Engine Controls - 4.8l, 5.3l & 6.0l (DTC p0136 to p0358) Chevrolet Cab & Chassis Silverado 3500

Circuit Description

Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature. The powertrain control module (PCM) supplies the HO2S with a reference, or bias, voltage of about 450 mV. When the engine is first started the PCM operates in open loop, ignoring the HO2S voltage signal. Once the HO2S reaches operating temperature and closed loop is achieved, the HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage. High HO2S voltage indicates a rich exhaust stream; low HO2S voltage indicates a lean exhaust stream.

The HO2S bank 1 sensor 2 and HO2S bank 2 sensor 2 are used for catalyst monitoring. This diagnostic runs once per ignition cycle. This diagnostic consists of two tests, a passive test and an intrusive test. During the passive test, if the HO2S bank 1 sensor 2 or HO2S bank 2 sensor 2 voltage transitions less than 349 mV and greater than 710 mV, the DTC will pass for this ignition cycle. If the DTC does not pass during the passive test, the intrusive test will begin. During the intrusive test, the control module will force the air-to-fuel ratio rich and/or lean. The control module then waits for a predicted response from the HO2S. If the HO2S voltage transitions less than 349 mV or greater than 710 mV, the DTC will pass for this ignition cycle. If the control module does not receive the expected response from the HO2S, DTC P0136 will set for HO2S bank 1 sensor 2 or DTC P0156 will set for HO2S bank 2 sensor 2.

DTC Descriptors

This diagnostic procedure supports the following DTCs

1. DTC P0136 HO2S Performance Bank 1 Sensor 2
2. DTC P0156 HO2S Performance Bank 2 Sensor 2

Conditions for Running the DTC

DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0151, P0152, P0153, P0154, P0155, P0157, P0158, P0160, P0161, P0200, P0442, P0443, P0446, P0449, P0455, P0496, P1133, P1134, P1153, P1154 are not set.

Passive Test

1. The engine is running.
2. The Engine Run Time parameter is less than 13.5 minutes.
3. The above conditions are met for 2 seconds.
4. This diagnostic runs one time per drive cycle once the above conditions are met.

Intrusive Test

1. The Engine Run Time parameter is more than 13.5 minutes.
2. The Ignition 1 Signal parameter is between 10-18 volts.
3. The Engine Speed parameter is between 900-5,000 RPM.
4. The MAF Sensor parameter is between 5-55 g/s.
5. The Vehicle Speed parameter is between 24-131 km/h (15-82 mph).
6. The Short Term FT Bank 1 and Bank 2 parameter is between -10 and +10 percent.
7. The maximum number of intrusive attempts is less than 100.
8. The above conditions are met for one second.
9. This diagnostic runs one time per drive cycle once the above conditions are met.

Conditions for Setting the DTC

1. The PCM detects that the HO2S bank 1 sensor 2 or HO2S bank 2 sensor 2 did not transition less than 349 mV and greater than 710 mV during the passive test.
2. One of the following tests fail: Lean Intrusive Test The PCM detects that the HO2S bank 1 sensor 2 or HO2S bank 2 sensor 2 is greater than 349 mV for 25.4 seconds. The HO2S bank 1 sensor 1 and HO2S bank 2 sensor 1 is less than 300 mV.

Rich Intrusive Test

1. The PCM detects that the HO2S bank 1 sensor 2 or HO2S bank 2 sensor 2 is less than 710 mV for 25.4 seconds.
2. The HO2S bank 1 sensor 1 and HO2S bank 2 sensor 1 is greater than 600 mV.

Action Taken When the DTC Sets

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 2: If the voltage does not change more than the specified value, the condition is present.

DTC P0136 or P0156

Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature. The powertrain control module (PCM) supplies the HO2S with a reference, or bias, voltage of about 450 mV. When the engine is first started, the PCM operates in Open Loop, ignoring the HO2S voltage signal. Once the HO2S reaches operating temperature and Closed Loop is achieved, the HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage. High HO2S voltage indicates a rich exhaust stream. Low HO2S voltage indicates a lean exhaust stream. If the PCM detects an HO2S voltage that stays below a specified value, DTC P0137 sets for HO2S bank 1 sensor 2 or DTC P0157 sets for HO2S bank 2 sensor 2.

This diagnostic procedure supports the following DTCs

1. DTC P0137 HO2S Circuit Low Voltage Bank 1 Sensor 2
2. DTC P0157 HO2S Circuit Low Voltage Bank 2 Sensor 2

Lean Test Enable

1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0128, P0169, P0178, P0179, P0200, P0220, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1516, P2101, P2108, P2135, U0107 are not set.
2. The Loop Status parameter is closed.
3. The Ignition 1 Signal parameter is between 10-18 volts.
4. The Fuel Alcohol content parameter is less than 90 percent.
5. The Fuel Tank Level Remaining parameter is greater than 10 percent.
6. The TP Indicated Angle parameter is between 3-70 percent more than the value observed at idle.
7. The above conditions are met for 2 seconds.
8. This diagnostic runs continuously when the above conditions are met.

Power Enrichment Test Enable

1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0128, P0169, P0178, P0179, P0200, P0220, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1516, P2101, P2108, P2135, U0107 are not set.
2. The Loop Status parameter is closed.
3. The Ignition 1 Signal parameter is between 10-18 volts.
4. The Fuel Alcohol content parameter is less than 90 percent.
5. The Fuel Tank Level Remaining parameter is greater than 10 percent.
6. The Engine Run Time parameter is greater than 30 seconds.
7. The Power Enrichment parameter is active for greater than 2 seconds.
8. This diagnostic runs continuously when the above conditions are met.

Lean Test

The PCM detects that the affected HO2S voltage parameter is less than 80 mV for 200 seconds.

Power Enrichment Test

The PCM detects that the affected HO2S voltage parameter is less than 420 mV for 10 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The number below refers to the step number on the diagnostic table.

1. 2: If the voltage does not change more that the specified value, the condition is present.

DTC P0137 or P0157

Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature. The powertrain control module (PCM) supplies the HO2S with a reference, or bias, voltage of about 450 mV. When the engine is first started, the PCM operates in Open Loop, ignoring the HO2S voltage signal. Once the HO2S reaches operating temperature and Closed Loop is achieved, the HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage. High HO2S voltage indicates a rich exhaust stream. Low HO2S voltage indicates a lean exhaust stream. If the PCM detects an HO2S voltage that stays above a specified value, DTC P0138 sets for HO2S bank 1 sensor 2 or DTC P0158 sets for HO2S bank 2 sensor 2.

This diagnostic procedure supports the following DTCs

1. DTC P0138 HO2S Circuit High Voltage Bank 1 Sensor 2
2. DTC P0158 HO2S Circuit High Voltage Bank 2 Sensor 2

Rich Test Enable

1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0128, P0169, P0178, P0179, P0200, P0220, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1516, P2101, P2108, P2135, U0107 are not set.
2. The Loop Status parameter is closed.
3. The Ignition 1 Signal parameter is between 10-18 volts.
4. The Fuel Alcohol content parameter is less than 90 percent.
5. The Fuel Tank Level Remaining parameter is greater than 10 percent.
6. The TP Indicated Angle parameter is between 3-70 percent more than the value observed at idle.
7. The above conditions are met for 2 seconds.
8. This diagnostic runs continuously when the above conditions are met.

Deceleration Fuel Cutoff Test Enable

1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0128, P0169, P0178, P0179, P0200, P0220, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1516, P2101, P2108, P2135, U0107 are not set.
2. The Loop Status parameter is closed.
3. The Ignition 1 Signal parameter is between 10-18 volts.
4. The Fuel Alcohol content parameter is less than 90 percent.
5. The Fuel Tank Level Remaining parameter is greater than 10 percent.
6. The Engine Run Time parameter is greater than 30 seconds.
7. The Decel. Fuel Cutoff parameter is active for more than 4 seconds.
8. This diagnostic runs continuously when the above conditions are met.

Rich Test

The PCM detects that the affected HO2S voltage parameter is greater than 950 mV for 200 seconds.

Deceleration Fuel Cutoff Test

The PCM detects that the affected HO2S voltage parameter is greater than 480 mV for 5 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The number below refers to the step number on the diagnostic table.

1. 2: If the voltage does not change more that the specified value, the condition is present.

DTC P0138 or P0158

Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature. The powertrain control module (PCM) supplies the HO2S with a reference, or bias, voltage of about 450 mV. When the engine is first started, the PCM operates in Open Loop, ignoring the HO2S voltage signal. Once the HO2S reaches operating temperature and Closed Loop is achieved, the HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage. High HO2S voltage indicates a rich exhaust stream. Low HO2S voltage indicates a lean exhaust stream. This diagnostic will only run once per ignition cycle. If the PCM detects that the HO2S voltage remains within the bias voltage range, DTC P0140 sets for HO2S bank 1 sensor 2, or DTC P0160 sets for HO2S bank 2 sensor 2.

This diagnostic procedure supports the following DTCs

1. DTC P0140 HO2S Circuit Insufficient Activity Bank 1 Sensor 2
2. DTC P0160 HO2S Circuit Insufficient Activity Bank 2 Sensor 2

1. DTCs P0054, P0060, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0128, P0141, P0161, P0169, P0178, P0179, P0200, P0220, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1516, P2101, P2108, P2135, U0107 are not set.
2. The Fuel Alcohol content parameter is less than 90 percent.
3. The Engine Run Time parameter is more than 300 seconds.
4. The Loop Status is closed.
5. The Ignition 1 Signal parameter is between 10-18 volts.
6. This diagnostic runs one time per drive cycle once the above conditions are met.

1. The PCM detects that the affected HO2S voltage parameter is between 410-490 mV for 150 seconds.
2. The TP Indicated Angle parameter changes more than 5 percent within 1 second, 6 times.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The number below refers to the step number on the diagnostic table.

1. 3: If the voltage is varying above and below the specified value, the condition is not present.

DTC P0140 or P0160

The heated oxygen sensor (HO2S) must reach operating temperature to provide an accurate voltage signal. A heating element inside the HO2S minimizes the time required for the sensor to reach operating temperature. Voltage is provided to the heater by the ignition 1 voltage circuit through a fuse. With the engine running, ground is provided to the heater by the HO2S heater low control circuit, through a low side driver within the powertrain control module (PCM). The PCM commands the heater ON or OFF to maintain a specific HO2S operating temperature range. The PCM determines the temperature by measuring the current flow through the heater. When the heater is in the ON state, the PCM will pulse the heater OFF for a duration of 50 ms, once per second. When the heater is in the OFF state, the PCM will pulse the heater ON for a duration of 50 ms, once per second. The PCM monitors the heater current with the engine running. This diagnostic will only run once per ignition cycle. If the PCM detects that the heater current is not within an expected range, DTC P0141 sets for HO2S bank 1 sensor 2, or DTC P0161 sets for HO2S bank 2 sensor 2.

This diagnostic procedure supports the following DTCs

1. DTC P0141 HO2S Heater Performance Bank 1 Sensor 2
2. DTC P0161 HO2S Heater Performance Bank 2 Sensor 2

1. DTCs P0054, P0060, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0128, P0169, P0178, P0179, P0200, P0220, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1516, P2101, P2108, P2135, U0107 are not set.
2. The ECT Sensor parameter is greater than 50°C (122°F).
3. The Ignition 1 Signal parameter is between 10-18 volts.
4. The Fuel Alcohol content parameter is less than 90 percent.
5. The MAF Sensor parameter is between 3-40 g/s.
6. The Engine Speed parameter is between 500-3,000 RPM.
7. The Engine Run Time parameter is more than 120 seconds.
8. The above conditions are met for 2 seconds.
9. This diagnostic runs one time per drive cycle once the above conditions are met.

1. The PCM detects that the affected HO2S Heater current parameter is greater than 1. 375 amps or less than 0. 25 amps.
2. The above condition is met for 10 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The number below refers to the step number on the diagnostic table.

1. 7: With no fault present, the test lamp will blink once per second.

DTC P0141 or P0161 (w/4.8L or 6.0L)

The heated oxygen sensor (HO2S) must reach operating temperature to provide an accurate voltage signal. A heating element inside the HO2S minimizes the time required for the sensor to reach operating temperature. Voltage is provided to the heater by the ignition 1 voltage circuit through a fuse. With the engine running, ground is provided to the heater by the HO2S heater low control circuit, through a low side driver within the powertrain control module (PCM). The PCM commands the heater ON or OFF to maintain a specific HO2S operating temperature range. The PCM determines the temperature by measuring the current flow through the heater. When the heater is in the ON state, the PCM will pulse the heater OFF for a duration of 50 ms, once per second. When the heater is in the OFF state, the PCM will pulse the heater ON for a duration of 50 ms, once per second. The PCM monitors the heater current with the engine running. This diagnostic will only run once per ignition cycle. If the PCM detects that the heater current is not within an expected range, DTC P0141 sets for HO2S bank 1 sensor 2, or DTC P0161 sets for HO2S bank 2 sensor 2.

This diagnostic procedure supports the following DTCs

1. DTC P0141 HO2S Heater Performance Bank 1 Sensor 2
2. DTC P0161 HO2S Heater Performance Bank 2 Sensor 2

1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0128, P0169, P0178, P0179, P0200, P0220, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1516, P2101, P2108, P2135, U0107 are not set.
2. The ECT Sensor parameter is greater than 50°C (122°F).
3. The Ignition 1 Signal parameter is between 10-18 volts.
4. The Fuel Alcohol content parameter is less than 90 percent.
5. The MAF Sensor parameter is between 3-40 g/s.
6. The Engine Speed parameter is between 500-3,000 RPM.
7. The Engine Run Time parameter is more than 120 seconds.
8. The above conditions are met for 2 seconds.
9. This diagnostic runs one time per drive cycle once the above conditions are met.

1. The PCM detects that the affected HO2S Heater current parameter is greater than 3.125 amps or less than 0.25 amps.
2. The above condition is met for 10 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The number below refers to the step number on the diagnostic table.

1. 7: With no fault present, the test lamp will blink once per second.

DTC P0141 or P0161 (w/5.3L)

The heated oxygen sensor (HO2S) must reach operating temperature to provide an accurate voltage signal. A heating element inside the HO2S minimizes the time required for the sensor to reach operating temperature. Voltage is provided to the heater by the ignition 1 voltage circuit through a fuse. With the engine running, ground is provided to the heater by the HO2S heater low control circuit, through a low side driver within the powertrain control module (PCM). The PCM commands the heater ON or OFF to maintain a specific HO2S operating temperature range. The PCM determines the temperature by measuring the current flow through the heater. When the heater is in the ON state, the PCM will pulse the heater OFF for a duration of 50 ms, once per second. When the heater is in the OFF state, the PCM will pulse the heater ON for a duration of 50 ms, once per second. The PCM monitors the heater current with the engine running. The PCM also calculates the heater resistance on a cold start. Both diagnostics will only run once per ignition cycle. If the PCM detects that the heater current or the heater calculated resistance is not within an expected range, DTC P0141 sets for HO2S bank 1 sensor 2, or DTC P0161 sets for HO2S bank 2 sensor 2.

This diagnostic procedure supports the following DTCs

1. DTC P0141 HO2S Heater Performance Bank 1 Sensor 2
2. DTC P0161 HO2S Heater Performance Bank 2 Sensor 2

Heater Current Test

1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0128, P0169, P0178, P0179, P0200, P0220, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1516, P2101, P2108, P2135, U0107 are not set.
2. The ECT Sensor parameter is more than 50°C (122°F).
3. The Ignition 1 Signal parameter is between 10-18 volts.
4. The Fuel Alcohol content parameter is less than 90 percent.
5. The MAF Sensor parameter is between 3-40 g/s.
6. The Engine Speed parameter is between 500-3,000 RPM.
7. The Engine Run Time parameter is more than 120 seconds.
8. The above conditions are met for 2 seconds.
9. This diagnostic runs one time per drive cycle when the above conditions are met.

Heater Resistance Test

1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0169, P0178, P0179, P0200, P0220, P0300, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1516, P2101, P2108, P2135, U0107 are not set.
2. The ignition is OFF for more than 10 hours.
3. The ECT Sensor parameter is between -30°C and +45°C (-22°F and +113°F) at engine start-up.
4. The ECT Sensor parameter minus the IAT Sensor parameter is less than 8°C (14°F) at engine start-up.
5. The engine is started.
6. This diagnostic runs one time per drive cycle when the above conditions are met.

Heater Current Test

1. The PCM detects that the affected HO2S Heater current parameter is more than 3.125 amps or less than 0.25 amps.
2. The above condition is met for 10 seconds.

Heater Resistance Test

The PCM detects that the affected HO2S heater calculated resistance is not within an expected range at engine start-up.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The number below refers to the step number on the diagnostic table.

1. 9: With no fault present, the test lamp will blink once per second.

DTC P0141 or P0161 (with HP2)

The powertrain control module (PCM) uses information from the intake air temperature (IAT) and the engine coolant temperature (ECT) sensors to determine ambient temperature at cold startup. Alcohol content, percentage information is supplied to the PCM from the fuel composition sensor. This information is used by the technician in diagnosing symptom related complaints such as hard starting in cold ambient temperatures. The PCM monitors the fuel frequency during the first 30 seconds of run time. When the PCM detects alcohol content that is too high for a given ambient temperature, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC P0169 Incorrect Fuel Composition

The ECT and IAT have less than 4.5°C (8°F) difference at cold start up.

If the fuel composition is above the given threshold for the ambient temperature, for 25 seconds of the 30 second interval.

1. The control module stores the DTC in history after the first failure but will not illuminate the malfunction indicator lamp (MIL).
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores the failure information in the scan tools Freeze Frame and Failure Records.

1. A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles.
2. A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant temperature exceeds 70°C (160°F) during the same ignition cycle.
3. Use the scan tool Clear Information function.

Diagnostic Aids

1. The system is designed for use of regular unleaded fuel to any ethanol concentration up to 85 percent (E85).
2. When the ambient temperature drops below -10°C (+14°F), a winter blend of 70 percent (E70), or less is recommended for cold weather starting.
3. The use of methanol fuels may set this DTC.
4. Use of methanol fuel or high concentration of ethanol may cause DTCs P0169 and P0179 to set.
5. Other contamination such as water and salts may cause this DTC to set.

The table below shows the maximum thresholds of a given ethanol content (percentage) versus the ambient temperature at which a DTC P0169 will set.

DTC P0169

The number below refers to the step number on the diagnostic table.

1. 3: The frequency read on the scan tool should be stable. A lower reading that momentarily rises above 100 Hz may indicate that water droplets in the fuel are present.

DTC P0169

The powertrain control module (PCM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. Fuel delivery is controlled differently during Open and Closed Loop. During Open Loop, the PCM determines fuel delivery based on sensor signals without oxygen sensor input. During Closed Loop, the PCM adds oxygen sensor inputs and level of purge to calculate short and long term fuel trim adjustments. If the oxygen sensors indicate a lean condition, fuel trim values will be above 0 percent. If the oxygen sensors indicate a rich condition, fuel trim values will be below 0 percent. The values for the short term fuel trim change rapidly in response to the heated oxygen sensor (HO2S) voltage signals. Long term fuel trim makes course adjustments in order to maintain an air/fuel ratio of 14.7:1. A block of cells contain information arranged in combinations of engine RPM and engine load for a full range of vehicle operating conditions. The long term fuel trim diagnostic is based on an average of cells currently being used. The PCM selects the cells based on the engine speed and engine load. If the PCM detects an excessively lean condition, DTC P0171 or P0174 sets.

This diagnostic procedure supports the following DTCs

1. DTC P0171 Fuel Trim System Lean Bank 1
2. DTC P0174 Fuel Trim System Lean Bank 2

1. DTCs P0053, P0054, P0059, P0060, P0101, P0102, P0103, P0106, P0107, P0108, P0131, P0132, P0133, P0134, P0135, P0136, P0137, P0138, P0140, P0141, P0151, P0152, P0153, P0154, P0155, P0156, P0157, P0158, P0160, P0161, P0200, P0300, P0442, P0443, P0446, P0449, P0452, P0453, P0455, P0496, P0506, P0507, P1133, P1134, P1153, P1154, P2A01, or P2A04 are not set.
2. The engine coolant temperature (ECT) is between -40 to +140°C (-40 to +284°F).
3. The intake air temperature (IAT) is between -20 to +152°C (-4 to +304°F).
4. The manifold absolute pressure (MAP) is between 15-105 kPa (2.2-15.2 psi).
5. The vehicle speed is less than 132 km/h (82 mph).
6. The engine speed is between 400-6,500 RPM.
7. The barometric pressure (BARO) is more than 74 kPa (10.7 psi).
8. The mass air flow (MAF) is between 1-250 g/s.
9. The fuel level is more than 10 percent.
10. The throttle position is less than 90 percent.
11. This diagnostic runs continuously once the above conditions are met.

The long term fuel trim weighted average value is more than a calibrated value for 2 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Excessive resistance in the fuel injector control and/or the ignition 1 voltage circuits may cause the following symptoms: A lean condition Misfire Rough idle Refer to «DTC P0200»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-48l-53l-60l-dtc-p0136-to-p0358) .
2. The system may become lean if an injector is not suppling enough fuel.
3. A lean condition could be present during high fuel demand.
4. Review the Failure Records with a scan tool. If an intermittent condition is suspected, refer to «Testing for Intermittent Conditions and Poor Connections»(ref-197325-S02683201702005101100000) .

DTC P0171 or P0174

The powertrain control module (PCM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. Fuel delivery is controlled differently during Open and Closed Loop. During Open Loop, the PCM determines fuel delivery based on sensor signals without oxygen sensor input. During Closed Loop, the PCM adds oxygen sensor inputs and level of purge to calculate short and long term fuel trim adjustments. If the oxygen sensors indicated a lean condition, fuel trim values will be above 0 percent. If the oxygen sensors indicate a rich condition, fuel trim values will be below 0 percent. The values for the short term fuel trim change rapidly in response to the heated oxygen sensor (HO2S) voltage signals. Long term fuel trim makes coarse adjustments in order to maintain an air/fuel ratio of 14.7:1. A block of cells contain information arranged in combinations of engine RPM and engine load for a fuel range of vehicle operating conditions. The long term fuel trim diagnostic is based on an average of cells currently being used. The PCM selects the cells based on the engine speed and engine load. The fuel trim diagnostic will conduct a test to determine if a rich failure actually exists, or if excessive vapor from the evaporative emission (EVAP) canister is causing a rich condition. If the PCM detects an excessively rich condition, DTC P0172 or P0175 sets.

This diagnostic procedure supports the following DTCs

1. DTC P0172 Fuel Trim System Rich Bank 1
2. DTC P0175 Fuel Trim System Rich Bank 2

1. DTCs P0053, P0054, P0059, P0060, P0101, P0102, P0103, P0106, P0107, P0108, P0131, P0132, P0133, P0134, P0135, P0136, P0137, P0138, P0140, P0141, P0151, P0152, P0153, P0154, P0155, P0156, P0157, P0158, P0160, P0161, P0200, P0300, P0442, P0443, P0446, P0449, P0452, P0453, P0455, P0496, P0506, P0507, P1133, P1134, P1153, P1154, P2A01, or P2A04 are not set.
2. The engine coolant temperature (ECT) is between -40 to +140°C (-40 to +284° F).
3. The intake air temperature (IAT) is between -20 to +152°C (-4 to +304°F).
4. The manifold absolute pressure (MAP) is between 15-105 kPa (2.2-15.2 psi).
5. The vehicle speed is less than 132 km/h (82 mph).
6. The engine speed is between 400-6,500 RPM.
7. The barometric pressure (BARO) is more than 74 kPa (10.7 psi).
8. The mass air flow (MAF) is between 1-250 g/s.
9. The fuel level is more than 10 percent.
10. The throttle position is less than 90 percent.
11. This diagnostic runs continuously once the above conditions are met.

The long term fuel trim weighted average value is more than a calibrated value for 6 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Fuel contamination, such as water or alcohol, will effect fuel trim.
2. A malfunctioning MAF sensor can cause a rich condition and set this DTC. Refer to «DTC P0101 (With Throttle Actuator Control)»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-48l-53l-60l-dtc-p0053-to-p0155) .
3. Review Failure Records with a scan tool. If an intermittent condition is suspected, refer to «Testing for Intermittent Conditions and Poor Connections»(ref-197325-S02683201702005101100000) .

The number below refers to the step number on the diagnostic table.

1. 7: An EVAP canister that is saturated will cause a rich condition.

DTC P0172 or P0175

Alcohol content and fuel temperature information is supplied to the powertrain control module (PCM) from the fuel composition sensor (FCS). The FCS has an ignition 1 circuit, a signal circuit, and a ground circuit. The FCS uses a microprocessor inside the sensor to measure the ethanol percentage and fuel temperature, and changes output signals accordingly. The signal circuit carries both the ethanol percentage, and the fuel temperature within the same signal. The signal is both variable frequency and variable pulse width. The frequency signal indicates the ethanol percentage, and the pulse width indicates fuel temperature. The PCM provides an internal pull up to 5 volts on the signal circuit, and the FCS pulls the 5 volts to ground in pulses. The normal range of operating frequency is between 50-150 Hz. The normal pulse width ranges between 1-5 milliseconds. If the PCM detects a signal less than 45 Hz, DTC P0178 will set.

This diagnostic procedure supports the following DTC

DTC P0178 Fuel Composition Sensor Circuit Low Frequency

1. The engine run time is more than 30 seconds.
2. The ignition voltage is more than 10.9 volts.

The FCS frequency is below 45 Hz for 12.5 seconds.

1. The hertz and millisecond parameters react immediately to any change in the FCS circuits, but may not react long enough to set this DTC.
2. A reading of 16 Hz in the Freeze Frame/Failure Records indicates a circuit failure.
3. An intermittent condition may not be detected because the sensor does not immediately power down and the connection may be restored before voltage drops below the operating threshold.
4. If this DTC will not reset and the parameters are steady, thoroughly inspect all FCS circuits for an intermittent open.
5. If a intermittent condition is suspected, refer to «Testing for Intermittent Conditions and Poor Connections»(ref-197325-S02683201702005101100000) in Wiring Systems.

DTC P0178

Alcohol content and fuel temperature information is supplied to the powertrain control module (PCM) from the fuel composition sensor (FCS). The FCS has the following circuits

1. An ignition 1 circuit
2. A signal circuit
3. A ground circuit

The FCS uses a microprocessor inside the sensor to measure the ethanol percentage and fuel temperature and changes output signals accordingly. The signal circuit carries both the ethanol percentage and the fuel temperature within the same signal. The signal is both variable frequency and variable pulse width. The frequency signal indicates the ethanol percentage and the pulse width indicates fuel temperature. The PCM provides an internal pull up to 5 volts on the signal circuit and the FCS pulls the 5 volts to ground in pulses. The normal range of operating frequency is between 50-150 hertz. The normal pulse width ranges between 1-5 milliseconds. The microprocessor inside the sensor is capable of a certain amount of self-diagnosis. An output frequency of 170 hertz indicates that the fuel is contaminated or an internal sensor fault has been detected. If the PCM detects a signal more than 155 hertz, DTC P0179 will set.

This diagnostic procedure supports the following DTC

DTC P0179 Fuel Composition Sensor Circuit High Frequency

1. The engine run time is more than 30 seconds.
2. The system voltage is greater than 10.9 volts.

The FCS frequency is more than 155 Hz for 12.5 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC P0179

The control module enables the appropriate fuel injector pulse for each cylinder. Ignition voltage is supplied to the fuel injectors. The control module controls each fuel injector by grounding the control circuit via a solid state device called a driver. The control module monitors the status of each driver. If the control module detects an incorrect voltage for the commanded state of the driver, DTC P0200 sets.

This diagnostic procedure supports the following DTC

DTC P0200 Injector Control Circuit

1. The engine speed is more than 400 RPM.
2. The ignition voltage is between 6-18 volts.

1. The powertrain control module (PCM) detects an incorrect voltage on a fuel injector control circuit.
2. The condition exists for 5 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Performing the Fuel Injector Coil Test may help to isolate an intermittent condition. Refer to «Fuel Injector Coil Test»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-48l-53l-60l-troubleshooting-diagnosis) .
2. For an intermittent condition, refer to «Testing for Intermittent Conditions and Poor Connections»(ref-197325-S02683201702005101100000) .

The numbers below refer to the step numbers on the diagnostic table.

1. 5: This step verifies that the PCM is able to control the fuel injector.
2. 7: This step tests if a ground is constantly being applied to the fuel injector.

DTC P0200

The throttle position (TP) sensor incorporates 2 ratio metric TP sensors into one housing. TP sensor 1 and TP sensor 2 each have a 5-volt reference circuit supplied by the throttle actuator control (TAC) module. The TAC module supplies each TP sensor with a low reference circuit. Each TP sensor supplies the TAC module with a signal voltage that is proportional to the throttle blade position. Both TP signal voltages increase as the throttle blade is opened. The TP sensor 1 and the accelerator pedal position (APP) sensor 1 share a 5-volt reference circuit that is bussed within the TAC module. The TP sensor 2 and the APP sensor 2 share a 5-volt reference circuit that is also bussed within the TAC module. When this DTC sets, the Reduced Engine Power indicator will be displayed.

This DTC incorporates the following diagnostic tests

1. The TP sensor 2 signal circuit voltage out of range
2. The throttle blade minimum position for the TP sensor 2 out of range
3. The 5-volt reference of the TP sensor 2 tests out of range.

If the PCM detects one or more of the TP sensor 2 tests are out of range, DTC P0220 sets.

This diagnostic procedure supports the following DTC

DTC P0220 Throttle Position (TP) Sensor 2 Circuit

1. DTCs P2108 or U0107 are not set.
2. The ignition switch is in the Crank or Run position.
3. The ignition voltage is more than 5.23 volts.
4. The TP sensor 2 signal voltage test runs continuously once the above conditions are met.
5. The throttle blade minimum position for the TP sensor 2 test runs once when the ignition is turned ON and the above conditions are met.
6. The 5-volt reference of the TP sensor 2 voltage test runs continuously once the above conditions are met.

1. The TP sensor 2 signal voltage is less than 0.28 volts, or more than 4.6 volts, for more than 0.1 second. OR
2. The TP sensor 2 minimum throttle blade position is less than 0.28 volts, or more than 0.81 volts, for less than 1 second. OR
3. The 5-volt reference circuit of the TP sensor 2 is less than 0.5 volts for more than 0.01 second.

1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.
3. The control module commands the TAC system to operate in the Reduced Engine Power mode.
4. A message center or an indicator displays Reduced Engine Power.
5. Under certain conditions the control module commands the engine OFF.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Inspect the TAC module connectors for signs of water intrusion. If water intrusion occurs, multiple DTCs may set without any circuit or component conditions found during diagnostic testing.
2. When the TAC module detects a condition within the TAC system, more than one TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Disconnecting components during testing may set additional DTCs. Remember this if you review the stored information in Capture Info.
3. If this DTC is determined to be intermittent, refer to «Testing for Intermittent Conditions and Poor Connections»(ref-197325-S02683201702005101100000) .

The number below refers to the step number on the diagnostic table.

1. 31: When the TAC module detects a condition within the TAC system, more than one TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Disconnecting components during testing may set additional DTCs. Keep this in mind when reviewing the stored information, Capture Info.

DTC P0220

The control module enables the fuel pump relay when the ignition switch is turned ON. The control module will disable the fuel pump relay within 2 seconds unless the control module detects ignition reference pulses. The control module continues to enable the fuel pump relay as long as ignition reference pulses are detected. The control module disables the fuel pump relay within 2 seconds if ignition reference pulses cease to be detected and the ignition remains ON.

The control module monitors the voltage on the fuel pump relay control circuit. If the control module detects an incorrect voltage on the fuel pump relay control circuit, a fuel pump relay control DTC sets.

This diagnostic procedure supports the following DTC

DTC P0230 Fuel Pump Relay Control Circuit

1. The engine speed is more than 400 RPM.
2. The ignition voltage is between 6-18 volts.

1. The powertrain control module (PCM) detects that the commanded state of the driver and the actual state of the control circuit do not match.
2. The above conditions are present for a minimum of 2.5 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The numbers below refer to the step numbers on the diagnostic table.

1. 4: This step verifies that the PCM is providing voltage to the fuel pump relay.
2. 5: This step tests for an open in the ground circuit to the fuel pump relay.
3. 6: This step tests if the voltage is constantly being applied to the control circuit of the fuel pump relay.

DTC P0230

System Description

The powertrain control module (PCM) uses information from the crankshaft position (CKP) sensor and the camshaft position (CMP) sensor in order to determine when an engine misfire is occurring. By monitoring variations in the crankshaft rotation speed for each cylinder, the PCM is able to detect individual misfire events. A misfire rate that is high enough can cause the 3-way catalytic converter (TWC) to overheat under certain driving conditions. The malfunction indicator lamp (MIL) will flash ON and OFF when the conditions for TWC overheating are present. If the PCM detects a misfire rate sufficient to cause emission levels to exceed mandated standards, DTC P0300 will set.

This diagnostic procedure supports the following DTC

DTC P0300 Engine Misfire Detected

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0125, P0128, P0220, P0315, P0335, P0336, P0341, P0342, P0343, P0502, P0503, P1114, P1115, P1120, P1258 are not set.
2. The engine speed is between 450-5,000 RPM.
3. The ignition voltage is between 10-18 volts.
4. The engine coolant temperature (ECT) is between -7 and +130°C (+19 and +266°F).
5. The fuel level is more than 10 percent.
6. The throttle angle is steady within 1 percent.
7. The antilock brake system (ABS) and the traction control system (TCS) are not active.
8. The transmission is not changing gears.
9. The A/C clutch is not changing states.
10. The PCM is not in fuel shut-off or decel fuel cut-off mode.
11. The PCM is not receiving a rough road signal.
12. DTC P0300 runs continuously once the above conditions are met.

The PCM is detecting a crankshaft rotation speed variation indicating a misfire sufficient to cause emission levels to exceed mandated standards.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Excessive vibration from sources other than the engine could cause DTC P0300 to set. The following are possible sources of vibration: Thickness variation of the brake rotors-Refer to «Symptoms - Hydraulic Brakes»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/mechanical-hydraulic/#hydraulic-brake-system__symptoms-hydraulic-brakes) in Hydraulic Brakes. The drive shaft not balanced-Refer to «Vibration Analysis - Driveline»(ref-197433-S23292295772005101100000) in Vibration Diagnosis and Correction. Worn or damaged accessory drive belt-Refer to «Symptoms - Engine Mechanical»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/mechanical/#engine-mechanical-48l-53l-60l-introduction) in Engine Mechanical - 4.8L, 5.3L and 6.0L.
2. There may be more or less cylinders actually misfiring than indicated by the scan tool.
3. Spray water on the secondary ignition components using a spray bottle. Look and listen for arcing or misfiring.
4. If there are multiple misfires on only one bank, inspect the fuel injector and ignition coil, power and ground circuits for that bank. Refer to «Engine Controls Schematics»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-48l-53l-60l-introduction) .

The number below refers to the step number on the diagnostic table.

1. 2: If the actual CKP variation values are not within the learned values, the misfire counters may increment.

DTC P0300

The crankshaft position (CKP) system variation learn feature is used to calculate reference period errors caused by slight tolerance variations in the crankshaft, and the CKP sensor. The calculated error allows the powertrain control module (PCM) to accurately compensate for reference period variations. This enhances the ability of the PCM to detect misfire events over a wide range of engine speed and load. The PCM stores the Crankshaft Position System Variation values after a learn procedure has been performed. If the actual crankshaft position variation is not within the Crankshaft Position System Variation compensating values stored in the PCM, DTC P0300 may set. If the CKP system variation values are not stored in the PCM memory, DTC P0315 sets.

This diagnostic procedure supports the following DTC

DTC P0315 Crankshaft Position (CKP) System Variation Not Learned

1. DTCs P0335, P0336, P0341, P0342, or P0343 are not set.
2. DTC P0315 runs every 100 milliseconds.

1. The CKP system variation values are not stored in the PCM memory.
2. The enable counter equals 0.

1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

1. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
3. Clear the MIL and the DTC with a scan tool.

DTC P0315

The knock sensors (KS) produce an AC signal under all engine operating conditions. When the engine is running, the powertrain control module (PCM) learns a minimum and maximum frequency of normal engine noise. The KS system monitors both knock sensors in order to determine if knock is present. If the KS system determines that excessive knock is present, the PCM retards the spark timing based on the signals from the KS. The PCM continues to retard timing until no knock is present. If the PCM malfunctions in a manner that will not allow proper diagnosis of the KS system, DTC P0325 sets.

This diagnostic procedure supports the following DTC

DTC P0325 Knock Sensor (KS) Circuit

1. The engine run time is more than 10 seconds.
2. The ignition voltage is more than 10 volts.
3. DTC P0325 runs continuously once the above conditions are met.

The PCM malfunctions in a manner that will not allow proper diagnosis of the KS system for more than 15 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC P0325

The knock sensors (KS) produce an AC signal under all engine operating conditions. When the engine is running, the powertrain control module (PCM) learns a minimum and maximum frequency of normal engine noise. The KS system monitors both knock sensors in order to determine if knock is present. If the KS system determines that excessive knock is present, the PCM retards the spark timing based on the signals from the KS. The PCM continues to retard timing until no knock is present. If the PCM detects that the frequency is out of the normal range, DTC P0327 or P0332 will set.

This diagnostic procedure supports the following DTCs

1. DTC P0327 Knock Sensor (KS) 1 Circuit Low Frequency
2. DTC P0332 Knock Sensor (KS) 2 Circuit Low Frequency

1. DTCs P0116, P0117, P0118, P0120, P0122, P0123, P0125, P0128, P0220, or P2135 are not set.
2. The minimum noise level must be learned. The minimum noise level is learned when the following conditions are met: The engine coolant temperature (ECT) is more than 60°C (140°F). The engine RPM is between 475-975 for 10 seconds.
3. The engine speed is between 1,500-3,000 RPM.
4. The manifold absolute pressure (MAP) is less than 45 kPa.
5. The engine run time is more than 10 seconds.
6. The ignition voltage is more than 10 volts.
7. DTC P0327 or DTC P0332 runs continuously once the above conditions are met.

The PCM detects that the affected KS signal is less than the expected amount for more than 9 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Inspect the KS for proper installation. A knock sensor that is loose or over torqued may cause the DTC to set.
2. If DTCs P0327 and P0332 are set at the same time, inspect for poor connections at the KS harness jumper, located at the left rear side of the intake manifold.
3. For an intermittent, refer to «Testing for Intermittent Conditions and Poor Connections»(ref-197325-S02683201702005101100000) .

DTC P0327 or P0332

The crankshaft position (CKP) sensor signal indicates the crankshaft speed and position. The CKP sensor circuits are connected directly to the powertrain control module (PCM) and consists of the following circuits

1. The 12-volt reference circuit
2. The low reference circuit
3. The CKP sensor signal circuit

If the PCM detects there is no signal from the CKP sensor for 8 seconds, DTC P0335 sets.

This diagnostic procedure supports the following DTC

DTC P0335 Crankshaft Position (CKP) Sensor Circuit

1. DTCs P0101, P0102, P0103, P0341, P0342, or P0343 are not set.
2. The camshaft position (CMP) sensor signal is incrementing.
3. The mass air flow (MAF) is more than 3 g/s.
4. The ignition switch is in the Crank position.
5. DTC P0335 runs continuously once the above conditions are met.

The PCM detects there is no signal from the CKP sensor for 8 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The numbers below refer to the step numbers on the diagnostic table.

1. 3: This step determines if the fault is present.
2. 6: This step simulates a CKP sensor signal to the PCM. If the PCM receives the signal, the fuel pump will operate for about 2 seconds.

DTC P0335

The crankshaft position (CKP) sensor signal indicates the crankshaft speed and position. The CKP sensor circuits are connected directly to the powertrain control module (PCM) and consists of the following circuits

1. The 12-volt reference circuit
2. The low reference circuit
3. The CKP sensor signal circuit

If the PCM detects that the CKP sensor signal is inconsistent, DTC P0336 sets.

This diagnostic procedure supports the following DTC

DTC P0336 Crankshaft Position (CKP) Sensor Performance

1. The engine is cranking or running.
2. DTC P0336 runs continuously once the above conditions are met.

The PCM detects that the CKP sensor signal is inconsistent for 3 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC P0336

The camshaft position (CMP) sensor works in conjunction with a 1 X reluctor wheel on the camshaft. The powertrain control module (PCM) provides a 12-volt reference to the CMP sensor as well as a low reference and a signal circuit.

As the camshaft rotates, the reluctor wheel interrupts a magnetic field produced by a magnet within the sensor. The sensors internal circuitry detects this and produces a signal which the PCM reads.

The CMP sensor 1 X signal is used by the PCM to determine if the cylinder at top dead center (TDC) is on the firing stroke or the exhaust stroke. The PCM can determine TDC for all cylinders by using the crankshaft position (CKP) sensor 24 X signal alone. The engine will start without a CMP signal as long as the PCM receives the CKP sensor 24 X signal. A slightly longer cranking time may be a symptom of this condition. The system attempts synchronization and looks for an increase in engine speed indicating that the engine started. If the PCM does not detect an increase in engine speed, the PCM assumes that the PCM incorrectly synchronized to the exhaust stroke and re-syncs to the opposite cam position. If the PCM detects that a CMP to CKP mis-match has occurred DTC P0341 sets.

This diagnostic procedure supports the following DTC

DTC P0341 Camshaft Position (CMP) Sensor Performance

1. The engine is running and the engine speed is less than 4,000 RPM.
2. DTC P0341 runs continuously once the above conditions are met.

The PCM detects that a CMP to CKP mis-match has occurred for more than 10 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The numbers below refer to the step numbers on the diagnostic table.

1. 3: This step inspects for electromagnetic interference (EMI) on the CMP sensor circuits.
2. 6: Damage to the face of the sensor could indicate foreign material passing between the CMP sensor and the reluctor wheel. This condition would cause this DTC to set. Damage to the reluctor wheel would affect the CMP sensor output.

DTC P0341

The camshaft position (CMP) sensor works in conjunction with a 1 X reluctor wheel on the camshaft. The powertrain control module (PCM) provides a 12-volt reference to the CMP sensor as well as a low reference and a signal circuit.

As the camshaft rotates, the reluctor wheel interrupts a magnetic field produced by a magnet within the sensor. The sensors internal circuitry detects this and produces a signal which the PCM reads.

The CMP sensor 1 X signal is used by the PCM to determine if the cylinder at top dead center (TDC) is on the firing stroke or the exhaust stroke. The PCM can determine TDC for all cylinders by using the crankshaft position (CKP) sensor 24 X signal alone. The engine will start without a CMP signal as long as the PCM receives the CKP sensor 24 X signal. A slightly longer cranking time may be a symptom of this condition. The system attempts synchronization and looks for an increase in engine speed indicating that the engine started. If the PCM does not detect an increase in engine speed, the PCM assumes that the PCM incorrectly synchronized to the exhaust stroke and re-syncs to the opposite cam position. If the PCM detects that a CMP signal is constantly low, DTC P0342 sets.

This diagnostic procedure supports the following DTC

DTC P0342 Camshaft Position (CMP) Sensor Circuit Low Voltage

1. The engine is running.
2. The engine speed is less than 4,000 RPM.
3. DTC P0342 runs continuously once the above conditions are met.

The PCM detects that the CMP sensor signal is low for more than 5 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The number below refers to the step number on the diagnostic table.

1. 5: This step tests the CMP sensor signal circuit. Applying a voltage causes the CMP sensor high to low and low to high parameter to increase if the circuit and the PCM are operating properly.

DTC P0342

The camshaft position (CMP) sensor works in conjunction with a 1 X reluctor wheel on the camshaft. The powertrain control module (PCM) provides a 12-volt reference to the CMP sensor as well as a low reference and a signal circuit.

As the camshaft rotates, the reluctor wheel interrupts a magnetic field produced by a magnet within the sensor. The sensors internal circuitry detects this and produces a signal which the PCM reads.

The CMP sensor 1 X signal is used by the PCM to determine if the cylinder at top dead center (TDC) is on the firing stroke or the exhaust stroke. The PCM can determine TDC for all cylinders by using the crankshaft position (CKP) sensor 24 X signal alone. The engine will start without a CMP signal as long as the PCM receives the CKP sensor 24 X signal. A slightly longer cranking time may be a symptom of this condition. The system attempts synchronization and looks for an increase in engine speed indicating that the engine started. If the PCM does not detect an increase in engine speed, the PCM assumes that the PCM incorrectly synchronized to the exhaust stroke and re-syncs to the opposite cam position. If the PCM detects that the CMP signal is constantly high, DTC P0343 sets.

This diagnostic procedure supports the following DTC

DTC P0343 Camshaft Position (CMP) Sensor Circuit High Voltage

1. The engine is running.
2. The engine speed is less than 4,000 RPM.
3. DTC P0343 runs continuously once the above conditions are met.

The PCM detects that the CMP sensor signal is high for more than 5 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The number below refers to the step number on the diagnostic table.

1. 5: This step tests the CMP sensor signal circuit. Applying a voltage causes the CMP sensor high to low and low to high parameter to increase if the circuit and the PCM are operating properly.

DTC P0343

The ignition system on this engine uses an individual ignition coil for each cylinder. The powertrain control module (PCM) controls the spark event for each cylinder through 8 individual ignition control (IC) circuits. When the PCM commands the IC circuit ON, electrical current will flow through the primary winding of the ignition coil, creating a magnetic field. When a spark event is requested, the PCM will command the IC circuit OFF, interrupting current flow through the primary winding. The magnetic field created by the primary winding will collapse across the secondary coil winding, producing a high voltage across the spark plug electrodes. The PCM uses information from the crankshaft position (CKP) and the camshaft position (CMP) sensor for sequencing and timing of the spark events. Each ignition coil/module has the following circuits

1. An ignition 1 voltage circuit
2. A ground circuit
3. An ignition control (IC) circuit
4. A low reference circuit

If the PCM detects that the IC circuit has an incorrect voltage level, DTC P0351-P0358 will set.

This diagnostic procedure supports the following DTCs

1. DTC P0351 Ignition Coil 1 Control Circuit
2. DTC P0352 Ignition Coil 2 Control Circuit
3. DTC P0353 Ignition Coil 3 Control Circuit
4. DTC P0354 Ignition Coil 4 Control Circuit
5. DTC P0355 Ignition Coil 5 Control Circuit
6. DTC P0356 Ignition Coil 6 Control Circuit
7. DTC P0357 Ignition Coil 7 Control Circuit
8. DTC P0358 Ignition Coil 8 Control Circuit

1. The engine is running.
2. DTC P0351-P0358 runs continuously once the above condition is met.

The PCM detects the IC circuit is grounded, open, or shorted to voltage for less than 1 second.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The numbers below refer to the step numbers on the diagnostic table.

1. 3: This step verifies the integrity of the IC circuit and the PCM output.
2. 4: This step tests for a short to ground on the IC circuit.

DTC P0351-P0358

See also:
• Engine Controls Schematics
• Engine Controls Connector End Views
• Powertrain Control Module (PCM) Connector End Views
• Scan Tool Data List
• Fuel System Diagnosis
• DTC P0132 or P0152
• Fuel Tank Draining Procedure (5.3L (L59) Engine)
• Crankcase Ventilation System Inspection/Diagnosis
• Symptoms - Engine Mechanical
• Special Tools
• Symptoms - Hydraulic Brakes
• CKP System Variation Learn Procedure
• Spark Plug Wire Inspection
• Spark Plug Inspection
• DTC P0420 or P0430 (Without HP2)
• Engine Sight Shield Replacement (4.8L, 5.3L, and 6.0L (RPO LQ4))
• Crankshaft and Bearings Cleaning and Inspection
• Camshaft and Bearings Cleaning and Inspection
• DTC P0141 or P0161 (w/4.8L or 6.0L)