Acura TSX / Honda Accord CL. Manual - part 625

Fig. 124: Measuring Voltage Between Body Ground & ECM/PCM Connector Terminal A21 

66. Turn the ignition switch OFF.  

67. Jump the SCS line with the HDS.  

68. Disconnect the connectors from the following sensors: 

z

Manifold absolute pressure (MAP) sensor  

z

Accelerator pedal position (APP) sensor  

z

Mainshaft speed sensor (A/T)  

69. Disconnect ECM/PCM connector A (31P).  

70. Check for continuity between ECM/PCM connector terminal A21 and body ground. 

Is there continuity? 

YES: Repair short in the wire between the ECM/PCM (A21) and the MAP sensor, APP 
sensor or mainshaft speed sensor (A/T).  

NO: Update the ECM/PCM if it does not have the latest software, or substitute a known-
good, ECM/PCM, then recheck (see HOW TO SUBSTITUTE THE ECM/PCM ). If the 
symptom/indication does away with a known-good ECM/PCM, replace the original 
ECM/PCM.  

 

2004 Acura TSX 

2004 ENGINE PERFORMANCE PGM-FI System - TSX

  

 

Fig. 125: Checking For Continuity Between ECM/PCM Connector Terminal A21 & Body 
Ground 

71. Measure voltage between body ground and ECM/PCM connector terminal A20. 

Is there about 5 V? 

YES: Go to step 79 .  

NO: Go to step 72.  

 

2004 Acura TSX 

2004 ENGINE PERFORMANCE PGM-FI System - TSX

  

 

Fig. 126: Measuring Voltage Between Body Ground & ECM/PCM Connector Terminal A20 

72. Turn the ignition switch OFF.  

73. Disconnect the connector from each of these sensors, one at a time, and measure voltage between body 

ground and ECM/PCM connector terminal A20 with the ignition switch ON (II): 

z

Throttle position (TP) sensor  

z

Accelerator pedal position (APP) sensor  

z

Countershaft speed sensor 

Is there about 5 V? 

YES: Replace the sensor that restored 5 V when disconnected.  

NO: Go to step 74. 

 

2004 Acura TSX 

2004 ENGINE PERFORMANCE PGM-FI System - TSX

  

 

Fig. 127: Measuring Voltage Between Body Ground & ECM/PCM Connector Terminal A20 

74. Turn the ignition switch OFF.  

75. Jump the SCS line with the HDS.  

76. Disconnect the connector from the following sensors: 

z

Throttle position (TP) sensor  

z

Accelerator pedal position (APP) sensor  

z

Countershaft speed sensor  

77. Disconnect ECM/PCM connector A (31P).  

78. Check for continuity between ECM/PCM connector terminal A20 and body ground. 

Is there continuity? 

YES: Repair short in the wire between the ECM/PCM (A20) and the TP sensor, APP sensor, 
EGR valve or countershaft speed sensor.  

NO: Update the ECM/PCM if it does not have the latest software, or substitute a known-
good, ECM/PCM, then recheck (see HOW TO SUBSTITUTE THE ECM/PCM ). If the 
symptom/indication goes away with a known-good ECM/PCM, replace the original 

 

2004 Acura TSX 

2004 ENGINE PERFORMANCE PGM-FI System - TSX