DTC P1300: IGNITOR CIRCUIT Toyota Tundra I

Circuit Description

Direct Ignition System (DIS) ignites 2 cylinders simultaneously with one ignition coil. Ignitor is integral to ignition coil. Direct ignition system may also be referred to as distributorless ignition system. ECM determines ignition timing and outputs ignition signal (IGT signal) for each cylinder. Based on IGT signals, ignitor controls primary ignition signals (IGC) for all ignition coils. At the same time, the ignitor delivers an ignition confirmation signal (IGF signal) to ECM to verify ignition coil has fired. DTC is set when there is no IGF signal to ECM for 6 consecutive IGT signals when engine is running. If DTC P1300 exists, ECM will operate in fail-safe mode. Possible causes are

1. Ignition system malfunction.
2. IGF or IGT circuit from ignition coil to ECM is open or shorted.
3. Defective ignition coil or ignitor.
4. Defective ECM.

Diagnostic Aids

Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

Scheme 264

1. Check for spark at misfiring cylinder. See SPARK TEST under IGNITION SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article. If spark exists, go to next step. If spark does not exist, go to step 4.
2. Check for open and short in Black/Yellow wire (IGF circuit) and electrical connectors between terminal No. 25 at ECM electrical connector E7 and terminal No. 4 at ignitor. See WIRING DIAGRAMS article. ECM is located behind glove box and heater duct. see scheme 2 For ECM electrical connector terminal identification see scheme 4 Ignitor is located at passenger's side of engine compartment, just behind the air cleaner assembly and contains a Black 10-pin electrical connector. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair as necessary.
3. Disconnect Black 10-pin electrical connector at ignitor. Remove glove box and heater duct (if necessary) for access to ECM with electrical connectors still installed on ECM. see scheme 2 Turn ignition on. Using voltmeter, check voltage between body ground and terminal No. 25 (Black/Yellow wire) at ECM electrical connector E7. see scheme 4 This is the IGF terminal on ECM. Voltage should 4.5-5.5 volts. If voltage is within specification, replace ignitor. If voltage is not within specification, replace ECM.
4. Remove glove box and heater duct (if necessary) for access to ECM with electrical connectors still installed on ECM. see scheme 2 Check for open and short in IGT1 circuit (Black/Blue wire), IGT2 circuit (Red/Blue wire) and IGT3 circuit (Light Green wire) and electrical connectors between ECM and ignitor. See WIRING DIAGRAMS article. Ignitor is located at passenger's side of engine compartment, just behind the air cleaner assembly and contains a Black 10-pin electrical connector. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair as necessary.
5. Using voltmeter, check voltage between body ground and terminals No. 11 (Black/Blue wire), No. 12 (Red/Blue wire) and No. 13 (Light Green wire) at ECM electrical connector E7 while cranking engine. see scheme 4 This is the IGT1, IGT2 and IGT3 terminals on ECM. Voltage should be more than.1 volt and less than 4.5 volts. If voltage is not within specification, go to next step. If voltage is within specification, go to step 7.
6. Disconnect electrical connector at ignitor. Using voltmeter, check voltage between body ground and terminals No. 11 (Black/Blue wire), No. 12 (Red/Blue wire) and No. 13 (Light Green wire) at ECM electrical connector E6 while cranking engine. see scheme 4 Voltage should be more than.1 volt and less than 5.0 volts. If voltage is not within specification, replace ECM. If voltage is within specification, replace ignitor.
7. Disconnect electrical connector at ignitor. Using voltmeter, check voltage between body ground and terminal No. 9 (Black/Red wire) at electrical connector for ignitor with ignition switch in ON and START positions. (Scheme 264) Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, repair Black/Red wire between ignition switch and ignitor. See WIRING DIAGRAMS article.
8. Check for open and short in wiring harness and electrical connectors between ignition switch and ignition coils, and between ignition coils and ignitor. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair components as necessary.
9. Check ignition coil resistance. See IGNITION COIL RESISTANCE under IGNITION SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article. If ignition coil is okay, go to next step. If ignition coil is defective, replace ignition coil.
10. Verify that White/Black wire (ground circuit) between terminal No. 3 at ignitor and ground connection are okay. See WIRING DIAGRAMS article. If ground circuit is okay, replace ignitor. If ground circuit is defective, repair as necessary.