DTC B144B
Diagnostic Instructions
DTC Descriptor
| DTC B144B 02: RUN/CRNK Relay Circuit Short to
Ground |
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
RUN/CRNK Relay Control
|
B144B 02
|
1
|
2
|
-
|
1. No Start.
2. Vehicle will start and continue to run after the ignition key
is removed.
|
|
| |
Circuit/System Description
The body control module (BCM) controls the RUN/CRNK relay
through the control circuit by applying voltage to the circuit. The
ignition RUN/CRNK is energized when the ignition switch is in ON or
START, or when a remote start is requested.
Conditions for Running the DTC
| • |
The system voltage is between
9-16 V. |
| • |
The DTC can only run when the
output is activated. |
Conditions for Setting the DTC
The BCM detects a short to ground in the RUN/CRNK relay control
circuit.
Action Taken When the DTC Sets
The module output driver will be shut down and not supply
voltage to the RUN/CRNK relay control circuit.
Conditions for Clearing the DTC
| • |
The current DTC will clear
when the module request for the output is removed or the
malfunction is no longer present. |
| • |
A history DTC clears when the
module ignition cycle counter reaches the reset threshold of 50,
without a repeat of the malfunction. |
Diagnostic Aids
Short to voltage in the RUN/CRNK relay control circuit will
cause the malfunction indicator lamp (MIL) to illuminate with the
ignition key OFF, and the engine will remain running if started and
the ignition key is removed.
Reference Information
Schematic Reference
Connector End View Reference
Component Connector End Views
Description and Operation
Power Mode Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
| 1. |
Ignition OFF, disconnect the
KR73 RUN/CRNK relay. |
| 2. |
Connect a test lamp between
the relay control circuit terminal 85 and terminal 86. |
| 3. |
Cycle the ignition ON and OFF.
The test lamp should turn ON and OFF when changing S39 ignition
switch positions. |
| ⇒ |
If the test lamp is always ON, test the control
circuit for a short to voltage. If the circuit tests normal,
replace the K9 BCM. |
| ⇒ |
If the test lamp is always OFF, test the control
circuit for a short to ground or open/high resistance. If the
circuit tests normal, replace the K9 BCM. |
| 4. |
If all circuits test normal,
test or replace the KR73 RUN/CRNK relay. |
Component Testing
| 1. |
Ignition OFF, disconnect the
KR73 RUN/CRNK relay. |
| 2. |
Test for 70-150 Ω
between terminals 85 and 86. |
| ⇒ |
If the resistance is not within the specified
range, replace the KR73 RUN/CRNK relay. |
| 3. |
Test for infinite resistance
between the following terminals: |
| ⇒ |
If less than specified, replace the KR73 RUN/CRNK
relay. |
| 4. |
Install a 3 A fused jumper
wire between relay terminal 86 and 12 V. Install a jumper wire
between relay terminal 85 and 86. Measure for less than 5 Ω
between terminals 87 and 85. |
| ⇒ |
If greater than specified, replace the KR73
RUN/CRNK relay. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the repair.
|
