GM 97 GM 6.5L Diesel OBD1 Codes

P0101	Mass Air Flow (MAF) System Performance
P0102	Mass Air Flow Sensor Circuit Low Frequency
P0103	Mass Air Flow (MAF) Sensor Circuit High Frequency
P0112	IAT Sensor Circuit Low Voltage
P0113	IAT Sensor Circuit High Voltage
P0117	Engine Coolant Temperature (ECT) Sensor CKT Low Voltage
P0118	Engine Coolant Temperature (ECT) Sensor CKT High Voltage
P0121	APP Sensor 1 Circuit Performance
P0122	APP Sensor 1 Circuit Low Voltage
P0123	APP Sensor 1 Circuit High Voltage
P0126	Insufficient ECT For Stable Operation
P0182	Fuel Temperature Sensor Circuit Low Voltage
P0183	Fuel Temperature Sensor Circuit High Voltage
P0215	Engine Shutoff Control Circuit
P0216	Injection Timing Control Circuit
P0218	Transaxle Fluid Overtemperature
P0219	Engine Overspeed Condition
P0220	APP Sensor 2 Circuit
P0221	APP Sensor 2 Circuit Performance
P0222	APP Sensor 2 Circuit Low Voltage
P0223	APP Sensor 2 Circuit High Voltage
P0225	APP Sensor 3 Circuit
P0226	APP Sensor 3 Circuit Performance
P0227	APP Sensor 3 Circuit Low Voltage
P0228	APP Sensor 3 Circuit High Voltage
P0231	Fuel Pump Feedback Circuit Low Voltage
P0236	TC Boost System
P0237	TC Boost Sensor Circuit Low Voltage
P0238	TC Boost Sensor Circuit High Voltage
P0251	Injection Pump Cam System
P0263	Cylinder 8 Balance System
P0266	Cylinder 7 Balance System
P0269	Cylinder 2 Balance System
P0272	Cylinder 6 Balance System
P0275	Cylinder 5 Balance System
P0278	Cylinder 4 Balance System
P0281	Cylinder 3 Balance System
P0284	Cylinder 1 Balance System
P0301	Cylinder 1 Misfire Detected
P0302	Cylinder 2 Misfire Detected
P0303	Cylinder 3 Misfire Detected
P0304	Cylinder 4 Misfire Detected
P0305	Cylinder 5 Misfire Detected
P0306	Cylinder 6 Misfire Detected
P0307	Cylinder 7 Misfire Detected
P0308	Cylinder 8 Misfire Detected
P0335	Crankshaft Position (CKP) Sensor Circuit
P0370	Timing Reference High Resolution
P0380	Glow Plug Circuit Performance
P0400	EGR Flow Malfunction
P0401	Exhaust Gas Recirculation (EGR) Insufficient Flow
P0402	EGR Flow Excessive
P0404	EGR System Performance
P0405	EGR Sensor Circuit Low Voltage
P0406	EGR Sensor Circuit High Voltage
P0501	Vehicle Speed Sensor Circuit
P0560	System Voltage Malfunction Low
P0567	Cruise Resume Circuit
P0568	Cruise Set Circuit
P0571	Cruise Brake Switch Circuit
P0601	Internal Control Module Memory Check Sum Error
P0602	Control Module Programming
P0604	Control Module Random Access Memory
P0606	PCM Internal Communication Interrupted
P0711	Fluid Temperature Sensor Circuit Range/Performance
P0712	Fluid Temperature Sensor Low Input
P0713	Fluid Temperature Sensor Circuit High Input
P0716	Input Speed Sensor Circuit Range/Performance
P0717	Input Speed Sensor Circuit No Signal
P0719	TCC Brake Switch Circuit Low
P0722	Output Speed Sensor Low Input
P0723	Output Speed Sensor Intermittent
P0724	TCC Brake Switch Circuit High
P0741	Torque Converter Clutch Circuit Stuck Off
P0742	Torque Converter Clutch (TCC) Stuck On
P0748	PC Solenoid Valve Circuit Electrical
P0751	1-2 (A) Shift Solenoid Performance
P0753	1-2 (A) Shift Solenoid Electrical
P0756	2-3 (B) Shift Solenoid Performance
P0758	2-3 (B) Shift Solenoid Electrical
P1125	APP System
P1191	Intake Air Duct Leak
P1214	Injection Pump Timing Offset
P1216	Fuel Solenoid Response Time Too Short
P1217	Fuel Solenoid Response Time Too Long
P1218	Injection Pump Calibration Circuit
P1406	EGR Valve Pintle Position Circuit
P1409	EGR Vacuum System Leak
P1621	EEPROM Write
P1627	A/D Performance
P1635	5 Volt Reference Low
P1641	Malfunction Indicator Lamp (MIL) Control Circuit
P1643	Wait to Start Lamp Control Circuit
P1653	EGR Vent Solenoid Control Circuit
P1654	Service Throttle Soon Lamp Control Circuit
P1655	EGR Solenoid Control Circuit
P1656	Wastegate Solenoid Control Circuit
P1810	TFP Valve Position Switch Circuit Malfunction
P1811	Maximum Adapt and Long Shift
P1860	TCC PWM Solenoid Electrical
P1870	Transmission Component Slipping
P1871	Undefined Gear Ratio

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2 Comments

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Shannon Springer

3 years ago

I keep getting the P0404 code on my 97 6.5 GMC Sierra diesel what is the sensor

Randy

Reply to Shannon Springer

Shannon,
This code relates to the EGR Valve position sensor.
Try these steps.
Using the scan tool, check the actual (where the EGR pintle is positioned in the valve) to the desired (where the PCM is commanding the EGR to be), they should be within 1-2% of each other.

If the actual and desired are not reading the same. Use the bi-directional part of the scan tool to command the EGR to 20%, 50%, 70%, and 100% and see if the actual will follow the commanded.

If the actual does not follow the commanded, check the EGR valve for sticking due to carbon.

Also, note there is a TSB available for this issue as well. It is #61-65-59.
Hope this helps.