PRE-RELEASE
DTC B1370
| DTC B1370 |
| Diagnostic Instructions |
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Perform the
Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
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Review
Strategy Based Diagnosis
for an overview of the diagnostic approach.
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Diagnostic Procedure Instructions
provides an overview of each diagnostic category.
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| DTC Descriptors |
DTC B1370 01
Control Module Ignition On and Start Circuit Short to Battery
DTC B1370 06
Control Module Ignition On and Start Circuit Open
| Diagnostic Fault Information |
| Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
| Instrument Cluster Ignition Terminal 19 | B1370 06 | B1370 06 | B1370 01 | - |
| Ignition Run/Crank Relay Ignition | B1370 06 | B1370 06 | - | - |
| Ignition Run/Crank Relay Ground | - | B1370 06 | - | - |
| Ignition Run/Crank Relay B+ | - | B1370 06 | - | - |
| Circuit/System Description |
The vehicle power mode master is the body control module (BCM). The ignition switch is a low current switch with multiple discrete circuits to the BCM.
The power mode master will activate relays and other direct outputs of the power mode master as needed according to the calculated power mode. Some relays controlled by the BCM are switched ignition voltage outputs that are pass through circuits within the BCM directly from the ignition switch. If these circuits short to ground, the B+ circuit fuse to the ignition switch will open.
| Conditions for Running the DTC |
B1370 01
Ignition switch is in the Accessory position.B1370 06
Ignition switch is in the Accessory, Run, or Crank positions.| Conditions for Setting the DTC |
B1370 01
Ignition circuit is shorted to voltage.B1370 06
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Ignition circuit is open.
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Ignition or run/crank relay circuit is shorted to ground.
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B+ circuit of the ignition run/crank relay is open or shorted to ground.
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Ignition run/crank relay control circuit open, including relay coil and ground.
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| Action Taken When the DTC Sets |
The Instrument Cluster still functions except check engine light is always off.
| Conditions for Clearing the DTC |
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The condition responsible for setting the DTC no longer exists.
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A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.
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| Reference Information |
Schematic Reference
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Instrument Cluster Schematics
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Power Distribution Schematics
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Power Moding Schematics
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Connector End View Reference
Component Connector End Views
Description and Operation
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Instrument Cluster Description and Operation
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Power Mode Description and Operation
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Electrical Information Reference
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Circuit Testing
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Connector Repairs
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Testing for Intermittent Conditions and Poor Connections
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Wiring Repairs
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Scan Tool Reference
Control Module References for scan tool information
| Circuit/System Verification |
Verify that DTC B144B is not set.
| Circuit/System Testing |
| 1. |
Ignition OFF, disconnect the KR74 ignition run relay.
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| 2. |
Test for less than 10 Ω between the ground circuit terminal 86 and ground.
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| 3. |
If greater than the specified range, test the ground circuit for an open/high resistance.
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Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 30 and ground.
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If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.
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Ignition ON, verify that a test lamp illuminates between the Ignition circuit terminal 85 and ground.
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| 7. |
If the test lamp does not illuminate, test the Ignition circuit for an open/high resistance. If the circuit tests normal replace the K9 BCM.
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Ignition OFF, reconnect the KR74 ignition run relay.
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| 9. |
Disconnect the harness connector at the P16 instrument cluster.
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| 10. |
Ignition ON, verify that a test lamp illuminates between the ignition terminal 19 and ground.
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| 11. |
If the test lamp does not illuminate and the Ignition fuse is good, test the ignition circuit for an open/high resistance. If the circuit tests normal, replace the KR74 ignition run relay. If the ignition fuse is open, test the ignition circuit for a short to ground. If the circuit tests normal, replace the P16 instrument cluster.
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If all circuits test normal, replace the P16 instrument cluster.
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| Repair Instructions |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
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Instrument Cluster Replacement
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Relay Replacement (Attached to Wire Harness)
Relay Replacement (Within an Electrical Center)
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Control Module References
for BCM replacement, programming and setup
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