My 1988 chevy truck is reading code 33 - 1988 Chevrolet K1500

1988-98 Chevy and GMC C/K 1500/2500/3500 Pickup Trucks ...

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OBD-I trouble code chart ; 32, Exhaust Gas Recirculation (EGR) failure, Check the vacuum source and all vacuum lines. Check the system electrical connectors at ...

OBD1 Codes - Trouble Code List & Reading (GM) - Mechanic ...

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Jan 15, 2022 - In this guide, we will go through everything you have to know about OBD1 Trouble Codes. Learn to read the trouble codes without a scanner ...
‎OBD1 Trouble Code List · ‎OBD1 Connector Wirings Pinout

GM OBD/OBD2 Codes - TroubleCodes.net

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GM Specific Codes ; 64. MAP sensor voltage low; RH side O2 sensor lean ; 65, RH side O2 sensor rich ; 66. 3-2 Control solenoid circuit fault(4L60-E); A/C pressure ...

GM OBD I Trouble Code Chart - RepairPal

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Jul 5, 2018 - GM OBD I Trouble Code Chart ; Code 15, Engine coolant temp sensor error (low temp indicated) ; Code 16, System voltage too low ; Code 17, Camshaft position sensor ...
‎Code 12 · ‎Code 32 · ‎Code 42
GM OBD Trouble Code 12
Sept 5, 2012
GM OBD Trouble Code 32
Sept 5, 2012
GM OBD Trouble Code 33
Sept 5, 2012
GM OBD Trouble Code 22
Sept 17, 2012
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on the gm generic code list.lists it as a coolant sensor/high temp.

Code 33 means MAP sensor signal has low vacuum or circuit voltage is high here is the tricky part it can also point to a failed distributor reluctor so do this inspect the vacuum hose that attached to it at idle is there full vacuum then check the connection it safer just to replace it including the vacuum hoses if the code comes on check the timing make sure it correct also when you floor it does it stumble or cough if it does its the whole distributor will need to be replaced

Code 33 indicates a problem with the MAP sensor
Code 45 indicate exhaust is rich

CODE 33 MAP SENSOR SIGNALVOLTAGE OUT OF RANGE HIGH. CODE 34 MAP SENSOR SIGNAL VOLTAGE OUT OF RANGE LOW.

33 is map sensor voltage low and 35 is idle air controll valve

code 33 is the a/c clutch relay will be an open or shorted condition detected in the a/c clutch relay circuit. hop this will help!!!!!

12= battery power was disconnected,
33= air conditioner clutch relay circuit

DTC - 32 EGR system failure
DTC - 33 MAP sensor circuit error (signal high indicating low vacuum)

The EGR failure is causing the DTC 33 code to show up. Check the vacuum lines to the EGR valve.

Good luck and keep me posted

CODE 14
Trouble Code 14 indicates that the Coolant Temperature Sensor (CTS) is reporting abnormally high readings. CTS is used to control fuel mixture, timing, idle speed, TCC and EGR operations among others. The thermistor used has a low resistance when hot, rising as the coolant cools. This error then, indicates a very low resistance in the CTS circuit.
CODE 15
Trouble Code 15 indicates that the Coolant Temperature Sensor (CTS) is reporting abnormally low readings. CTS is used to control fuel mixture, timing, idle speed, TCC and EGR operation, among others. The thermistor used has a high resistance when cold, lowering as the coolant warms. This error then, indicates a very high resistance in the CTS circuit.
CODE 33
Trouble Code 33 indicates that the Mass Air Flow (MAF) sensor is reporting more air is entering the engine than makes sense based on RPM and TPS. The MAF sensor produces a frequency output; around 30 Hz at idle to 150 Hz under acceleration. The frequency varies proportionally to airflow. The ECM monitors the frequency and thus determines airflow into the engine. Typical idle MAF is 5 to 7 grams per second.