The ignition relay is a normally open relay. The relay armature is held in the open position by spring tension. When the ignition switch is turned to the run or start position, current will flow through the relay coil. A wire connected to the other end of the relay coil completes the path to ground. The electromagnetic field created by the relay coil, overcomes the spring tension and moves the armature allowing the relay contact to close. The closed relay contacts allow current to flow from the battery to the following fuses:
• | OXY SEN |
• | ELEK IGN |
• | F/INJR |
• | TRANS |
• | ENG EMIS |
When the ignition switch is turned to the off position, the electromagnetic field collapses. This action allows the spring tension to move the armature away from the relay contacts, which interrupts current flow to the fuses.
If the ignition relay fails to close, the engine will crank, but will not run. The class 2 communications will be available with the use of a scan tool.
The ignition relay table assumes that the vehicle battery is fully charged. Refer to Battery Inspection/Test in Engine Electrical.
Step | Action | Yes | No | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Power Distribution Schematics and Ground Distribution Schematics in Wiring Systems and Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module Connector End Views | |||||||||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | |||||||||||||
2 |
Does the test lamp illuminate on at least one test point of each fuse? | Go to Step 3 | Go to Step 11 | ||||||||||||
3 |
Does the test lamp illuminate on either test point of the fuse? | Go to Step 4 | Go to Step 36 | ||||||||||||
4 |
Does the test lamp illuminate on any of the fuse test points? | Go to Step 8 | Go to Step 5 | ||||||||||||
5 | Test the ignition relay load circuit bus bar of the underhood junction block between the ignition relay and the fuses to the circuit components for a short to battery positive voltage. Refer to Circuit Testing in Wiring Systems. Did you find a condition? | Go to Step 35 | Go to Step 6 | ||||||||||||
6 |
Does the test lamp illuminate at any of the fuse terminals? | Go to Step 7 | Go to Step 32 | ||||||||||||
7 |
Does the test lamp illuminate on either fuse terminal? | Go to Diagnostic System Check - Engine Electrical in Engine Electrical | Go to Step 34 | ||||||||||||
8 |
Does the test lamp illuminate? | Go to Step 33 | Go to Step 9 | ||||||||||||
9 |
Does the test lamp illuminate? | Go to Step 30 | Go to Step 10 | ||||||||||||
10 |
Does the test lamp illuminate? | Go to Step 31 | Go to Step 35 | ||||||||||||
11 |
Does the test lamp illuminate on both test points of the fuse? | Go to Step 15 | Go to Step 12 | ||||||||||||
12 | Does the test lamp illuminate on one test point of the 30-amp IGN 1 fuse? | Go to Step 13 | Go to Step 21 | ||||||||||||
13 | Test the battery positive voltage circuit between the underhood junction block and the ignition switch for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 36 | Go to Step 14 | ||||||||||||
14 | Test the ignition 1 voltage circuit between the ignition switch and the 10-amp PCM, BCM, U/H relay fuse terminals in the I/P fuse block for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 36 | Go to Step 33 | ||||||||||||
15 |
Does the test lamp illuminate on both test point of the fuse? | Go to Step 22 | Go to Step 16 | ||||||||||||
16 | Does the test lamp illuminate on one test point of the 10-amp PCM, BCM, U/H relay fuse? | Go to Step 19 | Go to Step 17 | ||||||||||||
17 | Test the ignition 1 voltage circuit between the ignition switch and the PCM, BCM, U/H relay fuse for a high resistance or for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 36 | Go to Step 18 | ||||||||||||
18 | Test the battery positive voltage circuit between the underhood junction block and the ignition switch for a high resistance or for an open. Refer to Circuit Testing in Wiring Systems. Did you find and correct the condition? | Go to Step 36 | Go to Step 33 | ||||||||||||
19 | Test the ignition 1 voltage circuit between the I/P fuse block and the underhood junction block for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 36 | Go to Step 20 | ||||||||||||
20 | Test the underhood junction block, ignition 1 voltage bus bar circuit to the ignition relay for a short to ground. Refer to Circuit Testing in Wiring Systems. Did you find a condition? | Go to Step 35 | Go to Step 32 | ||||||||||||
21 |
Does the test lamp illuminate? | Go to Step 35 | Go to Diagnostic System Check - Engine Electrical in Engine Electrical | ||||||||||||
22 |
Does the test lamp illuminate? | Go to Step 23 | Go to Step 35 | ||||||||||||
23 |
Does the test lamp illuminate? | Go to Step 25 | Go to Step 24 | ||||||||||||
24 | Test the ignition 1 voltage circuit between the I/P fuse block and the underhood junction block for a high resistance or for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 36 | Go to Step 35 | ||||||||||||
25 |
Does the test lamp illuminate? | Go to Step 27 | Go to Step 26 | ||||||||||||
26 |
Did you find and correct the condition? | Go to Step 36 | Go to Step 35 | ||||||||||||
27 |
Does the test lamp illuminate on at least one test point of each fuse? | Go to Step 28 | Go to Step 35 | ||||||||||||
28 |
Does the test lamp illuminate? | Go to Step 29 | Go to Step 35 | ||||||||||||
29 | Test for an intermittent and for a poor connection at the underhood junction block, ignition relay connector location. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find a condition? | Go to Step 35 | Go to Step 32 | ||||||||||||
30 | Repair the short to battery positive voltage in the ignition 1 voltage circuit between the ignition switch and the I/P fuse block. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 36 | -- | ||||||||||||
31 | Repair the short to battery positive voltage in the ignition 1 voltage circuit between the I/P fuse block and the underhood junction block electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 36 | -- | ||||||||||||
32 | Replace the ignition relay. Refer to Relay Replacement in Wiring Systems. Did you complete the replacement? | Go to Step 36 | -- | ||||||||||||
33 | Replace the ignition switch. Refer to Ignition and Start Switch Replacement in Steering Wheel and Column. Did you complete the replacement? | Go to Step 36 | -- | ||||||||||||
34 | Replace the A/C clutch relay. Refer to Relay Replacement in Wiring Systems. Did you complete the replacement? | Go to Step 36 | -- | ||||||||||||
35 | Replace the underhood electrical center. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Did you complete the replacement? | Go to Step 36 | -- | ||||||||||||
36 |
Does the engine start and run? | Go to Step 37 | |||||||||||||
37 |
Does a DTC set during this ignition cycle? | System OK |