Cummins ISB4.5 CM2150 Fault Code: 691 PID: 351 SPN: 1172 FMI: 3 Turbocharger 1 Compressor Intake Temperature Sensor Circuit – Voltage Above Normal or Shorted to High Source.
Circuit Description
The compressor intake air temperature sensor is a variable resistor sensor and is used to measure the temperature of the air entering the compressor intake of the turbocharger. The engine control module (ECM) supplies 5 volts to the compressor intake temperature signal circuit. The ECM monitors the change in voltage caused by changes in the resistance of the sensor to determine the air temperature.
Component Location
Some engines use a combination ambient air temperature/pressure sensor located in the OEM intake air plumbing rather than a turbocharger compressor intake temperature sensor. Refer to the engine wiring diagram to determine which sensor this application uses.
Conditions for Running the Diagnostics
This diagnostic runs continuously when the keyswitch is in the ON position.
Conditions for Setting the Fault Codes
The ECM detects that the compressor intake temperature signal voltage is greater than 4.8-VDC for more than 1 second.
Action Taken When the Fault Code is Active
-The ECM illuminates the amber CHECK ENGINE light and/or the malfunction indicator lamp (MIL) immediately when the diagnostic runs and fails.
-A default value for the compressor intake temperature reading is used.
Conditions for Clearing the Fault Code
-To validate the repair, start the engine and let it idle for 1 minute.
-The ECM will turn off the amber CHECK ENGINE light immediately after the diagnostic runs and passes.
-The ECM will turn off the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and passes.
-This fault code and malfunction indicator lamp (MIL) can also be cleared with INSITE™ electronic service tool.
Shop Talk
The turbocharger compressor intake air temperature sensor shares return wires in the engine harness with other sensors. An open return can cause multiple fault codes to be active. Before troubleshooting Fault Code 691, check for multiple fault codes. An extension harness between the main engine harness turbocharger compressor intake temperature sensor can be used, depending on the turbocharger arrangement.
Possible Causes
-Open return circuit in the harness, connectors, or sensor
-Open signal circuit or short circuit to a voltage source
-Damaged sensor.
Related
-
download MANCATS II v14.01 2014 Diagnostic software MAN CATS ( virtual machine )
MAN $75.00Rated 0 out of 5 -
VOLVO PREMIUM TECH TOOL PTT 2.7.116 + APCI 2021 + devtool ( ONLINE )
Trucks software $80.00Rated 0 out of 5
Related products
-
Allison 1000 & 2000 Gen 4 P0719 Brake Switch ABS Input Low
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: U1301 J1850 (Class 2) Serial Data Communication Link Low
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P0870 Transmission Pressure Switch Solenoid E Circuit
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P1891 Engine Throttle Position Sensor Pulse Width Modulation (PWM) Signal Low Input
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P0848 Transmission Pressure Switch Solenoid D Circuit High
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P0872 Transmission Pressure Switch Solenoid E Circuit Stuck Closed
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P0871 Transmission Pressure Switch Solenoid E Circuit Stuck Open
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P2810 Solenoid G Electrical
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P2771 Four-Wheel Drive Switch Circuit
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P0847 Transmission Pressure Switch Solenoid D Circuit Stuck Closed
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: U2104 CAN Bus Reset Counter Overrun
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P0873 Transmission Pressure Switch Solenoid E Circuit High
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: U0100 CAN Bus ECM Error
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: U1000 Class 2 Loss of Serial Data Communication
1000 & 2000 Gen 4 $50.00Rated 0 out of 5
-
SERVICE MANUAL 3000 AND 4000 SERIES GEN 4 GENERATION – ALLISON
Allison$19.00Original price was: $19.00.$17.00Current price is: $17.00.Rated 0 out of 5