp have a dim glow while cranking?
Yes

• REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Programming and Relearning\Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM). GO to A6

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No

• No light or continuously bright light. GO to HA47 See: Pinpoint Tests\HA: Natural Gas Fuel Control - Pinpoint Test

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A17 CHECK PCM DRIVER TO COILS

• Connect incandescent test lamp between B+ and each coil driver circuit at the harness connector.
• Crank engine.

Does lamp blink consistently and brightly (one blink per engine revolution)?
Yes

• KEY OFF. GO to A7

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No

• KEY OFF. GO to JD1 See: JD: Crankshaft Position (CKP) Sensor - Pinpoint Test

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