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