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Tahoe / Yukon Service Manual

DTC P0340 or P0341

Engine Controls and Fuel - 3.0L LM2 Diesel | Diagnostic Information and Procedures | Document ID: 5492925 Diagnostic Instructions Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis An overview of each diagnostic category can be found here: Diagnostic Procedure Instructions DTC Descriptor DTC P0340 Intake/Single Camshaft Position Sensor Circuit DTC P0341 Intake/Single Camshaft Position Sensor Performance Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performanc
5 V Reference P0641* P0340 P0641* —
Signal P0340 P0340 P0181, P0340, P10D1 P0341
Low Reference — P0340 — —
* Additional DTCs may set

Circuit/System Description

Circuit Description
5 V Reference Regulated voltage supplied by the control module.
Signal The control module input circuit has an internal resistance connected to 5 V.
Low Reference Grounded through the control module.
Component Description
B23 Camshaft Position Sensor The sensor contains a hall-effect sensor and additional electronics that processes the signal. It detects the change of strength of the magnetic field caused by the reluctor ring. When the strength changes, the sensor changes the amount of current it
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Component Description
current and voltage. The control module detects the frequency in which the signal changes, which is proportional to the rotational speed.
K20 Engine Control Module The control module controls a series of actuators to ensure optimal engine performance. The control module does this by reading values from a variety of sensors, interprets the data and adjusts the engine actuators accordingly.
Reluctor Ring There are 4 teeth on the edge of the camshaft position reluctor ring mounted on the camshaft.

The ECM uses information from the crankshaft position sensor and the camshaft position sensor(s) for sequencing and timing of the spark events. Conditions for Running the DTC P0340 Condition 1 DTC P0101, P0102, P0103 = Not set MAF Sensor = Greater than 2.0 g/s Condition 2 M64 Starter Motor = Active Crankshaft Position Sensor = Signal received Condition 3 M64 Starter Motor = Inactive Engine = Running Condition 4 DTC P0335, P0336 = Not set M64 Starter Motor = Active Crankshaft = Synchronized Condition 5 DTC P0335, P0336 = Not set Crankshaft = Synchronized Frequency the DTC runs = Continuously — After the running conditions are met P0341 Condition 1 DTC P0335, P0336 = Not set M64 Starter Motor = Active Crankshaft = Synchronized Condition 2 DTC P0335, P0336 = Not set Crankshaft = Synchronized Frequency the DTC runs = Continuously — After the running conditions are met Conditions for Setting the DTC P0340 Condition 1 Camshaft Position Sensor = No Signal — For greater than 5.5 s Condition 2 Camshaft Position Sensor = No Signal — For greater than 4 s — Starter is engaged. Condition 3 Camshaft Position Sensor = Less than 4 pulse(s) — For greater than 3 s Condition 4 Camshaft Position Sensor = No Signal — During the first 1 engine revolutions. Condition 5 Camshaft Position Sensor = No Signal — During 100 engine revolution(s) P0341 Condition 1 Camshaft Position Sensor = Less than 4 pulse(s) — During 1 engine revolution(s) Condition 2 Camshaft Position Sensor = Greater than 6 pulses — During 1 engine revolution(s) Condition 3 Camshaft Position Sensor = Less than 398 pulse(s) — Greater than 402 pulses — During 100 engine revolution(s) Actions Taken When the DTC Sets DTCs listed in the DTC Descriptor category = Type A DTC Conditions for Clearing the DTC DTCs listed in the DTC Descriptor category = Type A DTC Diagnostic Aids If there is a condition with the component/system, extended crank time during start-up may be observed. Reference Information Schematic Reference Engine Controls Schematics Connector End View Reference Master Electrical Component List Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs DTC Type Reference Powertrain Diagnostic Trouble Code (DTC) Type Definitions Scan Tool Reference Control Module References Circuit/System Verification

  1. Ignition » On / Vehicle » In Service Mode
  2. Verify DTC P0641, P0651 is not set. ⇒ If the DTC is set Refer to: DTC P0641, P0651, P0697, or P06A3 ⇓ If the DTC is not set
  3. Engine » Running
  4. Verify DTC P0341 is not set. ⇒ If the DTC is set Refer to: Circuit/System Testing ⇓ If the DTC is not set
  5. Verify the scan tool parameter: Intake/Single Camshaft Position Active Counter = Increments ⇒ If the parameter value does not increment Refer to: Circuit/System Testing ⇓ If the parameter value increments
  6. Verify the scan tool parameter: Intake/Single Camshaft Position Active Counter = Increments Perform the action while monitoring the parameter: Wiggle the harness and connector: B23 Camshaft Position Sensor Wiggle the harness and connector: K20 Engine Control Module ⇒ If the parameter value does not increment Repair as necessary » Wiring / Terminal(s) / Electrical Connector(s) ⇓ If the parameter value increments
  7. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data. Verify the DTC does not set. ⇒ If the DTC sets Refer to: Circuit/System Testing ⇓ If the DTC is not set
  8. All OK. Circuit/System Testing
  1. Ignition/Vehicle & All vehicle systems » Off
  2. Disconnect the electrical connector: B23 Camshaft Position Sensor
  3. Test for less than 10 Ω between the test points: Low Reference circuit terminal 2 & Ground ⇒ If 10 Ω or greater 3.1. Disconnect the electrical connector: K20 Engine Control Module 3.2. Test for less than 2 Ω between the test points: Low Reference circuit terminal 2 @ Component harness & The other end of the circuit @ Control module harness ⇒ If 2 Ω or greater » Repair the open/high resistance in the circuit. ⇒ If less than 2 Ω » Replace the component: K20 Engine Control Module ⇓ If less than 10 Ω
  4. Ignition » On / Vehicle » In Service Mode
  5. Test for 4.8 to 5.2 V between the test points: 5 V Reference circuit terminal 1 & Ground ⇒ If less than 4.8 V 5.1. Ignition/Vehicle » Off 5.2. Disconnect the electrical connector: K20 Engine Control Module 5.3. Test for infinite resistance between the test points: 5 V Reference circuit terminal 1 @ Component harness & Ground ⇒ If less than infinite resistance » Repair the short to ground on the circuit. ⇓ If infinite resistance 5.4. Test for less than 2 Ω between the test points: 5 V Reference circuit terminal 1 @ Component harness & The other end of the circuit @ Control module harness ⇒ If 2 Ω or greater » Repair the open/high resistance in the circuit. ⇒ If less than 2 Ω » Replace the component: K20 Engine Control Module ⇒ If greater than 5.2 V 5.1. Ignition/Vehicle » Off 5.2. Disconnect the electrical connector: K20 Engine Control Module 5.3. Ignition » On / Vehicle » In Service Mode 5.4. Test for less than 1 V between the test points: 5 V Reference circuit terminal 1 @ Component harness & Ground ⇒ If 1 V or greater » Repair the short to voltage on the circuit. ⇒ If less than 1 V » Replace the component: K20 Engine Control Module ⇓ If between 4.8 and 5.2 V
  6. Test for 4.8 to 5.2 V between the test points: Signal circuit terminal 3 & Ground ⇒ If less than 4.8 V 6.1. Ignition/Vehicle » Off 6.2. Disconnect the electrical connector: K20 Engine Control Module 6.3. Test for infinite resistance between the test points: Signal circuit terminal 3 @ Component harness & Ground ⇒ If less than infinite resistance » Repair the short to ground on the circuit. ⇓ If infinite resistance 6.4. Test for less than 2 Ω between the test points: Signal circuit terminal 3 @ Component harness & The other end of the circuit @ Control module harness ⇒ If 2 Ω or greater » Repair the open/high resistance in the circuit. ⇒ If less than 2 Ω » Replace the component: K20 Engine Control Module ⇒ If greater than 5.2 V 6.1. Ignition/Vehicle » Off 6.2. Disconnect the electrical connector: K20 Engine Control Module 6.3. Ignition » On / Vehicle » In Service Mode 6.4. Test for less than 1 V between the test points: Signal circuit terminal 3 @ Component harness & Ground ⇒ If 1 V or greater » Repair the short to voltage on the circuit. ⇒ If less than 1 V » Replace the component: K20 Engine Control Module ⇓ If between 4.8 and 5.2 V
  7. Verify DTC P0341 is not set. ⇒ If the DTC is set Verify the following conditions do not exist: B23 Camshaft Position Sensor & Reluctor Ring — Excessive play / Foreign material passing between the components / Incorrect air gap / Incorrect installation / Loose / Visible Damage Engine Oil — Contaminated / Dirty Timing Chain or Timing Belt — Visible Damage / Worn Timing Chain Tensioner or Timing Belt Tensioner — Visible Damage / Worn ⇒ If a condition exists » Repair or replace as necessary ⇒ If all conditions test normal » Test or replace the component: B23 Camshaft Position Sensor ⇓ If the DTC is not set
  8. Test or replace the component: B23 Camshaft Position Sensor Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Camshaft Position Sensor Replacement For control module replacement, programming, and setup refer to: Control Module References