Refer to Engine Controls Schematics .
Circuit Description
The vehicle theft deterrent (VTD) module produces the theft deterrent fuel enable signal when ignition is ON and the proper key resistor pellet is detected. The powertrain control module (PCM) monitors the fuel enable signal during crank. If the proper signal is present on the Class II Serial Data Circuit, the PCM enables the fuel delivery in order to allow the engine to start. If the PCM determines that the fuel enable signal is not present or incorrect while the engine is running, DTC P1626 is set. The engine continues to start and run as long as DTC P1626 is stored. If the problem affects inputs to the VTD signal, the starter motor may be disabled. Refer to and .
Test Description
The numbers below refer to the step numbers on the diagnostic table:
-
The J 26792 spark tester presents a more difficult load on the secondary ignition than a normal spark plug. If a miss, stumble, or hesitation is being caused by a spark plug not firing, the spark tester should also not fire.
-
Use a 5 percent saltwater solution in a spray bottle to induce voltage arcing to ground through faulty insulation of the spark plug wires.
-
If the no-spark condition follows the suspected coil, the coil is faulty. Otherwise, the ignition module is the cause of the no-spark. This test could also be performed by substituting a known good coil for the coil causing the no-spark condition.
Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On Board Diagnostic (OBD) System Check? | -- | ||||||
Does the scan tool indicate 3X reference signal present? | -- | |||||||
Did you observe any non-sparking cylinders? | -- | |||||||
Inspect and test the affected cylinder spark plug wire(s), Ignition coil(s), and Spark plugs for a short to ground or arching to ground. If Carbon tracking or corrosion is present, replace both components affected. Refer to Spark Plug Wire Harness Replacement in Engine Electrical, and Ignition Coil Replacement . Did you find and correct the condition? | -- | |||||||
5 | Test affected spark plug wire(s) for proper resistance. Replace spark plug wire(s) not near specification. Refer to Spark Plug Wire Harness Replacement in Engine Electrical. Did you find and correct the condition? | 600ohms per ft (1,968ohms per M) | ||||||
Switch the affected cylinder coil with a known good one. If the fault follows the affected coil replace it. Refer to Ignition Coil(s) Replacement, in Engine Controls. Did you find and correct the condition? | -- | |||||||
7 | Inspect the spark plug wires for proper routing and for the correct firing order. If any spark plug wires are found to be misrouted, reroute as necessary. Refer to Spark Plug Wire Harness Replacement in Engine Electrical. Did you find and correct the condition? | -- | ||||||
8 | With a DMM, test spark plugs for internal short to ground. Replace any grounded Spark plugs found. Refer to Spark Plug Replacement in Engine Electrical. Did you find and correct the condition? | -- | ||||||
9 |
If any spark plugs are found to be bad, replace the affected spark plugs. Refer to Spark Plug Replacement in Engine Electrical. Did you complete the replacement? | -- | -- | |||||
10 |
Does the test lamp illuminate? | -- | ||||||
11 | Connect a test lamp between the IC Module ignition feed circuit and IC Module ground circuit. Does the test lamp illuminate? | -- | ||||||
12 |
Does the test lamp illuminate when probing either circuits? | -- | ||||||
13 |
Does the test lamp illuminate when probing either circuits? | -- | ||||||
14 |
Does the DMM indicate AC Duty Cycle present? | -- | ||||||
15 | Test the 7X Crank Sensor circuits for the following conditions:
Repair any damaged wiring. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||||||
16 |
Did you complete the repair? | -- | -- | |||||
17 | Repair the short to ground in the 7X Reference circuit which illuminated the test lamp. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |||||
18 | Repair the short to voltage in the 7X Reference circuit which illuminated the test lamp. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |||||
19 | Repair the open in the IC Module ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |||||
20 | Replace the IC Module. Refer to Ignition Coil Replacement . Did you complete the replacement? | -- | -- | |||||
21 | Replace the 7X Crank Sensor. Refer to Crankshaft Position Sensor Replacement . Did you complete the replacement? | -- | -- |
